JP2019182448A - Packaging container - Google Patents

Abstract

To provide a packaging container having enough sealability by an inner ring, and causing no lowering of the sealability of a cap even when applied to hot filling.SOLUTION: A packaging container has a container body 2 and a cap 1. The cap has a cap top plate 11 closing a mouth cylindrical part of the container body, a cap peripheral wall 12 hanging from an outer periphery of the cap top plate, and an inner ring 14 hanging from the cap top plate at an inside position of the cap peripheral wall. The inner ring is closely attached to a cylinder wall 21 of the mouth cylindrical part to close the mouth cylindrical part. A vertical section of the inner ring forms an outward protruded circular arc, a maximum outer diameter d2 of the inner ring is larger than an inner diameter d1 of the cylinder wall, outer diameters of an upper end 14b and a lower end 14c of the inner ring are smaller than the inner diameter of the cylinder wall, and a thickness of the cap top plate is thicker in the area surrounded by the cap peripheral wall and the inner ring, than that in the area inside the inner ring.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a packaging container with a cap configured to include a container main body and a cap, and more particularly to a packaging container in which a sealed state is maintained well even in hot filling in which contents are filled at a high temperature.

  Conventionally, a packaging container with a cap has been provided with a seal member or packing made of a rubber-like material or the like on the inner surface of the cap in contact with the end of the mouth tube portion of the container body in order to prevent leakage of the contents. However, since providing a seal member and packing is expensive, instead of installing an inner ring that slides in contact with the inner surface of the mouth tube portion, and further providing a contact ring that contacts the tip surface of the mouth tube portion The mouth tube part of the main body has been closed and sealed (for example, Patent Document 1). At this time, the outer diameter of the inner ring is set to be slightly larger than the inner diameter of the mouth tube portion (this difference is referred to as “slip amount”), and the inner ring is pressed against the inner surface of the mouth tube portion. Increases sealing performance.

  Further, an outer ring that slides on the outer surface of the mouth tube portion is further provided, and the mouth tube portion of the container body is closed by sandwiching the tube wall of the mouth tube portion of the container body between the outer ring and the inner ring. Sealing has been performed (for example, Patent Document 2). In addition, at this time, the shape of the hanging inner ring is not a straight shape but a shape that is bent in a “shape”, and there is a case where the sealing performance is improved (for example, Patent Document 3).

  However, a container having a linear inner ring as disclosed in Patent Document 1 and Patent Document 2, particularly when applied to so-called hot filling in which the contents are filled in a high temperature state, the temperature after filling. When the volume of the contents and the enclosed air contracts and the container is in a negative pressure state, the top surface 41 of the cap 40 is recessed and deformed as shown in FIG. 42, the outer ring 43, and the contact ring 44 may be displaced from the mouth tube portion 45, resulting in unstable sealing performance.

  Further, in a container having an inner ring with a "<" shape as shown in Patent Document 3, the apex portion 52 of the "<" shape is usually formed on the mouth tube portion 55 as shown in FIG. When applied to hot filling, the shape of the inner ring 54 may be distorted and contact with the unstable surface 52 due to deformation of the top surface 51 of the cap. In some cases, the sealing performance may become unstable.

Japanese Patent No. 3212267 JP-A-8-40444 Japanese Patent No. 4393092

  Therefore, the present invention provides a packaging container that has a sufficient sealing force by the inner ring without using a sealing material or other member such as packing, and does not deteriorate the sealing performance of the cap even when applied to hot filling. Let it be an issue.

In order to solve the above problems, the invention according to claim 1 of the present invention provides:
A container body and a cap;
A cap top plate for closing the mouth tube portion of the container body; a cap peripheral wall depending from the outer periphery of the cap top plate; and an inner ring depending from the cap top plate at a position inside the cap peripheral wall. With
The inner ring is a packaging container that closes the mouth tube portion in close contact with the tube wall of the mouth tube portion,
The longitudinal section of the inner ring has an outwardly convex arc shape, the maximum outer diameter of the inner ring is larger than the inner diameter of the cylindrical wall, and the outer diameters of the upper and lower ends of the inner ring are the inner diameter of the cylindrical wall. Smaller,
In the packaging container, the thickness of the cap top plate is thicker in a region sandwiched between the cap peripheral wall and the inner ring than in a region inside the inner ring.

The invention according to claim 2 of the present invention is
In the vicinity of the portion where the inner ring and the cylindrical wall abut, the radius of the arc that protrudes outward from the longitudinal section of the inner ring is 3 mm or more and the distance from the center of the inner ring to the apex that abuts the cylindrical wall The packaging container according to claim 1, wherein:

The invention according to claim 3 of the present invention is
The packaging container according to claim 1 or 2, wherein the cap is made of a material having a bending elastic modulus equal to or less than that of the container body.

  According to the first aspect of the present invention, the longitudinal section of the inner ring is an outwardly convex arc shape, and the maximum outer diameter of the inner ring is larger than the inner diameter of the cylindrical wall of the mouth tube portion of the container body. Therefore, when the cap is attached to the container body, the inner ring is point-contacted with the inner surface of the mouth tube at the top of the arc of the inner ring, and the tube wall of the mouth tube is pressed from the inside at the top of the arc. As described above, in a state where the cap is mounted, since the outward stress is maintained by the arc of the inner ring, both are in close contact with each other with a strong force. In addition, when this is seen in the cylinder circumferential direction, it becomes an aspect in line contact with the inner surface of the cylinder wall, and an aspect in which it is in close contact over the entire circumference. And a container is sealed by this linear contact part.

  Next, since the outer diameter of the upper end portion and the lower end portion of the inner ring is configured to be smaller than the inner diameter of the cylinder wall of the mouth tube portion of the container body, when the cap is attached to the container body, the mouth tube portion of the container body The tube wall does not hit the lower end of the inner ring. Moreover, the inner ring has an arc shape whose longitudinal section is convex outward, that is, both the outer surface and the inner surface of the inner ring have a shape that expands from the cap top plate toward the top of the arc. Moreover, since it has a shape that decreases in diameter from the apex of the arc toward the lower end, the inner ring can be easily bent inward as the tube wall of the mouth tube portion enters. For this reason, even after the tube wall of the mouth tube portion is sandwiched between the lower end portion of the inner ring and the peripheral wall of the cap, it can smoothly enter without receiving strong resistance.

  In addition, the cap top plate is thicker in the area between the cap peripheral wall and the inner ring than in the area inside the inner ring. When this happens, the cap top plate is deformed mainly as a dent in the inner region of the inner ring. As the inner area of the inner ring of the cap top plate is recessed, the upper end portion of the inner ring, that is, the portion connected to the cap top plate is rotated outward. A force that is pressed outward is applied, and the position of the vertex of the arc is slightly shifted. Even when such a force is applied, the inner ring has a circular cross section that is convex outward, so that the contact between the inner ring and the inner surface of the tube wall of the mouth tube portion remains in a point contact state and does not change. . That is, since there is little change in the contact state between the inner ring and the inner surface of the cylindrical wall of the mouth tube portion, a stable sealed state can be maintained.

  Thus, according to the present invention, the longitudinal section of the inner ring is an arc shape convex outward, and the maximum outer diameter is configured to be larger than the inner diameter of the cylindrical wall of the mouth tube portion of the container body. The tube wall of the mouth tube portion of the container body does not hit the lower end portion of the inner ring even though it can be sealed tightly in a state where the pressure is applied at the top of the inner ring, and entry is facilitated. . Moreover, even if the container is in a negative pressure state after hot filling and the cap top plate is deformed, the sealed state is not changed and the sealed state can be stably maintained.

  According to the second aspect of the present invention, the radius of the arc that protrudes outward from the longitudinal section of the inner ring is 3 mm or more and less than or equal to the distance from the center of the inner ring to the apex that contacts the cylindrical wall. When applied to hot filling, the sealed state can be more reliably maintained even if the temperature drops after filling and the container is in a negative pressure state and the cap top plate is deformed. That is, the cap top plate is recessed and a force is exerted to strongly press the inner ring against the cylindrical wall, and even if it rotates in the arc direction, there is no change in the manner of contact at the arc-shaped part, It is possible to reduce a change in the close contact state with the tube wall of the mouth tube portion of the container body, and to keep the sealed state stably. When the radius of the arc is smaller than 3 mm, the effect of the arc shape is weakened, and the mode of contact greatly varies due to slight rotation, and the sealed state may vary. Further, when the radius of the arc is larger than the distance from the center of the inner ring to the apex that contacts the cylindrical wall, the surface of the inner ring is in a state of surface contact when the inner ring is close to a plane and strongly pressed by the cylindrical wall. Thus, since the frictional resistance is increased, there is a possibility that the torque when the cap is screwed becomes excessive.

  According to the invention described in claim 3, since the cap is made of a material having a bending elastic modulus equal to or less than that of the container body, that is, made of a material having flexibility equal to or more than that, The inner ring flexes flexibly when screwed into the container body, making it easier to enter the tube wall of the mouth tube part, and when the container is in a negative pressure state after hot filling, the cap top plate is deformed first. It is easy to make a packaging container that does not easily lose its appearance when the container body is deformed into a product.

It is the schematic diagram which looked through in combination with the nozzle part and cap of the packaging container of this invention. It is a partial longitudinal cross-section schematic diagram of the cap cylinder part and cap of the packaging container of this invention. It is a partial longitudinal cross-sectional schematic diagram of the state which the cap top plate of the packaging container of this invention deform | transformed. It is a partial longitudinal cross-sectional schematic diagram of the packaging container which has the conventional linear inner ring. It is a partial longitudinal cross-sectional schematic diagram of the packaging container which has the conventional "ring shape" -shaped inner ring. It is a partial longitudinal cross-section schematic diagram of the cap cylinder part and cap of the packaging container of the comparative example 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below.

FIG. 1 is a schematic view seen through a combination of a cap portion and a cap according to an embodiment of the packaging container of the present invention. As can be seen from FIG. 1, the cap 1 of the packaging container of the present invention has a cap top plate 11 that closes the mouth tube portion of the container body 2, and the cap peripheral wall 12 is suspended from the outer periphery of the cap top plate 11. is doing. Further, an inner ring 14 hangs from the cap top plate 11 at a position inside the cap peripheral wall 12.

  The mouth tube portion of the container body 2 is surrounded by a cylindrical tube wall 21. A screw portion 22 is provided on the outer periphery of the cylindrical wall 21 of the mouth tube portion, and a screw portion 13 is also provided on the inner surface of the cap peripheral wall 12. Then, the cap 1 is attached to the container body 2 by screwing the threaded portion 22 of the container body 2 and the threaded portion 13 of the cap peripheral wall 12 together. Of course, the cap 1 and the container main body 2 can be repeatedly opened and attached (that is, removed). In the state where the cap 1 is attached to the container main body 2, the cap top plate 11 closes the mouth tube portion of the container main body 2.

  The inner ring 14 has an arc shape with a longitudinal section protruding outward from the cap top plate 11 toward the lower end portion 14c. The outer diameter d2 is the maximum at the top 14b of the arc, and is configured to be larger than the outer diameter of the upper portion 14a and the outer diameter of the lower end portion 14c. That is, among the portions of the inner ring 14, the portion having the largest outer diameter is obtained. The outer diameter d2 of the apex 14b is configured to be larger than the inner diameter d1 of the cylindrical wall 21 of the mouth tube portion of the container body 2, and the difference s on one side is the amount of protrusion s. With the cap 1 mounted on the container body 2, the cap 1 and the container body 2 are point-contacted when viewed in the longitudinal section at the apex 14b of this arc, and line-contacted in a ring shape when viewed in the cylinder circumferential direction. The apex 14b of the arc presses the tube wall 21 of the mouth tube portion from the inside to seal it.

  If the radius of the arc is 3 mm or more and not more than the distance from the center of the inner ring 14 to the apex 14b contacting the cylinder wall 21, that is, not more than r1 shown in FIG. It can be reduced and is preferable. As described above, when the radius of the arc is smaller than 3 mm, the contact state becomes closer to the point contact than the arc contact, and the contact state may greatly vary due to slight rotation, and the sealed state may vary. There is. Further, if the radius of the arc is larger than the distance from the center of the inner ring 14 to the apex 14b contacting the cylinder wall 21, the longitudinal section of the inner ring 14 becomes close to a plane, and the cap 1 is deformed by decompression. Then, when it is strongly pressed by the cylinder wall 21, it comes into a surface contact state and the frictional resistance increases, so that there is a possibility that the torque when screwing the cap becomes excessive.

  FIG. 2 is a partial vertical cross-sectional schematic view of a state where a cap is screwed into the mouth tube portion of one embodiment of the packaging container of the present invention. As can be seen from FIG. 2, when the cap 1 is actually screwed, the inner ring 14 bends inward by the amount of protrusion s, and the reaction force causes the inner ring 14 to be a cylinder in the mouth tube portion as indicated by a white arrow. The wall 21 is pressed from the inside to be sealed. It is also possible to adjust the pressure by changing the amount of sledge s, and it can be appropriately set according to the contents to be filled, filling conditions, and the like. In the case of a conventional container having a linear inner ring as shown in FIG. 4, the entire outer peripheral surface of the inner ring is in contact with the inner surface of the mouth tube portion. It was difficult to make adjustments.

  Returning to FIG. 1, the upper end portion 14 a and the lower end portion 14 c of the inner ring 14 are configured to be smaller than the inner diameter of the tube wall 21 of the mouth tube portion of the container body 2. Therefore, when the cap is attached to the container body, the tube wall 21 of the mouth tube portion of the container body 2 does not hit the lower end portion 14c of the inner ring 14, and the mouth tube of the container body 2 when the screwing is advanced. The cylindrical wall 21 does not hit the upper end portion 14 a of the inner ring 14. Further, the distal end of the cylindrical wall 21 abuts against a contact ring 15 provided around the cap top plate 11 in a ridge shape and sealed.

  The cap top plate 11 has a thickness t 1 in a region sandwiched between the cap peripheral wall 12 and the inner ring 14 larger than a thickness t 2 in a region inside the inner ring 14. Therefore, when a force such as internal pressure is applied to the cap top plate 11, the inner region of the inner ring 14 is more likely to be deformed.

  FIG. 3 is a partial cross-sectional schematic view of a state where the cap top plate of the packaging container of the present invention is deformed. Such deformation typically occurs during hot filling, for example. That is, in hot filling, the contents are filled at a high temperature, and therefore, when the temperature drops after filling and attaching the cap 1 and sealing the packaging container 2, the contents and the air enclosed together contract. The packaging container 2 is in a negative pressure state. At this time, the cap top plate 11 of the cap 1 may be deformed and recessed.

  When recessed in this way, the thickness of the cap top plate 11 is less likely to deform because it is thicker in the region sandwiched between the cap peripheral wall 12 and the inner ring 14 than in the region inside the inner ring 14. The area inside is easy to deform as shown by arrow A1. Due to this deformation, the inner ring 14 is applied with a force that spreads outward as indicated by an arrow A2. When a force such as the arrow A2 is applied, the arc apex 14b of the inner ring 14 is more strongly pressed against the inner surface of the cylindrical wall 21, so that there is no possibility that the sealing by the inner ring 14 becomes unstable. Further, at this time, the inner ring 14 may move slightly in the direction of the arc, but the inner ring 14 is attached to the cylindrical wall 21 by setting the radius of the arc to an appropriate range as described above. The abutting portion can be continuously arc-shaped and contacted at the apex of the arc, so that the sealing state of the inner ring 14 and the cylinder wall 21 does not change.

  The cap 1 and the container main body 2 as described above can be formed using any thermoplastic resin as a material. For example, low density polyethylene, high density polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyester, polyamide, polystyrene and the like. Moreover, it is also possible to mix and mold these resins with appropriate additives. For example, a colorant, a lubricant, an antistatic agent, or an ultraviolet absorber. If both the cap 1 and the container main body 2 are molded with a resin to which an ultraviolet absorber is added, both the cap 1 and the container main body 2 result in ultraviolet blocking properties. Suitable as a container for housing. Moreover, the cap 1 and the container main body 2 which have ultraviolet-blocking property can also be manufactured by shape | molding with the black resin which added carbon black. This container is also suitable as a container for storing contents that are easily deteriorated by ultraviolet rays. Examples of the contents that are easily deteriorated by ultraviolet rays include, in addition to various foods, photosensitive films, ultraviolet curable inks, and ultraviolet curable paints.

  The cap 1 is preferably made of a material whose bending elastic modulus is equal to or less than that of the container body 2, that is, has a flexibility equal to or higher than that. For example, the container body 2 is made of polypropylene and the cap 1 is made of high-density polyethylene that is more flexible than polypropylene. When the cap 1 is made of a more flexible material, the inner ring 14 bends more flexibly toward the inside, so that the tube wall 21 of the mouth tube portion can be more easily entered.

  Further, when a negative pressure generated during hot filling is applied, the cap top plate 11 of the cap 1 formed of a material more flexible than the container main body 2 is deformed first by being dented or the like, whereby the container main body 2 Can be made difficult to occur, and there is little risk of damaging the appearance of the product. In addition, when the cap 1 is made of a material that is more flexible than the container body 2, there is an advantage that even if the cap 1 is repeatedly attached and detached, the occurrence of shavings due to repeated screwing can be prevented.

  The cap 1 according to the present invention can be molded by an injection molding method. After the injection molding, when taking out from the mold, the die can be punched by so-called forcible punching. That is, when the inner ring 14 is pulled out from the mold with a strong force, the inner ring 14 is easily bent without being damaged because it has an arc shape.

Moreover, the container main body 2 can be shape | molded by arbitrary shaping | molding methods. For example, there are an extrusion blow molding method and an injection blow molding method. When blowing by these extrusion blow molding methods or injection blow molding methods, it is also possible to stretch. It is also possible to form the container body 2 by an injection molding method. Alternatively, in order to impart heat resistance to the container body 2, heat treatment such as crystallization treatment may be performed. Or you may form the container main body 2 with a material with high heat resistance, such as glass.

  In addition, although this invention was demonstrated taking the case of what screw-fits to the container main body 2 as the cap 1, it is also possible to use the cap with which it installs not only in this but a stoppering system.

  The present invention will be specifically described below with reference to examples.

<Example 1>
A cap made of a high-density polyethylene resin having a bending elastic modulus of 1050 MPa provided with an inner ring similar to that illustrated in FIG. The container body (capacity 225 ml) made of polyethylene terephthalate resin having a thickness of 1.4 mm and a flexural modulus of 1200 MPa was used.
-200ml of shochu (alcohol 25%) was filled as the contents.
・ The cap was tightened with a torque of 60 ± 5N.

<Comparative example>
A cap made of a high-density polyethylene resin having a bending elastic modulus of 1050 MPa provided with an inner ring hanging down in a straight line illustrated in FIG. 6 with a thickness of 0.8 mm and a protruding amount of 0.15 mm, a cylindrical wall thickness of 1.4 mm, It was set as the structure mounted | worn with the container main body (capacity | capacitance 225 ml) made from a polyethylene terephthalate resin with a bending elastic modulus of 1200 MPa.
Others were the same as in Example 1.

<Evaluation method>
Evaluation was made by the following method, and the results are summarized in Table 1.
(Drop test)
・ Drop once from a height of 1 m in the side and upside down directions, and visually check for liquid leaks.
(Preservation test)
-Store in an inverted state at 40 ° C for 1 week and visually check for liquid leakage.

  Clearly from Table 1, it was confirmed that the packaging container of the present invention maintained good sealing performance.

DESCRIPTION OF SYMBOLS 1 ... Cap 2 ... Container main body 11 ... Cap top plate 12 ... Cap peripheral wall 13 ... Screw part 14 ... Inner ring 14b ... Arc vertex 15 ... Contact ring 21 ... Cylinder wall 22 ... Screw part

Claims (3)

A container body and a cap;
A cap top plate for closing the mouth tube portion of the container body; a cap peripheral wall depending from the outer periphery of the cap top plate; and an inner ring depending from the cap top plate at a position inside the cap peripheral wall. With
The inner ring is a packaging container that closes the mouth tube portion in close contact with the tube wall of the mouth tube portion,
The longitudinal section of the inner ring has an outwardly convex arc shape, the maximum outer diameter of the inner ring is larger than the inner diameter of the cylindrical wall, and the outer diameters of the upper and lower ends of the inner ring are the inner diameter of the cylindrical wall. Smaller,
The packaging container, wherein the cap top plate is thicker in a region sandwiched between the cap peripheral wall and the inner ring than in a region inside the inner ring.   In the vicinity of the portion where the inner ring and the cylindrical wall abut, the radius of the arc that protrudes outward from the longitudinal section of the inner ring is 3 mm or more and the distance from the center of the inner ring to the apex that abuts the cylindrical wall The packaging container according to claim 1, wherein:   The packaging container according to claim 1 or 2, wherein the cap is made of a material having a bending elastic modulus equal to or less than that of the container body.

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