JP7099016B2 - Packaging container - Google Patents

Description

The present invention relates to a packaged container with a cap provided with a container body and a cap, and more particularly to a packaged container in which a well-sealed state is maintained even in hot filling in which the contents are filled in a high temperature state.

Conventionally, in a packaging container with a cap, a sealing member or packing is provided on the inner surface of the cap that comes into contact with the tip of the mouthpiece of the container body with a rubber-like material or the like in order to prevent leakage of the contents. However, since it is costly to provide a sealing member and packing, instead, an inner ring that slides into the inner surface of the mouthpiece is hung, and a contact ring that comes into contact with the tip of the mouthpiece is provided to make the container. The mouthpiece of the main body was 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 (this difference is referred to as "slip amount"), and the inner ring is pressed against the inner surface of the mouth tube. It enhances the sealing performance.

Further, an outer ring that is in sliding contact with the outer surface of the mouth tube is further provided, and the tube wall of the mouth tube of the container body is sandwiched between the outer ring and the inner ring to close the mouth tube of the container body. It was sealed (for example, Patent Document 2). At this time, the shape of the hanging inner ring may be bent into a "dogleg" shape instead of a straight line to improve the sealing property (for example, Patent Document 3).

However, a container having a linear inner ring as disclosed in Patent Document 1 and Patent Document 2 has a temperature after filling, particularly when applied to so-called hot filling in which the contents are filled in a high temperature state. When the volume of the contents and the enclosed air contracts and the inside of the container becomes a negative pressure state, the top surface 41 of the cap 40 is dented and deformed as shown in FIG. 4, and the inner ring is formed accordingly. The 42, the outer ring 43, and the contact ring 44 may be displaced from the mouth tube portion 45 and the sealing property may become unstable.

Further, in a container having a "dogleg" shape as shown in Patent Document 3, the apex portion 52 of the "dogleg" is usually the mouthpiece 55 as shown in FIG. When applied to hot filling, the shape of the inner ring 54 may be distorted due to the deformation of the top surface 51 of the cap, resulting in contact on the unstable surface 52. There was a case where the sealing property became unstable.

Japanese Patent No. 322167 Japanese Unexamined Patent Publication No. 8-40444 Japanese Patent No. 4393092

Therefore, according to the present invention, it is possible to obtain a packaging container having a sufficient sealing force by the inner ring without using other members such as a sealing material and packing, and the sealing property of the cap does not deteriorate even when applied to hot filling. Make it an issue.

In order to solve the above problems, the invention according to claim 1 of the present invention is
Equipped with a container body and a cap,
The cap has a cap top plate that closes the mouthpiece of the container body, a cap peripheral wall that hangs from the outer periphery of the cap top plate, and an inner ring that hangs from the cap top plate at a position inside the cap peripheral wall. Equipped with
The inner ring is a packaging container that is in close contact with the cylinder wall of the mouth cylinder portion and closes the mouth cylinder portion.
The vertical cross section of the inner ring has an arcuate shape that is convex outward, the maximum outer diameter of the inner ring is larger than the inner diameter of the cylinder wall, and the outer diameters of the upper end and the lower end of the inner ring are the inner diameter of the cylinder wall. Smaller,
The thickness of the cap top plate is thicker in the region sandwiched between the cap peripheral wall and the inner ring than in the region inside the inner ring .
In the vicinity of the portion where the inner ring and the cylinder wall abut, the radius of the arc convex to the outside of the vertical cross 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 on the cylinder wall. Is below
In addition, even when the contents are filled in a high temperature state, a cap is attached to lower the temperature, and the packaging container is in a negative pressure state, the inner ring comes into contact with the cylinder wall of the mouth cylinder portion at the apex of the arc. It is a packaging container characterized by this.

Further, the invention according to claim 2 of the present invention is:
The packaging container according to claim 1 , wherein the cap is made of a material having a flexural modulus equal to or lower than that of the container body.

According to the first aspect of the present invention, the vertical cross section of the inner ring has an arcuate shape that is convex outward, and the maximum outer diameter of the inner ring is larger than the inner diameter of the cylinder wall of the mouth cylinder portion of the container body. Therefore, when the cap is attached to the container body, the apex of the arc of the inner ring makes point contact with the inner surface of the mouth tube, and the apex of this arc presses the tube wall of the mouth tube from the inside. As described above, in the state where the cap is attached, the arc of the inner ring maintains the state in which the outward stress is applied, so that the two are in close contact with each other with a strong force. When this is viewed in the circumferential direction of the cylinder, it is in a mode of line contact with the inner surface of the cylinder wall, and is in a mode of being in close contact over the entire circumference. Then, the container is sealed at this linear contact portion.

Next, since the outer diameters of the upper and lower ends of the inner ring are smaller than the inner diameter of the cylinder wall of the mouth cylinder of the container body, when the cap is attached to the container body, the mouth cylinder of the container body The cylinder wall does not hit the lower end of the inner ring. Moreover, the inner ring has an arc shape whose vertical cross section is convex outward, that is, both the outer surface and the inner surface of the inner ring have a shape in which the diameter increases from the cap top plate toward the apex of the arc. Further, since the diameter is reduced from the apex to the lower end of the arc, the inner ring can be easily bent inward as the cylinder wall of the mouth cylinder enters. Therefore, even after the cylinder wall of the mouth cylinder 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.

Further, since the thickness of the cap top plate is thicker in the region sandwiched between the cap peripheral wall and the inner ring than in the region inside the inner ring, the container is under negative pressure as the temperature drops after hot filling. When the state is reached, the deformation of the cap top plate occurs mainly as a dent in the inner region of the inner ring. By denting the inner area of the inner ring of the cap top plate, the upper end of the inner ring, that is, the part connected to the cap top plate becomes a force to rotate outward, and as a result, the lower end side is A force is applied that pushes it outward, and the position of the apex of the arc is slightly displaced. Even when such a force is applied, the vertical cross section of the inner ring has an arcuate shape that is convex outward, so the contact between the inner ring and the inner surface of the cylinder wall of the mouth cylinder remains in the mode of point contact and does not change. .. That is, since there is little change in the state of close contact between the inner ring and the inner surface of the tube wall of the mouth tube portion, a stable sealed state can be maintained.

As described above, according to the present invention, the vertical cross section of the inner ring is an arc shape that is convex outward, and the maximum outer diameter thereof is larger than the inner diameter of the cylinder wall of the mouth cylinder portion of the container body. Despite being able to be tightly and sufficiently sealed with pressure applied at the apex of the container, the cylinder wall of the mouth cylinder of the container body does not hit the lower end of the inner ring, making it easier to enter. .. Further, even if the container is in a negative pressure state after hot filling and the cap top plate is deformed, the sealed state does not change and the sealed state can be stably maintained.

Further, according to the invention of claim 2, the radius of the arc convex to the outside of the vertical cross section of the inner ring is set to 3 mm or more and the distance from the center of the inner ring to the apex abutting on the cylinder wall or less. When applied to hot filling, the sealed state can be more reliably maintained even if the temperature drops after filling and the container becomes in a negative pressure state and the cap top plate is deformed such that the top plate is dented. That is, even if the cap top plate is dented and a force is applied to press the inner ring more strongly against the cylinder wall, and even if it rotates in the arc direction, there is no change in the mode of contact at the arc-shaped portion, and the inner ring and the inner ring. The change in the state of close contact with the tube wall of the mouth tube of the container body can be reduced, and the sealed state can be stably maintained. If the radius of the arc is smaller than 3 mm, the effect of the arc shape is diminished, and the contact mode is greatly changed by a slight rotation, and the sealed state may be changed. If the radius of the arc is larger than the distance from the center of the inner ring to the apex that abuts on the cylinder wall, the vertical cross section of the inner ring becomes close to a flat surface and is in a state of surface contact when it is strongly pressed against the cylinder wall. As a result, the frictional resistance becomes large, and there is a risk that the torque when screwing the cap becomes excessive.

Further, according to the invention of claim 3, since the cap is made of a material having a bending elasticity equal to or less than the material of the container body, that is, made of a material having a bending elasticity equal to or higher than that of the container body, the cap is made of a material. The inner ring flexibly bends when screwed into the container body, making it easier for the tube wall of the mouth tube to enter, and when the container becomes negative pressure after hot filling, the cap top plate is deformed first. It is possible to make a packaging container that is easy to deform and does not easily lose its appearance when it is made into a product.

It is a schematic diagram which saw through the combination of the mouth tube portion and the cap of the packaging container of this invention. It is a partial vertical cross-sectional schematic diagram of the mouth tube portion and the cap of the packaging container of the present invention. It is a partial vertical cross-sectional schematic diagram in a state where the cap top plate of the packaging container of this invention is deformed. It is a partial vertical cross-sectional schematic diagram of a packaging container having a conventional linear inner ring. It is a partial vertical cross-sectional schematic diagram of a packaging container having a conventional "dogleg" -shaped inner ring. It is a partial vertical cross-sectional schematic diagram of the mouth tube portion and the cap of the packaging container of 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 of a combination of a mouthpiece and a cap according to an embodiment of the packaging container of the present invention and viewed transparently. 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 mouthpiece portion of the container body 2, and the cap peripheral wall 12 hangs down from the outer periphery of the cap top plate 11. is doing. Further, the inner ring 14 hangs down from the cap top plate 11 at the position inside the cap peripheral wall 12.

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

The inner ring 14 has an arcuate shape whose vertical cross section is convex outward from the cap top plate 11 toward the lower end portion 14c thereof. The outer diameter d2 is the maximum at the apex 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, it is the portion having the largest outer diameter among the portions of the inner ring 14. The outer diameter d2 of the apex 14b is larger than the inner diameter d1 of the cylinder wall 21 of the mouth cylinder portion of the container body 2, and the difference s on one side thereof is the shear amount s. With the cap 1 attached to the container body 2, the cap 1 is in point contact with the container body 2 at the apex 14b of this arc, when viewed in the vertical cross section, and in line contact in a ring shape when viewed in the circumferential direction. The apex 14b of the arc presses the cylinder wall 21 of the mouth cylinder portion from the inside to seal it.

Further, if the radius of this arc is 3 mm or more and the distance from the center of the inner ring 14 to the apex 14b that abuts on the cylinder wall 21, that is, r1 or less shown in FIG. 2, the change in the state of close contact with the cylinder wall 21 is changed. It can be reduced and is preferable. As described above, if the radius of the arc is smaller than 3 mm, the contact is closer to the point contact than the contact in the arc, and the contact mode is greatly changed by a slight rotation, and the sealed state may be changed. 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 that abuts on the cylinder wall 21, the vertical cross section of the inner ring 14 becomes close to a flat surface, and the cap 1 is deformed by decompression. When it is strongly pressed against the cylinder wall 21, it is in a state of surface contact and the frictional resistance becomes large, so that there is a possibility that the torque when screwing the cap becomes excessive.

FIG. 2 is a schematic partial vertical cross-sectional view in a state where a cap is screwed into a mouthpiece portion of an embodiment of the packaging container of the present invention. As can be seen from FIG. 2, when the cap 1 is actually screwed in, the inner ring 14 bends inward by the amount of the shear amount s, and the reaction force causes the inner ring 14 to bend as shown by the white arrow. The wall 21 is pressed from the inside to seal it. It is also possible to adjust the pressing by changing the amount of auction s, and it can be appropriately set according to the contents to be filled, the filling conditions, and the like. In 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 mouthpiece, so if the amount of shrinkage is slightly increased, the resistance at the time of screwing increases at once. It was difficult to make adjustments.

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

The thickness t1 of the cap top plate 11 in the region sandwiched between the cap peripheral wall 12 and the inner ring 14 is thicker than the thickness t2 of the inner region of the inner ring 14. Therefore, when a force such as an 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 schematic partial cross-sectional view of the cap top plate of the packaging container of the present invention in a deformed state. Such deformation typically occurs during hot filling, for example. That is, in hot filling, the contents are filled in a high temperature state, so that when the temperature drops after filling and attaching the cap 1 and sealing the packaging container 2, the contents and the air enclosed together shrink. , 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 dented.

In the case of such a dent, the thickness of the cap top plate 11 is thicker than the inner region of the inner ring 14 in the region sandwiched between the cap peripheral wall 12 and the inner ring 14, so that it is difficult to deform, and the inner ring 14 is difficult to deform. The area inside the is easily deformed as shown by the arrow A1. Due to this deformation, a force that pushes the inner ring 14 outward as shown by arrow A2 is applied to the inner ring 14. When a force as shown by the arrow A2 is applied, the apex 14b of the arc of the inner ring 14 is pressed more strongly against the inner surface of the cylinder wall 21, so that there is no possibility that the sealing by the inner ring 14 becomes unstable. At this time, the inner ring 14 may move slightly in the direction of the arc, but by setting the radius of the arc to an appropriate range as described above, the inner ring 14 is attached to the cylinder wall 21. The contacting portion can be formed into an arc shape without change, and the contact is made at the apex of the arc, so that the sealing condition of the inner ring 14 and the cylinder wall 21 does not change.

The cap 1 and the container body 2 as described above can be molded from 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. It is also possible to mix and mold these resins with appropriate additives. For example, colorants, lubricants, antistatic agents, or UV absorbers. If both the cap 1 and the container body 2 are molded with a resin to which an ultraviolet absorber is added, both the cap 1 and the container body 2 have an ultraviolet blocking property, so that the contents easily deteriorated by ultraviolet rays can be obtained. Suitable as a container for accommodating. Further, by molding with a black resin to which carbon black is added, it is also possible to manufacture a cap 1 and a container body 2 having an ultraviolet blocking property. This container is also suitable as a container for accommodating contents that are easily deteriorated by ultraviolet rays. Examples of the contents that are easily deteriorated by ultraviolet rays include various foods, photosensitive films, ultraviolet curable inks, and ultraviolet curable paints.

It is desirable that the cap 1 is made of a material having a flexural modulus equal to or less than that of the container body 2, that is, having a flexibility equal to or higher than that of the container body 2. For example, the container body 2 is made of polypropylene, and the cap 1 is made of high-density polyethylene, which is more flexible than polypropylene. When the cap 1 is made of a more flexible material, the inner ring 14 bends more flexibly inward, so that the cylinder wall 21 of the mouth cylinder portion can easily enter.

Further, when the negative pressure generated during hot filling is applied, the cap top plate 11 of the cap 1 made of a material more flexible than the container body 2 is dented and deforms first, so that the container body 2 is deformed first. Deformation is unlikely to occur, and there is little risk of spoiling the appearance of the product. When the cap 1 is made of a material that is more flexible than the container body 2, it has the advantage that even if the cap 1 is repeatedly attached and detached, it is possible to prevent the generation of shavings due to repeated screwing.

The cap 1 according to the present invention can be molded by an injection molding method. After injection molding, when it is taken out from the mold, it 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 because it has an arc shape, and can be easily pulled out without being damaged.

Further, the container body 2 can be molded by any molding method. For example, an extrusion blow molding method, an injection blow molding method, and the like. When blowing by these extrusion blow molding methods or injection blow molding methods, it is also possible to stretch. It is also possible to mold the container body 2 by an injection molding method. Alternatively, in order to impart heat resistance to the container body 2, heat resistance treatment such as crystallization treatment may be performed. Alternatively, the container body 2 may be formed of a material having high heat resistance such as glass.

Although the present invention has been described by taking as an example a cap 1 screwed into the container body 2, the present invention is not limited to this, and a cap attached by a plugging method can also be used.

Hereinafter, the present invention will be specifically described with reference to Examples.

<Example 1>
A cap made of high-density polyethylene resin having a flexural modulus of 1050 MPa, which is provided with an inner ring similar to that illustrated in FIG. It was configured to be mounted on a polyethylene terephthalate resin container body (capacity 225 ml) having a thickness of 1.4 mm and a flexural modulus of 1200 MPa.
-As the content, 200 ml of shochu (25% alcohol) was filled.
-The cap was tightened with a torque of 60 ± 5N.

<Comparison example>
A cap made of high-density polyethylene resin having a flexural modulus of 1050 MPa, which is provided with an inner ring that hangs linearly as illustrated in FIG. It was configured to be mounted on a container body (capacity 225 ml) made of polyethylene terephthalate resin having a flexural modulus of 1200 MPa.
-Others were the same as in Example 1.

<Evaluation method>
The evaluation was performed by the following method, and the results are summarized in Table 1.
(Drop test)
・ Drop the product once from a height of 1 m in the side direction and the inverted direction, and visually check for liquid leakage.
(Preservation test)
・ Store in a constant temperature layer at 40 ° C in an inverted state for 1 week, and visually check for liquid leakage.

It was clearly confirmed from Table 1 that the packaging container of the present invention was able to maintain good sealing properties.

1 ... Cap 2 ... Container body 11 ... Cap top plate 12 ... Cap peripheral wall 13 ... Screw part 14 ... Inner ring 14b ... Arc apex 15 ... Contact ring 21・ ・ ・ Cylinder wall 22 ・ ・ ・ Screw part

Claims (2)

Equipped with a container body and a cap,
The cap has a cap top plate that closes the mouthpiece of the container body, a cap peripheral wall that hangs from the outer periphery of the cap top plate, and an inner ring that hangs from the cap top plate at a position inside the cap peripheral wall. Equipped with
The inner ring is a packaging container that is in close contact with the cylinder wall of the mouth cylinder portion and closes the mouth cylinder portion.
The vertical cross section of the inner ring has an arcuate shape that is convex outward, the maximum outer diameter of the inner ring is larger than the inner diameter of the cylinder wall, and the outer diameters of the upper end and the lower end of the inner ring are the inner diameter of the cylinder wall. Smaller,
The thickness of the cap top plate is thicker in the region sandwiched between the cap peripheral wall and the inner ring than in the region inside the inner ring .
In the vicinity of the portion where the inner ring and the cylinder wall abut, the radius of the arc convex to the outside of the vertical cross 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 on the cylinder wall. Is below
In addition, even when the contents are filled in a high temperature state, a cap is attached to lower the temperature, and the packaging container is in a negative pressure state, the inner ring comes into contact with the cylinder wall of the mouth cylinder portion at the apex of the arc. A packaging container characterized by that. The packaging container according to claim 1 , wherein the cap is made of a material having a flexural modulus equal to or lower than that of the container body.

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