JP7438633B2 - double container - Google Patents

Description

The present invention relates to a double container.

A container for storing liquid contents such as food seasonings, lotions, cosmetics, shampoos, conditioners, liquid soaps, etc., has a bottle-shaped outer layer with a mouth, a body, and a bottom, and an inner side of the outer layer. It has an inner layer body which is housed in a volume reducing and deformable body, and an outside air inlet provided in the outer layer body and communicating between the outer layer body and the inner layer body, and when the trunk of the outer layer body is squeezed, the inner layer body On the other hand, when the squeeze of the body is released, outside air is introduced between the inner layer body and the outer layer body from the outside air inlet, and the inner layer body remains reduced in volume and deformed. Double containers are known in which the outer layer can be restored to its original shape. According to such a double container, the contents stored in the inner layer can be poured out without being replaced with air, reducing the contact of the contents with air in the container and preventing deterioration of the contents. and deterioration can be suppressed.

A double container is known to be formed by extrusion blow molding a cylindrical laminated parison using a mold, and in this case, the bottom of the outer layer has a protrusion shape with the inner layer sandwiched between the layers. A pinch-off portion is formed. The pinch-off part has a structure in which the outer layer body and the inner layer body are welded together to close the space between the outer layer body and the inner layer body, and is likely to crack when a shock is applied such as when the container is dropped. If a crack occurs, even if you squeeze the body of the outer layer to pour out the contents, the air between the outer layer and the inner layer will leak out from the pinch-off part, making it difficult to pour out the contents. A problem will arise.

Therefore, conventionally, during extrusion blow molding, pins are inserted vertically alternately into both sides of the pinch-off part, and a groove is formed in the pinch-off part, with a groove opening on the side facing one side and a groove opening on the side facing the other side. By providing grooves arranged at intervals below the grooves provided on one side, the inner layer body is sandwiched between the outer layer body in a zigzag shape at the pinch-off portion, and the impact resistance of the pinch-off portion is improved. There are known devices that have improved performance (for example, see Patent Document 1).

JP2018-108824A

However, even in the above-mentioned conventional double container, the impact resistance of the pinch-off part may not be sufficient. In particular, the resin material constituting the outer layer is made of relatively hard polypropylene resin (PP), and the inner layer is made of ethylene. - When made of vinyl alcohol copolymer resin (EVOH), there was a risk that the pinch-off portion would crack due to impact, making it difficult to pour out the contents.

The present invention aims to solve these problems, and its purpose is to provide a double container in which the pinch-off portion is less likely to be cracked.

The double container of the present invention includes a bottle-shaped outer layer body having a mouth, a body, and a bottom, an inner layer body housed inside the outer layer body and capable of reducing and deforming the volume, and sandwiching the inner layer body. A double container having a pinch-off portion formed in a ridge shape and provided on the bottom portion, and an outside air inlet provided on the outer layer body and communicating between the outer layer body and the inner layer body, , the pinch-off portion includes a first groove that is open on a first side facing one side and recessed toward a second side that faces opposite to the first side; a second groove that is recessed toward the side surface and is disposed below the first groove at a distance from the first groove, and the depths of the first groove and the second groove are The pinch-off portion is formed in a straight line passing through the axis of the bottom portion when viewed from the bottom, and the first groove and the second groove are respectively 3.0 to 4.5 mm in the pinch-off portion. The distance from the axis of the bottom part to the end position of the first groove, and the distance from the axis of the bottom part to the end position of the second groove, Characterized by being identical .

In the double container of the present invention having the above configuration, it is preferable that the depths of the first groove and the second groove are each 3.5 to 4.2 mm.

In the double container of the present invention, in the above structure, it is preferable that the outer layer is made of polypropylene resin and the inner layer is made of ethylene-vinyl alcohol copolymer resin.

In the double container of the present invention, in the above configuration, preferably, in the pinch-off part, the lower end of the inner layer body terminates inside the pinch-off part.

In the double container of the present invention having the above structure, it is preferable that an end portion of the adhesive band layer provided between the outer layer body and the inner layer body reaches the pinch-off portion.

According to the present invention, it is possible to provide a double container in which cracks are less likely to occur at the pinch-off portion.

FIG. 1 is a partially cutaway front view of a double container according to an embodiment of the present invention. FIG. 2 is a side view of the double container shown in FIG. 1; FIG. 2 is a bottom view of the double container shown in FIG. 1; 3 is a sectional view taken along line AA in FIG. 2. FIG. 5 is a sectional view taken along line BB in FIG. 4. FIG.

Hereinafter, a double container 1 according to an embodiment of the present invention will be illustrated in detail with reference to FIGS. 1 to 5.

In addition, in this specification and the claims, the vertical direction shall mean the upper direction and the lower direction when the double container 1 is in an upright position as shown in FIG. Moreover, the radial direction shall mean a direction along a straight line passing through the axis O of the double container 1 and perpendicular to the axis O.

As shown in FIG. 1, a double container 1 according to an embodiment of the present invention includes an outer layer body 10 constituting an outer shell of the container, and an inner layer body 20 housed inside the outer layer body 10. It has a double structure.

As shown in FIGS. 1 and 2, the outer layer body 10 includes a substantially cylindrical mouth portion 11, a substantially cylindrical body portion 12 continuous to the lower end of the mouth portion 11, and a body portion 12 continuous to the lower end of the body portion 12. It has a bottle shape with a bottom part 13 that closes the bottom part 13. In the illustrated case, the body 12 is formed to have a larger diameter than the mouth 11, and between the mouth 11 and the body 12 is a shoulder 14 whose diameter increases downward. . The body 12 has flexibility, and can be elastically deformed into a concave state by being squeezed (pressed) inward in the radial direction, and can also be elastically deformed from the concave state to its original shape. It can be restored by force.

The outer layer body 10 may also be configured to include a plurality of concave ribs 15 extending in the vertical direction from the shoulder portion 14 to the body portion 12. In this case, the number and arrangement of the concave ribs 15 can be changed in various ways.

In this embodiment, the outer layer body 10 is made of polypropylene resin (PP). In this case, if the outer layer body 10 is mainly made of polypropylene resin, it has a laminated structure in which a layer made of polypropylene resin is laminated with a layer made of another synthetic resin material such as low-density polyethylene resin. You can also do that.

The outer layer body 10 is not limited to being made of polypropylene resin, but may be made of other synthetic resin materials such as polyethylene resin (PE) and polyethylene terephthalate resin (PET).

The outer layer body 10 is provided with an outside air inlet 16. In this embodiment, the outside air introduction port 16 is provided in the mouth portion 11 as a through hole that penetrates the mouth portion 11 in the radial direction. The outside air introduction port 16 communicates between the outer layer body 10 and the inner layer body 20, and can introduce outside air between the outer layer body 10 and the inner layer body 20.

The outside air introduction port 16 is not limited to the mouth portion 11 of the outer layer body 10, and may be provided at other portions such as the body portion 12 and the shoulder portion 14, for example.

The inner layer 20 is thinner and more flexible than the outer layer 10 and is formed into a bag shape, and its outer surface is in close contact with the inner surface of the outer layer 10 in a peelable manner. The opening of the inner layer 20 is connected to the open end of the mouth 11 of the outer layer 10, and the inside of the inner layer 20 is a storage space S that is connected to the opening. The storage space S can store, for example, food seasonings, cosmetics such as lotion, and liquid contents such as shampoo, conditioner, or liquid soap. The inner layer body 20 is deformable (volume reduction deformable) so that its internal volume can be reduced, and as the contents are poured out from the storage space S, the inner layer body 20 is deformed from the outer layer body 10. It can be deformed so as to reduce the internal volume while being peeled off.

In this embodiment, the inner layer body 20 is made of ethylene-vinyl alcohol copolymer resin (manufactured by EVOH). Note that if the inner layer body 20 is formed mainly of ethylene-vinyl alcohol copolymer resin, the layer made of ethylene-vinyl alcohol copolymer resin may be replaced with another synthetic resin material such as low-density polyethylene resin. It is also possible to have a laminated structure in which the formed layers are laminated.

The inner layer body 20 is not limited to being made of ethylene-vinyl alcohol copolymer resin, but may be made of other flexible synthetic resin materials such as nylon resin.

In this embodiment, the double container 1 is constructed by co-extruding a synthetic resin layer for the outer layer body 10 and a synthetic resin layer for the inner layer body 20 having the above configuration to form a cylindrical laminated parison. By blow molding (extrusion blow molding) using a left-right split mold, the container is constructed as a laminated peelable container having a laminated structure in which the inner layer 20 is releasably adhered to the inner surface of the outer layer 10. By performing blow molding using a left-right split mold, a parting line PL extending along the dividing surface of the mold is formed on the side surface of the outer layer 10. The parting line PL15 extends from the mouth portion 11 through the body portion 12 to the bottom portion 13 on the side surface of the outer layer body 10.

At the bottom 13 of the double container 1, a cylindrical laminated parison is crushed by a mold and cut off to close its opening, thereby forming a protrusion shape in which the outer layer 10 sandwiches the inner layer 20. A pinch-off portion 30 is provided. The pinch-off portion 30 is formed to extend linearly through the axis (axis O) of the bottom portion 13 when viewed from the bottom as shown in FIG. 3 . Note that the detailed structure of the pinch-off section 30 will be described later.

As shown in FIGS. 2 to 4, an adhesive band layer AL is provided between the outer layer body 10 and the inner layer body 20 to bond the outer layer body 10 and the inner layer body 20 to each other. The adhesive strip layer AL can be made of, for example, a modified polyolefin resin (“Admer” (registered trademark)). In this embodiment, there are eight wires in total, two on each side of the double container 1 with the parting line PL in between, and two on each side with the parting line PL on both sides. An adhesive strip layer AL is provided. Each adhesive strip layer AL extends from the mouth portion 11 through the body portion 12 to the bottom portion 13 and reaches the pinch-off portion 30. By providing such an adhesive band layer AL, when the contents are poured out, the inner layer body 20 is deformed to reduce its volume into a flat shape, and the inner layer body 20 is distorted and deformed. It is possible to prevent the contents from remaining inside without being poured out. Note that at least one adhesive band layer 40 may be provided.

The mouth portion 11 of the double container 1 is equipped with a spouting device (not shown) such as a spouting cap equipped with a spouting valve and a check valve for introducing outside air, various nozzles, or a spouting pump. It will be installed. The spouting tool can be attached by screwing to a male thread 11a integrally provided on the outer circumferential surface of the spout 11, but it can also be mounted by undercut engagement using a stopper, for example.

The double container 1 is equipped with a spouting cap provided with a spouting valve and a check valve for introducing outside air into the opening 11, so that the body 12 of the outer layer body 10 can be squeezed. The contents can be poured out from the spouting cap through the spout 11. When the outer layer body 10 restores its original shape after pouring out the contents, outside air is introduced between the outer layer body 10 and the inner layer body 20 through the outside air inlet 16 provided in the mouth portion 11, and the inner layer body Only the outer layer body 10 can be restored to its original shape while the outer layer body 20 is deformed to reduce its volume. Therefore, when the contents are poured out, air is prevented from flowing into the storage space S of the inner layer body 20 from the spout 11, making it difficult for the contents stored in the storage space S to come into contact with air. Deterioration can be prevented. When the body 12 is squeezed to pour out the contents again, the check valve for introducing outside air prevents the air between the outer layer 10 and the inner layer 20 from leaking outside, and the inner layer The body 20 can be pressed by the torso 12 through the air therebetween. In addition, by attaching a nozzle to the mouth part 11 and tilting the outer layer body 10, it is also possible to have a configuration in which the contents stored in the storage space S of the inner layer body 20 are poured out from the mouth part 11 by its own weight. Furthermore, when a spouting device equipped with a pump is attached to the mouth portion 11, a non-flexible material can be used as the outer layer body 10.

As shown in FIGS. 1 to 4, the bottom portion 13 has an annular outer edge portion 13a that serves as a ground surface, and a recessed portion 13b that is recessed upward on the inner peripheral side of the outer edge portion 13a. A pinch-off section 30 is provided. The pinch-off portion 30 is a straight protrusion that passes through the center of the recess 13b, has both ends reaching near the outer edge 13a, and has a height that is within the depth of the recess 13b (does not protrude below the outer edge 13a). It has a strip shape.

As shown in FIGS. 4 and 5, the pinch-off section 30 includes a first side surface 31 and a second side surface 32 that are perpendicular to the longitudinal direction of the pinch-off section 30 and oriented in the radial direction. The first side surface 31 and the second side surface 32 are planes parallel to each other. The lower surface 33 of the pinch-off part 30 is a plane perpendicular to the first side surface 31 and the second side surface 32, and a protrusion 34 having a triangular cross section is integrally provided at the center in the width direction along the longitudinal direction. There is. The lower end of the inner layer body 20 terminates inside the pinch-off portion 30 without reaching the lower end of the projection 34.

The pinch-off portion 30 includes a first groove 40 that is open to the first side surface 31 and recessed toward the second side surface 32; A second groove 41 is provided below and spaced apart from the first groove 40 . The cross-sectional shapes of the first groove 40 and the second groove 41 are each rectangular, and are symmetrical to each other with the axis O in between. Further, the first groove 40 and the second groove 41 each extend along the longitudinal direction of the pinch-off portion 30, and portions in a predetermined range on both ends in the longitudinal direction extend straight along the radial direction, and the intermediate portion is a recessed portion. It has a shape that curves and extends upwardly along the shape of 13b.

Both ends of the first groove 40 and the second groove 41 in the longitudinal direction do not reach the end of the pinch-off section 30, and the first side surface 31 to the second side surface 32 are located near the end of the pinch-off section 30. It terminates at. Further, the longitudinal end positions of the first groove 40 and the second groove 41 coincide with each other at both ends. That is, the distance from the axis of the bottom part 13 to one end position of the first groove 40 is the same as the distance from the axis of the bottom part 13 to one end position of the second groove 41; The distance from the axis of the bottom portion 13 to the other end position of the first groove 40 is the same as the distance from the axis of the bottom portion 13 to the other end position of the second groove 41. As shown in FIG. 4, the ends of the adhesive layer AL that extend from the mouth 11 through the body 12 to the bottom 13 and reach the pinch-off part 30 are located at both ends of the first groove 40 and the second groove 41. It is arranged between the outer layer body 10 and the inner layer body 20 in the portions on both longitudinal end sides of the pinch-off portion 30 that the pinch-off portions 30 do not reach. The portions on both longitudinal end sides of the pinch-off portion 30 have a structure in which the outer layer body 10 and the inner layer body 20 are bonded together by the adhesive band layer AL, making it difficult for cracks to occur. Note that the adhesive band layer AL may extend to a portion of the pinch-off portion 30 where the first groove 40 and the second groove 41 are provided.

The first groove 40 and the second groove 41 are spaced apart from each other vertically and are arranged so as to overlap each other when viewed from the bottom. Therefore, the cross-sectional shape of the portion of the pinch-off portion 30 where the first groove 40 and the second groove 41 are provided is a folded shape (crank shape). That is, the portion of the pinch-off portion 30 where the first groove 40 and the second groove 41 are provided includes a base portion 30a having a substantially rectangular cross section extending along the recess 13b, and a first vertical wall extending downward from the base portion 30a. portion 30b, a first horizontal wall portion 30c that is integrally connected to the lower end of the first vertical wall portion 30b at one side end and extends horizontally (radially) from the lower end of the first vertical wall portion 30b, and a first horizontal wall portion at the upper end. A second vertical wall portion 30d is integrally connected to the other side end of the first horizontal wall portion 30c and extends downward from the other side end of the first horizontal wall portion 30c; The second horizontal wall portion 30e extends horizontally from the lower end of the vertical wall portion 30d and is disposed opposite to the first horizontal wall portion 30c. The first vertical wall portion 30b and the second vertical wall portion 30d are substantially parallel to each other, and the first horizontal wall portion 30c and the second horizontal wall portion 30e are substantially parallel to each other. By having the above-described folded shape, the pinch-off section 30 can easily elastically deform so that the angles formed by each wall section 30b to 30e relative to the base section 30a and the other wall sections 30b to 30e increase or decrease. I can do it.

As shown in FIG. 5, in the double container 1 of this embodiment, the depth D1 of the first groove 40 and the depth D2 of the second groove 41 provided in the pinch-off part 30 are each 3.0 to 4.5 mm. , more preferably within the range of 3.5 to 4.2 mm. In the illustrated case, the thickness t of the pinch-off portion 30 is 4.0 mm, while the depth D1 of the first groove 40 and the depth D2 of the second groove 41 are each 3.8 mm. Note that the widths (vertical dimensions) of the first groove 40 and the second groove 41 are each 0.8 mm. Therefore, the thickness of the first vertical wall part 30b and the second vertical wall part 30d is 0.2 mm, and the first groove 40 and the second groove 41 are formed in the first vertical wall part 30b and the second vertical wall part 30d. They are arranged to overlap with each other in a bottom view within a range of 3.6 mm excluding the thickness.

Here, the depth D1 of the first groove 40 is the radial distance from the first side surface 31 to the bottom surface of the first groove 40, and the depth D2 of the second groove 41 is the distance from the second side surface 32 to the bottom surface of the first groove 40. This is the distance in the radial direction to the bottom surface of the groove 41. Further, the thickness t of the pinch-off portion 30 is the distance in the radial direction from the first side surface 31 to the second side surface 32.

The depth D1 of the first groove 40 and the depth D2 of the second groove 41 are preferably the same, but may be different from each other as long as they are within the range of the above numerical values. Further, the thickness t of the pinch-off portion 30 is larger than either the depth D1 of the first groove 40 or the depth D2 of the second groove 41, and the first groove 40 and the second groove 41 overlap each other when viewed from the bottom. The value can be arbitrarily set as long as the thickness is 0.0 than the larger of the depth D1 of the first groove 40 and the depth D2 of the second groove 41. It is preferable to set the value to a large value in the range of .2 to 1.0 mm.

As described above, in the double container 1 according to the present embodiment, the pinch-off portion 30 has the first groove 40 that is open to the first side surface 31 and recessed toward the second side surface 32, and the first groove 40 that is open to the second side surface 32. , the depth of the first groove 40 is recessed toward the first side surface 31, and a second groove 41 is provided below the first groove 40 at a distance from the first groove 40. Since the depth D1 and the depth D2 of the second groove 41 are each set within the range of 3.0 to 4.5 mm, the amount of pinching of the inner layer body 20 into the outer layer body 10 at the pinch-off portion 30 is sufficient. As a result, the impact strength (impact resistance) of the pinch-off portion 30 can be increased. Furthermore, in the double container 1 according to the present embodiment, the depth D1 of the first groove 40 and the depth D2 of the second groove 41 are each set within the range of 3.0 to 4.5 mm. When forming the double container 1 by extrusion blow molding, the inner layer body 20 is pulled upward relative to the outer layer body 10 by a pair of pin members forming the first groove 40 and the second groove 41, and the molding is performed. In the pinch-off section 30 of the later double container 1, the lower end of the inner layer body 20 may be configured to terminate inside the pinch-off section 30. As a result, the pinch-off section 30 can have a structure in which the lower end thereof is formed only of the outer layer body 10 and tightly adhered thereto, thereby increasing the strength of the pinch-off section 30 against impact. Therefore, even if a large impact is applied to the double container 1, such as by dropping it with contents stored therein, the pinch-off portion 30 can be made less likely to crack. As described above, the outer layer body 10 and the inner layer body 20 are bonded together by the adhesive strip layer AL in the portions of the pinch-off portion 30 at both ends in the longitudinal direction where both ends of the first groove 40 and the second groove 41 do not reach. This structure prevents cracking even if a large impact is applied.

In particular, as in the present embodiment, the outer layer 10 is made of relatively hard polypropylene resin, and the inner layer 20 is made of ethylene-vinyl alcohol copolymer resin, which has relatively low adhesiveness to polypropylene resin. Also, the impact resistance of the pinch-off portion 30 can be improved, and the double container 1 can be made such that the pinch-off portion 30 is less likely to be cracked.

Furthermore, if the depth D1 of the first groove 40 and the depth D2 of the second groove 41 are less than 3.0 mm, the strength of the pinch-off portion 30 will be insufficient, and the depth D1 of the first groove 40 and the depth D2 of the second groove 41 will be less than 3.0 mm. If the depth D2 of the groove 41 is greater than 4.5 mm, it will be difficult to form the first groove 40 and the second groove 41 in the pinch-off part 30 using a mold, but this embodiment In the double container 1 having the configuration shown in FIG. While ensuring the desired strength, the moldability of the double container 1 using a mold in extrusion blow molding can be made good.

In particular, when the depth D1 of the first groove 40 and the depth D2 of the second groove 41 are each set within the range of 3.5 to 4.2 mm, the strength of the pinch-off portion 30 is ensured to the desired strength. At the same time, the moldability of the double container 1 using a mold can be improved.

Furthermore, in the double container 1 of the present embodiment, the first groove 40 and the second groove 41 each extend to the vicinity of the longitudinal end of the pinch-off part 30, and the first groove 40 extends from the axis of the bottom part 13. Since the distance to the end position of the inner layer body 20 and the distance from the axis of the bottom part 13 to the end position of the second groove 41 are the same, at the pinch-off part 30 , the inner layer body 20 is inserted into the outer layer body 10 The impact resistance of the pinch-off portion 30 can be further improved by minimizing the number of locations where the amount of pinching is insufficient.

It goes without saying that the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the spirit thereof.

For example, the outer layer body 10 is not limited to the shape shown in FIG. 1, but can be changed in various shapes as long as it is in the shape of a bottle having a mouth portion 11, a body portion 12, and a bottom portion 13.

1 Double container 10 Outer layer body 11 Mouth portion 11a Male screw 12 Body portion 13 Bottom portion 13a Outer edge portion 13b Recessed portion 14 Shoulder portion 15 Recessed rib 16 Outside air inlet 20 Inner layer body 30 Pinch-off portion 30a Base portion 30b First vertical wall portion 30c First Horizontal wall portion 30e Second horizontal wall portion 31 First side surface 32 Second side surface 33 Lower surface 34 Protrusion 40 First groove 41 Second groove O Axis line S Storage space PL Parting line AL Adhesive band layer D1 First groove depth D2 Second Groove depth t Thickness of pinch-off part

Claims (5)

a bottle-shaped outer layer body having a mouth, a body, and a bottom;
an inner layer body that is housed inside the outer layer body and is deformable to reduce its volume;
a pinch-off portion formed in the shape of a protrusion sandwiching the inner layer body and provided on the bottom portion;
A double container having an outside air inlet provided in the outer layer body and communicating between the outer layer body and the inner layer body,
The pinch-off portion is
a first groove that is open to a first side facing one side and recessed toward a second side facing opposite to the first side;
a second groove that is open to the second side surface, is recessed toward the first side surface, and is disposed below the first groove and spaced apart from the first groove;
The depths of the first groove and the second groove are each 3.0 to 4.5 mm,
The pinch-off portion is formed in a straight line passing through the axis of the bottom portion when viewed from the bottom,
The first groove and the second groove each extend to the vicinity of the longitudinal end of the pinch-off part, and the distance from the axis of the bottom part to the end position of the first groove and the bottom part A double container characterized in that the distance from the axis to the end position of the second groove is the same . The double container according to claim 1, wherein the first groove and the second groove each have a depth of 3.5 to 4.2 mm. The double container according to claim 1 or 2 , wherein the outer layer is made of polypropylene resin, and the inner layer is made of ethylene-vinyl alcohol copolymer resin. The double container according to claim 3 , wherein, in the pinch-off part, a lower end of the inner layer body terminates inside the pinch-off part. The double container according to any one of claims 1 to 4 , wherein an end portion of the adhesive band layer provided between the outer layer body and the inner layer body reaches the pinch-off portion.

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