JP7675320B2 - double container - Google Patents

Description

The present invention relates to a double container in which the inner layer shrinks as the contents are dispensed, and in particular to a double container in which an air inlet hole without a valve is formed at the mouth.

Conventionally, double containers (so-called peelable laminated containers) have been proposed that have an outer container and an inner bag, and the inner bag shrinks as the contents decrease (see, for example, Patent Document 1 and Patent Document 2). In a double container of this configuration, the inner bag shrinks as the contents decrease, so air does not get into the inner bag, minimizing contact between the contents and air, and thus preventing oxidation and deterioration.

In the double container, it is necessary to introduce air between the outer container and the inner bag, so it is common to form an air inlet hole in the outer container and provide a valve member to regulate the flow of air in and out of the air inlet hole. In the peelable laminate containers of Patent Documents 1 and 2, a recess is formed in the shoulder of the container, and an air inlet hole that penetrates only the outer shell (outer container) is drilled in this recess and a valve member is attached. The valve member is attached to the air inlet hole formed in the outer shell of the container body, and the air inlet hole is opened and closed by the relative movement of this valve member with respect to the container body.

JP 2017-154802 A JP 2017-193342 A

The double-walled containers mentioned above prevent the contents from coming into contact with air, minimizing the effects of oxidation and the like. However, they are made up of three parts - the double-walled container body, the outside air intake valve, and the cap - and have a large number of parts, which poses a major challenge as it increases costs compared to regular plastic containers.

The present invention was made in consideration of the above-mentioned conventional circumstances, and aims to provide a double container that can reduce the number of parts and manufacturing costs while ensuring sufficient performance.

In order to achieve the above-mentioned object, the double container of the present invention is a double container having an outer layer and an inner layer, the inner layer shrinking as the content contained in the inner layer decreases, the double container having a body and a mouth having an outer dimension smaller than that of the body and having a discharge port, an air introduction hole not having a valve is formed in the outer layer in the mouth, a plug-type cap is attached to the mouth, the air introduction hole is not covered by the cap, an opening diameter d of the air introduction hole is 1.0 mm to 1.5 mm, and the air introduction hole is formed at a position 180° opposite to the hinge of the cap . Alternatively, the present invention is a double container having an outer layer and an inner layer, the inner layer shrinking as the content contained in the inner layer decreases, the double container having a body and a mouth having an outer dimension smaller than that of the body and having a discharge port, an air introduction hole not having a valve is formed in the outer layer in the mouth, the mouth has an annular recess, the air introduction hole is formed in the annular recess, a stopper-type cap is attached to the mouth, the annular recess is provided for gripping with a stopper machine when the cap is stopped onto the mouth, an opening diameter d of the air introduction hole is 1.0 mm to 1.5 mm, and the air introduction hole is formed at a position 180° opposite to the hinge of the cap .

The inventors' investigations revealed that in double containers, where the mouth is facing downwards and the contents are dispensed, the feel of use differs depending on the location of the air inlet. After further investigations, they discovered that by forming an air inlet in the mouth, particularly in the area near the base end (the so-called neck), they could achieve a feel of use that was comparable to that of a container with a valve member.

The double container of the present invention was devised based on this knowledge. When the mouth of the double container of the present invention is tilted downward and the contents are dispensed by squeezing, a pressing force is applied to the inside of the inner layer by the squeezing force and the weight of the contents, which presses it against the outer layer. As a result, the inner layer adheres closely to the air introduction hole formed in the outer layer and is in a sealed state, allowing the contents to be dispensed smoothly by squeezing. After dispensing, when the squeezing force is released and the double container is returned to an upright state, the pressing force applied to the inner layer is released, the inner layer quickly peels off from the outer layer, and air (outside air) is quickly introduced between the inner and outer layers.

The present invention makes it possible to provide a double container that provides a usability comparable to that of a container with a valve member in the air inlet, while also reducing the number of parts and manufacturing costs.

FIG. 2 is a schematic front view of a container body of the double container. FIG. 2 is a schematic side view showing the state in which the cap is attached to the container body. 3 is a schematic cross-sectional view of the vicinity of the mouth of the container body. FIG. 3 is a schematic cross-sectional view of the vicinity of the mouth of a container body with a cap attached. FIG. 2 is a schematic front view showing an enlarged view of the vicinity of the mouth of the container body. FIG. 1A is a schematic cross-sectional view of the main part showing the state in which the contents are being ejected, and FIG. 1B is a schematic cross-sectional view of the main part showing the state in which the double container is returned to the upright position.

Below, an embodiment of a double container to which the present invention is applied will be described with reference to the drawings.

As shown in FIG. 1, the double container 1 of this embodiment is mainly composed of a container body 2 having a storage section (body) 3 for storing the contents and a mouth section 4 having an opening 4a for discharging the contents from the storage section 3. In this embodiment, the storage section 3 is shaped to have a shoulder section, and has a shape with the mouth section 4 at the end of the shoulder section. The outer dimensions of the mouth section 3 are smaller than the outer dimensions of the storage section 3.

As shown in FIG. 2, a cap 5 is attached to the mouth 4 of the container body 2, and the contents of the container body 2 are discharged from a discharge port provided in the cap 5. Note that FIG. 2 is a side view of the container body 2 rotated 90° from the state shown in FIG. 1.

The double container 1 of this embodiment is a so-called peelable laminated container, and as shown in FIG. 3, the container body 2 has an outer layer 11, which is an outer shell, and an inner layer 12, which is an inner bag, in the storage section 3 and the mouth section 4, and the inner layer 12 shrinks as the contents decrease.

The outer layer 11 and the inner layer 12 are blow molded, for example, as a multi-layer parison, and molded in a state where they are bonded together. In terms of how it can be used, for example, the inner layer 12 is peeled off (pre-peeled off) from the outer layer 11 in advance, except for the mouth portion 4, before use, and the contents are filled until the inner layer 12 comes into contact with the outer layer 11, and the contents are pushed out, causing the inner layer 12 to shrink. Alternatively, the inner layer 12 may be left bonded to the outer layer 11, and the inner layer 12 may be peeled off from the outer layer 11 and shrink as the contents are discharged.

To further explain the layer structure of the container body 2, as described above, the container body 2 has an outer layer 11 and an inner layer 12, and the outer layer 11 is formed to be thicker than the inner layer 12 so as to have high restorability.

The outer layer 11 is composed of, for example, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof. The outer layer 12 may be composed of multiple layers. For example, the outer layer 12 may be composed of a recyclable layer sandwiched between layers made of virgin material. Here, the recyclable layer refers to a layer made of recycled flash produced during the molding of the container. A specific example of the layer composition of the outer layer 11 is a three-layer composition of a polypropylene (PP) layer/recyclable layer/polypropylene (PP) layer. Furthermore, it is possible to add a lubricant to the portion of the outer layer 11 that contacts the inner layer 12 to promote peeling between the outer layer 11 and the inner layer 12.

The inner layer 12 comprises, for example, an EVOH layer provided on the outer surface of the container, an inner surface layer provided on the inner surface side of the EVOH layer, and an adhesive layer provided between the EVOH layer and the inner surface layer. A specific example of the layer structure of the inner layer 12 is a three-layer structure of an EVOH layer/adhesive layer/polyethylene (PE) layer. By providing the EVOH layer, it is possible to improve the gas barrier properties and peelability from the outer layer 11.

The EVOH layer is a layer made of ethylene-vinyl alcohol copolymer (EVOH) resin, and is obtained by hydrolysis of ethylene and vinyl acetate copolymer. The ethylene content of the EVOH resin is, for example, 25 to 50 mol%, and is preferably 32 mol% or less from the viewpoint of oxygen barrier properties. There is no particular lower limit for the ethylene content, but since the flexibility of the EVOH layer is more likely to decrease as the ethylene content decreases, a content of 25 mol% or more is preferable. In addition, the EVOH layer preferably contains an oxygen absorber. By incorporating an oxygen absorber in the EVOH layer, the oxygen barrier properties of the EVOH layer can be further improved.

The inner surface layer is the layer that comes into contact with the contents of the double container 1, and is made of polyolefins such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymers, and mixtures thereof, and is preferably made of low-density polyethylene or linear low-density polyethylene.

The adhesive layer is a layer that functions to bond the EVOH layer and the inner surface layer, and is, for example, an acid-modified polyolefin (e.g., maleic anhydride-modified polyethylene) in which a carboxyl group has been introduced into polyolefin, or an ethylene-vinyl acetate copolymer (EVA). One example of an adhesive layer is a mixture of low-density polyethylene or linear low-density polyethylene and acid-modified polyethylene.

Next, we will explain the cap 5 that is attached to the mouth 4 of the container body 2.

The cap 5 is a so-called stopper-type cap, and in response to this, the mouth 4 of the container body 2 is configured with multiple steps with different outer diameters that are continuous along the axial direction. Specifically, the mouth 4 is provided with a large-diameter mouth 4a that is located at the upper end and extends in the axial direction, a small-diameter mouth 4b that is located below the large-diameter mouth 4a and extends in the axial direction with an outer diameter smaller than that of the large-diameter mouth 4a, and a maximum-diameter mouth 4c that is located below the small-diameter mouth 4b and extends in the axial direction with an outer diameter larger than that of the large-diameter mouth 4a. Below the maximum-diameter mouth 4c, a support mouth 4d is formed that is smaller in diameter than the maximum-diameter mouth 4c and larger in diameter than the large-diameter mouth 4a. In addition, between the support mouth 4d and the storage section 3, an annular recess 4e with approximately the same diameter as the small-diameter mouth 4b is formed. This annular recess 4e is provided to be gripped by a stopper when the cap 5 is stoppered into the mouth 4.

The cap 5 according to this embodiment applies internal pressure to the container body 2 by squeezing the storage section 3 of the container body 2, and immediately after using an appropriate amount of the contents, the check valve 51 seals the inside of the container body 2 without the user having to operate the cap 5 by hand. Specifically, as shown in FIG. 4, the cap 5 is composed of a cap body 5A having a discharge hole 52 for the contents, and a lid body 5B connected to a main cap body 53 constituting the cap body 5A via a hinge 5C. That is, the main components of the cap 5 are the main cap body 53 to which the lid body 5B is connected and which includes an annular wall portion, the check valve 51, and the inner plug 54 having the discharge hole 52. The lid body 5B may be configured as a separate body without being connected to the cap body 5A by the hinge 5C.

The check valve 51 has a valve portion that opens and closes the discharge hole 52 by releasably seating on or off the annular valve seat around the discharge hole 52, and is molded, for example, from a polyethylene elastomer. The inner plug 54, located above the check valve 51, has a discharge passage 55 that communicates with the discharge hole 52 and discharges the contents from the discharge hole 52 to the outside of the container. The main cap body 53 including the lid body 5B is made, for example, of polypropylene, and the inner plug 54 is made, for example, of polyethylene.

The double container 1, which is a peelable laminated container, must have an air inlet. The air inlet is a through hole provided only in the outer layer 11, and does not reach the inner layer 12. Air is then introduced from this air inlet into the space between the outer layer 11 and the inner layer 12, which are the outer shells, causing only the inner layer 12 to shrink as the contents are dispensed. On the other hand, the outer layer 11 is restored to its original shape by its own restoring force as air is introduced from the air inlet.

Generally, a valve member (check valve) is provided in the air introduction hole to allow smooth discharge of the contents and restoration of the outer layer, but providing a valve member increases the number of parts, which causes an increase in manufacturing costs. Therefore, in the double container 1 of this embodiment, the valve member is omitted, and the installation position of the air introduction hole is optimized to achieve the same feeling of use as when a valve member is provided, even without the valve member, thereby reducing the number of parts and suppressing increases in manufacturing costs.

In other words, the double container 1 of the present invention is characterized in that it has an air inlet 20 without a valve formed in the outer layer 11, and is characterized in function in that the air inlet 20 is opened and closed by the contact and separation of the inner layer 12. "Having no valve" means that, as described above, the inner layer 12 has the valve function, and no valve member formed as a separate member is provided.

The inventors had considered eliminating the valve member (check valve) in order to reduce the number of parts, but found that the location of the air inlet hole that separates the outer and inner layers of the double container made a difference in the feel when used. Furthermore, when dispensing the contents, the mouth needs to be on the bottom, and they found that the mouth (especially the neck, which is the base end part of the mouth) is the best place for the outer and inner layers to come into close contact. When they opened an air inlet hole in that location, they were able to obtain a feel that was comparable to that of a container with a valve. Generally, mouths and necks are circular, which has the advantage that they are less likely to deform when dispensed and are less likely to leak air.

Figure 5 is an enlarged view of the vicinity of the mouth 4 of the double container 1 of this embodiment. In this embodiment, an air inlet hole 20 is formed in the mouth 4 of the container body 2, particularly in the annular recess 4e formed near the base end of the mouth 4. As described above, the annular recess 4e is provided to be gripped by a capping machine when capping the mouth 4 with a cap. The annular recess 4e has a smaller diameter than the other parts, and is formed as an annular groove when viewed from the outside, by molding it in a shape that protrudes inward.

This annular recess 4e has a smaller diameter than the other parts, and because the blow ratio is small during blow molding, it is molded thicker than the other parts. The mouth and neck are circular and do not easily deform even when discharged, but the annular recess 4e is thicker, making it even more resistant to deformation, further suppressing air leakage. In addition, because the annular recess 4e is molded in a way that protrudes inward, it is easy to apply internal pressure, and the inner layer 12 is reliably pressed against the outer layer 11, ensuring that the air introduction hole 20 is reliably blocked.

In this case, the opening diameter d of the air inlet hole 20 is preferably 1.0 mm to 1.5 mm. If the opening diameter d of the air inlet hole 20 exceeds 1.5 mm, the air inlet hole 20 may not be sufficiently blocked by the pressure of the inner layer 12, which may cause air leakage. Conversely, if the opening diameter d of the air inlet hole 20 is less than 1.0 mm, it may cause problems in introducing air between the outer layer 11 and the inner layer 12.

The air introduction hole 20 is preferably formed at a position 180° opposite the hinge 5C of the cap 5. When dispensing the contents in the double container 1, the lid 5B connected by the hinge 5C is flipped up and the mouth 4 is squeezed downward. At this time, if the air introduction hole 20 is formed at a position 180° opposite the hinge 5C of the cap 5, the air introduction hole 20 is located below the mouth 4, making it easier for the gravity of the contents to be applied, and the air introduction hole 20 is reliably closed.

In addition, in the double container 1 of this embodiment, the annular recess 4e formed in the mouth 4 is not covered by the cap 5, and therefore the air inlet hole 20 formed in the annular recess 4e is also not covered by the cap 5. Furthermore, in the double container 1 of this embodiment, the air inlet hole 20 is not provided with a valve member (check valve) as described above, and the path for introducing air into the air inlet hole 20 does not have a valve. For example, it is known to provide the air inlet hole in a position covered by a cap and provide a valve in the air inlet path of the cap, but even in such a case, no valve member is provided.

Figure 6 shows how the double container 1 of this embodiment is used. Note that in Figure 6, the configuration of the cap 5 is simplified, and the check valve 51 and the like are omitted. The contents M filled into the double container 1 are, for example, mayonnaise, ketchup, soy sauce, ponzu sauce, olive oil, dressing, pork cutlet sauce, mustard paste, etc.

To dispense the contents M of the double container 1, as shown in FIG. 6(A), the double container 1 is tilted so that the mouth 4 is positioned downward, and the storage section 3 of the double container 1 is squeezed (pressed). At this time, the contents M of the double container 1 falls from the storage section 3 toward the mouth 4, and the force of gravity is applied to the inner layer 12 near the mouth 4. The force of the squeeze is also applied as a force pressing against the contents M, and as a result, the inner layer 12 is pressed from the inside and brought into close contact with the outer layer 11, sealing the air inlet hole 20.

When squeezed in this state, the air between the outer layer 11 and the inner layer 12 does not escape through the air inlet 20, and the squeezing force is applied to the contents M, causing the contents M to be discharged from the discharge passage 55 of the cap 5. It also feels good to use.

After dispensing, the double container 1 is placed in an upright position, and at this time, as shown in FIG. 6(B), the contents M fall toward the storage section 3, acting to peel the inner layer 12 away from the outer layer 11. Therefore, the air introduction hole 20 provided in the outer layer 11 is opened, and air is quickly introduced between the outer layer 11 and the inner layer 12. As a result, the inner layer 12 remains in a contracted state, and the outer layer 11 is restored to its original shape.

As described above, in the double container 1 of this embodiment, even if a valve member (check valve) is not provided in the atmosphere inlet hole 20, it is possible to achieve a usability that is comparable to that of a valve member provided in the atmosphere inlet hole 20 by simply adjusting the position of the atmosphere inlet hole 20.

Although an embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to this embodiment, and various modifications are possible without departing from the spirit of the present invention.

Reference Signs List 1 Double container 2 Container body 3 Storage section 4 Mouth section 4e Annular recess 5 Cap 11 Outer layer 12 Inner layer 20 Air introduction hole

Claims (6)

A double container having an outer layer and an inner layer, the inner layer shrinking as the content contained in the inner layer decreases,
A nozzle has a body and a mouth having an outer dimension smaller than that of the body and having a discharge port.
an air inlet hole having no valve is formed in the outer layer at the mouth portion,
A plug-type cap is attached to the mouth portion, and the air introduction hole is not covered by the cap,
The double container is characterized in that the opening diameter d of the air introduction hole is 1.0 mm to 1.5 mm, and the air introduction hole is formed at a position 180° opposite to the hinge of the cap . The double container according to claim 1, characterized in that the mouth portion has an annular recess, and the air inlet hole is formed in the annular recess. The double container according to claim 2, characterized in that the annular recess is provided for gripping by a capping machine when the cap is applied to the opening. A double container having an outer layer and an inner layer, the inner layer shrinking as the content contained in the inner layer decreases,
A nozzle has a body and a mouth having an outer dimension smaller than that of the body and having a discharge port.
an air inlet hole having no valve is formed in the outer layer at the mouth portion,
The mouth portion has an annular recess, and the air introduction hole is formed in the annular recess,
A plug-type cap is attached to the mouth portion,
The annular recess is provided for gripping the cap with a capping machine when the cap is capped on the opening,
The double container is characterized in that the opening diameter d of the air introduction hole is 1.0 mm to 1.5 mm, and the air introduction hole is formed at a position 180° opposite to the hinge of the cap . A double container according to any one of claims 1 to 4, characterized in that the mouth portion has, from the top, a large diameter mouth portion, a small diameter mouth portion, a maximum diameter mouth portion, a support mouth portion, and an annular recess portion. A double container according to any one of claims 1 to 5, characterized in that the path for introducing air into the air inlet does not have a valve.

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