JP7312353B2 - double container - Google Patents

Description

TECHNICAL FIELD The present invention relates to a double container whose inner layer shrinks as the contents are discharged, and more particularly to a novel double container capable of reducing the amount of residual liquid.

Conventionally, there has been known a double container (a so-called delamination container) comprising a container body having an outer layer container and an inner bag, the inner bag shrinking as the contents decrease, and a check valve for adjusting the inflow and outflow of air between the intermediate space between the outer layer container and the inner bag and the outer space of the container body (see, for example, Patent Documents 1 and 2).

In the delamination container disclosed in Patent Literature 1, a valve is incorporated in a cap attached to the mouth of the container body. In the delaminating container disclosed in Patent Document 2, a valve is provided inside the body of the outer shell.

JP 2013-35557 A JP-A-4-267727

By the way, in this type of double container, the inner layer (inner bag) tends to shrink as it is used, and the inner layer tends to adhere when the amount of residual liquid decreases. If the inner layer is in close contact with the inner layer, it becomes difficult to push out the contents below it, and there is a problem that the amount of residual liquid increases.

The present invention has been made in view of such conventional circumstances, and it is an object of the present invention to provide a double container that can prevent the adhesion of the inner layer and secure the flow path of the contents and can suppress the amount of residual liquid.

In order to achieve the above object, the double container of the present invention is a double container having an outer layer and an inner layer, wherein the inner layer shrinks as the content stored in the inner layer decreases, wherein an elongated insertion member is inserted into the inner layer, and the insertion member is inserted into the inner layer without being fixed to other members.

By inserting an elongated insertion member into the double container, the inner layers are prevented from coming into close contact with each other, and a flow path toward the discharge port is secured. As a result, even the contents near the bottom can be discharged to the end, and the amount of residual liquid is greatly reduced.

ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the double container which can prevent the inner layer from closely_contact|adhering, can ensure the flow path of a content, and can suppress the amount of residual liquids.

It is a schematic perspective view of the container main body of a double container. It is a principal part schematic sectional drawing of a container main body. It is a schematic sectional drawing which shows the layer structure of an outer layer and an inner layer. FIG. 4 is an exploded perspective view of the essential parts showing how the pump is attached to the double container. FIG. 4 is a schematic cross-sectional view of a main part showing how the pump is attached to the double container; Examples of the shape of the insertion member are shown, (A) is a tubular insertion member, (B) is a tubular insertion member having a hole in the wall surface, and (C) is a columnar insertion member with an X-shaped cross section. FIG. 4 is a cross-sectional view showing a state in which the inner layer (inner bag) is shrunk. FIG. 4 is a view showing a state in which an insertion member is inserted into a squeeze type double container.

EMBODIMENT OF THE INVENTION Hereafter, embodiment of the double container to which this invention is applied is described with reference to drawings.

As shown in FIGS. 1 and 2, the double container 1 of the present embodiment is mainly composed of a container body 2, and the container body 2 includes a storage portion 3 for storing contents and a mouth portion 4 for discharging the contents from the storage portion 3.

The double container 1 of the present embodiment is a so-called delamination container, and as shown in FIG. 2, the container body 2 includes an outer shell 11 and an inner bag inner layer 12 in the storage portion 3 and the mouth portion 4. The inner layer 12 shrinks as the contents decrease.

The outer layer 11 and the inner layer 12 are subjected to blow molding, for example, as a multi-layer parison, and are molded in an integrally joined state. As a form of use, for example, the inner layer 12 is separated from the outer layer 11 in advance except for the mouth portion 4 before use, and the content is filled until the inner layer 12 contacts the outer layer 11. By pushing out the contents, the inner layer 12 shrinks smoothly. Alternatively, the inner layer 12 may remain bonded to the outer layer 11, and the inner layer 12 may be peeled off from the outer layer 11 and contracted as the contents are discharged.

Further explaining the layer structure of the container body 2, as described above, the container body 2 includes the outer layer 11 and the inner layer 12, and the outer layer 11 is formed to be thicker than the inner layer 12 so as to increase the resilience.

The outer layer 11 is made of, for example, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer and mixtures thereof. The outer layer 11 has a single-layer or multi-layer structure, and preferably contains a lubricant in at least one of the innermost layer and the outermost layer. When the outer layer 11 has a single-layer structure, the single layer is the innermost layer and the outermost layer, so that layer may contain a lubricant. When the outer layer 11 has a two-layer structure, the layer on the inner surface side of the container is the innermost layer and the layer on the outer surface side of the container is the outermost layer, so at least one of them may contain a lubricant. When the outer layer 11 is composed of three or more layers, the layer closest to the inner surface of the container is the innermost layer, and the layer closest to the outer surface of the container is the outermost layer.

As shown in FIG. 3, the outer layer 11 preferably has a repro layer 11c between the innermost layer 11b and the outermost layer 11a. The repro layer is a layer made by recycling burrs generated during the molding of the container. When the outer layer 11 has a multilayer structure, it is preferable that both the innermost layer and the outermost layer contain a lubricant.

As the lubricant, those generally available on the market can be used, and may be any of hydrocarbon-based, fatty acid-based, aliphatic amide-based, and metallic soap-based lubricants, and two or more of them may be used in combination. Hydrocarbon-based lubricants include liquid paraffin, paraffin wax, synthetic polyethylene wax, and the like. Fatty acid-based lubricants include stearic acid and stearyl alcohol. Fatty acid amides such as stearic acid amide, oleic acid amide and erucic acid amide, alkylene fatty acid amides such as methylenebisstearic acid amide and ethylenebisstearic acid amide, and the like can be used as aliphatic amide lubricants. Examples of metal soap-based lubricants include metal stearates.

The innermost layer of the outer layer 11 is in contact with the inner layer 12, and the release property between the outer layer 11 and the inner layer 12 can be improved by incorporating a lubricant into the innermost layer of the outer layer 11. On the other hand, the outermost layer of the outer layer 11 is a layer that comes into contact with the mold during blow molding, and the releasability can be improved by incorporating a lubricant into the outermost layer of the outer layer 11 .

One or both of the innermost layer and the outermost layer of the outer layer 11 can be formed of a random copolymer between propylene and another monomer. As a result, the shape restorability, transparency, and heat resistance of the outer layer 11, which is the outer shell, can be improved.

If the container is excessively hard, the feeling of use of the container is poor. Therefore, the outer layer 11 may be formed by mixing the random copolymer with a flexible material such as linear low-density polyethylene. However, the material to be mixed with the random copolymer is preferably mixed in an amount of less than 50% by weight with respect to the entire mixture so as not to significantly impair the effective properties of the random copolymer. For example, the outer layer 11 can be made of a material in which a random copolymer and linear low-density polyethylene are mixed at a weight ratio of 85:15.

For example, as shown in FIG. 3, the inner layer 12 includes an EVOH layer 12a provided on the container outer surface side, an inner surface layer 12b provided on the container inner surface side of the EVOH layer 12a, and an adhesive layer 12c provided between the EVOH layer 12a and the inner surface layer 12b. By providing the EVOH layer 12a, the gas barrier properties and the peelability from the outer layer 11 can be improved.

The EVOH layer 12a is a layer made of ethylene-vinyl alcohol copolymer (EVOH) resin and obtained by hydrolysis of ethylene and vinyl acetate copolymer. The ethylene content of the EVOH resin is, for example, 25 to 50 mol %, preferably 32 mol % or less from the viewpoint of oxygen barrier properties. Although the lower limit of the ethylene content is not specified, it is preferably 25 mol % or more because the flexibility of the EVOH layer 12a tends to decrease as the ethylene content decreases. Also, the EVOH layer 12a preferably contains an oxygen absorber. By including an oxygen absorber in the EVOH layer 12a, the oxygen barrier properties of the EVOH layer 12a can be further improved.

The inner layer 12b is a layer that contacts the contents of the double container 1, and is made of polyolefin such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof, preferably low-density polyethylene or linear low-density polyethylene. The tensile modulus of the resin forming the inner layer 12b is preferably 50 to 300 MPa, more preferably 70 to 200 MPa. This is because the inner surface layer 13b is particularly flexible when the tensile modulus is within such a range.

The adhesive layer 12c is a layer having a function of bonding the EVOH layer 12a and the inner surface layer 12b, and is, for example, a layer obtained by adding an acid-modified polyolefin (e.g., maleic anhydride-modified polyethylene) obtained by introducing a carboxyl group to the above-described polyolefin, or an ethylene-vinyl acetate copolymer (EVA). An example of the adhesive layer 12c is a mixture of low density polyethylene or linear low density polyethylene and acid-modified polyethylene.

The above is the layer structure of the outer layer 11 and the inner layer 12. As shown in FIGS. 1 and 2, the double container 1 has a recess 7a formed in the outer layer 11 at the shoulder portion of the housing portion 3, and an air introduction hole 15 is formed in the recess 7a. The air introduction hole 15 is a through hole provided only in the outer layer 11 and does not reach the inner layer 12 . An intermediate space 21 is formed between the outer layer 11 and the inner layer 12, which are outer shells, by introducing air from the atmosphere introduction hole 15. As shown in FIG. That is, the intermediate space 21 and the external space are communicated with each other through the atmosphere introduction hole 15 .

A valve member 5 is provided in the atmosphere introduction hole 15. The valve member 5 includes a shaft portion 5a that is inserted through the outside air introduction hole 15 and is slidable relative to the outside air introduction hole 15, a lid portion 5c that is provided on the intermediate space 21 side of the shaft portion 5a and has a larger cross-sectional area than the shaft portion 5a, and a locking portion 5b that is provided on the outer space S side of the shaft portion 5a and prevents the valve member 5 from entering the intermediate space 21.

In this example, the atmosphere introduction hole 15 is provided in the shoulder portion of the container body 2 , but the formation position of the atmosphere introduction hole 15 is arbitrary. Alternatively, the outer layer 11 and the inner layer 12 may be peeled off at the bottom pinch portion and used as an air introduction hole.

Further, in the double container 1 composed of the outer layer 11 and the inner layer 12, for example, a band-shaped adhesive layer (adhesive band) may be provided in the vertical direction, and the outer layer 11 and the inner layer 12 may be adhesively fixed by this adhesive band, but such an adhesive band is not provided in the double container 1 of the present embodiment.

In the double container 1 configured as described above, for example, in a pump type double container, a pump is attached to the mouth portion 4 thereof. 4 and 5 show attachment of the pump 50 to the mouth 4 of the container body 2. FIG. The pump 50 is composed of a nozzle portion 51 for pressing operation, an attachment portion 52 to the container body 2, and a suction pipe 53 to be inserted into the container body 2. The pump 50 is attached to the mouth portion 4 of the container body 2 by a screwing method and is attached via a packing 60. By interposing the packing 60, airtightness is ensured.

In the double container 1 of this embodiment, before the pump 50 is attached, an elongated insertion member 70 is inserted into the inner layer (inner bag) 12 of the container body 2 to prevent the inner layer (inner bag) 12 from coming into close contact with the discharge of the contents, thereby ensuring a flow path.

In this example, the insertion member 70 is a straw-shaped tubular member as shown in FIG. 6A, which is inserted into the inner layer (inner bag) 12 of the container body 1 without being fixed. By inserting the insertion member 70, the flow path is secured as described above, and the contents in the inner layer 12 can be discharged to the end, thereby greatly reducing the amount of residual liquid.

FIG. 7 shows a state in which the inner layer (inner bag) 12 is shrunk. Even when the inner layer 12 is shrunk, the insertion member 70 is inserted inside, so that the inner layer 12 is prevented from coming into close contact with the inner layer 12. Since the inside of the insertion member 70 also functions as a flow path, the flow path for the contents is secured and the amount of residual liquid is suppressed.

Considering the function of the inserting member 70, it is preferable that the inserting member 70 is made of an elastic material (for example, silicone rubber or the like). When the insertion member 70 is a straw-shaped tubular member, the contents enter the inside of the insertion member 70, but if the insertion member 70 is made of an elastic material, the insertion member 70 is crushed and the contents inside can be quickly discharged.

Moreover, the form of the insertion member 70 is also arbitrary, and various forms other than a straw-shaped tubular member as shown in FIG. 6(A) can be adopted. For example, as shown in FIG. 6B, the insertion member 70 may be a straw-shaped tubular member, and holes 71 may be arranged and formed on the wall surface thereof at predetermined intervals. By providing the hole portion 71 in this way, it is possible to smoothly discharge the contents that have entered the insertion member 70 .

FIG. 6(C) shows an example of a columnar insertion member 70, which in this example has a form in which two plate-like portions 72 and 73 are crossed. The cross-sectional shape is X-shaped. By making the insertion member 70 columnar, it is possible to prevent the content from entering. Further, by crossing the two plate-like portions 72 and 73 to form an X-shaped cross section, it is possible to secure a sufficient flow path.

The length of the insertion member 70 is arbitrary, but is preferably about 50% to 90% of the height of the container body 2, for example. If the length of the insertion member 70 is too short, it may become difficult to smoothly discharge the contents at the bottom. Conversely, if the insertion member 70 is too long, it may interfere with other members.

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

For example, the applicable double container is not limited to the pump type, and a so-called squeeze type double container can also be applied.

FIG. 8 shows an example of application to a squeeze type double container. A squeeze type double container 80 is composed of a container body 81 and a cap 82 attached to the mouth. The container body 81 has an outer layer and an inner layer (inner bag) that are detachably laminated as in the previous embodiment.

In the squeeze-type double container 80, viscous substances such as mayonnaise and ketchup may be accommodated as contents, but there is a tendency for the amount of residual liquid to increase at the bottom. Therefore, even in the squeeze-type double container 80, by inserting the insertion member 70 into the container body (inner layer), it is possible to prevent the inner layer from sticking, secure the flow path, and reduce the amount of residual liquid.

1 double container 2 container main body 3 accommodating part 4 mouth part 5 valve member 11 outer layer 12 inner layer (inner bag)
15 outside air introduction hole 70 insertion member

Claims (6)

A double container having an outer layer and an inner layer, wherein the inner layer shrinks as the content stored in the inner layer decreases,
An elongated insertion member is inserted in the inner layer,
A double container, wherein the insertion member is inserted into the inner layer without being fixed to another member . 2. The double container according to claim 1, wherein said insert member is a tubular member. 3. The double container according to claim 2 , wherein said tubular member has holes arranged in a wall surface thereof at predetermined intervals. 2. The double container according to claim 1, wherein said insert member is a columnar member. 5. The double container according to claim 4 , wherein the columnar member has an X-shaped cross section. The double container according to any one of claims 1 to 5, wherein the container is a pump-type container, and the insert member is not fixed to the pump either.

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