JP7038289B2 - Double container - Google Patents

Description

The present invention relates to a double container in which the inner layer shrinks as the contents are discharged.

Conventionally, the air between the container body having the outer layer container and the inner bag and the inner bag shrinking as the contents decrease, the intermediate space between the outer layer container and the inner bag, and the outer space of the container body. A double container (so-called laminated peeling container) provided with a check valve for controlling the entry / exit is known (see, for example, Patent Document 1). In the laminated peeling container disclosed in Patent Document 1, a valve is provided inside the body of the outer shell.

In this type of double container, it is possible to prevent air from entering the inside of the container (the inside of the inner bag for accommodating the contents), and it is possible to minimize the deterioration of the contents.

Japanese Unexamined Patent Publication No. 4-267727

By the way, when various containers are filled with contents and sold, it is widely practiced to cover them with a shrink film or the like and provide them to consumers. Laminated peeling containers are no exception, and are supplied to the market in a state of being covered with a shrinky film on which the product name and various information are printed.

However, in a double container (laminated peeling container) in which an outside air introduction hole is provided in the accommodating portion of the container body, if a shrink film is attached so as to be in close contact with the outer periphery of the accommodating portion, the outside air introduction hole is blocked. Therefore, there is a problem that the outside air is not smoothly introduced between the outer shell and the inner bag, and the resilience of the outer shell deteriorates.

The present invention has been made in view of such circumstances, and even when a coating film such as a shrink film is attached to the container body, the outside air is smoothly introduced and the outer layer (outer shell) is excellently restored. The purpose is to provide a double container.

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, and the inner layer shrinks as the content contained in the inner layer decreases. A cap is attached to the portion, and an outside air introduction hole for introducing outside air is formed in the outer layer between the outer layer and the inner layer , and a recess is formed in the outer layer of the container body, and an atmosphere introduction hole is formed here. Along with being provided, a groove portion that communicates with this concave portion and extends upward is provided, and the outer peripheral surface of the cap is a concave portion or a convex portion extending from the lower end of the cap to at least the middle portion in the height direction. At least one is formed, and a coating film is provided so as to cover at least the outside air introduction hole, and the coating film is covered to the middle position in the height direction of the concave portion or the convex portion of the cap, and the base of the cap and the container. A gap is formed between the shoulder portion of the main body and the covering film, and the gap formed between the covering film and the covering film in the cap extends from the gap in the shoulder portion to the groove portion at the lower end portion thereof. It is characterized by communication.

When the circumference of the cap having recesses and protrusions formed on the outer peripheral surface is covered with a covering film, the covering film is not covered in a state of completely following the uneven shape, and a gap is formed between the covering film and the cap. It is formed. Further, if the covering film is covered to the middle position in the height direction of the concave portion or the convex portion of the cap, the gap is opened when the covering film is interrupted.

Therefore, by adopting the above configuration, the air is smoothly introduced into the air introduction hole by the gap of the covering film. As a result, the outer layer (outer shell) is also quickly restored to its original shape.

According to the present invention, even when a coating film such as a shrink film is attached to the container body, the outside air can be smoothly introduced, and it is possible to provide a double container having excellent resilience of the outer layer (outer shell). be.

It is a figure which shows an example of a double container, (a) is a state before a cap is attached, (b) is a state with a cap attached, and (c) is a shrink film covering state. It is a schematic perspective view of a container body. It is a schematic cross-sectional view of the main part of a container body. It is a schematic sectional drawing which shows the layer structure of the outer layer and the inner layer. It is a figure which shows an example of the unevenness formed on the outer peripheral surface of a cap. It is sectional drawing which shows the state which covered the cap of FIG. 5 with a shrink film. It is a figure which shows another example of the unevenness formed on the outer peripheral surface of a cap. FIG. 6 is a cross-sectional view taken along the line xx of FIG. 7.

Hereinafter, embodiments of the double container to which the present invention is applied will be described with reference to the drawings.

The double container 1 of the present embodiment is formed by filling the inner bag of the container body 2 with the contents and then attaching the cap 30 to the mouth portion 4. In FIG. 1, (a) shows a state before the cap is attached, and (b) shows a state in which the cap is attached.

After attaching the cap 30 to the container body 2, as shown in FIG. 1C, the container body 2 and the cap 30 are covered with the shrink film 40 as a covering film, and the shrink film 40 is shrunk by heating to shrink the container body 2. It is in close contact with 2 and the cap 30.

Here, it is assumed that the laminated peeling container is used without removing the cap 30 in order to prevent outside air from entering the inner bag, but a consumer who is unfamiliar with the laminated peeling container will remove the cap 30. May be. Therefore, in the present embodiment, the cap 30 is made difficult to remove by attaching the shrink film 40 so as to be in close contact with both the container body 2 and the cap 30.

However, when such a configuration is adopted, the region from the container body 2 to the cap 30 is covered with the shrink film 40, which causes a new problem that the outside air is not sufficiently introduced into the outside air introduction hole 15. ..

Therefore, in the present embodiment, as shown in FIG. 1 (c), the uneven portion 34 is formed on the outer peripheral surface on the lower end side of the cap 30 by so-called knurling, and the shrink film 40 is placed in the middle position of the uneven portion 34. It is configured to be covered up to the position indicated by the arrow A in the figure). The uneven portion 34 formed by knurling has grooves and ridges extending alternately in the height direction of the cap 30, and when covered with the shrink film 40, it is between the cap 30 and the shrink film 40. A gap is formed from which outside air can be introduced.

Next, each component of the double container 1 of the present embodiment will be described. As shown in FIG. 2, the double container 1 of the present embodiment is mainly composed of the container body 2, and the container body 2 is the main body. Provides an accommodating portion 3 for accommodating the contents and a mouth portion 4 for discharging the contents from the accommodating portion 3. Further, a cap 30 is attached to the mouth 4 of the container body 2.

The double container 1 of the present embodiment is a so-called laminated peeling 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 which is an inner bag in the accommodating portion 3 and the mouth portion 4. 12 is provided, and the inner layer 12 shrinks as the contents decrease.

The outer layer 11 and the inner layer 12 are subjected to blow molding as a multi-layer parison and are molded in a state of being integrally joined. As a usage form thereof, for example, the upper end joint portion of the mouth portion 4 (not shown) is used. The inner layer 12 is peeled off from the outer layer 11 in advance except for the above, and the contents are filled until the inner layer 12 comes into contact with the outer layer 11. By pushing out the contents, the inner layer 12 contracts smoothly. Alternatively, the inner layer 12 may be left in a state of being joined to the outer layer 11, and the inner layer 12 may be separated from the outer layer 11 and contracted as the contents are discharged.

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

The outer layer 11 is composed of, for example, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, an ethylene-propylene copolymer and a mixture thereof. The outer layer 11 has a single layer or a plurality of layers, and it is preferable that at least one of the innermost layer and the outermost layer contains a lubricant. When the outer layer 11 has a single layer structure, the single layer is the innermost layer and the outermost layer, so that the 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. Therefore, at least one of them may contain a lubricant. When the outer layer 11 is composed of three or more layers, the layer on the innermost surface side of the container is the innermost layer, and the layer on the outermost surface side of the container is the outermost layer.

As shown in FIG. 4, the outer layer 11 preferably includes 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 molding of a container. When the outer layer 11 has a plurality of layers, it is preferable that both the innermost layer and the outermost layer contain a lubricant.

As the lubricant, a commercially available lubricant can be generally used, and any of hydrocarbon-based, fatty acid-based, aliphatic amide-based, and metal soap-based lubricants may be used, and two or more of them may be used in combination. good. Examples of the hydrocarbon-based lubricant include liquid paraffin, paraffin wax, and synthetic polyethylene wax. Examples of the fatty acid-based lubricant include stearic acid and stearyl alcohol. Examples of the aliphatic amide-based lubricant include fatty acid amides of stearate amides, oleic acid amides and erucic acid amides, methylene bisstearic acid amides and alkylene fatty acid amides of ethylene bisstearic acid amides. Examples of the metal soap-based lubricant include stearic acid metal salts and the like.

The innermost layer of the outer layer 11 is a layer in contact with the inner layer 12, and by incorporating a lubricant in the innermost layer of the outer layer 11, the peelability between the outer layer 11 and the inner layer 12 can be improved. 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 mold releasability can be improved by incorporating a lubricant in 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. This makes it possible to improve the shape restoration property, transparency, and heat resistance of the outer layer 11 which is the outer shell.

The random copolymer has a monomer content other than propylene of less than 50 mol%, preferably 5 to 35 mol%. Specifically, this content is, for example, 5, 10, 15, 20, 25, 30 mol%, and may be in the range between any two of the numerical values exemplified here. The monomer copolymerized with propylene may be any one that improves the impact resistance of the random copolymer as compared with the homopolymer of polypropylene, and ethylene is particularly preferable. In the case of a random copolymer of propylene and ethylene, the ethylene content is preferably 5 to 30 mol%, specifically, for example, 5, 10, 15, 20, 25, 30 mol%, and the numerical values exemplified here. It may be within the range between any two of the above. The weight average molecular weight of the random copolymer is preferably 100,000 to 500,000, more preferably 100,000 to 300,000. Specifically, the weight average molecular weight is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 500,000, and is within the range between any two of the numerical values exemplified here. May be good.

The tensile elastic modulus of the random copolymer is preferably 400 to 1600 MPa, preferably 1000 to 1600 MPa. This is because the shape restoration property is particularly good when the tensile elastic modulus is in such a range. Specifically, the tensile modulus is, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600 Mpa, and is between any two of the numerical values exemplified here. It may be within the range of.

If the container is excessively hard, the feeling of use of the container is deteriorated. Therefore, a flexible material such as linear low-density polyethylene may be mixed with the random copolymer to form the outer layer 11. However, the material to be mixed with the random copolymer is preferably mixed so as to be 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 obtained by mixing a random copolymer and linear low-density polyethylene in a weight ratio of 85:15.

As shown in FIG. 4, the inner layer 12 is provided between the EVOH layer 12a provided on the outer surface side of the container, the inner surface layer 12b provided on the inner surface side of the container of the EVOH layer 12a, and the EVOH layer 12a and the inner surface layer 12b. The adhesive layer 12c is provided. By providing the EVOH layer 12a, the gas barrier property and the peelability from the outer layer 11 can be improved.

The EVOH layer 12a is a layer made of an ethylene-vinyl alcohol copolymer (EVOH) resin, and is obtained by hydrolysis of an ethylene-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. The lower limit of the ethylene content is not particularly specified, but 25 mol% or more is preferable because the flexibility of the EVOH layer 12a tends to decrease as the ethylene content decreases. Further, the EVOH layer 12a preferably contains an oxygen absorber. By containing the oxygen absorber in the EVOH layer 12a, the oxygen barrier property of the EVOH layer 12a can be further improved.

The melting point of the EVOH resin is preferably higher than the melting point of the random copolymer constituting the outer layer 11. The outside air introduction hole 15 is preferably formed in the outer layer 11 by using a heating type drilling device, but by making the melting point of the EVOH resin higher than the melting point of the random copolymer, the outside air introduction hole 15 is formed in the outer layer 11. When forming, it prevents the holes from reaching the inner bag 13. From this point of view, the difference between (melting point of EVOH) and (melting point of random copolymer layer) is preferably large, preferably 15 ° C. or higher, and particularly preferably 30 ° C. or higher. The difference in melting point is, for example, 5 to 50 ° C., specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 ° C., and any of the numerical values exemplified here. It may be within the range between the two.

The inner surface layer 12b is a layer that comes into contact with the contents of the double container 1, and is a polyolefin such as, for example, low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene-propylene copolymer and a mixture thereof. It consists of low density polyethylene or linear low density polyethylene, preferably. The tensile elastic modulus of the resin constituting the inner surface layer 12b is preferably 50 to 300 MPa, preferably 70 to 200 MPa. This is because the inner surface layer 13b is particularly flexible when the tensile elastic modulus is in such a range. The tensile modulus is, specifically, for example, specifically, for example, 50, 100, 150, 200, 250, 300 Mpa, and may be in the range between any two of the numerical values exemplified here. ..

The adhesive layer 12c is a layer having a function of adhering the EVOH layer 12a and the inner surface layer 12b. , 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.

Further, as shown in FIGS. 2 and 3, in the shoulder portion of the accommodating portion 3, a recess 7a is formed in the outer layer 11, and an air introduction hole 15 is formed therein. The atmosphere introduction hole 15 is a through hole provided only in the outer layer 11 and does not reach the inner layer 12. Then, by introducing air from the atmosphere introduction hole 15, an intermediate space 21 is formed between the outer layer 11 and the inner layer 12, which are the outer shells. That is, the intermediate space 21 and the external space are communicated with each other by the atmosphere introduction hole 15.

A valve member 5 is provided in the atmosphere introduction hole 15, and the valve member 5 is inserted between the shaft portion 5a and the shaft portion 5a which is inserted into the outside air introduction hole 15 and can be slidably moved with respect to the outside air introduction hole 15. A lid portion 5c provided on the space 21 side and having a larger cross-sectional area than the shaft portion 5a, and a locking portion 5b provided on the outer space S side of the shaft portion 5a and preventing the valve member 5 from entering the intermediate space 21. Be prepared.

The lid portion 5c is configured to substantially close the outside air introduction hole 15 when the outer layer 11 is compressed, and has a shape in which the cross-sectional area becomes smaller as it approaches the shaft portion 5a. Further, the locking portion 5b is configured so that air can be introduced into the intermediate space 21 when the outer layer 11 is restored after being compressed. When the outer layer 11 is compressed, the pressure in the intermediate space 21 becomes higher than the external pressure, and the air in the intermediate space 21 leaks to the outside from the outside air introduction hole 15. Due to this pressure difference and the air flow, the lid portion 5c moves toward the outside air introduction hole 15, and the lid portion 5c closes the outside air introduction hole 15. Since the lid portion 5c has a shape in which the cross-sectional area becomes smaller as it approaches the shaft portion 5a, the lid portion 5c easily fits into the outside air introduction hole 15 and closes the outside air introduction hole 15.

When the outer layer 11 is further compressed in this state, the pressure in the intermediate space 21 increases, and as a result, the inner layer 12 is compressed and the contents in the inner layer 12 are discharged. Further, when the compressive force on the outer layer 11 is released, the outer layer 11 tries to be restored by its own elasticity. At this time, the lid portion 5c is separated from the outside air introduction hole 15, the blockage of the outside air introduction hole 15 is released, and the outside air is introduced into the intermediate space 21. Further, the locking portion 5b is provided with a protrusion 5d at a portion that abuts on the outer layer 11 so that the locking portion 5b does not block the outside air introduction hole 15, and the protrusion 5d abuts on the outer layer 11. , A gap is provided between the outer layer 11 and the locking portion 5b. Instead of providing the protrusion 5d, a groove may be provided in the locking portion 5b to prevent the locking portion 5b from blocking the outside air introduction hole 15.

On the other hand, as shown in FIG. 5, the cap 30 is composed of a cap main body 31 having a spout and a lid portion 32 that is openably and closably attached to the cap main body 31 by a hinge 33, as described above. An uneven portion 34 formed by knurling is formed on the outer peripheral surface of the cap body 31 over the entire circumference.

In the uneven portion 34 formed by knurling, the groove portions 34a extending in the height direction of the cap 30 and the ridge portions 34b are alternately formed, and are formed from the lower end of the cap body 31 to the middle position in the upward direction. The uneven portion 34 formed by knurling may be formed on the entire surface of the cap body 31 in the height direction.

Then, the shrink film 40 is provided so as to cover almost the entire container body 2 with the cap 30 attached to the container body 2. The shrink film 40 is covered not only with the container body 2 but also with the cap 30, but in the cap 30, the shrink film 40 is covered up to the middle position of the uneven portion 34 (the position indicated by the arrow A in the figure). It is configured to be. That is, the dimension from the lower end of the cap main body 31 to the upper end of the shrink film 40 (the position indicated by the arrow A in the figure) is smaller than the dimension from the lower end of the cap main body 31 to the upper end of the uneven portion 34. The position of the upper end of the shrink film 40 (arrow A) is preferably 1/4 or more, more preferably 1/3 with respect to the height from the lower end of the cap body 31 to the upper end of the cap body 31. Above, more preferably 1/2 or more.

By forming the uneven portion 34 on the cap 30, as shown in FIG. 6, when the cap 30 is covered with the shrink film 40, a gap is formed between the cap 30 and the shrink film 40, and outside air is introduced from the gap. can do.

In the case of the double container 1 of the present embodiment, a recess 7a is formed in the outer layer 11 of the container body 2, and an air introduction hole 15 is formed in the recess 7a. A groove portion 7b extending toward the direction) is provided. Further, a gap (gap in the shoulder portion) is formed between the base of the cap 30 and the shoulder portion of the container body 2 and the shrink film 40. The gap formed between the cap 30 and the shrink film 40 has a shape that communicates from the gap of the shoulder portion to the groove portion 7b at the lower end portion thereof, and further, a recess 7a communicating with the groove portion 7b and an atmosphere introduction hole 15. , The outside air is smoothly introduced into the intermediate space 21.

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

For example, the concave portion or convex portion formed on the cap 30 is not limited to the uneven portion formed by knurling, and as shown in FIGS. 7 and 8, one (or a plurality) groove portions 35 are formed on the peripheral surface of the cap main body 31. It may be formed. Also in this case, the groove portion 35 may be formed so as to extend from the lower end of the cap main body 31 to the middle position in the height direction, and the middle portion of the groove portion 35 may be covered with the shrink film 40. In the case of forming one groove 35 as in the examples shown in FIGS. 7 and 8, when the cap 30 is attached to the container body 2, the position of the groove 35 and the outer layer 11 of the container body 2 are formed. It is necessary to match the groove portions 7b formed in the above.

Further, the cap main body 31 may be formed with one or a plurality of ridges instead of the groove 35. By forming the ridge portion, the shrink film 40 is lifted, and a gap is formed between the cap body 31 and the shrink film 40.

Further, although the shrink film is used as the coating film in the above embodiment, the present invention is not limited to this, and for example, a normal film having no heat shrinkage may be used.

Furthermore, in the above embodiment, the shrink film 40 is configured to be covered up to the middle position of the uneven portion 34 (the position indicated by the arrow A in the figure). An easy-to-cut line is formed on the covering film at an intermediate position in the height direction of the uneven portion 34 so as to cover substantially the entire surface, and the covering film covering the upper part of the cap is provided by using this easy-to-cut line at the start of use. It may be excised. By doing so, it is possible to reliably prevent the cap from being opened (prevention of tampering) before opening (before use).

As the form of the container, the cap type container has been described as an example in the previous embodiment, but a tapping type container or the like may be used.

1 Double container 2 Container body 3 Storage part 4 Mouth part 5 Valve member 11 Outer layer 11d End face 12 Inner layer 12d End face 15 Outside air introduction hole 30 Cap 31 Cap body 32 Cover part 33 Hinge part 34 Concavo-convex part 35 Groove part 40 Shrink film

Claims (5)

A double container having an outer layer and an inner layer, and the inner layer shrinks as the contents contained in the inner layer decrease.
A cap is attached to the mouth, and an outside air introduction hole for introducing outside air is formed between the outer layer and the inner layer in the outer layer.
A recess is formed in the outer layer of the container body, and an air introduction hole is formed in the recess, and a groove that communicates with the recess and extends upward is provided.
At least one of a concave portion or a convex portion extending from the lower end of the cap to at least the middle portion in the height direction is formed on the outer peripheral surface of the cap.
A covering film is provided so as to cover at least the outside air introduction hole, and the covering film is covered to a position halfway in the height direction of the concave portion or the convex portion of the cap .
A gap is formed between the base of the cap, the shoulder portion of the container body, and the covering film, and the gap formed between the base of the cap and the covering film in the cap is the shoulder portion at the lower end portion thereof. A double container characterized in that it communicates from the gap to the groove . The double container according to claim 1, wherein the concave portion or the convex portion is formed over the entire circumference of the cap by knurling. The double according to claim 1, wherein the concave portion or the convex portion has a groove portion extending from the lower end of the cap to at least the middle portion in the height direction corresponding to the formation position of the outside air introduction hole. container. The double container according to any one of claims 1 to 3, wherein the covering film is a shrink film. The coating film covers substantially the entire outer peripheral surface of the cap, and the easy-to-cut line is formed at an intermediate position in the height direction of the concave portion or the convex portion, according to claims 1 to 4. The double container according to any one item.

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