JP6802499B2 - Laminate peeling container - Google Patents

Description

The present invention relates to a laminated peeling container in which the inner layer peels from the outer layer and shrinks as the contents decrease.

Conventionally, there has been known a laminated peeling container that suppresses air from entering the inside of a container by peeling and shrinking the inner layer from the outer layer as the contents decrease (for example, Patent Document 1). Such a laminated peeling container includes an inner bag composed of an inner layer and an outer shell composed of an outer layer.

Japanese Patent No. 3650175

A laminated peeling container as in Patent Document 1 can be used as a container for storing soy sauce and ponzu vinegar, and suppresses deterioration of the contents by keeping the contents out of contact with air. In the evaluation of the laminated peeling container, the present inventor noticed that when a citrus seasoning such as ponzu was contained in the laminated peeling container, the citrus aroma was easily reduced.

The present invention has been made in view of such circumstances, and provides a laminated peeling container in which the citrus aroma emitted by a citrus seasoning is difficult to be reduced.

According to the present invention, it is a laminated peeling container provided with an outer layer and an inner layer, and the inner layer peels off from the outer layer and shrinks as the contents decrease, and the inner layer is an inner layer made of EVOH resin as the innermost layer. A laminated stripping container with an EVOH layer is provided.

The present inventors investigated the reason why the citrus scent is likely to be reduced, and found that limonene, which is one of the substances constituting the citrus scent, is easily adsorbed or absorbed on the inner surface of the laminated stripping container. I found out that. Then, based on this finding, we searched for a material that does not easily adsorb or absorb limonene. When the innermost layer of the inner layer is an EVOH layer made of EVOH resin, the citrus aroma emitted by the citrus seasoning is reduced. We found it difficult and reached the completion of the present invention.

Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.
Preferably, the inner EVOH layer has a thickness of 10 to 20 μm.
Preferably, the inner layer includes an outer EVOH layer made of an EVOH resin as the outermost layer, and the outer EVOH layer is thicker than the inner EVOH layer.
Preferably, both the inner EVOH layer and the EVOH resin constituting the outer EVOH layer have a tensile elastic modulus of 2000 MPa or less.
Preferably, the inner EVOH layer is made of an EVOH resin having a higher ethylene content than the outer EVOH layer.
Preferably, the inner layer comprises an adhesive layer between the inner EVOH layer and the outer EVOH layer.
Preferably, the thickness of the adhesive layer is greater than the sum of the thickness of the inner EVOH layer and the thickness of the outer EVOH layer.

It is a perspective view which shows the structure of the laminated peeling container 1 of one Embodiment of this invention, (a) shows the whole view, (b) shows the bottom. The laminated peeling container 1 of FIG. 1 is shown, (a) is a front view, (b) is a rear view, (c) is a plan view, and (d) is a bottom view. It is sectional drawing AA in FIG. 2 (d). However, FIGS. 1 to 2 show a state before the bottom seal protruding portion 27 is bent, and FIG. 3 shows a state after the bottom seal protruding portion 27 is bent. It is an enlarged view of the region including the mouth part 9 of FIG. It shows a state in which the inner layer 13 is peeled off from the state of FIG. It is an enlarged view of the region including the bottom surface 29 of FIG. 3, (a) shows the state before the bottom seal protrusion 27 is bent, and (b) shows the state after the bottom seal protrusion 27 is bent. Shown. It is sectional drawing which shows the layer structure of the inner layer 13. It is a perspective view which shows various configurations of a valve member 5. The manufacturing process of the laminated peeling container 1 of FIG. 1 is shown. The process following FIG. 9 of the laminated peeling container 1 of FIG. 1 is shown. Another example of the inner layer preliminary peeling / outside air introduction hole forming process is shown. The usage method of the laminated peeling container 1 of FIG. 1 is shown.

Hereinafter, embodiments of the present invention will be described. The various features shown in the embodiments shown below can be combined with each other. In addition, the invention is independently established for each feature.

As shown in FIGS. 1 and 2, the laminated peeling container 1 according to the embodiment of the present invention includes a container body 3 and a valve member 5. The container body 3 includes an accommodating portion 7 for accommodating the contents and a mouth portion 9 for discharging the contents from the accommodating portion 7.

As shown in FIG. 3, the container body 3 includes an outer layer 11 and an inner layer 13 in the accommodating portion 7 and the mouth portion 9, the outer layer 11 constitutes the outer shell 12, and the inner layer 13 constitutes the inner bag 14. To. As the content is reduced, the inner layer 13 is peeled from the outer layer 11, so that the inner bag 14 is peeled from the outer shell 12 and contracts.

As shown in FIG. 4, the mouth portion 9 is provided with a male screw portion 9d. A cap or a pump having a female screw is attached to the male screw portion 9d. FIG. 4 illustrates a part of the cap 23 having the inner ring 25. The outer diameter of the inner ring 25 is substantially the same as the inner diameter of the mouth portion 9, and the outer surface of the inner ring 25 comes into contact with the contact surface 9a of the mouth portion 9 to prevent leakage of the contents. In the present embodiment, the diameter-expanded portion 9b is provided at the tip of the mouth portion 9, and the inner diameter of the diameter-expanded portion 9b is larger than the inner diameter of the contact portion 9e. The outer surface is designed so as not to come into contact with the enlarged diameter portion 9b. If the mouth portion 9 does not have the diameter-expanded portion 9b, the inner ring 25 may enter between the outer layer 11 and the inner layer 13 if the inner diameter of the mouth portion 9 becomes even slightly smaller due to variations during manufacturing. However, when the mouth portion 9 has a diameter-expanded portion 9b, such a problem does not occur even if the inner diameter of the mouth portion 9 varies slightly.

Further, the mouth portion 9 is provided with an inner layer support portion 9c that suppresses slippage of the inner layer 13 at a position closer to the accommodating portion 7 than the contact portion 9e. The inner layer support portion 9c is formed by providing a constriction in the mouth portion 9. Even when the diameter-expanded portion 9b is provided in the mouth portion 9, the inner layer 13 may be peeled off from the outer layer 11 due to friction between the inner ring 25 and the inner layer 13. In the present embodiment, even in such a case, the inner layer support portion 9c suppresses the inner layer 13 from slipping off, so that the inner bag 14 can be prevented from falling into the outer shell 12.

As shown in FIGS. 3 to 5, the accommodating portion 7 has a body portion 19 having a substantially constant cross-sectional shape in the longitudinal direction of the accommodating portion, and a shoulder portion 17 connecting between the body portion 19 and the mouth portion 9. To be equipped. The shoulder portion 17 is provided with a bent portion 21. The bent portion 21 is a portion where the bending angle α shown in FIG. 3 is 140 degrees or less and the radius of curvature on the inner surface side of the container is 4 mm or less. If there is no bent portion 21, the peeling between the inner layer 13 and the outer layer 11 may spread from the body portion 19 to the mouth portion 9, and the inner layer 13 and the outer layer 11 may be peeled off also at the mouth portion 9. However, peeling of the inner layer 13 and the outer layer 11 at the mouth 9 is not desirable because the peeling of the inner layer 13 and the outer layer 11 causes the inner bag 14 to fall into the outer shell 12. In the present embodiment, since the bent portion 21 is provided, when the peeling between the inner layer 13 and the outer layer 11 spreads from the body portion 19 to the bent portion 21, the inner layer 13 is bent at the bent portion 21 as shown in FIG. The force for peeling the inner layer 13 from the outer layer 11 is not transmitted to the upper portion of the bent portion 21, and as a result, the peeling between the inner layer 13 and the outer layer 11 at the portion above the bent portion 21 is suppressed. To. Although the shoulder portion 17 is provided with the bent portion 21 in FIGS. 3 to 5, the bent portion 21 may be provided at the boundary between the shoulder portion 17 and the body portion 19.

The lower limit of the bending angle α is not particularly specified, but is preferably 90 degrees or more in consideration of ease of manufacturing. The lower limit of the radius of curvature is not particularly specified, but it is preferably 0.2 mm or more in consideration of ease of manufacture. Further, in order to more reliably prevent the inner layer 13 and the outer layer 11 from peeling off at the mouth portion 9, the bending angle α is preferably 120 degrees or less, and the radius of curvature is preferably 2 mm or less. Specifically, the bending angle α is, for example, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140 degrees, and is within the range between any two of the numerical values exemplified here. It may be. Specifically, the radius of curvature is, for example, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2 mm, and here. It may be in the range between any two of the illustrated values.

As shown in FIG. 4, in the bent portion 21, the distance L2 from the container center axis C to the container inner surface at the bent portion 21 is 1.3 of the distance L1 from the container center axis C to the container inner surface at the mouth portion 9. It is installed at a position that is more than doubled. The laminated peeling container 1 of the present embodiment is formed by blow molding, and the larger the L2 / L1, the larger the blow ratio at the bent portion 21 and the thinner the wall thickness. Therefore, L2 / L1 ≧ 1. By setting the value to 3, the wall thickness of the inner layer 13 at the bent portion 21 becomes sufficiently thin, the inner layer 13 becomes more easily bent at the bent portion 21, and the inner layer 13 and the outer layer 11 at the mouth portion 9 are more reliably separated. Be prevented. L2 / L1 is, for example, 1.3 to 3, preferably 1.4 to 2. Specifically, L2 / L1 is, for example, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.5, and 3 here. It may be within the range between any two of the numerical values exemplified in 1.

In one example, the wall thickness at the mouth portion 9 is 0.45 to 0.50 mm, the wall thickness at the bent portion 21 is 0.25 to 0.30 mm, and the wall thickness at the body portion 19 is 0. It is .15 to 0.20 mm. As described above, when the wall thickness of the bent portion 21 is sufficiently smaller than the wall thickness of the mouth portion 9, the bent portion 21 effectively exerts its function.

By the way, as shown in FIG. 4, the accommodating portion 7 has a valve member 5 that regulates the inflow and outflow of air between the intermediate space 21 between the outer shell 12 and the inner bag 14 and the outer space S of the container body 3. Is provided. The outer shell 12 is provided with an outside air introduction hole 15 that communicates the intermediate space 21 and the outer space S in the accommodating portion 7. The outside air introduction hole 15 is a through hole provided only in the outer shell 12, and does not reach the inner bag 14. The valve member 5 is provided on the intermediate space 21 side of 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, and has a larger cross-sectional area than the shaft portion 5a. A lid portion 5c 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 are provided.

The lid portion 5c is configured to substantially close the outside air introduction hole 15 when the outer shell 12 is compressed, and has a shape in which the cross-sectional area decreases 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 shell 12 is restored after being compressed. When the outer shell 12 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 decreases 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 shell 12 is further compressed in this state, the pressure in the intermediate space 21 increases, and as a result, the inner bag 14 is compressed and the contents in the inner bag 14 are discharged. Further, when the compressive force on the outer shell 12 is released, the outer shell 12 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 shell 12 so that the locking portion 5b does not block the outside air introduction hole 15, and the protrusion 5d abuts on the outer shell 12. As a result, a gap is provided between the outer shell 12 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. A specific example of the configuration of the valve member 5 is shown in FIG.

The valve member 5 can be attached to the container body 3 by inserting the valve member 5 into the lid portion 5c into the intermediate space 21 while the lid portion 5c expands the outside air introduction hole 15. Therefore, it is preferable that the tip of the lid portion 5c has a tapered shape. Since such a valve member 5 can be mounted by simply pushing the lid portion 5c into the intermediate space 21 from the outside of the container body 3, it is excellent in productivity.

The accommodating portion 7 is covered with a shrink film after the valve member 5 is attached. At this time, the valve member 5 is mounted in the valve member mounting recess 7a provided in the accommodating portion 7 so that the valve member 5 does not interfere with the shrink film. Further, an air flow groove 7b extending in the direction of the mouth portion 9 from the valve member mounting recess 7a is provided so that the valve member mounting recess 7a is not sealed with the shrink film.

As shown in FIG. 1B, the bottom surface 29 of the accommodating portion 7 is provided with a central concave region 29a and a peripheral region 29b provided around the central concave region 29a, and the central concave region 29a has a bottom protruding from the bottom surface 29. A seal protrusion 27 is provided. As shown in FIGS. 6A to 6B, the bottom seal projecting portion 27 is a sealing portion of the laminated parison in blow molding using a cylindrical laminated parison having an outer layer 11 and an inner layer 13. The bottom seal protruding portion 27 includes a base portion 27d, a thin-walled portion 27a, and a thick-walled portion 27b having a wall thickness larger than that of the thin-walled portion 27a in order from the bottom surface 29 side.

Immediately after blow molding, as shown in FIG. 6A, the bottom seal protrusion 27 stands substantially perpendicular to the surface P defined by the peripheral region 29b. In this state, the bottom seal protrusion 27 stands substantially perpendicular to the surface P. When an impact is applied to the container, the inner layers 13 in the welded portion 27c are easily separated from each other, and the impact resistance is insufficient. Therefore, in the present embodiment, the thin-walled portion 27a is softened by blowing hot air onto the bottom-sealing protruding portion 27 after blow molding, and as shown in FIG. 6B, the bottom-walled protruding portion 27 is bent at the thin-walled portion 27a. There is. In this way, the impact resistance of the bottom seal protruding portion 27 is improved by a simple process of simply bending the bottom seal protruding portion 27. Further, as shown in FIG. 6B, the bottom seal protruding portion 27 does not protrude from the surface P defined by the peripheral edge region 29b in the bent state. As a result, when the laminated peeling container 1 is erected, the bottom seal protruding portion 27 is prevented from protruding from the surface P and the laminated peeling container 1 is prevented from wobbling.

The base portion 27d is provided on the bottom surface 29 side of the thin-walled portion 27a and is thicker than the thin-walled portion 27a. The base portion 27d may be omitted, but the thin-walled portion 27a is provided on the base portion 27d. The impact resistance of the bottom seal protruding portion 27 can be further improved by providing.

Further, as shown in FIG. 1B, the concave region of the bottom surface 29 is provided so as to cross the entire bottom surface 29 in the longitudinal direction of the bottom seal protrusion 27. That is, the central concave region 29a and the peripheral concave region 29c are connected. With such a configuration, the bottom seal protrusion 27 can be easily bent.

Next, the layer structure of the container body 3 will be described in more detail. The container body 3 includes an outer layer 11 and an inner layer 13.

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 may have a plurality of layers. For example, both sides of the repro layer may be sandwiched between polypropylene layers. Here, the repro layer refers to a layer obtained by recycling burrs generated during molding of a container. Further, the outer layer 11 is formed to be thicker than the inner layer 13 so as to have high resilience.

In the present embodiment, the outer layer 11 includes a random copolymer layer made of a random copolymer between propylene and another monomer. The outer layer 11 may be a single layer of a random copolymer layer, or may have a plurality of layers. For example, both sides of the repro layer may be sandwiched between random copolymer layers. By forming the outer layer 11 with a random copolymer having a specific structure, the shape restoration property, transparency, and heat resistance of the outer shell 12 can be improved.

The content of the monomer other than propylene in the random copolymer is smaller 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. As the monomer copolymerized with propylene, ethylene is particularly preferable as long as it improves the impact resistance of the random copolymer as compared with the homopolymer of polypropylene. 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 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 elastic 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 formed of a material obtained by mixing a random copolymer and a linear low-density polyethylene in a weight ratio of 85:15.

As shown in FIG. 7, the inner layer 13 includes an inner EVOH layer 13a which is the innermost layer, an outer EVOH layer 13b which is the outermost layer, and an adhesive layer 13c provided between the two.

The inner EVOH layer 13a is made of an ethylene-vinyl alcohol copolymer (EVOH) resin. According to the experiment of the present inventor, when the innermost layer of the inner layer 13 is the inner EVOH layer 13a, the adsorption or absorption of limonene on the inner surface of the container is suppressed, and as a result, the citrus scent emitted by the citrus seasoning is produced. It was found that the reduction was suppressed.

By the way, since the EVOH resin has a relatively high rigidity, when the EVOH resin is used as the material of the inner layer 13, a softener is usually added to the EVOH resin to improve the flexibility. However, if a softener is added to the EVOH resin constituting the inner EVOH layer 13a, which is the innermost layer of the inner layer 13, there is a risk that the softener will be eluted into the contents. Therefore, the EVOH resin constituting the inner EVOH layer 13a There is no choice but to use one that does not contain a softener. On the other hand, since the EVOH resin containing no softener has high rigidity, if the inner EVOH layer 13a is too thick, there arises a problem that the inner bag 14 does not shrink smoothly when the contents are discharged. Further, if the inner EVOH layer 13a is too thin, the inner EVOH layer 13a is not uniformly formed and the adhesive layer 13c is exposed on the inner surface of the container, or pinholes are likely to be formed on the inner EVOH layer 13a. There is. From this point of view, the thickness of the inner EVOH layer 13a is preferably 10 to 20 μm.

The ethylene content of the EVOH resin constituting the inner EVOH layer 13a is, for example, 25 to 50 mol%, and the higher the ethylene content, the more flexible the inner EVOH layer 13a tends to be. Therefore, the ethylene content is the outer EVOH. It is preferably higher than the EVOH resin constituting the layer 13b, and is preferably 35 mol% or more. In another expression, the ethylene content of the EVOH resin constituting the inner EVOH layer 13a is preferably set so that the tensile elastic modulus of the EVOH resin is 2000 MPa or less.

The outer EVOH layer 13b is also made of an ethylene-vinyl alcohol copolymer (EVOH) resin like the inner EVOH layer 13a. However, since the outer EVOH layer 13b does not come into contact with the contents, it is possible to add a softener to increase the flexibility, and therefore, the thickness of the outer EVOH layer 13b can be made thicker than that of the inner EVOH layer. It is possible. The thickness of the outer EVOH layer 13b is not particularly limited, but is, for example, 20 to 30 μm. If the outer EVOH layer 13b is too thin, the gas barrier property of the inner layer 13 becomes insufficient, and if the outer EVOH layer 13b is too thick, the flexibility of the inner layer 13 becomes insufficient, and when the contents are discharged, the inner layer 13 becomes inadequate. There arises a problem that the bag 14 does not shrink smoothly. The ratio of the thickness of the outer EVOH layer 13b / the inner EVOH layer 13a is not particularly limited, but is, for example, 1.1 to 4, preferably 1.2 to 2.0. Specifically, this ratio is, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2. It is 1, 2.2, 2.3, 2.4, 2.5, 3, 4, and may be within the range between any two of the numerical values exemplified here. Further, by providing the outer EVOH layer 13b as the outermost layer of the inner layer 13, the peelability of the inner layer 13 from the outer layer 11 can be improved.

The ethylene content of the EVOH resin constituting the outer EVOH layer 13b is, for example, 25 to 50 mol%, preferably 32 mol% or less from the viewpoint of oxygen barrier property. The lower limit of the ethylene content is not particularly specified, but 25 mol% or more is preferable because the flexibility of the outer EVOH layer 13b tends to decrease as the ethylene content decreases.

The amount of the softener added to the EVOH resin constituting the outer EVOH layer 13b and the ethylene content of the EVOH resin are preferably set so that the tensile elastic modulus of the EVOH resin is 2000 MPa or less. By forming both the inner EVOH layer 13a and the outer EVOH layer 13b with an EVOH resin having a tensile elastic modulus of 2000 MPa or less, the inner bag 14 can be smoothly shrunk. Further, the outer EVOH layer 13b preferably contains an oxygen absorber. By containing the oxygen absorber in the outer EVOH layer 13b, the oxygen barrier property of the outer EVOH layer 13b can be further improved. The EVOH resin constituting the outer EVOH layer 13b preferably has a flexural modulus of 2350 MPa or less, and more preferably 2250 MPa or less. The lower limit of the flexural modulus of the EVOH resin is not particularly specified, but is, for example, 1800, 1900, or 2000 MPa. The flexural modulus can be measured by a test method compliant with ISO178. The test speed is 2 mm / min.

The melting point of the EVOH resin constituting the outer EVOH layer 13b 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 layer 13. From this point of view, the difference between (melting point of EVOH)-(melting point of random copolymer layer) is preferably large, preferably 15 ° C. or higher, and particularly preferably 30 ° C. or higher. This 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 adhesive layer 13c is a layer arranged between the inner EVOH layer 13a and the outer EVOH layer 13b, and is, for example, an acid-modified polyolefin in which a carboxyl group is introduced into the above-mentioned polyolefin (eg, maleic anhydride-modified polyethylene) added. Or ethylene vinyl acetate copolymer (EVA). An example of the adhesive layer 13c is a mixture of low density polyethylene or linear low density polyethylene and acid modified polyethylene. The adhesive layer 13c may directly bond the inner EVOH layer 13a and the outer EVOH layer 13b, and is separately provided between the adhesive layer 13c and the inner EVOH layer 13a or between the adhesive layer 13c and the outer EVOH layer 13b. It may be indirectly adhered through the layer of.

The adhesive layer 13c is a layer in which the rigidity per unit thickness is smaller than that of either the inner EVOH layer 13a or the outer EVOH layer 13b, that is, it is a layer having excellent flexibility. Therefore, the flexibility of the inner layer 13 is enhanced by increasing the ratio of the thickness of the adhesive layer 13c to the thickness of the entire inner layer 13 by making the adhesive layer 13 thicker, and the inner bag is discharged when the contents are discharged. 14 tends to contract smoothly. Specifically, the thickness of the adhesive layer 13c is preferably larger than the sum of the thickness of the inner EVOH layer 13a and the thickness of the outer EVOH layer 13b. The thickness ratio of the adhesive layer 13c / (inner EVOH layer 13a + outer EVOH layer 13b) is, for example, 1.1 to 8, and specifically, for example, 1.1, 1.5, 2, 2.5. , 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, and 8, and may be within the range between any two of the numerical values exemplified here.

Next, an example of the manufacturing method of the laminated peeling container 1 of the present embodiment will be described.
First, as shown in FIG. 9 (a), a laminated structure corresponding to the container body 3 to be manufactured (for example, as shown in FIG. 9 (a), an EVOH layer / adhesive layer / EVOH layer in order from the inner surface side of the container. / The laminated parison in the molten state having the laminated structure of the PP layer) is extruded, the laminated parison in the molten state is set in the blow molding die, and the split mold is closed.
Next, as shown in FIG. 9B, a blow nozzle is inserted into the opening on the mouth 9 side of the container body 3, and air is blown into the cavity of the split mold in a state where the mold is tightened.

Next, as shown in FIG. 9C, the split mold is opened and the blow-molded product is taken out. The split mold has a cavity shape such that various shapes of the container body 3 such as the valve member mounting recess 7a, the air flow groove 7b, and the bottom seal protrusion 27 are formed on the blow molded product. Further, the split mold is provided with a pinch-off portion on the lower side of the bottom seal protruding portion 27, and a lower burr is formed on the lower portion of the bottom seal protruding portion 27, and this is removed.

Next, as shown in FIG. 9D, the blow-molded products taken out are aligned.
Next, as shown in FIG. 9E, a hole is made only in the outer layer 11 in the upper tubular portion 31 provided on the upper side of the mouth portion 9, and a blower 33 is used between the outer layer 11 and the inner layer 13. By blowing air, the inner layer 13 is preliminarily peeled from the outer layer 11 at the portion (valve member mounting recess 7a) of the accommodating portion 7 where the valve member 5 is attached. This preliminary peeling facilitates the step of forming the outside air introduction hole 15 and the step of mounting the valve member 5. The tip end side of the upper tubular portion 31 may be covered with a cover member so that the blown air does not leak from the tip end side of the upper tubular portion 31. Further, in order to facilitate drilling only in the outer layer 11, the inner layer 13 may be peeled from the outer layer 11 in the upper tubular portion 31 by crushing the upper tubular portion 31 before drilling the hole. Well, the preliminary peeling may be performed on the entire accommodating portion 7 or on a part of the accommodating portion 7.
Next, as shown in FIG. 9 (f), an outside air introduction hole 15 is formed in the outer shell 12 by using a drilling device. The outside air introduction hole 15 is preferably a round hole, but may have a different shape.
Next, as shown in FIG. 10A, hot air is applied to the bottom seal protruding portion 27 to soften the thin-walled portion 27a, and the bottom seal protruding portion 27 is bent.
Next, as shown in FIG. 10B, the valve member 5 is inserted into the outside air introduction hole 15.
Next, as shown in FIG. 10 (c), the upper tubular portion 31 is cut.
Next, as shown in FIG. 10D, the inner bag 14 is inflated by blowing air into the inner bag 14.
Next, as shown in FIG. 10 (e), the inner bag 14 is filled with the contents.
Next, as shown in FIG. 10 (f), the cap 23 is attached to the mouth portion 9.
Next, as shown in FIG. 10 (g), the accommodating portion 7 is covered with a shrink film to complete the product.

The order of the various steps shown here can be changed as appropriate. For example, the hot air bending step may be performed before the outside air introduction hole opening step or before the inner layer preliminary peeling step. Further, the step of cutting the upper tubular portion 31 may be performed before inserting the valve member 5 into the outside air introduction hole 15.

Further, the inner layer preliminary peeling and the outside air introduction hole opening step can also be performed by the following methods.
First, as shown in FIG. 11A, the air inside the inner bag 14 is sucked from the mouth portion 9 to reduce the pressure inside the inner bag 14. In that state, a drilling device such as a heat pipe or pipe cutter is slowly pressed against the outer layer 11. This drilling device has a tubular cutter, and the air inside the cylinder is sucked. When there is no hole in the outer layer 11, air does not enter between the outer layer 11 and the inner layer 13, so that the inner layer 13 is not separated from the outer layer 11.

When the tubular cutter penetrates the outer layer 11, as shown in FIG. 11B, the hollowed-out piece is removed through the inside of the tubular cutter to form the outside air introduction hole 15. At this moment, air enters between the outer layer 11 and the inner layer 13, and the inner layer 13 is separated from the outer layer 11.

Next, as shown in FIG. 11C, the outside air introduction hole 15 is enlarged in diameter by using a drilling device. When the outside air introduction hole 15 having a size sufficient for inserting the valve member 5 is formed in the steps of FIGS. 11 (a) to 11 (b), the diameter-expanding step of FIG. 11 (c) is unnecessary.

Next, the operating principle when the manufactured product is used will be described.
As shown in FIGS. 12A to 12C, the product filled with the contents is tilted and the side surface of the outer shell 12 is grasped and compressed to discharge the contents. At the start of use, there is substantially no gap between the inner bag 14 and the outer shell 12, so that the compressive force applied to the outer shell 12 becomes the compressive force of the inner bag 14 as it is, and the inner bag 14 is compressed. And the contents are discharged.

The cap 23 has a built-in check valve (not shown), and although the contents in the inner bag 14 can be discharged, the outside air cannot be taken into the inner bag 14. Therefore, when the compressive force applied to the outer shell 12 after discharging the contents is removed, the outer shell 12 tries to return to its original shape by its own restoring force, but the inner bag 14 remains deflated and only the outer shell 12 remains deflated. It will expand. Then, as shown in FIG. 12D, the inside of the intermediate space 21 between the inner bag 14 and the outer shell 12 becomes decompressed, and the outside air enters the intermediate space 21 through the outside air introduction hole 15 formed in the outer shell 12. be introduced. When the intermediate space 21 is in a decompressed state, the lid portion 5c is not pressed against the outside air introduction hole 15, so that the introduction of outside air is not hindered. Further, the locking portion 5b is provided with airway securing means such as protrusions 5d and grooves so that the locking portion 5b does not interfere with the introduction of outside air even when the locking portion 5b is in contact with the outer shell 12.

Next, as shown in FIG. 12 (e), when the side surface of the outer shell 12 is gripped and compressed again, the pressure in the intermediate space 21 increases due to the lid portion 5c closing the outside air introduction hole 15. The compressive force applied to the outer shell 12 is transmitted to the inner bag 14 via the intermediate space 21, and this force compresses the inner bag 14 to discharge the contents.

Next, as shown in FIG. 12 (f), when the compressive force applied to the outer shell 12 after discharging the contents is removed, the outer shell 12 introduces the outside air from the outside air introduction hole 15 into the intermediate space 21. , It is restored to its original shape by its own restoring force.

In the following Examples and Comparative Examples, various laminated peeling containers having different layer structures are produced by blow molding, the obtained containers are filled with ponzu vinegar, allowed to stand for one week, and then the ponzu vinegar in the containers is used. The entire amount was discharged, and a sensory evaluation was performed on the citrus aroma of the discharged ponzu vinegar. In addition, the shape of the inner bag of the container when the ponzu vinegar was discharged was visually evaluated.

<Example 1>
In Example 1, the layer structure was a random copolymer layer / an outer EVOH layer (thickness 25 μm) / an adhesive layer (thickness 150 μm) / an inner EVOH layer (thickness 15 μm) in order from the outside of the container. The outer EVOH layer was formed of an EVOH resin to which a softener was added, and the inner EVOH layer was formed of an EVOH resin to which a softener was not added. The adhesive layer was formed by mixing linear low-density polyethylene and acid-modified polyethylene at a mass ratio of 50:50. As a result of the above evaluation, the intensity of the citrus aroma emitted by the discharged ponzu vinegar was almost the same as that at the time of filling. In addition, when the inner bag contracted with the discharge of ponzu vinegar, the inner bag contracted smoothly without bending.

<Example 2>
In Example 2, the layer structure was the same as that in Example 1 except that the thickness of the inner EVOH layer was 5 μm. As a result of the above evaluation, the intensity of the citrus scent emitted by the discharged ponzu vinegar was slightly inferior to that of Example 1. In addition, when the inner bag contracted with the discharge of ponzu vinegar, the inner bag contracted smoothly without bending.

<Example 3>
In Example 3, the layer structure was the same as in Example 1 except that the thickness of the inner EVOH layer was 25 μm. As a result of the above evaluation, the intensity of the citrus scent emitted by the discharged ponzu vinegar was about the same as in Example 1. In addition, when the inner bag contracted with the discharge of ponzu, the inner bag was more easily bent than in Example 1.

<Example 4>
In Example 4, the layer structure was the same as that of Example 1 except that the thickness of the outer EVOH layer was 75 μm and the thickness of the adhesive layer was 80 μm. As a result of the above evaluation, the intensity of the citrus scent emitted by the discharged ponzu vinegar was about the same as in Example 1. In addition, when the inner bag contracted with the discharge of ponzu, the inner bag was more easily bent than in Example 1.

<Example 5>
In Example 5, the layer structure was the same as in Example 1, and the outer EVOH layer was composed of an EVOH resin (model: Soanol SF7503B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., melting point 188 ° C., flexural modulus 2190 MPa). As a result of the above evaluation, the same effect as in Example 1 was obtained.

<Comparative example 1>
In Comparative Example 1, the layer structure was the same as that of Example 1 except that the inner EVOH layer was replaced with a linear low-density polyethylene layer (50 μm). As a result of the above evaluation, the intensity of the citrus scent emitted by the discharged ponzu vinegar was considerably inferior to that of Example 1. In addition, when the inner bag contracted with the discharge of ponzu vinegar, the inner bag contracted smoothly without bending.

<Comparative example 2>
In Comparative Example 2, the layer structure was the same as that of Example 1 except that the inner EVOH layer was replaced with a polyamide layer (50 μm). As a result of the above evaluation, the intensity of the citrus scent emitted by the discharged ponzu vinegar was considerably inferior to that of Example 1. In addition, when the inner bag contracted with the discharge of ponzu vinegar, the inner bag contracted smoothly without bending.

<Bending resistance test>
The EVOH resin used as the EVOH layer was subjected to a bending resistance test using an ASTM F392 compliant Gelboflex tester (KFT-C --Flex Durability Tester, manufactured by Brugger). The test environment was 23 ° C. and 50% RH.
First, a sample composed of a single-layer film of 28 cm × 19 cm × 30 μm was prepared.
Next, both ends of the sample were fixed to the pair of mandrels A and B by winding the long sides of the sample around a pair of mandrels (diameter 90 mm) arranged at intervals of 180 mm.
Next, with the mandrel A fixed, the mandrel B was gradually brought closer while twisting, and the twisting was stopped when the twist angle was 440 degrees and the horizontal movement distance was 9.98 cm. After that, the horizontal movement of the mandrel B was continued, and the horizontal movement was stopped when the horizontal movement distance after stopping the twisting became 6.35 cm. After that, the mandrel B was returned to the initial state by the reverse operation of the above. After performing such an operation 100 times, the presence or absence of a pinhole was examined. The results are shown in Table 1.

SF7503B in Table 1 is the EVOH resin used as the EVOH layer of Example 5. On the other hand, D2908 in Table 1 is Soanol D2908 (manufactured by Nippon Synthetic Chemistry Co., Ltd.), which is a general EVOH resin. Each EVOH resin was tested twice.

As shown in Table 1, the above test produced a large number of pinholes in D2908, whereas SF7503B did not have pinholes at all and was superior in bending resistance to general EVOH resin. It turned out.

The EVOH resin in which pinholes are not formed in the bending resistance test shown here is suitably used as the EVOH resin constituting the outer EVOH layer of the inner bag of the laminated stripping container.

1: Laminated peeling container 3: Container body, 5: Valve member, 7: Storage part, 9: Mouth part, 11: Outer layer, 12: Outer shell, 13: Inner layer, 14: Inner bag, 15: Outside air introduction hole, 23: Cap, 27: Bottom seal protrusion

Claims (4)

A laminated peeling container provided with an outer layer and an inner layer, wherein the inner layer peels off from the outer layer and shrinks as the contents decrease.
The inner layer includes an inner EVOH layer made of EVOH resin as the innermost layer, and an outer EVOH layer made of EVOH resin as the outermost layer.
The inner layer includes an adhesive layer between the inner EVOH layer and the outer EVOH layer.
The inner EVOH layer is a laminated stripping container made of an EVOH resin having a higher ethylene content than the outer EVOH layer. The laminated peeling container according to claim 1 .
The adhesive layer is a laminated stripping container in which the rigidity per unit thickness is smaller than that of either the inner EVOH layer or the outer EVOH layer. The laminated peeling container according to claim 1 or 2 .
The adhesive layer is a laminated stripping container made of a mixed resin of polyolefin and acid-modified polyethylene. The laminated peeling container according to any one of claims 1 to 3 .
A laminated stripping container in which another layer is provided between the adhesive layer and the inner EVOH layer, or between the adhesive layer and the outer EVOH layer.