Stackable peel container

Abstract

A laminated peeling container (1) is provided which is excellent in productivity. According to a first aspect of the present invention, there is provided a laminated peeling container (1) having a container body (3) with an outer shell (12) and an inner bag (14) which peels from the outer shell (12) and shrinks as the content is reduced, the container body (3) of the laminated peeling container (1) having a bottom seal protruding portion (27) protruding from the bottom surface of a content-containing accommodation portion (7), the bottom seal protruding portion (27) being a seal portion of a cylindrical laminated parison bent to be formed in blow molding of the laminated parison, the cylindrical laminated parison having an outer layer (11) constituting the outer shell (12) and an inner layer (13) constituting the inner bag (14).

Description

[0001] This application is a divisional application of Chinese patent application No. 202210118215.8, filed on November 20, 2014, entitled "Laminated Peeling Container". The parent Chinese patent application No. 201480064827.7 was filed on November 20, 2014, entitled "Laminated Peeling Container and Manufacturing Method Thereof". [Technical Field]

[0002] This invention relates to a stacked peeling container, in which the inner layer peels off from the outer layer and shrinks as the contents decrease. [Background Technology]

[0003] In the prior art, known laminated peel-off containers suffer from the problem that, as the contents decrease, the inner layer peels off from the outer layer and shrinks, thus preventing air from entering the container (e.g., Patent Documents 1-2). Such laminated peel-off containers have an inner bag made of an inner layer and an outer shell made of an outer layer.

[0004] Such stacked glass containers are generally manufactured by blow molding using cylindrical stacked preforms. Furthermore, a sealing portion is provided at the bottom of the container body where one end of the stacked preform is welded; however, because this sealing portion has weak impact resistance, it is designed to protrude from the bottom surface of the container to improve strength. In Patent Document 1, to further improve the strength of this sealing portion, the welded layers of the sealing portion are interlocked by a plurality of inserts.

[0005] [Background Technical Literature]

[0006] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent No. 3401519

[0008] [Patent Document 2] Japanese Patent No. 3650175 [Summary of the Invention]

[0009] [The problem the invention aims to solve]

[0010] (First viewpoint)

[0011] To achieve the configuration of Patent Document 1, it is necessary to set pins for the extrusion parison welding layer in the mold, which complicates the mold structure and increases production costs. Therefore, a simpler structure is needed to strengthen the sealing part.

[0012] The first aspect of the present invention is made in view of the following situation: providing a stacked peeling container with excellent productivity.

[0013] (Second viewpoint)

[0014] Stacked peel containers are typically installed with caps at the opening, but to prevent leakage of contents from the gap between the cap and the opening, a cap with an inner ring is attached to the inside of the opening.

[0015] However, during repeated experiments on installing caps on stacked glass containers, the inventors discovered that the inner ring gets stuck in the inner layer at the mouth, causing the inner layer to bend. In some cases, the inner layer at the mouth may even completely peel off from the outer layer, causing the inner bag to fall into the outer shell.

[0016] The second aspect of the present invention was made in view of such circumstances, providing a method to suppress inner layer peeling at the mouth of a stacked glass container.

[0017] [Technical means to solve the problem]

[0018] (First viewpoint)

[0019] According to a first aspect of the present invention, a stacked peelable container is provided, the stacked peelable container having a container body having an outer shell and an inner bag, wherein the inner bag peels off and shrinks from the outer shell as the contents decrease, the container body having a bottom sealing protrusion protruding from the bottom surface of a receiving portion for containing the contents, the bottom sealing protrusion being a sealing portion of the stacked preform used in blow molding of a cylindrical stacked preform and being bent, the cylindrical stacked preform having an outer layer constituting the provided outer shell and an inner layer constituting the inner bag.

[0020] After careful study, the inventors discovered that a simple structure in which the bottom sealing protrusion protruding from the bottom surface of the container body can be bent can strengthen the sealing part, thus completing the present invention.

[0021] The following describes various embodiments of the first aspect of the present invention. The embodiments shown below can be combined with each other.

[0022] Preferably, the bottom sealing protrusion has, in sequence from the ground side, a thin-walled portion and a thick-walled portion with a wall thickness greater than that of the thin-walled portion. Preferably, the bottom sealing protrusion is curved in the thin-walled portion.

[0023] Preferably, the bottom surface has a concave region and a peripheral region surrounding the concave region, and the bottom sealing protrusion is disposed in the concave region.

[0024] Preferably, the bottom sealing protrusion is configured so that it does not protrude from the surface defined by the surrounding area when bent.

[0025] Preferably, the recessed area is configured to traverse the entire bottom surface along the long side of the bottom sealing protrusion.

[0026] According to another viewpoint, the present invention provides a method for manufacturing the above-mentioned stacked peelable container, characterized in that it includes a step of softening and bending the bottom sealing protrusion by blowing hot air after the blow molding.

[0027] (Second viewpoint)

[0028] According to a second aspect of the present invention, a stacked peeling container is provided, having a container body having a receiving portion for containing contents and an outlet for discharging the contents from the receiving portion, wherein the receiving portion and the outlet have an outer layer and an inner layer, wherein as the contents decrease, the inner layer peels off from the outer layer and shrinks, wherein the stacked peeling container is characterized in that the outlet has an enlarged diameter portion disposed at the front end of the outlet and an inner layer support portion disposed closer to the receiving portion than the enlarged diameter portion and for inhibiting the shedding of the inner layer.

[0029] After careful research, the inventors discovered that the opening of the current stacked peeling container is roughly cylindrical. Due to deviations during production, when the inner diameter of the opening is smaller than the outer diameter of the inner ring, the front end of the inner ring at the front end of the opening sometimes enters between the inner and outer layers.

[0030] Based on this discovery, the idea of ​​setting an enlarged diameter section at the front end of the opening was conceived. After actually producing such a stacked peeling container, it was found that the inner ring could be prevented from entering between the inner and outer layers, and the peeling of the inner layer at the opening of the peeling container could be suppressed.

[0031] This method can prevent the inner bag from falling off the outer shell. However, due to friction between the inner layer and the inner ring, the inner layer may peel off and the inner bag may fall off the outer shell. To better prevent this phenomenon, further research was conducted, and an inner layer support portion to prevent the inner layer from falling off was proposed at a position closer to the main body than the enlarged diameter portion. This led to the completion of the present invention.

[0032] The following describes various embodiments of the second aspect of the present invention. The embodiments shown below can be combined with each other.

[0033] Preferably, the receiving portion has a torso with a generally constant cross-sectional shape in the direction of the field edge of the receiving portion, and a shoulder connecting the torso and the mouth portion. The shoulder portion or the boundary between the shoulder and the torso has a curved portion with a bending angle of less than 140 degrees and a radius of curvature of 4 mm on the inner side of the container of the curved portion.

[0034] Preferably, the bending angle is less than 120 degrees.

[0035] Preferably, the radius of curvature is less than 2 mm.

[0036] Preferably, the curved portion is located at a position where the distance from the container's central axis to the inner surface of the curved portion is more than 1.3 times the distance from the container's central axis to the inner surface of the container's opening.

[0037] Preferably, the wall thickness of the mouth is 0.45-0.50 mm, the wall thickness of the curved portion is 0.25-0.30 mm, and the wall thickness of the torso is 0.15-0.20 mm.

[0038] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease.

[0039] The present invention also provides a stacked peelable container, comprising a container body and a valve component, the container body having an outer shell and an inner bag, the inner bag shrinking as the contents decrease, and the valve component for regulating the airflow between the intermediate space between the outer shell and the inner bag and the external space of the container body.

[0040] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein the container body has a receiving portion for receiving the contents and an outlet for discharging the contents from the receiving portion, the outlet having a constricted neck.

[0041] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein the container body has a receiving portion for receiving the contents and an outlet for discharging the contents from the receiving portion, the outlet having an enlarged diameter portion.

[0042] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein the container body has a receiving portion for receiving the contents and an outlet for discharging the contents from the receiving portion, the receiving portion having a shoulder.

[0043] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein the outer shell has an external gas inlet opening communicating with the intermediate space between the outer shell and the inner bag and the external space of the container body.

[0044] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, and wherein the container body has a recess.

[0045] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, and wherein the container body has a sealing portion.

[0046] The present invention also provides a laminated peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein the outer shell is a layer composed of at least one of low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer and mixtures thereof.

[0047] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, and wherein the inner bag is an EVOH layer.

[0048] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein at least a portion of the container body is covered by a shrink film.

[0049] The present invention also provides a stacked peelable container, comprising a container body and a cap, the container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, and wherein the cap has an inner ring.

[0050] The present invention also provides a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, wherein the container body is pre-peeled.

[0051] The present invention also provides a stacked peeling container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, and wherein the stacked peeling container discharges the contents by compressing the outer shell.

[0052] The present invention also provides a method for manufacturing a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, the method comprising:

[0053] The procedure for inspecting the inner bag for pinholes.

[0054] The present invention also provides a method for manufacturing a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, the method comprising:

[0055] The process of forming the container body by blow molding.

[0056] The present invention also provides a method for manufacturing a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, the method comprising:

[0057] The process of cutting off the cylindrical part located on the upper part of the container body.

[0058] The present invention also provides a method for manufacturing a stacked peelable container, comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the contents decrease, the method comprising:

[0059] The process of forming an external gas inlet hole on the outer casing using a cutting edge.

[0060] Furthermore, in the embodiments described later, Test Example 1 relates to a valve component, Test Example 2 relates to the shape of the mounting portion of the valve component, Test Example 3 relates to the effect of using a random copolymer in the outer layer, and Test Example 4 relates to the effect of using an EVOH layer as the innermost layer of the inner layer. [Attached Image Description]

[0061]

【 Figure 1 [A] is a perspective view showing the structure of the stacked peeling container 1 according to the first embodiment of the present invention. (a) is an overall view, (b) is the bottom view, and (c) is an enlarged view showing the vicinity of the valve component mounting recess 7a. (c) shows the state with the valve component 5 removed.

[0062]

Figure 2

[0063]

【 Figure 4 [It contains] Figure 3 Enlarged view of region 9 in the middle of the mouth.

[0064]

Figure 5 The symbol

[0065]

Figure 6

[0066]

【 Figure 7The diagram shows a cross-sectional view of the outer layer 11 and the inner layer 13.

[0067]

Figure 8

[0068]

Figure 9

[0069]

【 Figure 10 This describes another embodiment of the molding process for preparing the inner layer for peeling off and the outer gas inlet hole.

[0070]

【 Figure 11 This describes another embodiment of the molding process for preparing the inner layer for peeling off and the outer gas inlet hole.

[0071]

Figure 12

[0072]

Figure 13

[0073]

Figure 14

[0074]

【 Figure 15 The diagram illustrates the structure of the stacked peeling container 1 according to the second embodiment of the present invention. (a) is a perspective view, (b) is an enlarged view near the valve component mounting recess 7a, and (c) is a cross-sectional view AA in (b). (b) to (c) show the state after the valve component 5 has been removed.

[0075]

【 Figure 16 The diagram shows an example 1 of the configuration of valve component 5. (a) is a perspective view and (b) is a front view.

[0076]

【 Figure 17 The diagram shows an example 2 of the configuration of valve component 5. (a) is a perspective view and (b) is a front view.

[0077]

【 Figure 18 The diagram shows an example 3 of the configuration of valve component 5. (a) is a perspective view and (b) is a front view.

[0078]

【 Figure 19 The diagram shows an example 4 of the configuration of valve component 5. (a) is a perspective view and (b) is a front view.

[0079]

【 Figure 20The diagram shows an example 1 of the configuration of valve component 5. (a) is a perspective view, (b) is a front view, and (c) is a perspective view from the bottom side.

[0080]

【 Figure 21 The diagram shows the valve component 5 of the stacked peeling container 1 according to the third embodiment of the present invention. (a) to (b) are perspective views of the valve component 5, (c) is a front view of the valve component 5, and (d) to (e) are front views of the valve component 5 with the external air inlet port 15 installed (the outer shell 12 is a cross-sectional view).

Detailed Implementation Methods

[0081] The following describes embodiments of the present invention. The various features shown in the following embodiments can be combined with each other. Furthermore, each feature independently enables the invention to succeed.

[0082] 1. First Implementation Method

[0083] like Figures 1-2 As shown, the first embodiment of the present invention, a stacked peeling container 1, has a container body 3 and a valve component 5. The container body 3 has a receiving portion 7 for containing contents and an outlet 9 for discharging contents from the receiving portion 7.

[0084] like Figure 3 As shown, the container body 3 has an outer layer 11 and an inner layer 13 in the receiving part 7 and the opening 9. The outer shell 12 is composed of the outer layer 11, and the inner bag 14 is composed of the inner layer 13. As the contents decrease, the inner layer 13 peels off from the outer layer 11, and the inner bag 14 peels off from the outer shell 12 and shrinks.

[0085] like Figure 4 As shown, the opening 9 is provided with an external threaded portion 9d. Caps and pumps with internal threads are installed on the external threaded portion 9d. Figure 4 The image shows a portion of a cap 23 with an inner ring 25. The outer diameter of the inner ring 25 is substantially the same as the inner diameter of the opening 9, and the outer surface of the inner ring 25 contacts the contact surface 9a of the opening 9 to prevent leakage of contents. In this embodiment, the front end of the opening 9 is provided with an enlarged diameter portion 9b. Because the inner diameter of the enlarged diameter portion 9b is larger than the inner diameter of the contact portion 9e, the outer surface of the inner ring 25 does not contact the enlarged diameter portion 9b. When the opening 9 does not have an enlarged diameter portion 9b, even a slight manufacturing deviation in the inner diameter of the opening 9 can result in a manufacturing defect such as the inner ring 25 entering between the outer layer 11 and the inner layer 13. However, when the opening 9 has an enlarged diameter portion 9b, even a slight change in the inner diameter of the opening 9 will not cause such a defect.

[0086] Furthermore, the opening 9 has an inner layer support portion 9c located closer to the receiving portion 7 than the contact portion 9e, which prevents the inner layer 13 from falling off. The inner layer support portion 9c is formed by a necking in the opening 9. Even when the opening 9 has an enlarged diameter portion 9b, the inner layer 13 may still peel off from the outer layer 11 due to friction between the inner ring 25 and the inner layer 13. In this embodiment, even in such cases, the inner layer support portion 9c prevents the inner layer 13 from falling off, thereby preventing the inner bag 14 from falling off inside the outer shell 12.

[0087] like Figures 3-5 As shown, the receiving portion 7 has a torso 19 with a substantially constant cross-sectional shape in the direction of its long side and a shoulder 17 connecting the torso 19 and the mouth 9. A bend 22 is provided in the shoulder 17. The bend 22 is as follows: Figure 3 This refers to the portion where the bending angle α is less than 140 degrees and the radius of curvature of the inner surface of the container is less than 4 mm. Without the bending portion 22, the peeling between the inner layer 13 and the outer layer 11 extends from the body 19 to the opening 9, resulting in the inner layer 13 also peeling from the outer layer 11 at the opening 9. If the inner layer 13 peels from the outer layer 11 at the opening 9, the inner bag 14 falls into the outer shell 12; therefore, peeling of the inner layer 13 from the outer layer 11 at the opening 9 is undesirable. In this embodiment, because the bending portion 22 is provided, if the peeling between the inner layer 13 and the outer layer 11 extends from the body 19 to the bending portion 22, as... Figure 5 As shown, the inner layer 13 is bent at the bend 22, and the force causing the inner layer 13 to peel from the outer layer 11 is not transmitted to the upper part of the bend 22. As a result, the peeling of the inner layer 13 from the outer layer 11 is suppressed in the portion above the bend 22. Furthermore, although in Figures 3-5 The bending portion 22 is located at the shoulder 17, or at the junction of the shoulder 17 and the torso 19.

[0088] Regarding the lower limit of the bending angle α, although no specific specification is given, it is preferably 90 degrees or higher for ease of manufacturing. The lower limit of the radius of curvature is also not specifically specified, but it is preferably 0.2 mm or higher for ease of manufacturing. Furthermore, to more reliably prevent the inner layer 13 of the opening 9 from peeling off from the outer layer 11, 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 can be, for example, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, or 140 degrees, or a value between any two numbers shown herein. Specifically, the radius of curvature can be, for example, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, or 2 mm, or a range between any two values ​​shown herein.

[0089] like Figure 4As shown, for the bend 22, the distance L2 from the container's central axis C to the inner surface of the container at the bend 22 is more than 1.3 times the distance L1 from the container's central axis C to the inner surface of the container at the opening 9. In this embodiment, the laminated peel container 1 is blow-molded. Because the larger L2 / L1 is, the greater the blow-up ratio at the bend 22 and the thinner the wall thickness, if L2 / L1 ≥ 1.3, the wall thickness of the inner layer 13 at the bend 22 becomes very thin, making the inner layer 13 easier to bend at the bend 22, and more reliably preventing the inner layer 13 from peeling off from the outer layer 11 at the opening 9. L2 / L1 is preferably, for example, 1.3 to 3, 1.4 to 2. Specifically, L2 / L1 can be, for example, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.5, 3, or any value between any two numbers shown here.

[0090] In one example, the wall thickness at the mouth 9 is 0.45–0.50 mm, the wall thickness at the bend 22 is 0.25–0.30 mm, and the wall thickness at the torso 19 is 0.15–0.20 mm. Thus, the wall thickness of the bend 22 is very small compared to the wall thickness of the mouth 9, thereby allowing the bend 22 to effectively perform its function.

[0091] like Figure 4 As shown, a valve component 5 is provided in the receiving portion 7 to regulate the airflow between the intermediate space 21 between the outer shell 12 and the inner bag 14 and the external space S of the container body 3. An external gas inlet hole 15 communicating between the intermediate space 21 and the external space S is provided in the receiving portion 7 of the outer shell 12. The external gas inlet hole 15 is a through hole only provided in the outer shell 12 and does not contact the inner bag 14. The valve component 5 has: a shaft portion 5a inserted into the external gas inlet hole 15; a cover portion 5c provided on one side of the intermediate space 21 of the shaft portion 5a and having a cross-sectional area larger than that of the shaft portion 5a; and a locking portion 5b provided on one side of the external space S of the shaft portion 5a and preventing the valve component 5 from entering the intermediate space 21. In this embodiment, the shaft portion 5a can slide relative to the external gas inlet hole 15.

[0092] The cover 5c is structured to substantially block the external gas inlet hole 15 when the outer casing 12 is compressed, and its cross-sectional shape decreases as it approaches the shaft portion 5a. Furthermore, the engaging portion 5b is structured to allow air to enter the intermediate space 21 when the outer casing 12 returns to its original position after compression. When the outer casing 12 is compressed, the pressure inside the intermediate space 21 becomes higher than the pressure outside, and the air inside the intermediate space 21 is discharged to the outside through the external gas inlet hole 15. Due to the pressure difference and airflow, the cover 5c moves toward the external gas inlet hole 15, thus blocking it. As for the cover 5c, its cross-sectional shape decreases as it approaches the shaft portion 5a, therefore the cover 5c easily embeds itself into the external gas inlet hole 15, thereby blocking it.

[0093] If the outer casing 12 is further compressed in this state, the pressure inside the intermediate space 21 increases, resulting in the compression of the inner bag 14 and the discharge of its contents. Furthermore, if the compressive force on the outer casing 12 is released, the outer casing 12 tends to recover due to its elasticity. At this time, the cover 5c moves away from the external gas inlet hole 15, the blockage of the external gas inlet hole 15 is released, and external gas enters the intermediate space 21. Furthermore, to prevent the engaging portion 5b from blocking the external gas inlet hole 15, a protrusion 5d is provided at the contact point between the engaging portion 5b and the outer casing 12. Since the protrusion 5d contacts the outer casing 12, a gap is provided between the outer casing 12 and the engaging portion 5b. Alternatively, as an alternative to providing the protrusion 5d, a groove can be provided in the engaging portion 5b to prevent it from blocking the external gas inlet hole 15. The specific configuration of the valve component 5 is as follows: Figure 8 as well as Figures 16-20 As shown.

[0094] Regarding valve component 5, the cover 5c pushes open the external gas inlet 15 and is inserted into the intermediate space 21, thereby allowing it to be installed in the container body 3. For this purpose, the front end of the cover 5c is preferably tapered. Such valve component 5 can be installed simply by pressing the cover 5c from the outside of the container body 3 into the intermediate space 21, resulting in excellent productivity.

[0095] After the valve component 5 is installed, the receiving part 7 is covered with a shrink film. At this time, the valve component 5 is installed in the mounting recess 7a provided in the receiving part 7 so that the valve component 5 does not interfere with the shrink film. Furthermore, an air passage groove 7b extending from the valve component mounting recess 7a toward the opening 9 is provided so that the valve component mounting recess 7a is not blocked by the shrink film.

[0096] A valve component mounting recess 7a is provided on the shoulder 17 of the outer casing 12. The shoulder 17 is a slope, and a flat area FR is provided within the valve component mounting recess 7a. Because the flat area FR is set to be substantially parallel to the slope of the shoulder 17, the flat area FR is also a slope. Because the external gas inlet hole 15 is provided on the flat area FR within the valve component mounting recess 7a, the external gas inlet hole 15 is provided on the slope. If the external gas inlet hole 15 were provided on, for example, a vertical surface of the body 19, it might hinder the movement of the valve component 5 once the peeled inner bag 14 comes into contact with it. In this embodiment, by providing the external gas inlet hole 15 on the slope, such an effect is avoided, ensuring smooth movement of the valve component 5. Furthermore, the inclination angle of the slope is not particularly limited, preferably 45 to 89 degrees, more preferably 55 to 85 degrees, and even more preferably 60 to 80 degrees.

[0097] And, as Figure 1As shown in (c), the flat area FR within the valve component mounting recess 7a is configured with a width W extending 3 mm or more (preferably 3.5 mm or 4 mm or more) outward from the external gas inlet hole 15. For example, if the external gas inlet hole 15 is φ4 mm and is located at the center of the flat area FR, the valve component mounting recess 7a is φ10 mm or more. There is no particular upper limit to the width W of the flat area FR, but as the width W of the flat area FR increases, the area of ​​the valve component mounting recess 7a increases, resulting in a larger gap area between the housing 12 and the shrink film. Therefore, the width W is preferably not too large, with an upper limit of, for example, 10 mm. Thus, the range W can be 3 to 10 mm, specifically, for example, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10 mm, or any value between any two numbers shown here.

[0098] Furthermore, through experiments (Experimental Example 2), the inventors discovered that the wider the flat region FR on the outer surface of the housing 12, the larger the radius of curvature of the inner surface of the housing 12. When the flat region FR on the outer surface of the housing is set to extend 3 mm or more around the gas inlet hole 15, the radius of curvature of the inner surface of the housing 12 becomes very large, resulting in improved sealing between the housing 12 and the valve component 5. The radius of curvature of the inner surface of the housing 12 within a 2 mm radius around the external gas inlet hole 15 is preferably 200 mm or more, more preferably 250 mm or more, or 300 mm or more. When the radius of curvature is at these values, the inner surface of the housing 12 is substantially flat, resulting in good sealing between the housing 12 and the valve component 5.

[0099] like Figure 1 As shown in (b), a central recessed region 29a and a peripheral region 29b are provided on the bottom surface 29 of the receiving part 7. A bottom sealing protrusion 27 protruding from the bottom surface 29 is provided in the central recessed region 29a. Figure 6 As shown in (a) to (b), the bottom sealing protrusion 27 is a blow-molded laminated preform sealing part using a cylindrical laminated preform having an outer layer 11 and an inner layer 13. The bottom sealing protrusion 27 has, in sequence from the bottom surface 29 side, a base portion 27d, a thin-walled portion 27a, and a thick-walled portion 27b, which is thicker than the thin-walled portion 27a.

[0100] After blow molding, such as Figure 6 As shown in (a), the bottom sealing protrusion 27 is generally vertically erected relative to the plane P defined by the peripheral region 29b. However, in this state, when the container is subjected to impact, the inner layer 13 of the welded part 27c is prone to detachment, resulting in insufficient impact resistance. In this embodiment, however... Figure 6As shown in (b), after blow molding, hot air is blown onto the bottom sealing protrusion 27 to soften the thin-walled portion 27a, and the bottom sealing protrusion 27 is bent at the thin-walled portion 27a. In this way, the impact resistance of the bottom sealing protrusion 27 can be improved simply by bending the bottom sealing protrusion 27. Furthermore, as... Figure 6 As shown in (b), the bent bottom seal protrusion 27 does not protrude from the plane P defined by the peripheral area 29b. In this way, when the stacked peeling container 1 is stood up, it can prevent the stacked peeling container 1 from shaking due to the bottom seal protrusion 27 protruding from the plane P.

[0101] In addition, the base portion 27d is a portion that is closer to the bottom surface 29 than the thin-walled portion 27a and is thicker than the thin-walled portion 27a. Even without the base portion 27d, the impact resistance of the bottom sealing protrusion 27 can be improved by providing the thin-walled portion 27a on the base portion 27d.

[0102] And, as Figure 1 As shown in (b), the concave region of the bottom surface 29 extends across the entire bottom surface 29 in the direction of the long side of the bottom sealing protrusion 27. That is, the central concave region 29a and the peripheral concave region 29c are connected. In such a structure, the bottom sealing protrusion 27 is easily bent.

[0103] The layer structure of the container body 3 will now be described in detail. The container body 3 has an outer layer 11 and an inner layer 13.

[0104] The outer layer 11 is composed of, for example, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof. The outer layer 11 can be a multi-layered structure. For example, the structure could be a polypropylene layer sandwiched between two recycled layers. The recycled layer, as referred to here, is a layer that reuses the burrs generated during the molding of the container. Furthermore, the outer layer 11 is thicker than the inner layer 13 to improve resilience.

[0105] In this embodiment, the outer layer 11 has a random copolymer layer composed of a random copolymer between propylene and another monomer. The outer layer 11 can be a single layer of random copolymer layer or a multilayer structure. For example, it can be a configuration in which random copolymer layers sandwich both sides of the recycled layer. Since the outer layer 11 is composed of a specific random copolymer, the shape recovery, transparency, and heat resistance of the outer shell 12 can be improved.

[0106] The content of monomers other than propylene in the random copolymer is less than 50 mol%, preferably 5 to 35 mol%. Specifically, this content can be, for example, 5, 10, 15, 20, 25, or 30 mol%, or any value between any two numbers shown herein. Ethylene is particularly preferred as the monomer that copolymerizes with propylene if it improves the impact resistance of the random copolymer compared to a homogeneous polymer of polypropylene. Regarding the random copolymer of propylene and ethylene, the ethylene content is preferably 5 to 30 mol%, specifically, for example, 5, 10, 15, 20, 25, or 30 mol%, or any value between any two numbers shown herein. The weight-average molecular weight of the random copolymer is preferably 100,000 to 500,000, more preferably 100,000 to 300,000. Specifically, this weight-average molecular weight can be, for example, 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, or any value between any two numbers shown herein.

[0107] Furthermore, the tensile modulus of the random copolymer is preferably 400–1600 MPa or 1000–1600 MPa. Within this range, shape recovery is particularly good. Specifically, the tensile modulus can be, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, or 1600 MPa, or any value between any two numbers shown here. Additionally, if the container is too rigid, the user experience will be poor; therefore, the outer layer 11 can be formed by mixing the random copolymer with a soft material such as linear low-density polyethylene. However, for mixtures of random copolymers, to avoid significantly hindering the effectiveness of the random copolymer, the weight of the mixture is preferably less than 50% of the total weight of the mixture. For example, a mixture of a random copolymer and linear low-density polyethylene in a weight ratio of 85:15 can be used to form the outer layer 11.

[0108] like Figure 7 As shown in (a), the inner layer 13 has an EVOH layer 13a disposed on the outer surface side of the container, an inner surface layer 13b disposed on the inner surface side of the container of the EVOH layer 13a, and an adhesive layer 13c disposed between the EVOH layer 13a and the inner surface layer 13b. The EVOH layer 13a improves gas barrier properties and peelability from the outer layer 11.

[0109] EVOH layer 13a is an ethylene-vinyl alcohol copolymer (EVOH) resin layer, obtained by hydrolysis of a copolymer of ethylene and vinyl acetate. The ethylene content of the EVOH resin can be 25-50 mol%, preferably 32 mol% or less, considering oxygen barrier properties. There is no particular lower limit for the ethylene content, but the lower the ethylene content, the easier it is for the flexibility of EVOH layer 13a to decrease; therefore, 25 mol% or more is preferred. Furthermore, EVOH layer 13a preferably contains a deoxidizer. The presence of a deoxidizer improves the oxygen barrier properties of EVOH layer 13a. The flexural modulus of the EVOH resin is preferably 2350 MPa or less, more preferably 2250 MPa or less. There is no particular lower limit for the flexural modulus of the EVOH resin; it can be, for example, 1800, 1900, or 2000 MPa. The flexural modulus can be measured according to the test method of ISO 178. The test speed is 2 mm / min.

[0110] The melting point of the EVOH resin is preferably higher than that of the random copolymer constituting the outer layer 11. External gas inlet holes 15 are preferably formed on the outer layer 11 using a heated perforation device. By ensuring that the melting point of the EVOH resin is higher than that of the random copolymer, it is possible to prevent the external gas inlet holes 15 from reaching the inner layer 13 when they are formed on the outer layer 11. From this perspective, the greater the difference between the melting point of EVOH and the melting point of the random copolymer, the better; preferably 15°C or higher, and particularly preferably 30°C or higher. This melting point difference can be, for example, 5 to 50°C, specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50°C, or any value between any two numbers shown herein.

[0111] The inner surface layer 13b is a contact layer for laminating and peeling off the contents of the container 1. It is composed of a 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 elasticity of the resin constituting the inner surface layer 13b is preferably 50 to 300 MPa, more preferably 70 to 200 MPa. This is because the inner surface layer 13b is particularly soft when the tensile modulus of elasticity is in this range. Specifically, the tensile modulus of elasticity can be, for example, 50, 100, 150, 200, 250, 300 MPa, or any value between any two numbers shown herein.

[0112] The adhesive layer 13c can be obtained by adding an acid-modified polyolefin (e.g., maleic anhydride-modified polyethylene) to which carboxyl groups are introduced into the aforementioned polyolefin, or by using ethylene vinyl acetate copolymer (EVA), which functions to bond the EVOH layer 13a and the inner surface layer 13b. An example of the adhesive layer 13c is a mixture of low-density polyethylene or linear low-density polyethylene and acid-modified polyethylene.

[0113] Figure 7 As shown in (b), the inner layer 13 may have an inner EVOH layer 13d as the innermost layer, an outer EVOH layer 13e as the outermost layer, and an adhesive layer 13c disposed between the two.

[0114] The inner EVOH layer 13d is composed of ethylene-vinyl alcohol copolymer (EVOH) resin. According to the inventors' experiments (Experimental Example 4), it was found that when the innermost layer of the inner layer 13 is used as the inner EVOH layer 13d, the adsorption or absorption of limonene on the surface of the container is suppressed, resulting in the suppression of the reduction of the citrus aroma emitted by the citrus flavoring.

[0115] However, because EVOH resin has relatively high rigidity, when used as the inner layer 13, a softener is usually added to improve its softness. However, if a softener is added to the EVOH resin constituting the innermost innermost EVOH layer 13d of the inner layer 13, the softener may dissolve into the contents. Therefore, a material without a softener must be used as the EVOH resin constituting the inner EVOH layer 13d. Because EVOH resin without a softener has high rigidity, if the inner EVOH layer 13d is too thick, it may cause the inner bag 14 to have difficulty shrinking smoothly when the contents are discharged. Furthermore, if the inner EVOH layer 13d is too thin, an uneven adhesive layer 13c will form on the inner surface of the container, and pinholes are likely to form in the inner EVOH layer 13d. From this perspective, the thickness of the inner EVOH layer 13d is preferably 10–20 μm.

[0116] The ethylene content of the EVOH resin constituting the inner EVOH layer 13d is, for example, 25-50 mol%, because a higher ethylene content results in better flexibility of the inner EVOH layer 13d. Preferably, the ethylene content is higher than that of the EVOH resin constituting the outer EVOH layer 13e, preferably 35 mol% or more. Furthermore, in other words, the ethylene content of the EVOH resin constituting the inner EVOH layer 13d preferably ensures that the tensile modulus of elasticity of the EVOH resin is below 2000 MPa.

[0117] The outer EVOH layer 13e, like the inner EVOH layer 13d, is made of ethylene-vinyl alcohol copolymer (EVOH) resin. However, since the outer EVOH layer 13e does not contact the contents, adding a softener can improve its softness; therefore, the thickness of the outer EVOH layer 13e can be greater than that of the inner EVOH layer. The thickness of the outer EVOH layer 13e is not particularly limited, and can be, for example, 20–30 μm. If the outer EVOH layer 13e is too thin, the gas barrier properties of the inner layer 13 become insufficient; if the outer EVOH layer 13e is too thick, the softness of the inner layer 13 becomes insufficient, making it difficult for the inner bag 14 to contract smoothly when the contents are discharged. The thickness ratio of the outer EVOH layer 13e to the inner EVOH layer 13d is not particularly limited, but preferably, for example, 1.1–4, 1.2–2.0. This ratio, specifically, can be, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 3, 4, or a value within a range of any two values ​​shown here. Furthermore, setting the outermost layer of the inner layer 13 as the outer EVOH layer 13e improves the peelability of the inner layer 13 from the outer layer 11.

[0118] The ethylene content of the EVOH resin constituting the outer EVOH layer 13e is, for example, 25 to 50 mol%, preferably 32 mol% or less from the viewpoint of oxygen barrier properties. There is no particular lower limit for the ethylene content; however, the lower the ethylene content, the easier it is for the flexibility of the outer EVOH layer 13e to decrease, so 25 mol% or more is preferred.

[0119] The amount of softener added to the EVOH resin constituting the outer EVOH layer 13e and the ethylene content of this EVOH resin are preferably set such that the tensile modulus of elasticity of this EVOH resin is below 2000 MPa. Since both the inner EVOH layer 13d and the outer EVOH layer 13e are composed of EVOH resin with a tensile modulus of elasticity of below 2000 MPa, the inner bag 14 can shrink smoothly. Furthermore, the outer EVOH layer 13e preferably contains a deoxidizer. Because the outer EVOH layer 13e contains a deoxidizer, its oxygen barrier properties are improved.

[0120] The melting point of the EVOH resin constituting the outer EVOH layer 13e is preferably higher than that of the resin constituting the outer layer 11. External gas inlet holes 15 are preferably machined on the outer layer 11 using a heated perforation device because the higher melting point of the EVOH resin compared to the resin constituting the outer layer 11 prevents the holes from reaching the inner layer 13. From this perspective, the greater the difference between the melting point of EVOH and the melting point of the resin constituting the outer layer 11, the better; preferably 15°C or higher, and particularly preferably 30°C or higher. This melting point difference can be, for example, 5 to 50°C, specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50°C, or any value between any two numbers shown herein.

[0121] Adhesive layer 13c is a layer disposed between the inner EVOH layer 13d and the outer EVOH layer 13e. It can be obtained by adding carboxyl groups to the aforementioned polyolefin (e.g., maleic anhydride-modified polyethylene), or ethylene vinyl acetate copolymer (EVA), and has the function of bonding EVOH layer 13a and inner surface layer 13b. An example of adhesive layer 13c is low-density polyethylene or a mixture of linear low-density polyethylene and acid-modified polyethylene. Adhesive layer 13c can directly bond the inner EVOH layer 13d and the outer EVOH layer 13e, or it can be indirectly bonded through another layer disposed between adhesive layer 13c and inner EVOH layer 13d, or between adhesive layer 13c and outer EVOH layer 13e.

[0122] The rigidity per unit thickness of the adhesive layer 13c is less than that of either the inner EVOH layer 13d or the outer EVOH layer 13e, meaning it exhibits good flexibility. Therefore, thickening the adhesive layer 13 increases the proportion of the adhesive layer 13c's thickness to the overall thickness of the inner layer 13, thereby improving flexibility and allowing the inner bag 14 to contract smoothly when the contents are discharged. Specifically, the thickness of the adhesive layer 13c is preferably greater than the sum of the thicknesses of the inner EVOH layer 13d and the outer EVOH layer 13e. The thickness ratio of adhesive layer 13c to (inner EVOH layer 13d + outer EVOH layer 13e) is, for example, 1.1 to 8, specifically, for example, 1.1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, or any value between any two numbers shown herein.

[0123] Next, an example of a method for manufacturing the stacked peeling container 1 of this embodiment will be described.

[0124] First, such as Figure 9 As shown in (a), the extrusion has a stacked structure corresponding to the container body 3 to be produced (an example is as follows). Figure 9As shown in (a), a molten preform (with a layered structure of PE layer / adhesive layer / EVOH layer / PP layer / recycled layer / PP layer in sequence from the inner side of the container) is placed on a blow molding die, and the die is closed. Then, as... Figure 9 As shown in (b), a blow molding nozzle is inserted into the opening on one side of the mouth 9 of the container body 3, and air is blown into the mold cavity of the dividing mold while the mold is closed.

[0125] Next, as Figure 9 (c) shows the opening of the dividing mold and the blow-molded product is removed. The dividing mold has a cavity shape for blow molding various shapes of the container body 3, such as the valve component mounting recess 7a, the air flow groove 7b, and the bottom sealing protrusion 27. Furthermore, the dividing mold has a clamping part below the bottom sealing protrusion 27 to remove the burrs formed on the lower side of the bottom sealing protrusion 27.

[0126] Secondly, such as Figure 9 As shown in (d), the removed blow-molded parts are arranged in a row.

[0127] Secondly, such as Figure 9 As shown in (e), an opening is made only in the outer layer 11 at the upper cylindrical portion 31 located above the opening 9. Air is blown between the outer layer 11 and the inner layer 13 using a blower 33, and the inner layer 13 is pre-peeled from the outer layer 11 at the location where the valve component 5 is installed in the receiving portion 7 (valve component mounting recess 7a). Pre-peeling makes the processing of the external gas inlet hole 15 and the installation of the valve component 5 easier. In addition, to prevent the blown air from leaking out from the top end of the upper cylindrical portion 31, a cover component can be used to cover the top end of the upper cylindrical portion 31. Furthermore, because the opening is only in the outer layer 11, squeezing the upper cylindrical portion 31 before opening the opening allows the inner layer 13 to peel off from the outer layer 11 at the upper cylindrical portion 31. Furthermore, pre-peeling can be performed on the entire receiving portion 7 or on a portion of the receiving portion 7.

[0128] Secondly, such as Figure 9 As shown in (f), an external gas inlet hole 15 is machined on the housing 12 using an opening device. The external gas inlet hole 15 is preferably a round hole, but other shapes are also possible.

[0129] The inner layer pre-peeling and external gas inlet hole opening processes can also be performed using the following method. First, as follows... Figure 10 As shown in (a), air is drawn out of the inner bag 14 through the opening 9, causing a decrease in air pressure inside the inner bag 14. In this state, a perforation device in the form of a heat pipe or a pipe cutter is used to slowly pressurize the outer layer 11. This perforation device has a cylindrical blade that draws out the air from inside the cylinder. When there is no perforation on the outer layer 11, no air enters between the outer layer 11 and the inner layer 13, and the inner layer 13 does not peel off from the outer layer 11.

[0130] When the tubular knife penetrates the outer layer 11, as Figure 11 As shown in (b), the cut piece is removed from the cylindrical blade, forming an external gas inlet 15. At this instant, air enters between the outer layer 11 and the inner layer 13, and the inner layer 13 peels off from the outer layer 11.

[0131] Secondly, such as Figure 10 As shown in (c) to (d), the diameter of the external gas inlet hole 15 is enlarged using an opening device. Additionally, if in Figure 10 If the external gas inlet hole 15 for inserting valve component 5 has already been formed in processes (a) to (b) to a sufficiently large size, then no further processing is required. Figure 10 (c)~(d) are the diameter expansion processes.

[0132] The pre-stripping of the inner layer and the opening of the external air inlet hole can be performed according to the following method. Here, using... Figure 11 (a) to (f), using a heated perforation device 2, an external air inlet 15 is opened in the outer shell 12 of the stacked peeling container 1, and then the pre-peeling method will be described.

[0133] First, such as Figure 11 As shown in (a), the lamination and peeling container 1 is positioned close to the perforation device 2. The perforation device 2 includes a cylindrical blade 2a, an electric motor 2c that drives the blade 2a to rotate via a conveyor belt 2b, and a heating device 2d that heats the blade 2a. The perforation device 2 can... Figure 11 (c) Arrow X1 direction and Figure 11 (e) moves in the direction of arrow X2 and is supported by a servo cylinder (not shown) that moves the piercing device 2 along a single axis due to the rotation of a servo motor. With this configuration, while the heated blade 2a rotates, its tip can press against the outer shell 12 of the stacking peeling container 1. Furthermore, by controlling the position and moving speed of the piercing device 2 with a servo motor, the production cycle can be shortened.

[0134] A vent pipe 2e, communicating with a cavity inside the blade 2a, is connected to the blade 2a. The vent pipe 2e is connected to an air intake / exhaust device (not shown). This allows air to be drawn out from inside the blade 2a and air to be blown into it. A heating device 2d has a coil 2e formed of wire, through which an alternating current is passed, heating the blade 2a according to the principle of electromagnetic induction. The heating device 2d is positioned close to the blow-molded part 1a and is not integral with the blade 2a. Due to this configuration, the wiring of the heating device 2d is simplified, and the tip of the blade 2a can be effectively heated.

[0135] Secondly, such as Figure 11 As shown in (b), the piercing device 2 is brought close to the stacking and peeling container 1, allowing the blade 2a to penetrate into the coil 2f. In this state, the blade 2a is heated by passing an alternating current through the coil 2f.

[0136] Secondly, such as Figure 11 As shown in (c), the perforating device 2 is moved at high speed in the direction of arrow X1 until the tip of the blade 2a reaches a position immediately before the stacking peeling container 1.

[0137] Secondly, such as Figure 11 As shown in (d), while the air inside the blade 2a is sucked out, creating an attractive force on the tip of the blade 2a, the piercing device 2 moves slowly towards the lamination and peeling container 1, allowing the tip of the blade 2a to penetrate the outer shell 12 of the lamination and peeling container 1. This combination of high-speed and slow-speed movement shortens the production cycle. Alternatively, in this embodiment, the piercing device 2 moves as a whole. In other embodiments, a cylinder mechanism or similar device can be used to move the blade 2a independently, moving it at high speed until the tip of the blade 2a reaches a position close to the lamination and peeling container 1, while the blade 2a moves slowly when penetrating the outer shell 12.

[0138] If the tip of the blade 2a reaches the boundary between the outer shell 12 and the inner bag 14, the outer shell 12 is pierced to form the shape of the tip of the blade 2a, creating an external air inlet 15. When the outer shell 12 is pierced, the cutting blade 15a is drawn into the cavity of the blade 2a. The blade 2a can stop moving when it reaches the boundary between the outer shell 12 and the inner bag 14. To more reliably form the external air inlet 15, the tip of the blade 2a can be moved until it exceeds the interface between the outer shell 12 and the inner bag 14 and is squeezed by the inner bag 14. At this time, in order to suppress damage to the inner bag 14 by the blade 2a, the shape of the tip of the blade 2a is compared to... Figure 12 The sharp shape shown in (a) is preferably as follows: Figure 12 (b) shows a circular shape. If the tip of the blade 2a is circular, it is difficult to process the external air inlet hole 15 in the outer casing 12. In this embodiment, by rotating the heated blade 2a, it is easy to process the external air inlet hole 15 in the outer casing 12. Furthermore, in order to prevent the heat of the blade 2a from causing the inner bag 14 to melt, the melting point of the resin constituting the outermost layer of the inner bag 14 is preferably higher than the melting point of the resin constituting the innermost layer of the outer casing 12.

[0139] Secondly, such as Figure 11 As shown in (e), the perforating device 2 is moved back in the direction of arrow X2, and air is blown into the cavity of the blade 2a, and the cutting blade 15a is released from the front end of the blade 2a.

[0140] The above processes complete the forming of the external air inlet hole 15 on the outer shell 12.

[0141] Secondly, such as Figure 11As shown in (f), air is introduced between the outer shell 12 and the inner bag 14 through the external air inlet 15 using a blower 33, causing the outer shell 12 to be pre-peeled from the inner bag 14. By ensuring the external air inlet 15 is airtight while simultaneously blowing in a predetermined amount of air, the pre-peeling of the inner bag 14 becomes easier to control. Pre-peeling can be performed on the entire receiving section 7 or on a portion of it, because pinholes in the inner bag 14 cannot be detected in areas where pre-peeling is not performed. Preferably, the inner bag 14 is pre-peeled from the outer shell 12 over a substantially uniform area of ​​the receiving section 7.

[0142] Secondly, such as Figure 13 As shown in (a), hot air is blown onto the bottom sealing protrusion 27 to soften the thin-walled portion 27a and bend the bottom sealing protrusion 27.

[0143] Secondly, such as Figure 13 (b) shows the pinhole inspection of the inner bag 14. Specifically, a connector 35 is first installed at the opening 9, and a test gas containing a specific type of gas is injected into the inner bag 14 through the opening 9. If a pinhole exists in the inner bag 14, the specific type of gas leaks out through the pinhole from the intermediate space 21 and is discharged out of the container through the external gas inlet 15. A specific gas sensing unit (detector) 37 is provided near the external gas inlet 15 outside the container to detect the leakage of the specific type of gas. If the concentration of the specific type of gas detected by the sensing unit 37 is below a threshold, it is determined that there is no pinhole in the inner bag 14, and the laminated peel container 1 is a qualified product. On the other hand, if the concentration of the specific type of gas detected by the sensing unit 37 exceeds the threshold, it is determined that there is a pinhole in the inner bag 14, and the laminated peel container 1 is a defective product. The laminated peel container 1 that is determined to be a defective product is removed from the production line.

[0144] As a specific type of gas, it is suitable to select a gas present in small amounts in the air (preferably less than 1%), such as hydrogen, carbon dioxide, helium, argon, neon, etc. There are no particular limitations on the concentration of the specific type of gas in the test gas; the test gas can consist only of the specific type of gas, or it can be a mixture of air and the specific gas.

[0145] There is no particular limitation on the injection pressure of the inspection gas, for example, it is 1.5 to 4.0 kPa. If the injection pressure is too low, the leakage of a certain type of gas will be too small, and the specific gas may not be detected regardless of whether there is a pinhole. If the injection pressure is too high, the inner bag 14 will expand and press against the outer shell 12 immediately after the inspection gas is injected, which will reduce the accuracy of pinhole inspection in the inner bag 14.

[0146] In this embodiment, the sensing unit 37 is disposed outside the stacked peeling container 1 near the external gas inlet 15. As a variation, by inserting the sensing unit 37 into the intermediate space 21 through the external gas inlet 15, a specific gas can be detected within the intermediate space 21. In this case, the specific gas passing through the pinhole of the inner bag 14 can be detected before diffusion, thereby improving the detection accuracy of the specific gas. As another variation, a test gas containing the specific gas is injected into the intermediate space 21 through the external gas inlet 15, and the specific gas leaking into the inner bag 14 through the pinhole is detected.

[0147] At this point, a sensing element 37 can be installed near the opening 9 outside the container, and the sensing element 37 can be inserted from the opening 9 into the inner bag 14.

[0148] After pinhole inspection, the laminated peeling container 1 can be directly sent to the next process. Alternatively, as a variation, it can undergo a process of inflating the inner bag 14 by blowing air into it before being sent to the next process. In the latter case, this step can be omitted. Figure 13 (e) is the process of blowing air in.

[0149] Secondly, such as Figure 13 As shown in (c), the valve component 5 is inserted into the external gas inlet hole 15.

[0150] Secondly, such as Figure 13 As shown in (d), the upper cylindrical part 31 is cut off.

[0151] Secondly, such as Figure 13 As shown in (e), air is blown into the inner bag 14, causing the inner bag 14 to bulge.

[0152] Secondly, such as Figure 13 As shown in (f), the contents are filled into the inner bag 14.

[0153] Secondly, such as Figure 13 As shown in (g), a cap 23 is installed at the mouth 9.

[0154] Secondly, such as Figure 13 As shown in (h), the receiving part 7 is packaged with shrink film to complete the product.

[0155] The order of the various processes shown here can be rearranged as appropriate. For example, the hot air bending process can be performed before the process of opening the external gas inlet hole, or before the inner layer pre-peeling process. And the process of cutting off the upper cylindrical portion 31 can be performed before inserting the valve component 5 into the external gas inlet hole 15.

[0156] The following explains how the product works when in use.

[0157] like Figure 14As shown in (a) to (c), with the product containing the contents tilted, the side of the outer casing 12 is grasped and squeezed to expel the contents. At the beginning of use, there is approximately no gap between the inner bag 14 and the outer casing 12. Pressure applied to the outer casing 12 is directly converted into pressure on the inner bag 14, compressing the inner bag 14 to expel the contents.

[0158] The cap 23 contains a check valve (not shown) that allows the contents of the inner bag 14 to drain while preventing outside air from entering. Therefore, after the contents are drained and the pressure applied to the outer casing 12 is removed, the outer casing 12 returns to its original shape due to its own restoring force, keeping the inner bag 14 in a contracted state while only the outer casing 12 expands. Furthermore, as... Figure 14 As shown in (d), the intermediate space 21 between the inner bag 14 and the outer shell 12 is in a depressurized state, and outside air enters the intermediate space 21 through the external gas inlet hole 15 on the outer shell 12. When the intermediate space 21 is in a depressurized state, the cover 5c does not block the external gas inlet hole 15 and does not obstruct the introduction of external gas. Furthermore, even when the engaging part 5b is in contact with the outer shell 12, the engaging part 5b does not hinder the introduction of external gas, and the engaging part 5b is provided with protrusions 5d or grooves to ensure unobstructed air passage.

[0159] Secondly, such as Figure 14 As shown in (e), the side of the outer casing 12 is gripped and compressed again. Because the cover 5c blocks the external gas inlet 15, the pressure inside the intermediate space 21 increases. The pressure applied to the outer casing 12 is transmitted to the inner bag 14 through the intermediate space 21. This force compresses the inner bag 14 to expel the contents.

[0160] Secondly, such as Figure 14 As shown in (f), after the contents are discharged and the pressure applied to the outer shell 12 is removed, the outer shell 12 will return to its original shape due to its own restoring force, while external gas enters the intermediate space 21 through the external gas inlet 15.

[0161] 2. Second Implementation Method

[0162] The following uses Figure 15 The second embodiment of the laminated peeling container of the present invention will be described. The laminated peeling container 1 in this embodiment has the same layer structure and function as that in the first embodiment, only the specific shape is different. The structure of the laminated peeling container 1 in this embodiment near the valve component mounting recess differs from that in the first embodiment. Hereinafter, the description will focus on this point.

[0163] like Figure 15As shown in (a), in the stacked peeling container 1 of this embodiment, the opening 9 and the body 19 are connected to the shoulder 17. In the first embodiment, a bending portion 22 is provided in the shoulder 17. In this embodiment, no bending portion 22 is provided in the shoulder 17. The boundary 20 between the shoulder 17 and the body 19 has the same function as the bending portion 22, which is to prevent the inner bag 14 from peeling off to the opening 9.

[0164] A valve component mounting recess 7a is provided in the body 19, which is composed of a generally vertical wall. The valve component mounting recess 7a has a flat area FR, which is a slope of approximately 70 degrees. An external air inlet 15 is provided in the flat area FR, and the width W of the flat area FR surrounding the external air inlet 15 is 3 mm or more, similar to the first embodiment. The sidewall 7c of the valve component mounting recess 7a extends outward into a tapered surface, making it easier for the mold forming the valve component mounting recess 7a to be removed. Furthermore, the inner bag 14... Figure 15 As shown in (c), peeling becomes easier with the upper edge 7d of the flat region FR as the starting point.

[0165] 3. Third Implementation Method

[0166] Secondly, using Figure 21 The stacked peeling container 1 in the third embodiment of the present invention will be described. The stacked peeling container 1 in this embodiment has the same layer structure and function as the first to second embodiments, but the structure of the valve component 5 is different.

[0167] Specifically, in this embodiment, the engaging portion 5b of the valve component 5 has a pair of base portions 5b1 and a bridge portion 5b2 disposed between the base portions 5b1. A shaft portion 5a is disposed on the bridge portion 5b2.

[0168] The structure of the cover 5c is such that it substantially blocks the external gas inlet hole 15 when the outer shell 12 is compressed, and has a tapered surface 5d that decreases in size as it approaches the cross-section of the shaft portion 5a. Figure 21 (c) The inclination angle β of the conical surface 5d shown is preferably 15 to 45 degrees with the extension direction D of the shaft portion 5a, more preferably 20 to 35 degrees. If the inclination angle β is too large, it is easy to leak air; if it is too small, the valve component 5 becomes too long.

[0169] Furthermore, the 5b locking part is as follows Figure 21 As shown in (d), when installed with the external air inlet 15, the base 5b1 abuts against the outer casing 12 via the abutment surface 5e, and the bridge portion 5b2 is bent. With this configuration, a restoring force is generated in the direction indicated by arrow FO of the bridge portion 5b2 in the direction away from the container, thereby applying a force in the same direction to the cover portion 5c, and the cover portion 5c is pressed against the outer casing 12.

[0170] In this state, the cover 5c is only lightly pressed against the outer shell 12. If the outer shell 12 is compressed, the pressure inside the intermediate space 21 is higher than the external pressure. Based on this pressure difference, the cover 5c is pressed against the external gas inlet 15 with greater force, thus blocking the external gas inlet 15. Because the cover 5c has a conical surface 5d, the cover 5c can easily embed itself into the external gas inlet 15, thereby blocking the external gas inlet 15.

[0171] If the outer shell 12 is further compressed in this state, the pressure inside the intermediate space 21 increases, resulting in the compression of the inner bag 14 and the discharge of its contents. Furthermore, if the pressure on the outer shell 12 is released, the elastic outer shell 12 has a tendency to recover. As the outer shell 12 recovers, the air pressure inside the intermediate space 21 decreases, thus... Figure 21 As shown in (e), a force FI is applied to the inner side of the cover 5c container. As a result, the bending of the bridge 5b2 increases, and a gap Z is formed between the cover 5c and the outer shell 12. External air is introduced into the intermediate space 21 through the passage 5f between the bridge 5b2 and the outer shell 12, the external air inlet hole 15, and the gap Z.

[0172] In this embodiment, valve component 5 utilizes along... Figure 21 (a) shows the parting line L, which is divided in the X direction to form a simple dividing mold, which can be used for injection molding and other processes to achieve good productivity.

[0173]

Implementation Method

[0174] 1. Experimental Example 1

[0175] In the following experimental example, a blow-molded laminated release container having an outer layer 11 and an inner layer 13 was formed. A heated perforation device was used to form a φ4mm external air inlet hole 15 only on the 0.7mm thick outer layer 11. And as... Figures 16-20 The valve component 5 in the configuration examples 1 to 5 shown in Table 1 is injection molded, and the cover 5c of the valve component 5 is pressed into the intermediate space 21 through the external air inlet hole 15.

[0176] The workability, formability, tilt resistance, and transportability of valve components 5 in Examples 1 to 5 were evaluated. The results are shown in Table 1 below. In Table 1, ×, △, and ○ represent relative evaluation results, where △ indicates a better result than × and ○ indicates a better result than △.

[0177] Table 1

[0178]

[0179] Operability is an evaluation of whether the valve component 5 can smoothly open and close the external air inlet port 15. In configuration example 1, where the length of the shaft portion 5a is shorter than the thickness of the outer layer 11, the possible sliding length is 0, and the external air inlet port 15 is in a closed state. In configuration example 2, the valve component 5 can open and close the external air inlet port 15, but sometimes the operation is not smooth. In configuration examples 3 to 5, the valve component 5 can smoothly open and close the external air inlet port 15. For example, in configuration example 2, the reason why the valve component 5 does not operate smoothly is that the possible sliding length (length of shaft portion 5a - thickness of outer layer 11) is 0.7 mm, which is insufficient, and the clearance corresponding to the external air inlet port 15 (diameter of external air inlet port 15 - diameter of shaft portion 5a) is 0.2 mm, which is not large enough. In configuration examples 3 to 5, the possible sliding length is more than 1 mm, which is sufficient, and the clearance corresponding to the external air inlet port 15 is more than 0.3 mm. Because it is large enough, the valve component 5 operates smoothly. In addition, if the sliding length exceeds 2 mm, the valve component 5 may easily interfere with the shrink film and the inner layer 13. Therefore, the sliding length of the valve component 5 is preferably 1 to 2 mm.

[0180] Formability is an evaluation of the ease with which the injection-molded valve component 5 is formed. When the surface of the shaft portion 5a side of the engaging portion 5b has a protrusion 5d as in Configuration 1, and four circumferentially spaced grooves 5e as in Configuration 2, the formed valve component 5 has poor formability because it is not properly removed from the dividing mold, or a mold with a special structure is required. However, when two circumferentially spaced grooves 5e are provided, as in Configurations 3-5, the valve component 5 is easily removed from the dividing mold, and its formability is good.

[0181] The tilt resistance is an evaluation of whether a gap easily forms at the air inlet 15 when the valve component 5 is tilted with the cover 5c pressed against it. When the shape of the boundary 5f between the cover 5c and the shaft 5a is concave inward into an R-shape as in Configuration Examples 1-2, a gap easily forms at the air inlet 15 when the valve component 5 is tilted. However, when the shape of the boundary 5f between the cover 5c and the shaft 5a is bulging outward into an R-shape as in Configuration Examples 3-5, it is difficult for a gap to form at the air inlet 15 when the valve component 5 is tilted. Furthermore, in Configuration Example 3, the gap corresponding to the air inlet 15 is 0.7 mm, which is too large, making it easier for a gap to form when the valve component 5 is tilted significantly. In Configuration Examples 4-5, the gap corresponding to the air inlet 15 is less than 0.6 mm, which is a suitable size, suppressing excessive tilting of the valve component 5. Considering workability and tilt resistance, the gap corresponding to the external air inlet 15 is preferably 0.2 to 0.7 mm, more preferably 0.3 to 0.6 mm.

[0182] The ease of transportability is evaluated by assessing how easily the valve component 5 can be transported using a parts feeder on two parallel tracks with a spacing slightly larger than the diameter of the cover 5c. The valve component 5 and cover 5c pass downwards between the two tracks, and the engaging part 5b is held in place by engaging the parallel tracks. Transportability can be further categorized into resistance to overlap and resistance to detachment.

[0183] The evaluation of the resistance to overlap concerns the difficulty of overlap occurring between the engaging portions 5b of the valve component 5. In configuration examples 1 to 4, the thickness of the engaging portions 5b is 1 mm, which is insufficient, making it easy for the engaging portions 5b to overlap. However, in configuration example 5, the thickness of the engaging portions 5b is 1.2 mm or more, which is sufficient, making it difficult for the engaging portions 5b to overlap.

[0184] Evaluation of whether the valve component 5 can be properly held by the parallel track without detaching from it. In configuration examples 1 to 4, the protrusion of the engaging part 5b (diameter of engaging part 5b - diameter of cover part 5c) is less than 1.5 mm. Because it is too small, the valve component 5 easily detaches from the parallel track. However, in configuration example 5, the protrusion of the engaging part 5b is more than 2 mm, so the valve component 5 does not detach from the parallel track, and it is easy to transport using the parallel track.

[0185] In the valve component 5 constituting Example 5, such as Figure 20 As shown in (c), the outer surface of the engaging part 5b has a recess 5g. When the injection molding valve part 5 is ejected, burrs are generated at the injection gate position. Since the injection gate position is within the recess 5g, the burrs can be prevented from interfering with the shrink film.

[0186] 2. Experimental Example 2

[0187] In the following experimental examples, a stacked release container with an outer layer 11 and an inner layer 13 was blow-molded. A φ4mm external air inlet hole 15 was machined only on the 0.7mm thick outer layer 11 using a heated perforation device. Various modifications were made to the internal volume of the stacked release container, the size of the external air inlet hole 15, and the width W of the flat area FR within the valve component mounting recess 7a around the external air inlet hole 15, resulting in stacked release container samples numbered 1 to 5. Furthermore, injection molding was used to manufacture... Figure 20 The valve component 5, as shown in the figure, has its cover 5c pressed into the intermediate space 21 through the external air inlet 15. After filling the resulting stacked peeling container with contents (water), the sides of the stacked peeling container are squeezed to discharge the contents. The discharge performance when 80% of the contents are discharged (discharge performance when the contents are small) is evaluated. Smooth discharge of contents is rated as "○", and difficulty in discharge of contents is rated as "×". The results are shown in Table 2.

[0188] Table 2

[0189] Sample No. 1 2 3 4 5 Content volume (ml) 200 200 200 200 500 Diameter of external air inlet 4.0 3.8 3.7 3.7 4.0 Width W of the flat region FR 2.0 2.1 2.2 4.2 4.0 Discharge performance when contents are small × × × ○ ○ Radius of curvature (mm) of the inner surface of the outer casing 30 30 30 300 750

[0190] As shown in Table 2, samples 1-3 exhibited low discharge performance when containing small amounts of contents, while samples 1-5 showed high discharge performance when containing small amounts of contents. To verify the reason for these results, the radius of curvature of the inner surface of the outer casing 12 was measured within a 2mm radius around the external air inlet 15 for each sample, yielding the results shown in Table 2. It was found that, as shown in Table 2, if the amplitude W of the flat area FR on the outer surface of the outer casing 12 was greater than 3mm, the radius of curvature of the inner surface of the outer casing 12 increased significantly, and the inner surface of the outer casing 12 became generally flat. On the other hand, it was found that if the amplitude W of the flat area FR on the outer surface of the outer casing 12 was less than 3mm, the inner surface of the outer casing 12 was not flat but curved. It was then discovered that this curved surface could not properly fit with the valve component 5, causing air to leak in from the external air inlet 15, resulting in lower discharge performance when containing small amounts of contents.

[0191] 3. Experimental Example 3

[0192] In the following experimental examples, blow molding was used to manufacture stacked and peeled containers with different layer structures. The resilience, rigidity, impact resistance, heat resistance, transparency, gas barrier properties, formability, and outer layer processability were evaluated. Furthermore, outer layer processability refers to the ease with which air inlet holes can be formed only in the outer layer using a heated perforation device.

[0193] <Example 1>

[0194] In Example 1, the layers, from the outside of the container, are in the following order: random copolymer layer / EVOH layer / adhesive layer / LLDPE layer. The random copolymer layer uses a random copolymer of propylene and ethylene (type: novaTecEG7FTB, manufactured by Polypuro Co., Ltd., Nippon, melting point 150°C). The EVOH layer uses high-melting-point EVOH (type: soanoruSF7503B, manufactured by Nippon Synthetic Chemicals Co., Ltd., melting point 188°C, flexural modulus 2190 MPa). After performing the above evaluations, excellent results were obtained in all evaluation items.

[0195] <Example 2>

[0196] In Example 2, the layers, from the outside of the container, are in the following order: random copolymer layer / recycled layer / random copolymer layer / EVOH layer / adhesive layer / LLDPE layer. The recycled layer is formed by reusing the burrs generated during container formation, and its composition is very similar to that of the random copolymer layer. The random copolymer layer and the EVOH layer are formed from the same materials as in Example 1. After performing the above evaluations, excellent results were obtained in all evaluation items.

[0197] <Example 3>

[0198] In Example 3, the layer structure is the same as in Example 1, except that a low-melting-point EVOH (type: Soanoru A4412, manufactured by Nippon Synthetic Chemicals, melting point 164°C) is used in the EVOH layer. After performing the various evaluations described above, excellent results were obtained in all evaluation items, with excellent results in all evaluation items except for the outer layer processability; however, the outer layer processability was slightly worse than in Example 1. This result, the difference between the melting point of the EVOH and the melting point of the random copolymer layer, confirms that a temperature of 15°C or higher is preferred.

[0199] <Comparative Example 1>

[0200] In Comparative Example 1, the layers, from the outside of the container, are in the following order: LDPE layer / EVOH layer / adhesive layer / LLDPE layer. The various evaluations performed above showed that at least rigidity and heat resistance were low.

[0201] <Comparative Example 2>

[0202] In Comparative Example 2, the layers, from the outside of the container, are in the following order: HDPE layer / EVOH layer / adhesive layer / LLDPE layer. The above evaluations show that the resilience and transparency are at least low.

[0203] <Comparative Example 3>

[0204] In Comparative Example 3, the layers, from the outside of the container, are in the following order: polypropylene layer / EVOH layer / adhesive layer / LLDPE layer. The polypropylene layer uses a homogeneous polymer of propylene with a melting point of 160°C. The EVOH layer uses the same material as in Example 1. The above evaluations show that the impact resistance is at least low. Furthermore, the outer layer's processability is worse than in Example 1.

[0205] <Comparative Example 4>

[0206] In Comparative Example 4, the layers, from the outside of the container, are in the following order: block copolymer layer / EVOH layer / adhesive layer / LLDPE layer. The various evaluations performed above showed that at least transparency and impact resistance were low.

[0207] <Comparative Example 5>

[0208] In Comparative Example 5, the layers, from the outside of the container, are in the following order: PET layer / EVOH layer / adhesive layer / LLDPE layer. The above evaluations show that at least the moldability and heat resistance are low.

[0209] <Comparative Example 6>

[0210] In Comparative Example 6, the layers, from the outside of the container, are in the following order: polyamide layer / EVOH layer / adhesive layer / LLDPE layer. After performing the various evaluations described above, the result was at least low moldability.

[0211] <Comparative Example 7>

[0212] In Comparative Example 6, the layers, from the outside of the container, are in the following order: polypropylene layer / polyamide layer / adhesive layer / LLDPE layer. The various evaluations performed above show that the gas barrier properties and moldability are at least low.

[0213] <Bending resistance test>

[0214] The EVOH resin used as the EVOH layer underwent flexural resistance testing using a flexural testing machine based on ASTM F392 (Brugger, KFT-C-Flex Durability Tester). The test environment was 23°C and 50% RH.

[0215] First, a sample was prepared by forming a single-layer membrane with a diameter of 28 cm × 19 cm × 30 μm.

[0216] Next, the long side of the sample is wound around a pair of mandrels (90mm in diameter) spaced 180mm apart, thereby fixing a pair of mandrels A and B to both ends of the sample.

[0217] Next, keeping mandrel A fixed, slowly move mandrel B closer while twisting it. Stop twisting when the mandrel has moved 9.98cm horizontally and the twisting angle is 440 degrees. Then, continue moving mandrel B horizontally until the mandrel has moved 6.35cm horizontally after stopping twisting.

[0218] Then, the mandrel B is restored to its initial state by performing the opposite action. After this process is repeated 100 times, the mandrel is checked for pinholes. The results are shown in Table 3.

[0219] Table 3

[0220]

[0221] SF7503B in Table 3 is the EVOH resin used as the constituent EVOH layer in Example 1. On the other hand, D2908 in Table 3 is the general EVOH resin soanoru D2908 (type: soanoru SF7503B, manufactured by Nippon Synthetic Chemicals Co., Ltd.). Two tests were conducted on each EVOH resin.

[0222] As shown in Table 3, the above tests revealed that, compared to D2908, which formed numerous pinholes, SF7503B did not form any pinholes at all, demonstrating superior flexural resistance compared to ordinary EVOH resins.

[0223] 4. Experimental Example 4

[0224] In the following experimental examples, various layered peelable containers with different layer structures were manufactured by blow molding. After filling the containers with orange vinegar, they were left to stand for one week, and then all the orange vinegar was drained. The citrus aroma of the drained orange vinegar was then evaluated by sensory evaluation. Furthermore, the shape of the inner bag of the container was visually evaluated during the draining process.

[0225] <Example 1>

[0226] The layers in Example 1, from the outside of the container, are in the following order: random copolymer layer / outer EVOH layer (25 μm thick) / adhesive layer (150 μm thick) / inner EVOH layer (15 μm thick). The outer EVOH layer is formed of EVOH resin with added softener, and the inner EVOH layer is formed of EVOH resin without added softener. The adhesive layer is formed by mixing linear low-density polyethylene and acid-modified polyethylene in a 50:50 mass ratio. The above evaluation showed that the intensity of the citrus aroma emitted by the discharged orange vinegar was almost unchanged from that during filling. Furthermore, as the orange vinegar was discharged, the inner bag shrank smoothly without bending.

[0227] <Example 2>

[0228] In the layer structure of Example 2, except that the thickness of the side EVOH layer is 5 μm, it is the same as that of Example 1. The above evaluation showed that the intensity of the citrus aroma emitted by the discharged orange vinegar was slightly weaker than that of Example 1. Furthermore, as the orange vinegar was discharged, the inner bag contracted smoothly without bending.

[0229] <Example 3>

[0230] In the layer structure of Example 3, except that the thickness of the inner EVOH layer is 25 μm, it is the same as that of Example 1. The above evaluation showed that the intensity of the citrus aroma emitted by the discharged orange vinegar was the same as that of Example 1. Furthermore, as the orange vinegar was discharged and the inner bag shrank, the inner bag was easier to bend than that of Example 1.

[0231] <Example 4>

[0232] The layer structure of Example 4 is the same as that of Example 1, except that the outer EVOH layer has a thickness of 75 μm and the adhesive layer has a thickness of 80 μm. The above evaluation showed that the intensity of the citrus aroma emitted by the discharged orange vinegar was the same as that of Example 1. Furthermore, the inner bag was more prone to bending than the inner bag of Example 1 when the orange vinegar was discharged and the bag shrank.

[0233] <Comparative Example 1>

[0234] The layer composition of Comparative Example 1 is the same as that of Comparative Example 1, except that the inner EVOH layer is replaced with a linear low-density polyethylene layer (50 μm). The above evaluation showed that the intensity of the citrus aroma emitted by the discharged orange vinegar was significantly worse than that of Comparative Example 1. Furthermore, as the orange vinegar was discharged, the inner bag contracted smoothly without bending.

[0235] <Comparative Example 2>

[0236] In Comparative Example 2, the layer composition was identical to that of Example 1, except that the inner EVOH layer was replaced with a polyamide layer (50 μm). The above evaluation showed that the intensity of the citrus aroma emitted by the discharged orange vinegar was significantly worse than that of Example 1. Furthermore, as the orange vinegar was discharged, the inner bag contracted smoothly without bending.

[0237] [Symbol Explanation]

[0238] 1: Stacked peelable container; 3: Container body; 5: Valve component; 7: Receiving part; 9: Mouth; 11: Outer layer; 12: Outer shell; 13: Inner layer; 14: Inner bag; 15: External air inlet; 23: Cap; 27: Bottom sealing protrusion.

Claims

1. A stacked peeling container, characterized in that, It has a container body, which has an outer shell and an inner bag, and the inner bag peels off and shrinks from the outer shell as the contents decrease. The container body has a bottom sealing protrusion that protrudes from the bottom surface of the receiving portion that contains the contents. The bottom sealing protrusion is a sealing portion of the stacked preform used in blow molding of a cylindrical stacked preform, the cylindrical stacked preform having an outer layer constituting the outer shell and an inner layer constituting the inner bag. The bottom sealing protrusion has, in sequence from one side of the bottom surface, a thin-walled portion and a thick-walled portion with a wall thickness greater than that of the thin-walled portion. The bottom sealing protrusion has a base portion that is closer to the bottom surface than the thin-walled portion. The base portion is thicker than the thin-walled portion. The thin-walled portion is formed by the bottom sealing protrusion recessing downwards from both sides along its thickness direction. The thin-walled portion extends along the long side of the bottom sealing protrusion.

2. The stacked peeling container as described in claim 1, characterized in that, The inner bag extends to the front end of the bottom sealing protrusion.

3. The stacked peeling container as described in claim 1, characterized in that, The bottom sealing protrusion is symmetrical with respect to the central surface of the bottom sealing protrusion.

4. The stacked peeling container as described in claim 1, characterized in that, The thin-walled portion extends along the entire length of the bottom sealing protrusion.

5. The stacked peeling container as described in claim 1 or 4, characterized in that, The bottom sealing protrusion bends in the thin-walled section.

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