JP7431106B2 - double container - Google Patents

Description

The present disclosure relates to a double container in which a volume-reducing and deformable inner layer body is housed inside an outer layer body.

For containers containing liquids such as mold removers, detergents, clothing glues, household waxes, hair conditioners, and fragrances, the container is attached to the mouth of the container, and the trigger is pulled to release the liquid into the main body. Trigger-type liquid ejectors are often used, which drive a pump installed to eject the liquid in the container in the form of a straight line, mist, or bubble (for example, see Patent Document 1), which improves the efficiency of the liquid content. This makes it possible to provide a high level of flexibility and high operability.

Japanese Patent Application Publication No. 11-290731

As a container body suitable for mounting the trigger-type liquid ejector as described above, one that ensures weight balance with the trigger-type liquid ejector, operability, storability, etc. is known. However, there is still room for improvement because the contents that cannot be spouted may remain inside the container body, or the contents may be affected by outside air entering the container body from the spout when spouting the contents. there were.

The present disclosure aims to solve the above-mentioned problems, and aims to provide a double-layered container that can reduce the amount of content remaining and prevent the content from coming into contact with the outside air.

The dual container of the present disclosure includes:
a bottle-shaped outer layer body having a mouth, a body, and a bottom;
A double container that is housed inside the outer layer body, and has an inner layer body that forms a storage space for contents and is deformable to reduce volume,
An outside air introduction hole is provided for introducing outside air into the space between the outer layer body and the inner layer body,
A cross section of the body at a predetermined height from the lower end of the bottom has a flat shape;
The thicknesses of the outer layer body and the inner layer body of the body at the ends in the major axis direction of the flat shape are greater than or equal to the thicknesses of the outer layer body and the inner layer body of the body at the ends in the minor axis direction, respectively ,
The thickness ratio of the lengthwise end of the inner layer body to the lengthwise end thereof is larger than the thickness ratio of the lengthwise end thereof to the breadthwise end of the outer layer body .

In the double container of the present disclosure, in the above configuration, the thickness of the body at the end in the major axis direction of the flat shape is 1.15 times or more and no more than 2.5 times the thickness of the body at the end in the minor axis direction. It is preferable that

In the double container of the present disclosure, in the above configuration, it is preferable that the flattened shape has an oblateness of 0.3 or more and 0.5 or less.

In the double container of the present disclosure, in the above configuration, it is preferable that the center axis of the mouth and the center axis of the body are spaced apart in the horizontal direction.

In the double container of the present disclosure, in the above configuration, it is preferable that an outside air introduction hole is formed in the bottom portion to introduce outside air between the outer layer body and the inner layer body.

In the double container of the present disclosure, in the above configuration, the inner layer body can be separated from the outer layer body over the entire circumference around the central axis of the body as the inner layer body undergoes volume reduction deformation. preferable.

According to the present disclosure, it is possible to provide a double-layered container that can reduce the amount of content remaining and prevent the content from coming into contact with the outside air.

FIG. 2 is a front partial cross-sectional view showing a state in which a trigger-type liquid ejector is attached to the mouth of a double container according to an embodiment of the present disclosure. It is an enlarged view of part B in FIG. 1A. FIG. 2 is a front view of a double container according to an embodiment of the present disclosure. FIG. 2 is a partial cross-sectional view of the bottom of a double container according to an embodiment of the present disclosure. FIG. 3 is a diagram showing the relationship between measurement position and thickness in a double container according to an embodiment of the present disclosure.

Hereinafter, the configuration of a double container 1 according to an embodiment of the present disclosure will be illustrated in detail with reference to the drawings.

Note that in this specification and claims, the vertical direction refers to the vertical direction when the double container 1 is in an upright position as shown in FIG. 1A. Further, the side where the nozzle 5 is provided is referred to as the front (left side in FIG. 1A), and the opposite side is referred to as the rear (right side in FIG. 1A). Further, the direction perpendicular to the up-down direction and the front-back direction (the direction perpendicular to the paper surface in FIG. 1A) is defined as the left-right direction. In addition, the radial direction refers to a direction along a straight line passing through the central axis O1 (see FIG. 2) and perpendicular to the central axis O1 with respect to the mouth 11 of the double container 1. Regarding the body 12 of the double container 1, this refers to a direction along a straight line passing through the central axis O2 (see FIG. 2) and perpendicular to the central axis O2.

As shown in FIGS. 1A to 3, a double container 1 according to an embodiment of the present disclosure includes an outer layer body 10 constituting an outer shell of the double container 1, and an inner layer housed inside the outer layer body 10. It has a double structure with a body 20.

The outer layer body 10 includes a substantially cylindrical opening 11, a shoulder 14 that extends downward in diameter and extends downwardly from the lower end of the opening 11, and a content storage space S that extends from the lower end of the shoulder 14 (see FIG. 1B). It has a bottle shape including a body 12 forming a body (see ) and a bottom 13 that is continuous with the lower end of the body 12 and closes the lower end of the body 12 . As shown in FIG. 1A, the front part of the shoulder part 14 has a grip part 14a that is recessed toward the rear and is used by the user to grip the double container 1 with his or her middle finger or the like when spouting the contents from the nozzle 5. is provided. The body portion 12 is provided with recesses 12a, one on each side, to which a label or the like is attached.

In this embodiment, the double container 1 has a flat shape in which the trunk 12 and the bottom 13 are long in the front-rear direction when viewed from above (see FIG. 3). Then, the center axis O2 (see FIG. 2) of the body 12 is shifted forward with respect to the center axis O1 (see FIG. 2) of the mouth 11 of the double container 1, and the body 12 is made to protrude forward. In addition to securing the amount, the weight balance with the trigger type liquid ejector 2, operability, and storability are also ensured.

The inner layer 20 is thinner and more flexible than the outer layer 10 and is formed into a bag shape, and is removably laminated on the inner surface of the outer layer 10. The opening of the inner layer body 20 is connected to the open end of the mouth portion 11 of the outer layer body 10, and the inside thereof is a housing space S that is connected to the opening. The storage space S can store liquid contents such as a mold remover, a detergent, a starch agent for clothing, a household wax, a hair conditioner, and an aromatic agent. The inner layer body 20 can be deformed to reduce its volume, and as the contents are poured out from the storage space S to the outside, it can be deformed so as to peel off from the outer layer body 10 and reduce its internal volume.

In this embodiment, the body portion 12 is configured to have a flat shape in which the longitudinal direction (the left-right direction in FIGS. 1A and 2) has a longer diameter in a cross section (a cross section taken on a plane perpendicular to the central axis O2). In addition, in normal extrusion blow molding, the wall thickness tends to be thicker at the shorter diameter end of the flat shape because the degree of elongation is smaller, but in this embodiment, the manufacturing process investigated by the inventor By adopting the structure, the thickness of the body 12 at the ends in the major axis direction (sections C and G in FIG. 3) is greater than or equal to the thickness at the ends in the minor axis direction (sections A and E in FIG. 3). There is. With this configuration, the rigidity at the short diameter end portions (sections A and E in FIG. 3) of the body portion 12 having a small wall thickness is reduced, so that the inner layer body 20 easily peels off from the outer layer body 10. In this way, by making the inner layer body 20 easy to peel off at the ends in the short diameter direction, the flat shape of the inner layer body 20 is deformed in a direction that further increases the oblateness, and the accommodation space S is maintained in a state extending in the long diameter direction. can do. Therefore, it is possible to maintain a state in which the storage space S filled with the contents is arranged adjacent to both sides in the longitudinal direction of the pipe for sucking up the contents hanging from the trigger type liquid ejector 2. Therefore, it is possible to prevent the contents from remaining in the accommodation space S without being poured out due to distortion and deformation of the inner layer body 20.

In this embodiment, the thickness of the trunk 12 at the end in the major axis direction at the height position where the maximum diameter of the trunk 12 is reached (the total thickness of the outer layer 10c and the inner layer 20c in FIG. 3, and the total thickness of the outer layer 10g and the inner layer 20g) ) is 1.15 times or more the thickness of the body 12 at the end in the minor axis direction (the total thickness of the outer layer 10a and the inner layer 20a in FIG. 3, and the total thickness of the outer layer 10e and the inner layer 20e) It is configured to be 2.5 times or less. By setting the thickness ratio to 1.15 times or more in this way, the rigidity of the body part 12 at the ends in the short axis direction (sections A and E in FIG. 3) can be lowered, so that at the ends in the short axis direction The inner layer body 20 can be easily peeled off. Further, by setting the thickness ratio to 2.5 times or less, the thickness deviation can be suppressed within an appropriate range and the mechanical rigidity of the double container 1 can be ensured. In the illustrated example, the height position of the maximum diameter in the body part 12 is a height position of 40 mm from the ground plane (outer edge part 13a) of the bottom part 13 (height position of point g in FIG. 2). There is.

Further, in this embodiment, the flattened shape has an oblateness of 0.3 or more and 0.5 or less at the height position of the body portion 12 where the diameter is the maximum. Here, the oblateness is an index showing how flat the flat shape is with respect to the circle (or flattened).If the major axis of the flat shape is a and the minor axis is b, then the oblateness F can be expressed by the following formula (1).

As a result of intensive studies by the inventors, the flattened shape of the body 12 can be easily maintained by setting the flatness F of the body 12 to 0.3 or more. Further, by setting the flatness factor F to 0.5 or less, it is possible to facilitate molding into a flat shape by extrusion blow molding of synthetic resin.

The bottom portion 13 has a concave portion 13b that is recessed upward on the inner peripheral side of an annular outer edge portion 13a that serves as a ground surface, and a pinch-off portion 15 is provided in a portion of the concave portion 13b. The pinch-off portion 15 is formed when the double container 1 is formed by extrusion blow molding, when a cylindrical laminated parison is crushed and cut off by a blow molding die to close its opening. There is. Therefore, the double container 1 has a structure in which the outer layer body 10 and the inner layer body 20 are laminated even in the pinch-off portion 15.

The pinch-off portion 15 projects downward from the recess 13b and has a ridge shape that passes through the approximate center of the recess 13b and extends straight in the front-rear direction. The thickness of the pinch-off portion 15 in the front-rear direction gradually decreases downward, and the height of the pinch-off portion 15 protruding downward from the recess 13b is within the depth of the recess 13b. This prevents the lower end surface 15a of the pinch-off portion 15 from protruding below the outer edge 13a serving as the ground surface when the double container 1 is placed in an upright position. It can be installed stably.

In the example of FIG. 1A, a pump is actuated by driving the trigger part 4 in the front-rear direction, and the contents stored in the storage space S of the double container 1 are ejected into the mouth part 11 of the outer layer body 10. A trigger-type liquid ejector 2 is installed to eject liquid from a nozzle 5 via a main body 6. The trigger-type liquid ejector 2 is attached to the double container 1 by screwing the cap 3 into a male thread 11a (see FIG. 2) provided at the mouth 11 of the double container 1.

Note that each component of the trigger type liquid ejector 2 can be a molded product using, for example, synthetic resin.

In this embodiment, the pinch-off portion 15 in the bottom portion 13 of the outer layer body 10 is provided with a slit that functions as an outside air introduction hole. When the contents are ejected from the nozzle 5 by actuation of the trigger part 4, the outer layer body 10 maintains its initial shape due to its own rigidity, while the outer layer body 10 and the inner layer body 20 are connected to each other through a slit serving as an outside air introduction hole in the bottom part 13. By introducing outside air into the space between them, the inner layer body 20 accommodating the contents can be peeled off from the outer layer body 10 and deformed to reduce its volume. As a result, it is possible to prevent outside air from entering the accommodation space S of the inner layer body 20 after the contents have been ejected, so that it is possible to prevent the contents from coming into contact with outside air and deteriorating/changing in quality.

Note that, in place of the trigger-type liquid ejector 2, another spouting tool (not shown) such as a spouting cap provided with a check valve for spouting may be attached. Further, the spouting tool may be attached, for example, by screw connection using the male threaded portion 11a provided in the mouth portion 11, or by undercut engagement using a stopper. Further, the outside air introduction hole may be provided in the mouth portion 11 or the like instead of being provided in the bottom portion 13.

In this embodiment, the double container 1 is formed by extrusion blow molding a parison formed by laminating the synthetic resin material of the inner layer body 20 and the synthetic resin material of the outer layer body 10 to form a laminated peelable container. ing. The material of the inner layer body 20 constituting the double container 1 is a two-layer structure of nylon/adhesive polyolefin from the outer layer side. Furthermore, the outer layer body 10 is made of high-density polyethylene resin (HDPE). When HDPE is used for the outer layer body 10, it is possible to impart high rigidity that makes it difficult for the inner layer body 20 to deform even if the inner layer body 20 undergoes volume reduction deformation. In this embodiment, HIZEX (manufactured by Prime Polymer Co., Ltd.) is used as the HDPE. Furthermore, NOVAMID (manufactured by Mitsubishi Chemical Corporation) is used as the nylon, and ADMER (manufactured by Mitsui Chemicals Corporation) is used as the adhesive polyolefin. However, the present invention is not limited to this embodiment, and the material of the inner layer body 20 may be ethylene-vinyl alcohol copolymer resin (EVOH) or the like. Further, as the material of the outer layer body 10, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), etc. can also be used instead of high density polyethylene resin (HDPE). Further, the outer layer body 10 may be a laminate made of a plurality of resins but not peeled off. In addition, when forming a laminated container by performing biaxial stretch blow molding, for example, polypropylene (PP) is used as the material for the inner layer 20 and polyethylene terephthalate (PET) is used as the material for the outer layer 10. You can. Moreover, other resins having low compatibility with each other can be used for the materials of the inner layer body 20 and the outer layer body 10. Furthermore, the double container 1 may be one in which the outer layer body 10 and the inner layer body 20 are separately formed and assembled, instead of being a laminated peelable container.

In addition, the thickness of the inner layer body 20 is made thinner than the thickness of the outer layer body 10 so that it may mention later.

The double container 1 having the above structure is formed by co-extruding a synthetic resin layer having a layer structure corresponding to the outer layer body 10 and a synthetic resin layer having a layer structure corresponding to the inner layer body 20 to form a cylindrical laminated parison. By extrusion blow molding this laminated parison using a left-right split mold, a laminated peelable container is constructed in which the inner layer 20 is releasably laminated on the inner surface of the outer layer 10. In addition, the mold used for extrusion blow molding is not limited to a left-right split type, but any mold that can be divided into at least two or more parts, such as a mold that is divided into three directions or a mold that is divided into four directions. A mold or the like may also be used.

In this embodiment, the double container 1 has a structure in which no adhesive band layer is provided between the outer layer body 10 and the inner layer body 20 to bond the outer layer body 10 and the inner layer body 20 to each other. With this configuration, the inner layer body 20 can be peeled off from the outer layer body 10 over the entire circumference of the body portion 12, but in this embodiment, as described above, the lengthwise end of the body portion 12 having a flat cross section The thickness of the body part 12 at the ends (parts C and G in FIG. 3) of the body part 12 is greater than or equal to the thickness of the body part 12 at the ends of the body part 12 in the short axis direction (parts A and E in FIG. 3). are doing. With this configuration, the rigidity at the shorter diameter end portions of the body portion 12 (sections A and E in FIG. 3), which have a thinner wall thickness, is reduced, so that the inner layer body 20 is likely to peel off from the outer layer body 10 at the short diameter end portions. Become. Therefore, even without providing an adhesive band layer for bonding the outer layer 10 and the inner layer 20 to each other, the inner layer 20 can be easily peeled off from the outer layer 10 at the ends of the short axis direction of the body 12, and the flatness of the inner layer 20 can be reduced. It can be deformed to reduce its volume in the direction of increasing. Therefore, even without providing an adhesive band layer, it is possible to prevent the contents from remaining inside the inner layer body 20 without being poured out.

Although it has been described that the inner layer 20 can be separated from the outer layer 10 over the entire circumference around the central axis O2 of the trunk 12 as the inner layer 20 is deformed to reduce its volume, the separation in this embodiment is as follows. This is lamination delamination between the outer layer body 10 and the inner layer body 20. Furthermore, "the inner layer body 20 can be separated from the outer layer body 10 over the entire circumference" means that the outer layer body 10 and the inner layer body 20 are configured without an adhesive band layer for bonding them to each other. This does not mean that the inner layer 20 is uniformly peeled off from the outer layer 10 over the entire circumference.

As described above, this embodiment includes a bottle-shaped outer layer body 10 having a mouth portion 11, a body portion 12, and a bottom portion 13, and a bottle-shaped outer layer body 10 that is housed inside the outer layer body 10 to form a storage space S for contents. The double container 1 has an inner layer body 20 that can be deformed to reduce its volume, and an outside air introduction hole for introducing outside air into the space between the outer layer body 10 and the inner layer body 20 is provided, and a predetermined opening is provided from the lower end of the bottom portion 13. The cross section of the body part 12 at the height position has a flat shape, and the thickness of the body part 12 at the end in the major axis direction of the flat shape is greater than or equal to the thickness of the body part 12 at the end in the minor axis direction. . By employing such a configuration, the rigidity decreases at the ends in the short diameter direction of the body section 12 where the wall thickness is thin, so that the inner layer body 20 is likely to peel off from the outer layer body 10 at the end portions. In this way, by making the inner layer body 20 easy to peel off at the ends in the short diameter direction, the flat shape of the inner layer body 20 is deformed in a direction that further increases the oblateness, and the accommodation space S is maintained in a state extending in the long diameter direction. can do. Therefore, it is possible to prevent the contents from remaining in the storage space S without being poured out due to inappropriate distortion and deformation of the inner layer body 20. Moreover, when the contents are ejected, outside air is introduced into the space between the outer layer body 10 and the inner layer body 20 from the outside air introduction hole, and the inner layer body 20 is deformed to reduce its volume. Therefore, it is possible to prevent outside air from entering the inner layer body 20 and touching the contents.

Further, in the present embodiment, the thickness of the body 12 at the ends in the major axis direction of the flat shape is 1.15 times or more and no more than 2.5 times the thickness of the body part 12 at the ends in the minor axis direction. . By setting the above-mentioned thickness ratio to 1.15 times or more, the inner layer body 20 at the shorter diameter direction end can be made to peel more easily than the inner layer body 20 at the longer diameter direction end. Furthermore, by setting the thickness ratio to 2.5 times or less, excessive thickness deviation in the double container 1 can be suppressed, so that the mechanical rigidity of the double container 1 can be ensured.

Further, in this embodiment, the flatness of the flat shape of the body portion 12 is configured to be 0.3 or more and 0.5 or less. By setting the oblateness F of the body portion 12 to 0.3 or more, it is possible to easily maintain the flat shape. On the other hand, by setting the flatness factor F to 0.5 or less, it is possible to facilitate molding into a flat shape by extrusion blow molding of synthetic resin.

Further, in this embodiment, the center axis O1 of the mouth portion 11 and the center axis O2 of the body portion 12 are configured to be separated from each other in the horizontal direction. By adopting such a configuration, by making the body 12 protrude forward, it is possible to ensure the capacity that can be stored in the storage space S, and also to ensure the weight balance with the trigger type liquid ejector 2, operability, and storage. be able to.

Further, in this embodiment, the bottom portion 13 is configured to have an outside air introduction hole for introducing outside air between the outer layer body 10 and the inner layer body 20. By adopting such a configuration, the pinch-off part 15 formed in the bottom part 13 is used to provide the outside air introduction hole when the double container 1 is manufactured by extrusion blow molding, so that the outside air can be newly introduced into the mouth part 11 etc. There is no need to place holes.

Further, in this embodiment, the inner layer body 20 is configured to be able to be separated from the outer layer body 10 over the entire circumference around the central axis O2 of the trunk portion 12 as the inner layer body 20 undergoes volume reduction deformation. By adopting such a configuration, it is possible to create a configuration in which no adhesive band layer is provided between the outer layer body 10 and the inner layer body 20 to bond them to each other, so that the manufacturing cost of the double container 1 can be suppressed, The manufacturing process can be simplified.

Although the present disclosure has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various changes and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications are included within the scope of the present invention. For example, functions included in each component can be rearranged so as not to be logically contradictory, and a plurality of components can be combined into one or divided. It is to be understood that these are also included within the scope of the present invention.

For example, in this embodiment, the outside air introduction hole is provided in the bottom portion 13, but the outside air introduction hole may be provided in a portion other than the bottom portion 13, such as the mouth portion 11 or the body portion 12. The number and shape can also be changed in various ways.

Further, in this embodiment, the adhesive band layer is not provided between the outer layer body 10 and the inner layer body 20, but the present invention is not limited to this embodiment. An adhesive band layer may also be provided. Alternatively, only one adhesive band layer may be provided.

Further, although the double container 1 has a structure in which a trigger type liquid ejector 2 equipped with a pump is attached to the mouth portion 11 and the contents are poured out by operating the pump, the present invention is not limited to this embodiment. The content may be poured out by squeezing the body 12, or the content stored in the storage space S of the inner layer 20 may be poured out by tilting the outer layer 10 so that the mouth 11 faces downward. A configuration may also be adopted in which the liquid is poured out from the mouth part 11 by its own weight. When the body 12 is squeezed to pour out the contents, a flexible material may be used as the outer layer 10.

In the present embodiment, the cross section of the body portion 12 is configured to have a flat shape, but this flat shape may include, in addition to the shape shown in FIG. It may be in the shape of

In order to confirm the effect of the double container 1 of this embodiment, the double container 1 shown in FIGS. 2 and 3 was manufactured as a prototype. In FIG. 4, the wall thicknesses at portions A, E, C, and G in FIG. 2 are plotted at each measurement position a to l shown in FIG. Note that the height position at which the maximum diameter of the body part 12 is reached (in the example, the height position of 40 mm from the ground plane (outer edge part 13a) of the bottom part 13) is the measurement position g in FIG. The width in the front-rear direction (width in the left-right direction in FIG. 2) of the trunk 12 at measurement position g is 100 mm, and the width in the left-right direction (width in the direction perpendicular to the plane of the paper in FIG. 2) is 55.7 mm. Therefore, the flatness F at the measurement position g is 0.443. The weight of the double container 1 is approximately 25 g.

According to FIG. 4, the outer layer body 10 and the inner layer body 20 are different from the A section and E section of FIG. It can be seen that the thickness is increased in both cases. In normal extrusion blow molding, the wall thickness tends to be thinner at the ends in the longer diameter direction than the ends in the short diameter direction because the distance from the center axis O2 is longer and the degree of stretching during extrusion blow molding is greater. The double container 1 according to this embodiment is configured such that the end portion in the major axis direction is thicker than the end portion in the minor axis direction. With such a configuration, the rigidity at the end portion in the short diameter direction of the body portion 12 having a thin wall is reduced, so that the inner layer body 20 is easily peeled off from the outer layer body 10. In this way, by making the inner layer body 20 easy to peel off at the ends in the short diameter direction, the flat shape of the inner layer body 20 is deformed in a direction that further increases the oblateness, and the accommodation space S is maintained in a state extending in the long diameter direction. can do. Therefore, it is possible to prevent the contents from remaining in the storage space S without being poured out due to inappropriate distortion and deformation of the inner layer body 20.

Further, according to FIG. 4, there is a noticeable difference in wall thickness between the measurement positions f, g, and h corresponding to the body 12 at any circumferential position of the A section, E section, C section, and G section. It is considered that the ease of peeling of the inner layer 20 does not depend much on the height position of the body 12 at the same circumferential position. Furthermore, the body portion 12 tends to have a thinner wall thickness than the mouth portion 11 because the degree of stretching during extrusion blow molding is greater than that of the mouth portion 11 (corresponding to measurement position a).

Table 1 below summarizes the thickness of the body portion 12 at the measurement position g in FIG. In Table 1, the "average of the ends in the short axis direction" indicates the average value of the thickness in parts A and E in FIG. The average value of the thickness is shown. According to Table 1, in each of the outer layer body, the inner layer body, and the entire body (the total of the outer layer body and the inner layer body), the thickness at the major axis direction end portion is larger than the thickness at the minor axis direction end portion. The thickness of the body 12 at the end in the major axis direction (the total thickness of the outer layer and the inner layer) was 1.393 times the thickness of the body 12 at the end in the minor axis direction.

Regarding the above-described double container 1, the storage space S of the inner layer body 20 was filled with the contents, and the trigger type liquid ejector 2 was attached to the mouth part 11 to conduct an ejection test. The inner layer 20 in the double container 1 is peeled off at each stage: "initial stage" when the contents are used, "middle stage" when about half of the contents are used, and "final stage" when there is only a small amount of the contents remaining. When the state was confirmed, from the "initial stage" to the "middle stage", peeling of the inner layer body 20 was not observed much, and volume reduction deformation occurred in the direction of further increasing the flatness of the outer layer body 10. This is because the volume reduction deformation of the inner layer body 20 is still small from the "initial stage" to the "middle stage", and the negative pressure in the space between the outer layer body 10 and the inner layer body 20 is small, so that sufficient outside air is supplied through the outside air introduction hole. It is considered that as a result of not introducing the outer layer body 10, the outer layer body 10 deforms following the volume reduction deformation of the inner layer body 20.

On the other hand, from the "middle stage" to the "final stage", most of the contents in the inner layer body 20 are used, the volume reduction deformation of the inner layer body 20 becomes large, and the difference between the outer layer body 10 and the inner layer body 20 increases. The negative pressure generated in the space between them increases. As a result, the outside air is introduced through the outside air introduction hole, so that the outer layer body 10 restores its original shape due to its own rigidity.

As a result of studies conducted by the inventor, the thickness of the body 12 at the ends in the major axis direction of the flat shape is 1.15 times or more the thickness of the body part 12 at the ends in the minor axis direction, thereby reducing the inner layer at the ends in the minor axis direction. The body 20 can be peeled off more easily than the inner layer body 20 at the longitudinal end. Furthermore, by making the thickness of the body 12 at the end in the major axis direction of the flat shape 2.5 times or less than the thickness of the body 12 at the end in the minor axis direction, excessive thickness deviation in the double container 1 is suppressed. Therefore, the mechanical rigidity of the double container 1 can be ensured. Therefore, it is preferable that the thickness of the body part 12 at the end in the major axis direction of the flat shape is 1.15 times or more and not more than 2.5 times the thickness of the body part 12 at the end in the minor axis direction.

Further, as a result of studies conducted by the inventor, the flattened shape can be easily maintained by setting the flattening factor F of the body portion 12 to 0.3 or more. Further, by setting the flatness factor F to 0.5 or less, it is possible to facilitate molding into a flat shape by extrusion blow molding of synthetic resin. Therefore, it is preferable that the flatness factor F of the flat shape of the body portion 12 is 0.3 or more and 0.5 or less.

1 Double container 2 Trigger type liquid ejector 3 Cap 4 Trigger part 5 Nozzle 6 Ejector main body 10, 10a, 10c, 10e, 10g Outer layer body 11 Mouth part 11a Male thread part 12 Body part 12a Recess 13 Bottom part 13a Outer edge part 13b Concave portion 14 Shoulder portion 14a Gripping portion 15 Pinch-off portion 15a Lower end surface 20, 20a, 20c, 20e, 20g Inner layer body O1, O2 Center axis S Accommodation space

Claims (6)

a bottle-shaped outer layer body having a mouth, a body, and a bottom;
A double container that is housed inside the outer layer body, and has an inner layer body that forms a storage space for contents and is deformable to reduce volume,
An outside air introduction hole is provided for introducing outside air into the space between the outer layer body and the inner layer body,
A cross section of the body at a predetermined height from the lower end of the bottom has a flat shape;
The thicknesses of the outer layer body and the inner layer body of the body at the ends in the major axis direction of the flat shape are greater than or equal to the thicknesses of the outer layer body and the inner layer body of the body at the ends in the minor axis direction, respectively ,
A double container characterized in that a wall thickness ratio of the longer diameter end to the shorter diameter end of the inner layer body is larger than a wall thickness ratio of the longer diameter end to the shorter diameter end of the outer layer body. The double container according to claim 1, wherein the thickness of the body at the end in the major axis direction of the flat shape is 1.15 to 2.5 times the thickness of the body at the end in the minor axis direction. . The double container according to claim 1 or 2, wherein the flattened shape has an oblateness of 0.3 or more and 0.5 or less. The double container according to any one of claims 1 to 3, wherein the central axis of the mouth and the central axis of the body are spaced apart in the horizontal direction. The double container according to any one of claims 1 to 4, wherein an outside air introduction hole is formed in the bottom portion to introduce outside air between the outer layer body and the inner layer body. 6. The inner layer body according to claim 1, wherein the inner layer body can be separated from the outer layer body over the entire circumference around the central axis of the body as the inner layer body undergoes volume reduction deformation. double container.

Images