CN114502475A

CN114502475A - Storage container and method for manufacturing same, double container and method for manufacturing same

Info

Publication number: CN114502475A
Application number: CN202080068814.2A
Authority: CN
Inventors: 仓桥雄飞; 樽野真辅
Original assignee: Kyoraku Co Ltd
Current assignee: Kyoraku Co Ltd
Priority date: 2019-10-31
Filing date: 2020-10-26
Publication date: 2022-05-13
Also published as: WO2021085374A1

Abstract

The invention provides a storage container with excellent appearance. According to the present invention, there is provided a storage container including a container body integrally formed with an outer cover so as to cover an outer peripheral surface of an inner container, the outer cover being injection-molded, the inner container including an outermost layer and an adjacent layer adjacent to the outermost layer, a melting point of an outermost layer resin constituting the outermost layer being lower than a melting point of an adjacent layer resin constituting the adjacent layer.

Description

Storage container and method for manufacturing same, double container and method for manufacturing same

Technical Field

The present invention relates to a storage container capable of storing contents and a method for manufacturing the same, and a double container and a method for manufacturing the same.

Background

(viewpoint 1)

Today, there is known a laminate peel-off container which suppresses entry of air into the interior of the container by reducing shrinkage of an inner bag with contents (for example, patent document 1).

(viewpoint 2)

A double container (a delamination container) having an outer shell and an inner bag and capable of containing contents in the inner bag is known (for example, patent document 2). The outer case is depressible from the outside, and the contents stored in the inner bag are discharged from the mouth by the depression. After the pressing, air is introduced between the outer case and the inner bag through a check valve provided in the outer case, so that the shape of the outer case is restored and the inner bag gradually collapses.

(viewpoint 3)

Patent document 3 discloses a method for manufacturing a double container by blow molding in a state where an inner preform and an outer preform are overlapped.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-163531

Patent document 2: japanese patent laid-open publication No. 2018-087036

Patent document 3: WO2004/071887

Disclosure of Invention

(problems to be solved by the invention)

(viewpoint 1)

The laminated and peeled container of patent document 1 is formed by covering the outer peripheral surface of a container formed by blow molding with a shrink film, but a design that more exhibits a high-grade feeling may be required.

The present invention has been made in view of the above circumstances, and provides a storage container having an excellent appearance.

(viewpoint 2)

However, in the conventional technique described in patent document 2, since the air inlet hole through which the check valve is inserted is located in the vicinity of the mouth portion, it is necessary to introduce air upward from below the container immediately after the contents are taken out, and therefore, the efficiency is not good.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a two-layer container in which an inner bag is more effectively peeled from an outer shell after taking out contents.

(viewpoint 3)

The inner preform constitutes an inner bag and the outer preform constitutes an outer shell. The inner bag shrinks as the content in the inner bag decreases, but the outer shell can maintain its original state by introducing external air into the intermediate space between the inner bag and the outer shell through an external air introduction hole provided in the outer shell.

In the double container, the inventors of the present invention have found that it is difficult to introduce the external air into the intermediate space between the inner bag and the outer shell when the external air introduction hole is provided in the bottom portion of the container in consideration of the appearance and the like.

The present invention has been made in view of the above circumstances, and provides a double container which can smoothly introduce external air into an intermediate space between an inner bag and a housing even when an external air introduction hole is provided in a bottom portion of a container body.

(means for solving the problems)

(viewpoint 1)

According to the present invention, there is provided a storage container including a container body integrally formed with an outer cover so as to cover an outer peripheral surface of an inner container, the outer cover being an injection-molded body, the inner container including an outermost layer and an adjacent layer adjacent to the outermost layer, a melting point of an outermost layer resin constituting the outermost layer being lower than a melting point of an adjacent layer resin constituting the adjacent layer.

The housing container of the present invention has an excellent appearance because the outer case made of an injection molded body is integrally molded with the outer peripheral surface of the inner container. Further, since the melting point of the outermost resin is lower than that of the adjacent layer resin, the thermal energy of the molten resin used to injection mold the jacket is less likely to be transmitted to the inner container, thereby suppressing deformation of the inner container. In addition, since the melting point of the resin of the outermost layer is lower than that of the resin of the adjacent layer, the adhesion between the outer jacket and the outermost layer is improved, and the peeling of the adhesion surface between the outer peripheral surface of the inner container and the outer jacket due to an impact such as dropping is suppressed.

Various embodiments of the present invention are described below. The embodiments shown below may be combined with each other.

Preferably, the difference between the melting point of the outermost resin layer and the melting point of the adjacent resin layer of the storage container is 5 ℃ or more.

Preferably, the outermost layer has a thickness of 10% or more of the thickness of the inner container of the storage container.

Preferably, the outermost resin of the storage container contains an unmodified polyolefin.

Preferably, the outermost resin of the storage container contains an acid-modified polyolefin and the unmodified polyolefin.

Preferably, the resin constituting the outer jacket of the storage container has the same monomer unit as the outermost resin.

Preferably, the inner container of the storage container is configured to have an outer shell and an inner bag, and the inner bag shrinks as the content decreases, and the outermost layer and the adjacent layer are provided on the outer shell.

Preferably, the method of manufacturing the storage container includes an integral molding step of integrally molding an inner container and an outer jacket, wherein in the integral molding step, the outer jacket is formed by filling a resin into a space outside the inner container in a cavity of a mold in a state where an outer peripheral surface of the inner container is disposed in the mold, the inner container includes an outermost layer and an adjacent layer adjacent to the outermost layer, and a melting point of an outermost layer resin constituting the outermost layer is lower than a melting point of an adjacent layer resin constituting the adjacent layer.

Preferably, the method includes pressurizing the inner container during the integral molding step.

In the integral molding step of the method, the resin is preferably filled in a state where an inner surface of a bottom surface of the inner container is pressed by a support rod inserted into the inner container.

(viewpoint 2)

According to one aspect of the present invention, there is provided a double container comprising an outer shell configured to be pressed from outside and to allow contents contained in an inner bag to flow out from a mouth portion by the pressing, an outside air introduction hole provided in a specific region on a bottom side of the outer shell, the bottom side being a side that is separated from the mouth portion by halving in a height direction of the double container and configured to be fitted with a check valve, and the double container is configured such that, after the contents flow out, air is introduced into an intermediate space between an inside of the outer shell and an outside of the inner bag to restore the outer shell to a shape, and the inner bag is configured such that the air introduced into the intermediate space is compressed when the contents decrease.

The double container has an advantageous effect that the inner bag can be efficiently peeled from the outer case immediately after the contents are taken out, by providing the specific region where the air introduction hole is provided on the bottom side of the outer case.

(viewpoint 3)

According to the present invention, there is provided a double container comprising a container body having an outer shell and an inner bag and shrinking the inner bag with a decrease in content, wherein the container body comprises a cylindrical trunk portion and a bottom portion provided at a lower end of the trunk portion, the bottom portion comprises a central recess provided at a center of the bottom portion and a peripheral edge portion surrounding the central recess, an external air introduction hole is provided in the outer shell in the central recess, and a spacer member for forming a gap between the outer shell and the inner bag is provided in the peripheral edge portion.

The present invention has been made in detail, and it has been found that when a central recessed portion is provided in the bottom portion of a container body, it is difficult to form a gap between an inner bag and an outer case at a peripheral portion around the central recessed portion, and therefore, when an outside air introduction hole is provided in the central recessed portion, it is difficult to introduce outside air into a trunk portion of the container body. Further, based on the finding, the present inventors have found that the external air can be smoothly introduced into the trunk portion from the external air introducing hole in the bottom portion through the peripheral portion by providing the spacer member for forming the gap between the outer case and the inner bag, and have completed the present invention.

Various embodiments of the present invention are described below. The embodiments shown below can be combined with each other.

Preferably, the spacer member of the double container is a protrusion provided on the outer shell or the inner bag.

Preferably, the partition members of the double container are arranged in a radial shape.

Preferably, the spacing members of the double container are configured to form a non-continuous circle.

Preferably, the container body of the double container is blow molded by heating an inner preform constituting the inner bag and an outer preform constituting the outer shell while covering the inner preform and the outer preform.

Preferably, the inner preform of the double container has a positioning pin at a bottom of the inner preform, the outer preform has a positioning hole at a bottom of the outer preform, and the blow molding is performed in a state where the positioning pin is inserted into the positioning hole.

Drawings

Fig. 1 is a perspective view of a storage container 101 according to embodiment 1 of point 1.

Fig. 2 is a perspective view of the container body 102.

Fig. 3 is a cross-sectional view of the container body 102.

Fig. 4 shows the layer structure of the container body 102 in the area a in fig. 3.

Fig. 5 is a perspective view of the inner container 104.

Fig. 6 is a cross-sectional view of the inner container 104.

Fig. 7 is a sectional view for explaining the integral molding process.

Fig. 8 is an enlarged view in the area B in fig. 7.

Fig. 9 is a perspective view of the storage container 101 according to embodiment 2, viewed from different directions, as shown in fig. 9A to 9B.

Fig. 10 is a cross-sectional view of the container body 102 of fig. 9A.

Fig. 11 shows the layer structure of the container body 102 in the region C in fig. 10.

Fig. 12 is a sectional view showing only the inner container 104 of fig. 10.

Fig. 13 is a perspective view of the pump 112.

Fig. 14 is an enlarged view showing the vicinity of the mouth portion 108 of fig. 5 in a state where the outside air introducing portion 115 is provided in the mouth portion 108 of the inner container 104 in embodiment 3.

Fig. 15 is a perspective view showing the double container 1 according to embodiment 1 of viewpoint 2.

Fig. 16 shows a state where the cover 30 is removed from the state of fig. 15.

Fig. 17 is a front view and a back view of the double container 1 according to embodiment 1 of point 2.

Fig. 18 shows a state where the cover 30 is removed from fig. 17.

Fig. 19 is a left side view and a right side view of the double container 1 according to embodiment 1 of point 2.

Fig. 20 shows a state where the cover 30 is removed from the state of fig. 19.

Fig. 21 is a top view and a bottom view of the double container 1 according to embodiment 1 of point 2.

Fig. 22 shows a state where the cover 30 is removed from the state of fig. 21.

Fig. 23 is an end view of the internal structure of the double container 1 according to embodiment 1 of point 2.

Fig. 24 shows the detailed structure of the check valve 6.

Fig. 25 is a perspective view of the double container 1 according to embodiment 2 of point 2.

Fig. 26 shows a state where the cover 30 is removed from the state of fig. 25.

Fig. 27 is a front view and a back view of the double container 1 according to embodiment 2 of point 2.

Fig. 28 shows a state where the cover 30 is removed from the state of fig. 27.

Fig. 29 is a left side view and a right side view of the double container 1 according to embodiment 2 of point 2.

Fig. 30 shows a state where the cover 30 is removed from the state of fig. 29.

Fig. 31 is a top view and a bottom view of the double container 1 according to embodiment 2 of point 2.

Fig. 32 shows a state where the cover 30 is removed from the state of fig. 31.

Fig. 33 is an end view showing the internal structure of the double container 1 according to embodiment 2 of point 2.

Fig. 34 shows a container main body 202 of a double container 201 according to embodiment 1 of viewpoint 3 of the present invention, fig. 34A is a front view, and fig. 34B is a bottom view.

In fig. 35, fig. 35A is a perspective view of the container main body 202 of fig. 34 viewed from the bottom 207, and fig. 35B is a sectional perspective view of the vicinity of the bottom 207 of the housing 203 viewed from the inside of the container.

In fig. 36, fig. 36A is a sectional view a-a in fig. 34B, and fig. 36B is a sectional view B-B in fig. 36A.

Fig. 37 is a perspective view showing a state where the inner preform 214 and the outer preform 213 are separated from each other.

Figure 38 is a cross-sectional perspective view of the outer preform 213 near the bottom 213c of the outer preform 213 of figure 37, viewed from the inside of the outer preform 213.

In fig. 39, fig. 39A is a perspective view of an assembly 215 configured by covering an inner preform 214 with an outer preform 213, and fig. 39B is a perspective view when viewing fig. 39A from another angle.

Fig. 40 is a cross-sectional view showing a biaxial stretch blow molding process in which the module 215 is mounted on the mouth support mold 221.

Fig. 41 is a sectional view showing a state where the forming

molds

223 and 224 are closed from the state of fig. 40 and the bottom support mold 222 supports the bottom 213c of the outer preform 213.

Fig. 42 is a sectional view of a state where the support bar 225 is elongated from the state of fig. 41 while the bottom support mold 222 is retreated to extend the assembly 215 longitudinally.

Figure 43 shows an outer preform 213 with a protrusion 213c1 having a non-continuous circular shape, which is a cross-sectional perspective view corresponding to figure 38.

Fig. 44 is a perspective view of an inner preform 214 having a structure in which radial projections 214c2 are provided on a bottom portion 214 c.

Fig. 45 is a perspective view showing an inner preform 214 having a configuration in which a protrusion 214c2 is provided on a bottom portion 214c in a discontinuous circle.

Fig. 46 is an enlarged view of the vicinity of the bottom 214g of the inner preform 214 of the modification.

Detailed Description

The following describes embodiments of the present invention. Various feature items shown in the embodiments shown below may be combined with each other. And each feature may independently constitute the present invention.

(viewpoint 1)

1. Embodiment 1

As shown in fig. 1, a storage container 101 according to embodiment 1 of the present invention includes: a container body 102; such as the opening member 103 of the cover whose upper surface is planar. The opening member 103 may be a pump or a hinge cover, etc. As shown in fig. 3, the container body 102 includes an inner container 104 and an outer cover 105 integrally formed therewith. The respective configurations are explained below.

< inner container 104 >

The inner container 104 shown in fig. 5 to 6 may be a container formed by any manufacturing method, and among them, a blow molded container formed by blow molding from a parison is preferable. Blow molding may be direct blow molding or injection blow molding. In direct blow molding, a container is manufactured by sandwiching a parison extruded from an extruder in a molten state between a pair of split molds and blowing air into the parison. The parison may be cylindrical or sheet-like. In injection blow molding, a bottomed parison in the shape of a test tube called a preform is formed by injection molding, and the parison is then subjected to blow molding to produce a container.

The application of the present invention to the inner container 104 of a multi-layer structure is particularly important because it is not easy to manufacture an injection molded container of a multi-layer structure. In forming the multi-layer inner container 104, the parison also has a multi-layer construction. The parison of the multilayer structure (multilayer parison) may be formed by coextrusion molding.

The inner container 104 has a bottomed cylindrical shape, and includes a storage portion 107 for storing the contents and a mouth portion 108 for discharging the contents from the storage portion 107. The storage portion 107 includes a trunk portion 107a and a bottom portion 107 b. The opening 108 is provided with an engagement portion (male screw portion) 8a to which the plug member 103 can be attached.

When the inner container 104 is formed by direct blow molding, the inner container 104 has a pinch-off portion 107c (shown in fig. 6) formed by pressing a parison with a pair of split molds. The pinch-off portion 107c is provided at the bottom portion 107b of the inner container 104, and the bottom portion of the inner container 104 is closed by welding the parison-facing surfaces to each other at the pinch-off portion 107 c. The shape of the housing portion 107 may be various shapes such as a cylindrical shape, a polygonal prism shape, a polygonal cone shape, and a spherical shape.

As shown in fig. 4, the inner container 104 includes an outermost layer 104c1, an adjacent layer 104c2, and another layer 104c3 in this order from the outside of the inner container 104. Examples of the material constituting the inner container 104 include unmodified polyolefin, acid-modified polyolefin, EVOH, and the like. Examples of the polyolefin include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymers, and mixtures thereof.

The melting point of the outermost layer resin constituting the outermost layer 104c1 is lower than the melting point of the adjacent layer resin constituting the adjacent layer 104c 2. Although the thermal energy of the molten resin may soften and deform the inner container 104 when the outer jacket 105 is injection molded, when the melting point of the outermost resin is lower than that of the adjacent layer resin, the outermost resin is melted by the thermal energy of the molten resin, and at this time, the outermost resin absorbs the thermal energy, so that the thermal energy transmitted to the inner container 104 is reduced, and the deformation of the inner container 104 due to the injection pressure can be suppressed. Further, since the outermost layer 104c1 is easily melted, the adhesiveness between the outer jacket 105 and the outermost layer 104c1 can be improved, and the peeling of the adhesive surface between the outer peripheral surface of the inner container 104 and the outer jacket 105 due to an impact such as dropping can be suppressed. Note that, in the present specification, the "melting point" means a melting point according to JIS K7121: 2012 peak melting temperature Tpm.

The difference between the melting point of the outermost resin and the melting point of the resin of the adjacent layer is preferably 5 ℃ or higher, more preferably 10 ℃ or higher, and still more preferably 20 ℃ or higher. This is because the effect of suppressing deformation and improving adhesiveness is remarkable in this case. The difference in melting point is, for example, 5 to 50 ℃ and, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 ℃ or may be in the range of any 2 values shown here.

The melting point of the outermost resin is, for example, 90 to 130 ℃, preferably 100 to 120 ℃. The melting point may specifically be, for example, 90, 95, 100, 105, 110, 115, 120, 125, 130 ℃, or may be a range between any 2 of the values shown herein.

The outermost layer 104c1 preferably has a wall thickness of 10% or more, preferably 15% or more, and more preferably 20% or more, relative to the wall thickness of the inner container 104. This is because the effect of suppressing deformation and improving adhesiveness is remarkable in this case. The outermost layer 104c1 may have a thickness of, for example, 10 to 50% of the thickness of the inner container 104, specifically, 10, 15, 20, 25, 30, 35, 40, 45, 50%, or any range of 2 values as shown herein.

The outermost resin preferably contains polyolefin. The polyolefin may be an unmodified polyolefin or a modified polyolefin (e.g., an acid-modified polyolefin).

The outermost resin preferably contains an unmodified polyolefin. When the outermost resin is composed of only the modified polyolefin, the outermost layer 104c1 may be so tacky that the handleability of the inner container 104 becomes poor. As the unmodified polyolefin, polyethylene is preferable, and one or both of LDPE and LLDPE are more preferably contained. This is because the melting point of the outermost resin tends to be low in this case.

The outermost resin may also comprise an acid-modified polyolefin and an unmodified polyolefin. Since the acid-modified polyolefin has excellent adhesiveness, the outermost resin layer contains the acid-modified polyolefin and the unmodified polyolefin, and thus the adhesiveness between the outer jacket 105 and the inner container 104 can be improved while suppressing excessive stickiness. The content of the acid-modified polyolefin in the outermost resin is, for example, 5 to 95% by mass, preferably 30 to 70% by mass. The content may be specifically 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95% by mass, or may be in a range of any 2 values shown herein.

The adjacent layer 104c2 is a layer adjacent to the outermost layer 104c 1. The adjacent layer resin constituting the adjacent layer 104c2 may be any resin having a higher melting point than the outermost layer resin. For example, when the outermost resin is LDPE, HDPE or PP having a higher melting point than LDPE, or the like can be used as the adjacent layer resin. Further, as the adjacent layer resin, a regenerated resin obtained by recovering and reusing the flash generated in the previous production flow may be used. When the melting point of the resin forming any of the layers constituting the inner container 104 is higher than that of the outermost layer 104c1, the melting point of the recycled resin is generally higher than that of the outermost layer.

The thickness of the adjacent layer 104c2 is, for example, 5 to 70% of the thickness of the inner container 104, and specifically may be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70%, or may be in the range of any 2 values shown here.

The other layer 104c3 refers to a layer located closer to the inside of the inner container 104 than the adjacent layer 104c 2. The other layer 104c3 is preferably made of a resin having excellent heat resistance and rigidity, and may be made of, for example, a polypropylene resin. The other layer 104c3 may be omitted when not needed. The wall thickness of the adjacent layer 104c2 is preferably 20% or more relative to the wall thickness of the inner container 104. In this case, the other layer 104c3 may facilitate increasing the heat resistance or rigidity of the inner container 104. The thickness of the adjacent layer 104c2 is, for example, 0 to 70% of the thickness of the inner container 104, and specifically, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, and 70%, and may be in the range of any 2 values shown here.

The inner container 104 is a 6-layer multi-layer container such as 5 types, the specific layer composition of which is shown in the following manner, for example. The adhesive layer is a layer made of an adhesive resin such as acid-modified polypropylene.

[ TABLE 1 ]

As shown in table 2, the adjacent layer 104c2 may be a recycled resin layer. The recycled resin contains various resins constituting the outermost layer 104c1 and the other layer 104c3, and the melting point of the resin constituting the other layer 104c3 is higher than that of the outermost layer resin, so that the melting point of the recycled resin is also higher than that of the outermost layer resin.

[ TABLE 2 ]

< jacket 105 >

As shown in fig. 2 to 3, the outer jacket 105 is an injection molded body integrally molded so as to cover the outer peripheral surface 104a (preferably, the outer peripheral surface 104a and the bottom surface 104b) of the inner container 104. The jacket 105 includes a cylindrical portion 105a and a bottom portion 105 b. The cylindrical portion 105a and the bottom portion 105b cover the outer peripheral surface 104a and the bottom surface 104b, respectively. The cover 105 covers at least the housing 107, and the mouth 108 may or may not be covered.

The resin constituting the outer jacket 105 preferably has the same monomer unit as the outermost resin constituting the outermost layer 104c 1. In this case, the peeling of the adhesive surface between the outer jacket 105 and the outer peripheral surface 104a can be suppressed when the outer jacket is dropped. For example, polyethylene may be used for the outermost layer 104c1 of the inner container 104, and an ionomer resin of ethylene- (meth) acrylic acid copolymer may be used for the outer jacket 105. In this case, both resins contain ethylene units.

The container body 102 can be manufactured by a method including an integral molding step of integrally molding the inner container 104 and the outer sleeve 105. As shown in fig. 7 to 8, in the integral molding step, the mouth portion 108 is fixed to a fixing portion 110 having an opening 110a, and the support rod 111 is inserted into the inner container 104 in a state where the outer peripheral surface 104a (preferably, the outer peripheral surface 104a and the bottom surface 104b) of the inner container 104 is disposed in a mold 109 for injection molding, and the support rod 111 is pressed against the inner surface of the bottom surface 104 b. This can suppress the displacement of the storage portion 107 of the inner container 104 during injection molding.

In this state, the outer jacket 105 is formed by filling the resin into the space outside the inner container 104 in the cavity 109a of the mold 109. At this time, it is preferable to pressurize the inside of the inner container 104 and not to deform the inner container 104 due to the resin pressure. The pressurization may be performed by blowing water or air. The resin is filled into the cavity 109a from the shutter 109 b. The shutter 109b is preferably disposed at a position facing the bottom surface 104b (preferably, the pinch-off portion 107c) of the inner container 104. This is because it is easy to fill the resin uniformly into the entire periphery of the inner container 104 in this case.

The resin for injection molding preferably has fluidity required for injection molding at a temperature lower than the melting point of the resin constituting the outermost layer 104c1 of the inner container 104. The melting point of the resin for injection molding is, for example, 60 to 100 ℃, preferably 70 to 90 ℃. Specific examples of the melting point include 60, 65, 70, 75, 80, 85, 90, 95, and 100 ℃, and may be in the range of any 2 values shown herein.

The difference between the melting point of the injection molding resin and the melting point of the outermost resin is preferably 5 ℃ or higher, more preferably 10 ℃ or higher, and still more preferably 20 ℃ or higher. The difference in melting point is, for example, 5 to 50 ℃, and specifically, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 ℃, and may be in the range of any 2 values shown here.

The resin temperature during injection molding is preferably 180 to 230 ℃. If the temperature is too low, the pressure at the time of injection becomes high, and if the temperature is too high, air is likely to be mixed at the time of injection. Specific examples of the resin temperature are 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, and 230 ℃, and may be in a range of any 2 values shown here.

2. Embodiment 2

Embodiment 2 of the present invention will be described below. This embodiment is similar to embodiment 1 in that the inner container 104 has an outer shell 113 and an inner bag 114 as shown in fig. 11 to 12, and the contraction of the inner bag 114, i.e., the portion constituting the laminate peel container, is the main difference as the content decreases. The following description will focus on this difference.

In the present embodiment, the delamination container separates the inner bag 114 from the outer case 113 and shrinks the inner bag 114 from the outer case 113 as the content decreases. In this container, since the outside air does not easily enter the inner bag 114, the deterioration of the contents can be suppressed.

As shown in fig. 11, the outer case 113 is composed of, for example, an outermost layer 113c1, an adjacent layer 113c2, and another layer 113c 3. The inner bag 114 includes, for example, an outermost layer 114c1, an adhesive layer 114c2, and an inner layer 114c 3. The outermost layer 113c1 and the adjacent layer 113c2 correspond to the outermost layer 104c1 and the adjacent layer 104c2 according to embodiment 1, and the configuration and the operational effects thereof are the same as those of embodiment 1.

The other layer 113c3, the outermost layer 114c1, the adhesive layer 114c2, and the inner surface layer 114c3 correspond to the other layer 104c3 of embodiment 1. The other layer 113c3 and the inner face layer 114c3 may be composed of low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene-propylene copolymers, mixtures thereof, and the like. The outermost layer 114c1 is a layer having excellent peelability from the other layer 113c3, and is preferably made of an ethylene-vinyl alcohol copolymer (EVOH) resin or the like. The adhesive layer 114c2 is preferably made of an adhesive resin such as acid-modified polyolefin.

As shown in fig. 12, the pinch-off portion 107c blocks the bottom of each of the outer case 113 and the inner bag 114, but since the strength of the pinch-off portion 107c on the outer case 113 is particularly weak, the pinch-off portion 107c can be opened on the outer case 113 by applying an impact to the outer case 113, thereby forming the outside air introducing portion 115. External air may be introduced between the outer case 113 and the inner bag 114 through the external air introducing unit 115. The outside air introducing portion 115 may be formed by punching a hole in the casing 113. The outside air introducing portion 115 may be provided in the receiving portion 107 or may be provided in the mouth portion 108.

When the outside air introducing part 115 of the inner container 104 is covered with the outer jacket 105, the outside air cannot be introduced through the outside air introducing part 115. Therefore, the jacket 105 is provided with a ventilation portion 105c that communicates the outside space of the storage container 101 with the outside air introduction portion 115. The ventilation portion 105c may be a through hole or a groove. The vent portion 105c may be formed at the time of injection molding, or may be formed by post-processing after injection molding.

When the outer cover 105 does not cover the mouth portion 108, the ventilation portion 105c is not necessary if the outside air introducing portion 115 is provided in the mouth portion 108.

When the vent part 105c is formed during injection molding, for example, a pin may be arranged at a position corresponding to the vent part 105c, and the pin may be pulled out from the jacket 105 when the container body 102 is taken out from the mold 109.

The inner container 104 is preferably peeled off the inner bag 114 in advance before the integral molding process. This is because the outer jacket 105 is easily pre-peeled before being integrally formed in the inner container 104.

< Pump 112 >

The pump 112 is configured to discharge the contents from the inner container 104. When the inner container 104 is a laminated peel container, the pump 112 is preferably configured not to introduce outside air into the inner container 104.

As shown in fig. 13, the pump 112 includes a body 112a, a piston 112b, a nozzle 112c, and a tube 112 d. The body portion 112a includes a tube portion 112a1, a cylinder portion 112a2, and an upper wall portion 112a 3. An engagement portion (female screw portion) (not shown) that engages with the engagement portion (male screw portion) 108a is provided on the inner surface of the cylindrical portion 112a 1. The cylinder portion 112a2 is inserted into the mouth portion 108. The outer diameter of cylinder portion 112a2 substantially coincides with the inner diameter of mouth portion 108. Cylinder section 112a2 is cylindrical, and piston section 112b is slidable within cylinder section 112a 2. The inner space of the cylinder portion 112a2 communicates with the nozzle 112c and the tube 112 d. A valve mechanism including an elastic member and a valve is housed in the inner space of the cylinder portion 112a 2. The valve mechanism is operated by sliding the piston portion 112b, and the sucked contents can be discharged from the nozzle 112c through the tube 112 d.

3. Embodiment 3

Embodiment 3 of the present invention is explained with reference to fig. 14. The present embodiment is similar to embodiment 2, and is mainly characterized in that an outside air introducing portion 115 is provided at the mouth portion 108 of the inner container 104. Next, description will be made about the distinctive feature.

When the case 113 is sealed, the outside air introducing portion 115 is not provided in the pinch-off portion 107c, and the outside air introducing portion 115 is preferably formed by providing a through hole in the case 113. In this case, the outside air introducing unit 115 is preferably provided at a portion of the inner container 104 not covered by the outer jacket 105. In this case, the vent portion 105c may not be provided in the outer jacket 105.

As shown in fig. 14, the outside air introducing portion 115 is preferably provided at the mouth portion 108, and particularly preferably at a position covered with the tube portion 112a1 of the pump 112 shown in fig. 12. In this case, the external air introducing portion 115 is not visible in a state where the pump 112 is attached, and thus the external appearance is beautiful. The outside air introducing part 115 can be ventilated to the outside through a gas passage such as a gap between the piston part 112b and the tube part 112a1 or a gap between the lower end of the tube part 112a1 and the inner container 104.

The outside air introducing portion 115 is preferably provided in the flat portion 108b provided in the mouth portion 108. In this case, the outside air introducing portion 115 can be easily formed by using a boring tool such as a drill. The flat portion 108b may be provided at a position closer to the receiving portion 107 than the engaging portion 108a, or may be provided as a divided engaging portion 108 a. In the latter case, there is an advantage that there is no need to extend the mouth portion 108 in order to provide the flat portion 108 b.

(viewpoint 2)

1. Embodiment 1 of viewpoint 2

In this section, the structure of the double container 1 according to embodiment 1 will be described. Fig. 15 is a perspective view of the double container 1 according to embodiment 1. Fig. 16 shows a state in which the cover 30 is removed from the state of fig. 15. Fig. 17 is a front view and a back view of the double container 1 according to embodiment 1. Fig. 18 shows a state in which the cover 30 is removed from the state of fig. 17. Fig. 19 is a left side view and a right side view of the double container 1 according to embodiment 1. Fig. 20 shows a state in which the cover 30 is removed from the state of fig. 19. Fig. 21 is a top view and a bottom view of the double container 1 according to embodiment 1. Fig. 22 shows a state in which the cover 30 is removed from the state of fig. 21.

1.1 Main body 2

The double container 1 is a so-called laminated peel container. As shown in fig. 15 to 22, the double container 1 includes a main body 2 (an outer case 21 and an inner bag 22) and an outside air inlet 52. The housing 21 is depressible from the outside. The content contained in the inner bag 22 (the containing space 26) is discharged from the mouth 3 by pressing. The inner bag 22 is configured to be compressed by air introduced into the intermediate space 25 through the outside air introduction hole 52 after the content is reduced.

The outer shell 21 and the inner bag 22 are blow-molded in a multilayer parison manner and are molded in an integrally molded state, and the use state is that the inner bag 22 is peeled off from the outer shell 21 before use, and then the contents are filled until the inner bag 22 comes into contact with the outer shell 21. The contents are extruded and the inner bag 22 is smoothly contracted. Alternatively, the inner bag 22 may be joined to the outer shell 21, and then the inner bag 22 may be peeled off from the outer shell 21 as the content is discharged.

The main body 2 includes the outer shell 21 and the inner bag 22 as described above, and the outer shell 21 is formed thicker than the inner bag 22 to improve shape recovery.

The outer shell 21 is made of, for example, low density polyethylene, linear low density polyethylene, and polyethylene, polypropylene, ethylene-propylene copolymer, and a mixture thereof. The outer shell 21 is a single-layer or multi-layer structure, and preferably contains a lubricant in at least one of the innermost layer and the outermost layer. When the outer shell 21 has a single-layer structure, the single layer may be the innermost layer and the outermost layer, and the lubricant may be contained in the layer. When the housing 21 has a 2-layer structure, the layer on the inner surface side of the container is the innermost layer, and the layer on the outer surface side of the container is the outermost layer, and at least one of them may contain a lubricant. When the outer shell 21 is formed of 3 or more layers, the layer on the innermost surface side is the innermost layer, and the layer on the outermost surface side is the outermost layer.

The innermost layer of the outer shell 21 is a layer in contact with the inner bag 22, and the releasability between the outer shell 21 and the inner bag 22 can be improved by containing a lubricant in the innermost layer of the outer shell 21. The outermost layer of the outer shell 21 is a layer that comes into contact with a mold during blow molding, and by including a lubricant in the outermost layer of the outer shell 21, the mold release property can be improved.

One or both of the innermost layer and the outermost layer of the outer shell 21 may be formed of a random copolymer between propylene and other monomers. This can improve the shape recovery, transparency, and heat resistance of the housing 21 as a housing.

The random copolymer is a copolymer having a monomer content other than propylene of less than 50 mol%, preferably 5 to 35 mol%. The monomer copolymerizable with propylene may be any monomer as long as it improves the impact resistance of the random copolymer as compared with a homopolymer of polypropylene, and ethylene is particularly preferable. When the copolymer is a random copolymer of propylene and ethylene, the ethylene content is preferably 5 to 30 mol%. The weight average molecular weight of the random copolymer is preferably 10 to 50 ten thousand, more preferably 10 to 30 ten thousand.

The random copolymer preferably has a tensile modulus of elasticity of 400 to 1600MPa, more preferably 1000 to 1600 MPa. When the tensile modulus of elasticity is in this range, the shape recovery property is particularly good.

When the container is too hard, the feeling of use of the container becomes poor, and therefore, the random copolymer may be mixed with a soft material such as linear low density polyethylene to constitute the outer shell 21. However, it is preferred that the material blended with the random copolymer is less than 50% by weight relative to the blend as a whole, so as not to significantly impair the effective properties of the random copolymer. For example, random copolymers and linear low density polyethylene can be blended according to a ratio of 85: 15 weight ratio to form the outer shell 21.

The inner bag 22 includes an EVOH layer provided on the outer surface side of the container, an inner surface layer provided on the inner surface side of the EVOH layer container, and an adhesive layer provided between the EVOH layer and the inner surface layer. By providing the EVOH layer, the gas barrier property and the peelability from the outer case 21 can be improved.

The EVOH layer is a layer composed of an ethylene-vinyl alcohol copolymer (EVOH) resin, which can be produced by hydrolysis of an ethylene and ethyl acetate copolymer. The ethylene content of the EVOH resin is, for example, 25 to 50 mol%, and preferably 32 mol% or less from the viewpoint of oxygen barrier property. The lower limit ratio of the ethylene content is particularly limited, and the flexibility of the EVOH layer is more likely to be reduced as the ethylene content is smaller, and therefore, it is preferably 25 mol% or more. Further, the EVOH layer preferably contains an oxygen absorber. When the EVOH layer contains an oxygen absorbent, the oxygen barrier property of the EVOH layer can be further improved.

The melting point of the EVOH resin is preferably higher than the melting point of the random copolymer constituting the outer shell 21. The outside air introduction hole 52 is preferably formed in the outer case 21 by a heating type hole forming device, and by setting the melting point of the EVOH resin to be higher than the melting point of the random copolymer, it is possible to prevent the hole from reaching the inner bag 22 when the outside air introduction hole 52 is formed in the outer case 21. From this viewpoint, the difference between (the melting point of EVOH) and (the melting point of the random copolymer layer) is preferably large, and it is preferably 15 ℃ or higher, and particularly preferably 30 ℃ or higher. The difference in melting points is, for example, 5 to 50 ℃.

The inner layer is a layer which comes into contact with the contents of the double container 1 and is preferably composed of, for example, polyolefin such as low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene-propylene copolymer, and a mixture thereof, or low density polyethylene or linear low density polyethylene. The tensile modulus of elasticity of the resin constituting the inner layer is preferably 50 to 300MPa, more preferably 70 to 200 MPa. When the tensile elastic modulus is in this range, the inner layer is particularly soft.

The adhesive layer is a layer having a function of bonding the EVOH layer and the back surface layer, and may be, for example, an acid-modified polyolefin (for example, maleic anhydride acid-modified polyethylene) having a carboxyl group introduced therein and an ethylene vinyl acetate copolymer (EVA) as described above. An example of an adhesive layer is low density polyethylene or a mixture of linear low density polyethylene and acid modified polyethylene.

Further, it is to be noted that the main body 2 has a flat shape as a whole. This configuration has the advantageous effect that the user can easily press the contents and the contents can be easily squeezed out.

1.2 check valve 6

The outside air introduction hole 52 and the check valve 6 will be described below. Fig. 23 is a diagram showing an end face constituting an internal structure of the double container 1 according to embodiment 1. The area surrounded by dotted lines in fig. 23 has design features. Fig. 24 shows a detailed structure of the check valve 6.

As shown in fig. 23, the outside air introducing hole 52 is provided in a specific region 51 on the bottom side of the housing 21. The bottom side is a side separated from the mouth 3 when the double container 1 is halved in the height direction. In the present embodiment, the specific region 51 is a part of the side surface of the housing 21. Specifically, the specific region 51 is located in the recess 5 of the housing 21.

The outside air introduction hole 52 is configured to fit the check valve 6. The check valve 6 may be, for example, a ball valve. The check valve 6 allows air to be introduced into the intermediate space 25 inside the outer case 21 and outside the inner bag 22 after the contents flow out, so that the shape of the outer case 21 can be restored. That is, the intermediate space 25 and the external space communicate with each other through the external air introduction hole 52.

Thus, the outside air is introduced into the intermediate space 25 from above to below through the outside air introduction hole 52 by the outside air introduction hole 52 provided in the specific region 51 on the bottom side of the housing 21, and after the contents are taken out. That is, the inner bag 22 can be peeled off from the outer shell 21 more efficiently than in the prior art.

Next, the check valve 6 fitted in the outside air introduction hole 52 will be described. As shown in fig. 24A to 24G, the check valve 6 is a ball valve composed of a cylinder 60 and a ball 69. The cylindrical body 60 has a hollow portion 6s provided to communicate the external space and the intermediate space 25. The ball 69 is movably housed in the hollow 6s in a specific direction. Specifically, the diameter of the cross section of the hollow portion 6s is slightly larger than the diameter of the cross section corresponding to the ball 69, and the ball 69 has a shape that can freely move in a specific direction (here, the up-down direction of the paper surface).

The cylinder 60 has a spindle portion 61 disposed in the outer air intake hole 52, a locking portion 62 provided on a space outside the spindle portion 61 to prevent the cylinder 60 from being inserted into the intermediate space 25, and a diameter-expanding portion 63 provided on the intermediate space 25 side of the spindle portion 61 to prevent the cylinder 60 from being pulled out of the outer side of the body 2. The axle portion 61 is configured to have a tapered shape (tapered shape) toward the intermediate space 25. The cylinder 60 is mounted to the body 2 such that an outer circumferential surface of the axial portion 61 is in close contact with an edge of the outside air introduction hole 52.

A stopper 65 for engaging the ball 69 when the ball 69 moves from the intermediate space 25 side to the external space side is provided on the surface 66 surrounding the hollow portion 6 s. The stopper 65 is formed of an annular protrusion, and when the ball 69 contacts the stopper 65, the flow of air through the hollow 6s is blocked.

The front end of the cylindrical body 60 is a flat surface 641, and the flat surface 641 is provided with an opening 64 communicating with the hollow portion 6s and has a plurality of slit portions 642 radially extending from the opening 64.

As shown in fig. 24F, when the check valve 6 is inserted into the outside air introduction hole 52 from the enlarged diameter portion 63 side and the locking portion 62 is pressed against the outer surface of the housing 21, the check valve 6 supports the housing 21 in a state where the outer circumferential surface of the axial portion 61 is in close contact with the edge of the outside air introduction hole 52. When the housing 21 is compressed in a state where air enters the intermediate space 25, the air in the intermediate space 25 enters the hollow portion 6s through the opening portion 64, and pushes the ball 69 upward to abut against the stopper portion 65. When the ball 69 contacts the stopper 65, the flow of air through the hollow 6s is blocked.

When the outer shell 21 is further compressed in this state, the pressure in the intermediate space 25 increases, and as a result, the inner bag 22 is compressed, and the content is discharged from the storage space 26 in the inner bag 22. When the compression force to the housing 21 is released, the housing 21 is elastically restored. As shown in fig. 24G, as the pressure in the intermediate space 25 is reduced as the housing 21 is restored, a force F is applied to the ball 69 in the container inner direction. Thereby, the ball 69 moves toward the bottom surface of the cavity 6s, and as shown in fig. 24F, the outside air (air) is introduced into the intermediate space 25 through the gap between the ball 69 and the surface 66 and the opening 64.

The check valve 6 is a ball valve as described above, and is merely an example, and the present invention is not limited thereto. Any structure may be used as long as it can introduce the outside air into the intermediate space 25 and prevent backflow.

1.3 mouthpiece 3 and cap 30

In the body 2, the mouth portion 3 is configured to be attachable with a cap 30 as a cover member. The mouth portion 3 is provided with an external thread portion, and a cap 30 having an internal thread is attached to the external thread portion. The lid 30 is configured to have a top surface 31 as a ground surface and to be placed upside down. Of course, the bottom surface 23 of the double container 1 may be placed upright as a placement surface. In order to enable stable inversion, in the double container 1, when the area of the top surface 31 of the lid 30 is S1 and the area of the mouth portion 3 is S2, the following conditions are preferably satisfied: s1 is more than or equal to 1.5 multiplied by S2.

Specifically, when S1 is k × S2, the number of points where k is 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.1, 7.2, 7.8, 7, 8.9, 8, 7.8, 8, 7.1, 8.2, 8, 7.8, 8, 7.8, 8, 7.6, 8, 8.6.6.6, 6.6, 6.1, 6.2, 6.3, 6.6, 6.3, 6.8, 6.6, 8, 8.8, 8, 7, 8.8.8.8.7, 7, 8, 8.8.8.8, 8.7, 8, 7.8.8.8.8, 7, 8, 7.8.8.8, 8, 8.8, 7, 8.7.8, 8.8.9, 7, 8.8, 7, 8, 8.8, 8, 8.8.9, 8.9, 8, 7, 8, 8.9, 8, 7, 8, 7, 8, 8.9, 7.9, 8, 8.9, 8, 8.9, 8, 7, 8, 8.9, 7.9, 8, 8.9, 8, 6.9, 8.9, 8, 8.9, 8, 8.9, 8, 8.9, 8, or more than 1, 6.9, or more than 1, or more than. Since the container can be placed in an inverted state, the remaining rate can be suppressed even when a viscous substance such as jam, mayonnaise, or ketchup is contained as a content.

Referring again to fig. 23, the specific region 51 is configured to have an inclination angle with respect to the opening face 53 defining the concave portion 5. When the inclination angle is θ, the inclination angle θ may be 5 degrees or more and 45 degrees or less in the double container 1. Specifically, for example: θ is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45 degrees, and may be a range between any 2 of the values shown herein.

With such an inclination angle θ, the outside air can be introduced into the intermediate space 25 more smoothly from above to below. That is, such a configuration helps to effectively peel off the inner bag 22 from the outer shell 21.

The wall 54 defining the recess 5 is formed not perpendicular to the opening surface 53. If the angle is phi, the angle phi in the double container 1 may be 5 degrees or more and 75 degrees or less. Specifically, for example: phi is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75 degrees, and may be a range between any 2 of the values shown herein. Further, it is preferable to satisfy: phi is more than or equal to theta.

With such an angle Φ, when the inner bag 22 is peeled off from the outer case 21, the inner bag 22 can be suppressed from being caught in the recess 5 (convex when viewed from the inner bag 22 side). That is, such a constitution contributes to effectively peeling off the inner bag 22 from the outer shell 21.

The double container 1 further includes a groove 55. Specifically, the groove portion 55 is provided on the housing 21 at a position closer to the bottom side than the positioning region 51. By providing such a groove portion 55, when the outside air introduction hole 52 is drilled by a drill in a licensing process, a fixing jig (not shown) having a convex portion which can be accommodated in the groove portion 55 is used as a positioning reference. However, the depth of groove 55 is preferably shallower than the depth of recess 5. When a shrink film made of a content of a label or the like is attached to the outside of the double container 1, the dent is not conspicuous, and the appearance is beautiful.

2. Embodiment 2 of claim 2

In this section, a double container 1 according to embodiment 2 will be described. Fig. 25 is a perspective view of the double container 1 according to embodiment 2. Fig. 26 shows a state in which the cover 30 is removed from the state of fig. 25. Fig. 27 is a front view and a back view of the double container 1 according to embodiment 2. Fig. 28 shows a state in which the cover 30 is removed from the state of fig. 27. Fig. 29 is a left side view and a right side view of the double container 1 according to embodiment 2. Fig. 30 shows a state where the cover 30 is removed from the state of fig. 29. Fig. 31 is a top view and a bottom view of the double container 1 according to embodiment 2. Fig. 32 shows a state in which the cover 30 is removed from the state of fig. 31. Fig. 33 is an end view showing the internal structure of the double container 1 according to embodiment 2. It should be noted that the region surrounded by dotted lines in fig. 33 has design features.

The double container 1 according to embodiment 2 has the same basic configuration as the double container 1 according to embodiment 1, and is different in the shape of the body 2 as shown in fig. 25 to 33. The double container 1 according to embodiment 2 has a circular bottom surface 23 (upper side of the drawing) and cannot stand when the bottom surface 23 is used as a placement surface. Therefore, embodiment 2 is configured on the premise that the top surface 31 of the lid 30 is a placement surface.

In the double container 1 according to embodiment 2, the extended surface of the specific region 51 is configured to intersect with the cut piece 231 of the bottom surface 23. With this structure, the inner bag 22 tends to collapse with the cut-out 231 as a fulcrum, and there is an advantageous effect that the content does not remain on the bottom side.

In embodiment 2, by providing the outside air introduction hole 52 in the specific region 51 on the bottom side of the housing 21, the outside air is introduced into the intermediate space 25 from above downward through the outside air introduction hole 52 immediately after the contents are taken out. That is, the inner bag 22 can be peeled off from the outer shell 21 more efficiently than in the prior art.

3. Final phrase

As described above, according to the embodiments described so far, it is possible to realize a two-layered container that can more efficiently peel off the inner bag from the outer case after the contents are taken out. It can also be implemented in various ways as described below. In the double container, the mouth portion is configured to be attachable with a lid, and the lid is configured to have a top surface as a ground surface and to be placed upside down. In the double container, assuming that the area of the top surface of the lid is S1 and the area of the mouth is S2, the following relationship is satisfied: s1 is more than or equal to 1.5 multiplied by S2. In the double container, the specific region is a part of a side surface of the outer shell. In the double container, the specific region is located in a recess of the outer shell and has an inclination angle with respect to an opening plane defining the recess. In the double container, the inclination angle is 5 degrees or more and 45 degrees or less. In the double container, a wall defining the recess is formed not to be perpendicular to the opening surface. The double container further includes a groove portion provided on the bottom side of the specific region of the outer case. In the double container, the depth of the groove portion is shallower than the depth of the recess portion. In the double container, the check valve is a ball valve. Of course, the present invention is not limited thereto.

(viewpoint 3)

1. Embodiment 1 of viewpoint 3

As shown in fig. 34, the double container 201 according to embodiment 1 of the present invention includes a container main body 202. As shown in fig. 36A, the container body 202 has an outer shell 203 and an inner bag 204, and the inner bag 204 is contracted as the content decreases.

As shown in fig. 34, the container body 202 includes a mouth portion 205, a trunk portion 206, and a bottom portion 207. The mouth portion 205 includes an engagement portion 205a to which a pump, not shown, can be attached. The engaging portion 205a is a male screw portion in the case of a screw pump, and is an annular protrusion protruding in the circumferential direction in the case of a press pump. The mouth portion 205 is provided to extend from an upper end portion 206a of the trunk portion 206. The mouth portion 205 is cylindrical. The trunk portion 206 has an outer diameter larger than the mouth portion 205 (in this specification, when the cross section is not circular, the "outer diameter" refers to the diameter of a circumscribed circle).

The body 206 is cylindrical, and the bottom 207 is provided at the lower end of the body 206 to close the lower end of the body 206. The bottom portion 207 includes a central recessed portion 207a provided in the center of the bottom portion 207 and a peripheral portion 207b surrounding the central recessed portion 207 a.

As shown in fig. 35A, the center recess 207a is provided with a locking portion 207a1, an outside air inlet hole 207a2, an annular protrusion 207a3, and a positioning recess 207a 4. As shown in fig. 36A, the locking portion 207a1 is configured such that a locking protrusion 204a provided on the inner bag 204 is inserted into an insertion hole 203a provided on the housing 203. The inner bag 204 can be prevented from being detached from the outer case 203 by the locking portion 207a 1. The outside air introduction hole 207a2 is a through hole penetrating the outer case 203, and the outside air can be introduced into an intermediate space between the outer case 203 and the inner case 204 through the outside air introduction hole 207a2 as the inner case 204 contracts. The locking portion 207a1 and the outside air inlet hole 207a2 are disposed in the annular projection 207a 3. The positioning recess 207a4 is used to position the container body 202 in the circumferential direction when the container body 202 is subjected to a process such as printing.

The peripheral edge portion 207b is provided with a ground portion 207b1 and a peripheral edge recess portion 207b 2. The grounding portion 207b1 is a portion that contacts the placement surface on which the container body 202 is placed when the container body 202 is standing. If the entire peripheral edge portion 207b is used as the grounding portion 207b1, the central recessed portion 207a may form a closed space between the container main body 202 and the mounting surface when the container main body 202 is standing, and the introduction of the external air through the external air introduction hole 207a2 may be blocked. Therefore, the peripheral edge recess 207b2 is provided to serve as a gas passage to prevent the formation of a closed space in the central recess 207 a.

When the contents in the inner bag 204 are discharged by a pump mounted on the mouth portion 205, the inner bag 204 is contracted and separated from the outer case 203. At this time, the outside air can be introduced into the space between the inner bag 204 and the outer case 203 through the outside air introduction hole 207a 2. As shown in fig. 36A, since the radius of curvature of the peripheral edge portion 207b is small, the inner bag 204 is not easily separated from the outer case 203 at the peripheral edge portion 207b, and it is difficult to form a gas passage through which the outside gas introduced from the outside air introduction hole 207a2 flows. Therefore, it is not easy to introduce the outside air into the barrel portion 206. In this case, a problem occurs in that the outer case 203 is shrunk together with the inner bag 204 as the content decreases. In the present embodiment, a spacer 209 is disposed between the outer case 203 and the inner bag 204. In the present embodiment, a protrusion 203b protruding from the outer case 203 toward the inner bag 204 is provided as the spacer 209. When the spacer member 209 is provided, a gap 208 is formed between the outer case 203 and the inner bag 204 at a position adjacent to the spacer member 209, the gap 208 can form an air passage that communicates the trunk portion 206 and the bottom portion 207, and the outside air introduced from the outside air introduction hole 207a2 can be easily introduced into the trunk portion 206 through the peripheral portion 207 b. The spacer member 209 is disposed radially across the base 207 and the barrel 206, and this structure facilitates formation of an air passage across the base 207 and the barrel 206.

As shown in fig. 37 to 39, the container body 202 can be formed by heating and biaxially stretch blow molding the inner preform 214 and the outer preform 213 while covering the inner preform 214 constituting the inner bag 204 with the outer preform 213 constituting the outer shell 203.

As shown in fig. 37, the inner preform 214 has a bottomed tubular shape, and includes a mouth portion 214a, a trunk portion 214b, and a bottom portion 214 c. A flange 214a1 is provided at the open end of the mouth 214 a. A dowel pin 214c1 is provided on the bottom 214 c.

As shown in fig. 37, the outer preform 213 has a bottomed tubular shape, and includes a mouth portion 213a, a trunk portion 213b, and a bottom portion 213 c. As shown in fig. 38, the outer preform 213 has a radially arranged protrusion 213c1 on the inner surface of the bottom 213 c. The bottom 213c is provided with a positioning hole 213c2 and an outside air introduction hole 213c 3. As shown in fig. 39B, an annular projection 213c4 is provided on the outer surface of the bottom portion 213 c. The positioning hole 213c2 and the outside air introduction hole 213c3 are disposed in the region inside the annular projection portion 213c 4. The outer preform 213 is sized to be inserted into the inner preform 214.

The inner preform 214 and the outer preform 213 can be formed by blow molding or injection molding a thermoplastic resin such as polyester (e.g., PET) or polyolefin (e.g., polypropylene or polyethylene). In one example, the inner preform 214 can be formed by blow molding of polypropylene and the outer preform 213 can be formed by injection molding of PET. By making the material of the inner preform 214 different from that of the outer preform 213, welding between the preforms can be suppressed during blow molding. Further, when the outer preform 213 is formed by injection molding, the outer air introduction hole 213c3 can be formed at the time of injection molding, and time required for post-processing can be saved.

2. Biaxial stretch blow molding

The biaxial stretch blow molding can be carried out by the following method.

First, as shown in fig. 39, the outer preform 213 is overlaid on the inner preform 214 (in other words, the inner preform 214 is inserted into the outer preform 213) to form an assembly 215. At this time, the flange 214a1 comes into contact with the open end of the mouth 213a, and the positioning pin 214c1 is inserted into the positioning hole 213c 2. Thereby, the inner preform 214 and the outer preform 213 are positioned to each other. In this state, the mouth portion 214a and the mouth portion 213a face each other, and the body portion 214b and the body portion 213b face each other.

The softening assembly 215 is then heated.

Subsequently, the assembly 215 is placed in a mold for blow molding, and air is blown into the inner preform 214 while supporting the mouth portion 213a and the annular convex portion 213c4 with a jig, so that the assembly 215 is expanded and closely attached to the inner surface of the cavity of the mold. At this time, the not-shown support rod is pressed against the inner bottom surface of the inner preform 214, thereby suppressing the component 215 from wobbling in the mold. Further, the inner bottom surface of the inner preform 214 may be provided with a concave portion for engaging the support rod, so that the support rod can be easily fixed to the inner preform 214.

By blow molding, the assembly 215 expands to the container body 202 as shown in fig. 34-36. The

mouth portions

213a and 214a serve as the mouth portion 205, the

trunk portions

213b and 214b serve as the trunk portion 206, and the

bottom portions

213c and 214c serve as the bottom portion 207. The protrusion 213c1, the annular protrusion 213c4, and the outside air introduction hole 213c3 serve as the protrusion 203b, the annular protrusion 207a3, and the outside air introduction hole 207a2, respectively. During blow molding, the

mouth portions

213a, 214a, the annular convex portion 213c4, and the region inside thereof are hardly deformed, and the other portions are mainly deformed. Since the outside air introduction hole 213c3 is disposed in the region inside the annular protrusion 213c4, it is possible to prevent the outside air introduction hole from being blocked by deformation during blow molding. The flange 214A1 constitutes a flange 204b covering the opening end of the mouth 205 of the container body 202 as shown in fig. 34A.

After the blow molding, the positioning hole 213c2 becomes the insertion hole 203a as shown in fig. 36A, and a state is formed in which the positioning pin 214c1 is inserted in the insertion hole 203 a. Subsequently, the lock pin 214c1 is deformed (i.e., crushed or bent) to form the locking projection 204a as shown in fig. 36A. Thereby, the locking portion 207a1 of the container body 202 is formed.

3. Details of biaxial stretch blow molding

The biaxial stretch blow molding can be performed by using a mold unit 220 shown in fig. 40 to 42, for example. The mold unit 220 includes a mouth support mold 221, a bottom support mold 222, and forming

molds

223 and 224.

The mouth portion supporting mold 221 is configured to support the mouth portion 213a of the outer preform 213. An insertion hole 221a is provided in the mouth support mold 221, and the support bar 225 is inserted into the insertion hole 221 a. The support rod 225 is extendable and retractable by a drive mechanism not shown. The bottom support mold 222 is configured to be driven by a driving mechanism 222c and movable in a longitudinal extending direction (vertical direction in fig. 40). The molding dies 223, 224 are openable and closable, and have

cavity surfaces

223a, 224a, respectively. The cavity surfaces 223a, 224a are closed to form a cavity having a shape corresponding to the outer shape of the container main body 202.

The method includes a preform heating step, a bottom supporting step, an extending step, and a blow molding step.

< preform heating Process >

In the preform heating step, the assembly 215 including the inward preform 214 and the outer preform 213 is attached to the mouth support mold 221 as shown in fig. 40, and the assembly 215 is heated and softened in this state. The heating of the assembly 215 may be performed in a state where the assembly 215 is disposed between the molding dies 223, 224, or may be performed outside the space between the molding dies 223, 224. Before the preform heating step, the distal end of the support rod 225 may be brought into contact with the inner bottom surface of the inner preform 214. Thereby, the softened assembly 215 can be suppressed from shaking.

< bottom supporting Process >

In the bottom support procedure, as shown in fig. 41, the bottom support die 222 is moved toward the bottom part 213c of the outer preform 213 and supports the bottom part 213c of the outer preform 213 with the bottom support die 222. The bottom support mold 222 is provided with a recessed portion 222a capable of accommodating the annular protrusion 213c4, and the bottom support mold 222 preferably supports the bottom portion 213c such that the annular protrusion 213c4 is accommodated in the recessed portion 222 a. This can prevent the annular convex portion 213c4 and the inner region from being stretched during the blow molding process. The recess 222a is preferably annular. The bottom support mold 222 includes a recess 222b capable of accommodating the pin 214c1, and preferably supports the bottom 213c so that the pin 214c1 is accommodated in the recess 222 b. In this manner, the dowel pins 214c1 may be inhibited from interfering with the bottom support mold 222. Although fig. 41 shows the closed state of the molding dies 223, 224, the molding dies 223, 224 need only be closed at any time before the blow molding step, and may be closed after the longitudinal stretching step.

< longitudinal extension Process >

In the longitudinal extending step, as shown in fig. 41 to 42, the support rod 225 may extend the inner bottom surface of the inner preform 214 so as to extend the assembly 215 in the longitudinal direction (vertical direction in fig. 42). At this time, it is preferable to retract the bottom support mold 222 in synchronization with the extension of the support rod 225. Thereby stabilizing and extending the assembly 215. The vertical stretching step may be performed without using the bottom support die 222 to support the bottom portion 213c, or the bottom support step may be performed after the vertical stretching step.

< blow Molding Process >

In the blow molding step, the module 215 is laterally extended (i.e., expanded) by blowing air into the inner preform 214 in the state shown in fig. 42, and the

cavity surfaces

223a and 224a can be given shapes. The air may be blown through the air passage 226 between the mouth support mold 221 and the support bar 225, or may be blown from the side surface of the support bar 225 by providing an air passage in the support bar 225.

In the present embodiment, since air is blown into the bottom portion 213c of the outer preform 213 while being supported by the bottom support mold 222, the bottom portion 213c of the outer preform 213 can be prevented from extending.

The blow molding process may be performed simultaneously with the longitudinal stretching process. That is, air can be blown into the preforms 214 while extending the assembly 215 longitudinally. In addition, the longitudinal extending step may be omitted, and only air may be blown without longitudinally extending the unit 215 after the bottom supporting step.

4. Other embodiments

In the above embodiment, the spacer members 209 are provided in a radial shape, but the spacer members 209 may have other shapes. For example, the spacing members 209 may be configured as non-continuous circles. In this case, the gas passage is formed at the position of the notch of the circle. The discontinuous circles are preferably arranged concentrically with respect to each other. As shown in fig. 43, such spacer members 209 can be formed by using an outer preform 213 having a non-continuous round protrusion 213c 1.

In the above embodiment, the protrusion 203b protruding from the outer case 203 toward the inner pouch 204 is formed by providing the protrusion 213c1 on the outer preform 213, but as shown in fig. 44 to 45, the protrusion 214c2 (for example, a radial protrusion as shown in fig. 44 or a non-circular protrusion as shown in fig. 45) may be provided on the bottom 214c of the inner preform 214 to form the protrusion (spacer) protruding from the inner pouch 204 toward the outer case 203.

The spacer 209 may be formed of another member. The spacer member 209 between the outer shell 203 and the inner bag 204 can be disposed by blow molding in a state where a member as a spacer member is disposed between the inner preform 214 and the outer preform 213.

5. Inventions from other viewpoints

When the inner preform 214 is a blow-molded article (specifically, a direct blow-molded article), as shown in fig. 46, a blank-cut portion 214h is formed at a position where the bottom portion 214g of the inner preform 214 plugs the parison. Since the blank-cut portion 214h has a relatively weak strength, the blank-cut portion 214h may be cracked when a portion near the blank-cut portion 214h is strongly stretched during the biaxial stretching blow molding.

In one example, as shown in fig. 46, the inner preform 214 has a multilayer structure, and includes an innermost layer 214d, a gas barrier layer (for example, EVOH layer) 14e, and an outermost layer 214f in this order from the inside. The innermost layer 214d and the outermost layer 214f may be composed of polyolefin (e.g., polyethylene, polypropylene), PET, and the like. At the blank-cut portion 214h, even if the opposing gas barrier layers 214e1, 214e2 are connected to or separated from each other, the gap G therebetween becomes very small. When the portion near the blank-cut portion 214h is stretched with a large force in the biaxial stretch blow molding, the gas barrier layer 214e may be cracked or the gap G may be enlarged, thereby causing problems such as deterioration of the gas barrier property.

As described in "2. biaxial stretch blow molding" and "3. biaxial stretch blow molding" in detail, the above problem can be solved by expanding the unit 215 while suppressing the stretching of the bottom portion 213c of the outer preform 213. Since the blank-cut portion 214h is disposed at a position facing the bottom portion 213c of the outer preform 213, when the extension of the bottom portion 213c is suppressed, the extension of a portion near the blank-cut portion 214h can be suppressed, and the above-described problem can be solved.

In the "2-axis stretch blow molding", the annular convex portion 213c4 is provided on the bottom portion 213c of the outer preform 213, whereby the rigidity of the bottom portion 213c can be increased and the bottom portion 213c can be prevented from stretching. The structure provided to increase the rigidity of the bottom portion 213c may be a reinforcing structure other than the annular protrusion 213c 4.

In the "3. details of biaxial stretch blow molding", the bottom portion 213c of the outer preform 213 is supported by the bottom support mold 222, and the blow molding step is performed in this state, whereby the stretch of the bottom portion 213c is suppressed. Although the annular convex portion 213c4 is received in the concave portion 222a in the above description, even if the annular convex portion 213c4 is not present in the bottom portion 213c, the bottom portion 213c can be restrained from extending by friction between the bottom portion 213c and the bottom portion support mold 222 so that the bottom portion 213c is supported by the bottom portion support mold 222.

In view of the above, the present invention provides a method for manufacturing a double container, including a blow molding step of heating and softening an inner preform and an outer preform in a state where the inner preform covers the outer preform, and blowing air into the inner preform in the state, the inner preform being a blow molded body, and the blow molding step being performed in a state where bottom extension of the outer preform is suppressed.

Preferably, the outer preform is provided with a reinforcing structure for suppressing extension of a bottom portion of the outer preform.

Preferably the reinforcing formation is an annular protrusion provided at the bottom of the outer preform.

Preferably, the blow molding step is performed in a state in which the bottom portion of the outer preform is supported by a bottom support mold and the bottom portion is prevented from extending.

In another aspect, there is provided a method for manufacturing a double container, comprising a blow molding step of heating an inner preform and an outer preform in a state where the inner preform is covered with the outer preform, and blowing air into the inner preform while softening the inner preform and the outer preform, wherein the inner preform is a blow molded body, and the outer preform has an annular convex portion at a bottom thereof.

In the invention according to another aspect, the position of the outside air introduction hole is not limited, and the outside air introduction hole may be provided in any one of the mouth portion 205, the trunk portion 206, and the bottom portion 207 of the container main body 202. Further, a spacer member 209 for forming a gap between the outer case 203 and the inner bag 204 is not necessary.

[ examples ] A method for producing a compound

Hereinafter, examples related to the 1 st aspect are shown.

1. Manufacture of the container body 102

< example 1>

An inner container 104 having a structure shown in fig. 12 was manufactured by direct blow molding and the layer structure shown in table 3. The thickness of the inner container 104 at the center in the height direction of the housing portion 107 was 1500. mu.m.

[ TABLE 3 ]

The layers in table 3 were made of the following materials.

LDPE/LLDPE layer: the mass ratio of LDPE (melting point 110 ℃, manufactured by Asahi Kasei corporation, type: F2206) to LLDPE (melting point 120 ℃, manufactured by Japan polyethylene, type: NF325N) was 50: 50 of mixed resin

And (3) PP layer: polypropylene (Sumitomo chemical company, type: FH3315)

EVOH layer: EVOH (model SF7503B, made by Mitsubishi chemical corporation)

Acid modified PE/LDPE layer: the mass ratio of acid-modified polyethylene (model: L522, manufactured by Mitsubishi chemical corporation) to LDPE (melting point 110 ℃, manufactured by Asahi chemical corporation, model: F2206) was 50: 50 of a mixed resin

LDPE layer: LDPE (model F2206 manufactured by Xu Kangsu)

Next, according to the method described in embodiment 1, the container body 102 is manufactured by forming the outer jacket 105 by injection molding at a resin temperature of 220 ℃ so as to cover the outer peripheral surface and the bottom surface of the inner container 104. An ionomer resin (manufactured by Dow-Mitsui Polychemicals, model: PC2000, melting point 80 ℃ C.) of an ethylene- (meth) acrylic acid copolymer was used for injection molding.

< example 2 >

The container body 102 was produced in the same manner as in example 1, except that the LDPE/ADH layer was used instead of the LDPE/LLDPE layer as the outermost layer 113c1 of the outer shell 113.

The LDPE/ADH layer is prepared by mixing LDPE (melting point 110 ℃, manufactured by Asahi Kasei corporation, type: F2206) and adhesive resin (melting point 120 ℃, manufactured by Mitsubishi chemical corporation, type: L522) in a mass ratio of 50: 50, the melting point of the mixed resin is 115 ℃.

< comparative example 1>

The container body 102 was produced in the same manner as in example 1, except that the PP layer was used instead of the LDPE/LLDPE layer as the outermost layer 113c1 of the outer shell 113.

The PP layer consists of polypropylene (model: FH3315, manufactured by Sumitomo chemical Co., Ltd.) with a melting point of 140 ℃.

2. Evaluation of

The following evaluations were made for the above examples and comparative examples, and the results are shown in table 4. As shown in table 4, in the examples, the deformability and adhesiveness were good. In contrast, the comparative examples were poor in deformability and adhesiveness.

[ TABLE 4 ]

TABLE 4	Example 1	Example 2	Comparative example 1
				Deformation ofProperty of (2)	○	○	×
Adhesion Property	△	○	×

< deformability >

Whether or not the inner container 104 in the outer jacket 105 is deformed is visually checked, and the evaluation is performed according to the following criteria.

O: is not deformed

X: deformation of

< adhesion >

The container body 102 was cut in the vertical direction to confirm whether the inner container 104 could be peeled from the outer jacket 105 by hand, and evaluated according to the following criteria.

O: will not peel off even if pulled by hand

And (delta): can be peeled off after being pulled by hand

X: can be easily peeled off by hand

(description of symbols)

1: double-layer container, 2: main body, 3: mouth part, 5: recess, 6: check valve, 6 s: hollow portion, 21: housing, 22: inner bag, 23: bottom surface, 25: intermediate space, 26: housing space, 30: cover, 31: top surface, 51: specific region, 52: outside air introduction hole, 53: open face, 54: wall, 55: groove portion, 60: cylinder, 61: axle portion, 62: locking part, 63: diameter-expanding section, 64: opening, 65: stopper, 66: face, 69: ball, 101: storage container, 102: container body, 103: plug opening member, 104: inner container, 104 a: outer peripheral surface, 104 b: bottom surface, 104c 1: outermost layer, 104c 2: adjacent layer, 104c 3: other layers, 105: outer cover, 105 a: barrel portion, 105 b: bottom, 105 c: vent section, 107: accommodating portion, 107 a: carcass part, 107 b: bottom, 107 c: pinch-off portion, 108: mouth portion, 108 a: engaging portion, 108 b: flat portion, 109: mold, 109 a: cavity, 109 b: a gate, 110: fixing part, 110 a: opening, 111: support rod, 112: pump, 112 a: main body portion, 112a 1: tube portion, 112a 2: cylinder portion, 112a 3: upper wall portion, 112 b: piston portion, 112 c: nozzle, 112 d: a tube, 113: housing, 113c 1: outermost layer, 113c 2: adjacent layer, 113c 3: other layers, 114: inner bag, 114c 1: outermost layer, 114c 2: adhesive layer, 114c 3: inner layer, 115: outside air introducing unit, 201: double container, 202: container body, 203: housing, 203 a: insertion hole, 203 b: projection, 204: inner bag, 204 a: locking projection, 204 b: flange, 205: mouth portion, 205 a: engaging portion, 206: carcass, 206 a: upper end portion, 207: bottom, 207 a: central recess, 207a 1: locking portion, 207a 2: outside air introduction hole, 207a 3: annular projection 207a 4: positioning recess, 207 b: peripheral edge portion 207b 1: land portion, 207b 2: peripheral edge recess, 208: gap, 209: spacer member, 213: outer preform, 213 a: mouth portion, 213 b: carcass portion, 213 c: bottom, 213c 1: projection, 213c 2: positioning hole, 213c 3: outside air introduction hole 213c 4: annular projection, 214: inner preform, 214 a: mouth portion, 214a 1: flange, 214 b: carcass, 214 c: bottom, 214c 1: locating pin, 214c 2: projection, 214 d: innermost layer, 214 e: gas barrier layer, 214e 1: gas barrier layer, 214e 2: gas barrier layer, 214 f: outermost layer, 214 g: bottom, 214 h: embryo cutting part, 215: assembly, 220: mold unit, 221: mouth portion supporting mold, 221 a: insertion hole, 222: bottom support mold, 222 a: concave portion, 222 b: recess, 222 c: drive mechanism, 223: forming die, 223 a: cavity surface, 224: forming die, 224 a: cavity surface, 225: support rod, 226: gas passage, 231: embryo cutting, 641: flat surface, 642: slit portion, a: region, B: region, C: region, F: force, G: gap, Tpm: melting peak temperature, θ: inclination angle, φ: and (4) an angle.

Claims

1. A storage container includes a container body integrally formed with an outer cover so as to cover an outer peripheral surface of an inner container,

the outer casing is an injection molded body,

the inner container is provided with an outermost layer and an adjacent layer adjacent to the outermost layer,

the outermost layer resin constituting the outermost layer has a lower melting point than the adjacent layer resin constituting the adjacent layer.

2. The containment vessel according to claim 1,

the difference between the melting point of the outermost layer resin and the melting point of the adjacent layer resin is 5 ℃ or more.

3. The containment vessel according to claim 1 or 2,

the outermost layer has a wall thickness of 10% or more relative to the wall thickness of the inner container.

4. The containment vessel according to any one of claims 1 to 3, wherein,

the outermost resin contains an unmodified polyolefin.

5. The containment vessel according to claim 4,

the outermost resin contains an acid-modified polyolefin and the unmodified polyolefin.

6. The containment vessel according to any one of claims 1 to 5, wherein,

the resin constituting the outer jacket has the same monomer unit as the outermost resin.

7. The containment vessel according to any one of claims 1 to 6, wherein,

the inner container is configured to have an outer shell and an inner bag and the inner bag is shrunk as the content decreases,

the outermost layer and the adjoining layer are disposed at the outer shell.

8. A method for manufacturing a storage container includes an integral molding step of integrally molding an inner container and an outer sleeve,

in the integral molding step, the outer jacket is formed by filling resin into a space outside the inner container in the cavity of the mold with the outer peripheral surface of the inner container disposed in the mold,

the outermost layer resin constituting the outermost layer has a melting point lower than that of an adjacent layer resin constituting the adjacent layer.

9. The method of claim 8, wherein,

in the integral molding step, the inner container is pressurized.

10. The method of claim 8 or 9,

in the integral molding step, the resin is filled in a state where an inner surface of a bottom surface of the inner container is pressed by a support rod inserted into the inner container.

11. A double container comprising an outer shell, an external air inlet hole, and an inner bag,

the outer case is configured to be pressed from the outside, and the pressing causes the contents stored in the inner bag to flow out from the mouth portion,

the outside air introduction hole is provided in a specific region on a bottom side of the case, the bottom side being a side which is apart from the mouth when the double container is halved in the height direction,

and is configured to be fitted into a check valve, and air is introduced into an intermediate space between the inside of the outer shell and the outside of the inner bag through the check valve after the contents flow out, so that the shape of the outer shell is restored to its original shape,

the inner bag is configured to be compressed by the air introduced into the intermediate space when the content decreases.

12. The double-layered container according to claim 11,

the mouth portion is configured to receive a cap,

the top surface of the cover can be placed in an inverted manner as a ground plane.

13. The double-layered container according to claim 12,

the top surface of the cap has an area of S1, the mouth has an area of S2,

satisfies the condition that S1 is more than or equal to 1.5 multiplied by S2.

14. The double-layered container according to any one of claims 11 to 13,

the specific area is a portion of a side of the housing.

15. The double-layered container according to any one of claims 11 to 14,

the specific region is located in a recess of the housing,

and is configured to have an inclination angle with respect to an opening plane defining the recess.

16. The double-layered container according to claim 15,

the inclination angle is 5 degrees to 45 degrees.

17. The double-layered container according to claim 15 or 16,

the wall defining the recess is configured not to be perpendicular to the opening surface.

18. The double-layered container according to any one of claims 15 to 17,

further comprises a groove part, and the groove part,

the groove portion is provided on the housing at a position closer to the bottom side than the specific region.

19. The double-layered container according to claim 18,

the groove portion has a depth shallower than a depth of the recess portion.

20. The double-layered container according to any one of claims 11 to 19,

the check valve is a ball valve.

21. A double container comprising a container body having an outer shell and an inner bag, wherein the inner bag shrinks as the content decreases,

the container body is provided with a cylindrical trunk part and a bottom part arranged at the lower end of the trunk part,

the bottom portion includes a central recessed portion provided at a center of the bottom portion and a peripheral portion surrounding the central recessed portion,

an external air introducing hole is provided in the housing at the central recess,

a spacer member for forming a gap between the outer case and the inner bag is provided at the peripheral edge portion.

22. The bi-layered container according to claim 21,

the spacer member is a protrusion provided at the outer shell or the inner bag.

23. The double-layered container according to claim 21 or 22,

the spacing members are arranged radially.

24. The double-layered container according to claim 21 or 22,

the spacing members are configured to form a non-continuous circle.

25. The double-layered container according to any one of claims 21 to 24,

the container body is formed by heating an inner preform constituting the inner bag and an outer preform constituting the outer shell in a state where the inner preform and the outer preform are covered with the outer preform.

26. The bi-layered container according to claim 25,

the inner preform is provided with a positioning pin at the bottom of the inner preform,

the outer preform is provided with a locating hole at the bottom of the outer preform,

the blow molding is performed in a state where the positioning pin is inserted into the positioning hole.

27. A method for manufacturing a double container, comprising a blow molding step,

the blow molding step is performed by: heating and softening the inner preform and the outer preform in a state where the inner preform is covered with the outer preform, and blowing air into the inner preform in this state,

the inner preform is a blow-molded body,

the blow molding step is performed in a state in which the bottom portion of the outer preform is prevented from extending.

28. The method of claim 27, wherein,

the outer preform is provided with a reinforcing structure for suppressing extension of the bottom of the outer preform.

29. The method of claim 28, wherein,

the reinforcing formation is an annular protrusion provided at the bottom of the outer preform.

30. The method of any one of claims 27 to 29,

the blow molding step is performed in a state in which the bottom portion of the outer preform is supported by a bottom support mold to suppress extension of the bottom portion.