Accommodating container and manufacturing method thereof, and double-layer container and manufacturing method thereof

Abstract

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

Description

This application is a divisional application of the Chinese patent application with the application number: 202080068814.2, the application date: October 26, 2020, and the invention title "Containment Vessel and Method for Manufacturing the Same, Double-Walled Vessel and Method for Manufacturing the Same". Technical Field

[0001] The present invention relates to a containment vessel for containing contents and a method for manufacturing the same, and a double-walled vessel and a method for manufacturing the same. Background Art

[0002] (First Viewpoint) Currently, there is known a laminated peelable container (for example, Patent Document 1) that suppresses air from entering the interior of the container by shrinking an inner bag as the contents decrease.

[0003] (Second Viewpoint) There is known a double-walled vessel (laminated peelable container) having an outer shell and an inner bag and capable of containing contents in the inner bag (for example, Patent Document 2). The outer shell can be pressed from the outside, and the contents contained in the inner bag flow out of the mouth portion by the pressing. After the pressing, air is introduced between the outer shell and the inner bag through a check valve provided in the outer shell, so that the shape of the outer shell is restored and the inner bag gradually shrinks.

[0004] (Third Viewpoint) Patent Document 3 discloses a method for manufacturing a double-walled vessel by blow molding in a state where an inner preform and an outer preform are overlapped. Prior Art Documents Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015 - 163531 Patent Document 2: Japanese Unexamined Patent Application Publication No. 2018 - 087036 Patent Document 3: WO2004 / 071887 Summary of the Invention (Problems to be Solved by the Invention)

[0006] (First Viewpoint) The laminated peelable container of Patent Document 1 is configured by covering the outer peripheral surface of a container formed by blow molding with a shrink film, but there is sometimes a need for a more sophisticated appearance design.

[0007] The present invention has been completed in view of the above circumstances, and provides a containment vessel having excellent appearance.

[0008] (Second Viewpoint) However, in the prior art described in Patent Document 2, since the air inlet hole of the check valve is located near the mouth portion, when the content is taken out, it is necessary to immediately introduce air from the bottom to the top of the container, so the efficiency is poor.

[0009] The present invention has been completed in view of the above circumstances, and its object is to provide a double-layer container that can more effectively peel the inner bag from the outer shell after taking out the content.

[0010] (Third aspect) The inner bag is formed by an inner preform, and the outer shell is formed by an outer preform. As the content in the inner bag decreases, the inner bag shrinks, but external gas is introduced into the intermediate space between the inner bag and the outer shell from the outer gas inlet hole provided in the outer shell, and the outer shell can maintain its original state.

[0011] In this double-layer container, in consideration of factors such as aesthetics, the inventor of the present invention found that when the outer gas inlet hole is provided at the bottom of the container, external gas is sometimes difficult to be introduced into the intermediate space between the inner bag and the outer shell.

[0012] The present invention has been completed in view of the above circumstances, and it provides a double-layer container that can smoothly introduce external gas into the intermediate space between the inner bag and the outer shell even when the outer gas inlet hole is provided at the bottom of the container body. (Technical solution for solving the problem)

[0013] (First aspect) According to the present invention, there is provided a storage container including a container body integrally formed with an outer sleeve in a manner covering the outer peripheral surface of an inner container, the outer sleeve being an injection-molded body, and the inner container including an outermost layer and an adjacent layer adjacent to the outermost layer, and a melting point of the outermost layer resin constituting the outermost layer being lower than a melting point of the adjacent layer resin constituting the adjacent layer.

[0014] The storage container of the present invention has excellent appearance because the outer sleeve formed by the injection-molded body is integrally formed on the outer peripheral surface of the inner container. In addition, since the melting point of the outermost layer resin is lower than the melting point of the adjacent layer resin, the thermal energy of the molten resin used for injection-molding the outer sleeve is not easily transmitted to the inner container, thereby suppressing deformation of the inner container. Further, since the melting point of the outermost layer resin is lower than the melting point of the adjacent layer resin, the adhesiveness between the outer sleeve and the outermost layer is improved, thereby suppressing peeling of the adhesive surface between the outer peripheral surface of the inner container and the outer sleeve due to impacts such as dropping.

[0015] Hereinafter, various embodiments of the present invention are listed. The embodiments shown below can be combined with each other. Preferably, a difference between the melting point of the outermost layer resin and the melting point of the adjacent layer resin of the storage container is 5 °C or more. Preferably, the wall thickness of the outermost layer is 10% or more relative to the wall thickness of the inner container with respect to the storage container. Preferably, the outermost layer resin of the storage container contains unmodified polyolefin. Preferably, the outermost layer resin of the storage container contains acid-modified polyolefin and the unmodified polyolefin. Preferably, the resin constituting the jacket of the storage container has the same monomer unit as the outermost layer 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 manufacturing method of the storage container includes an integral molding process of integrally molding the inner container and the jacket. In the integral molding process, in a state where the inner container is disposed on the outer peripheral surface in a mold, resin is filled into the space outside the inner container in the cavity of the mold to form the jacket. The inner container has an outermost layer and an adjacent layer adjacent to the outermost layer, and the melting point of the outermost layer resin constituting the outermost layer is lower than the melting point of the adjacent layer resin constituting the adjacent layer. Preferably, the method pressurizes the inside of the inner container during the integral molding process. Preferably, in the integral molding process of the method, the resin is filled in a state where the inner surface of the bottom surface of the inner container is pressed by a support rod inserted into the inner container.

[0016] (Second aspect) According to one aspect of the present invention, there is provided a double-layer container including an outer shell, an outside air introduction hole, and an inner bag. The outer shell is configured to be pressed from the outside, and by this pressing, the content stored in the inner bag flows out from the mouth portion. The outside air introduction hole is provided in a specific area on the bottom side of the outer shell. The bottom side means the side away from the mouth portion when the double-layer container is bisected in the height direction, and is configured to be fitted with a check valve. Through the check valve, after the content flows out, air is introduced into the intermediate space between the inside of the outer shell and the outside of the inner bag to restore the shape of the outer shell. The inner bag is configured to be pressed and shrunk by the air introduced into the intermediate space when the content decreases.

[0017] Since the specific area provided with the air introduction hole is provided on the bottom side of the outer shell, this double-layer container has the advantageous effect that the inner bag can be effectively peeled off from the outer shell immediately after taking out the content.

[0018] (Third aspect) According to the present invention, there is provided a double-layer container including a container body configured to have an outer shell and an inner bag, and the inner bag shrinks as the content decreases. The container body includes a cylindrical body portion and a bottom portion provided at the lower end of the body portion. The bottom portion includes a central concave portion provided at the center of the bottom portion and a peripheral portion surrounding the central concave portion. In the central concave portion, an external air introduction hole is provided in the outer shell, and a spacer member for forming a gap between the outer shell and the inner bag is provided in the peripheral portion.

[0019] Through detailed research on the present invention, it is found that when a central concave portion is provided at the bottom of the container body, it is difficult to form a gap between the inner bag and the outer shell in the peripheral portion surrounding the central concave portion. Therefore, when an external air introduction hole is provided in the central concave portion, it is not easy to introduce external gas into the body portion of the container. In addition, based on this finding, by providing a spacer member for forming a gap between the outer shell and the inner bag, external gas can be smoothly introduced from the external air introduction hole at the bottom through the peripheral portion into the body portion, thus completing the present invention.

[0020] Hereinafter, various embodiments of the present invention will be listed. The embodiments shown below can be combined with each other. Preferably, the spacer member of the double-layer container is a protrusion provided on the outer shell or the inner bag. Preferably, the spacer members of the double-layer container are arranged radially. Preferably, the spacer members of the double-layer container are arranged to form a discontinuous circle. Preferably, the container body of the double-layer container is blow-molded by heating the inner preform constituting the inner bag and the outer preform constituting the outer shell in a state where the outer preform covers the inner preform. Preferably, the inner preform of the double-layer container has a positioning pin at the bottom of the inner preform, and the outer preform has a positioning 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. Description of the Drawings

[0021] Figure 1 It is a perspective view of the storage container 101 according to the first embodiment of the first aspect. Figure 2 It is a perspective view of the container body 102. Figure 3 It is a cross-sectional view of the container body 102. Figure 4 It is Figure 3 The layer structure of the container body 102 within the region A in Figure 5 It is a perspective view of the inner container 104. Figure 6It is a cross-sectional view of the inner container 104. Figure 7 It is a cross-sectional view for explaining the integral forming process. Figure 8 It is Figure 7 an enlarged view of the area B in Figure 9 In Figure 9 A to Figure 9 B are perspective views of the housing container 101 according to the second embodiment as viewed from different directions. Figure 10 It is Figure 9 a cross-sectional view of the container body 102 of A. Figure 11 It is Figure 10 the layer structure of the container body 102 in the area C in Figure 12 It only shows Figure 10 a cross-sectional view of the inner container 104 in Figure 13 It is a perspective view of the pump 112. Figure 14 It shows the state where an outside air introduction part 115 is provided at the mouth part 108 of the inner container 104 in the third embodiment, Figure 5 an enlarged view of the vicinity of the mouth part 108 of Figure 15 It is a perspective view of the double-layer container 1 according to the first embodiment from the second perspective. Figure 16 It shows Figure 15 the state after removing the lid 30 from the state of Figure 17 It is a front view and a rear view of the double-layer container 1 according to the first embodiment from the second perspective. Figure 18 It shows Figure 17 the state after removing the lid 30. Figure 19 It is a left side view and a right side view of the double-layer container 1 according to the first embodiment from the second perspective. Figure 20 It shows Figure 19 the state after removing the lid 30 from the state of Figure 21 It is a top view and a bottom view of the double-layer container 1 according to the first embodiment from the second perspective. Figure 22 It shows Figure 21 the state after removing the lid 30 from the state. Figure 23It shows an end view of the internal structure of the double-layer container 1 related to the first embodiment of the second aspect. Figure 24 It shows the detailed structure of the check valve 6. Figure 25 It shows a perspective view of the double-layer container 1 related to the second embodiment of the second aspect. Figure 26 It shows the state after removing the lid 30 from the Figure 25 state. Figure 27 It shows a front view and a rear view of the double-layer container 1 related to the second embodiment of the second aspect. Figure 28 It shows the state after removing the lid 30 from the Figure 27 state. Figure 29 It shows a left side view and a right side view of the double-layer container 1 related to the second embodiment of the second aspect. Figure 30 It shows the state after removing the lid 30 from the Figure 29 state. Figure 31 It shows a top view and a bottom view of the double-layer container 1 related to the second embodiment of the second aspect. Figure 32 It shows the state after removing the lid 30 from the Figure 31 state. Figure 33 It is an end view showing the internal structure of the double-layer container 1 related to the second embodiment of the second aspect. Figure 34 It shows the container body 202 of the double-layer container 201 related to the first embodiment of the third aspect of the present invention. Figure 34 A is a front view. Figure 34 B is a bottom view. Figure 35 Among them, Figure 35 A is a perspective view of the container body 202 seen from the bottom 207. Figure 34 of the container body 202, Figure 35 B is a sectional perspective view of the vicinity of the bottom 207 of the outer shell 203 seen from the inside of the container. Figure 36 Among them, Figure 36 A is the Figure 34 A - A sectional view in B, Figure 36 B is the Figure 36 B - B sectional view in A. Figure 37 It shows a perspective view of the separated state of the inner preform 214 and the outer preform 213. Figure 38Viewed from the inside of the outer preform 213 Figure 37 is a cross-sectional perspective view near the bottom 213c of the outer preform 213. Figure 39 In Figure 39 A is a perspective view of an assembly 215 formed by covering an inner preform 214 with an outer preform 213, Figure 39 B is a perspective view when viewing Figure 39 A from another angle. Figure 40 represents a biaxially stretched blow molding process, which is a cross-sectional view of the state after the assembly 215 is installed on the mouth support die 221. Figure 41 represents the state of Figure 40 closing the forming dies 223 and 224 and the bottom support die 222 supporting the bottom 213c of the outer preform 213. Figure 42 is from Figure 41 the state of extending the support rod 225 and simultaneously retracting the bottom support die 222 to longitudinally extend the assembly 215. Figure 43 represents an outer preform 213 having a non-continuous circular protrusion 213c1, which is Figure 38 the corresponding cross-sectional perspective view. Figure 44 represents a perspective view of an inner preform 214 having a radially protruding protrusion 214c2 provided at the bottom 214c. Figure 45 is a perspective view of an inner preform 214 having a non-continuous circular protrusion 214c2 provided at the bottom 214c. Figure 46 is an enlarged view near the bottom 214g of the inner preform 214 of a modified example. DETAILED DESCRIPTION

[0022] The following describes embodiments of the present invention. Various characteristic matters shown in the following embodiments can be combined with each other. And each characteristic can independently constitute the present invention.

[0023] (First Aspect) 1. First Embodiment As Figure 1 shown, the storage container 101 according to the first embodiment of the present invention includes: a container body 102; an opening and closing member 103 such as a lid with a flat upper surface. The opening and closing member 103 can be a pump or a hinge lid, etc. As Figure 3As shown in the figure, the container body 102 includes an inner container 104 and a jacket 105 integrally formed therewith. Each component will be described below.

[0024] <Inner container 104> As Figures 5 - 6 shown, the inner container 104 can be a container formed by any manufacturing method. Preferably, it is a blow-molded container formed by blow molding a parison. The blow molding can be direct blow molding or injection blow molding. In direct blow molding, a pair of split molds hold the parison extruded from an extruder in a molten state, and air is blown into the parison to manufacture the container. The parison can be cylindrical or sheet-like. In injection blow molding, a test tubular bottomed parison called a preform is formed by injection molding, and then the parison is blow molded to manufacture the container.

[0025] Since it is not easy to manufacture an injection-molded container with a multi-layer structure, it is particularly important to apply the present invention to the multi-layer inner container 104. When forming the multi-layer inner container 104, the parison also has a multi-layer structure. The multi-layer parison (multi-layer parison) can be formed by co-extrusion.

[0026] The inner container 104 is a bottomed cylindrical shape and includes a storage portion 107 for storing the content and a mouth portion 108 for discharging the content from the storage portion 107. The storage portion 107 includes a barrel portion 107a and a bottom portion 107b. A engaging portion (external thread portion) 8a is provided at the mouth portion 108 so that the opening / closing member 103 can be installed.

[0027] When the inner container 104 is formed by direct blow molding, a pinch-off portion 107c (as Figure 6 shown) is formed in the inner container 104 by squeezing the parison with a pair of split molds. The pinch-off portion 107c is provided at the bottom portion 107b of the inner container 104. At the pinch-off portion 107c, the opposite surfaces of the parison are welded to each other to close the bottom of the inner container 104. The shape of the storage portion 107 can be various shapes such as cylindrical, polygonal prism-shaped, pyramidal, spherical, etc.

[0028] As Figure 4 shown, the inner container 104 sequentially includes an outermost layer 104c1, an adjacent layer 104c2, and other layers 104c3 from the outside of the inner container 104. Examples of the raw materials constituting the inner container 104 include unmodified polyolefins, acid-modified polyolefins, EVOH, etc. Examples of polyolefins include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymers, and mixtures thereof.

[0029] The melting point of the outermost layer resin that constitutes the outermost layer 104c1 is lower than the melting point of the adjacent layer resin that constitutes the adjacent layer 104c2. Although there is a concern that 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 layer resin is lower than that of the adjacent layer resin, the outermost layer resin is melted by the thermal energy of the molten resin, and at this time, the outermost layer resin absorbs the thermal energy, so that the thermal energy transferred to the inner container 104 is reduced, and thus the deformation of the inner container 104 caused by the injection pressure can be suppressed. In addition, since the outermost layer 104c1 is easily melted, the adhesiveness between the outer jacket 105 and the outermost layer 104c1 can be improved, and thus the peeling of the bonding surface between the outer peripheral surface of the inner container 104 and the outer jacket 105 due to impacts such as dropping can be suppressed. It should be noted that in this specification, the "melting point" refers to the melting peak temperature Tpm measured according to JIS K7121:2012.

[0030] The difference between the melting point of the outermost layer resin and the melting point of the adjacent layer resin is preferably 5 °C or more, more preferably 10 °C or more, and still more preferably 20 °C or more. This is because in this case, the effects of suppressing deformation and improving adhesiveness are significant. The difference in melting point is, for example, 5 to 50 °C, specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 °C, and it can also be a range between any two values shown here.

[0031] The melting point of the outermost layer resin is, for example, 90 to 130 °C, preferably 100 to 120 °C. The melting point can specifically be, for example, 90, 95, 100, 105, 110, 115, 120, 125, 130 °C, and it can also be a range between any two values shown here.

[0032] The wall thickness of the outermost layer 104c1 is preferably 10% or more, preferably 15% or more, and more preferably 20% or more with respect to the wall thickness of the inner container 104. This is because in this case, the effects of suppressing deformation and improving adhesiveness are significant. The wall thickness of the outermost layer 104c1 is, for example, 10 to 50% with respect to the wall thickness of the inner container 104, and specifically can be, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50%, and it can also be a range between any two values shown here.

[0033] The outermost layer resin preferably contains polyolefin. The polyolefin can be an unmodified polyolefin or a modified polyolefin (for example: acid-modified polyolefin).

[0034] The outermost resin preferably contains unmodified polyolefin. When the outermost resin consists only of modified polyolefin, the outermost layer 104c1 may become sticky, resulting in poor operability of the inner container 104. As the unmodified polyolefin, polyethylene is preferred, and more preferably, one or both of LDPE and LLDPE are included. This is because the melting point of the outermost resin is likely to be low in this case.

[0035] The outermost resin may also contain acid-modified polyolefin and unmodified polyolefin. Since the acid-modified polyolefin has excellent adhesiveness, by containing acid-modified polyolefin and unmodified polyolefin in the outermost resin, it is possible to improve the adhesiveness between the outer jacket 105 and the inner container 104 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. This content can specifically be 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95% by mass, or it can be a range between any two of the values shown here.

[0036] The adjacent layer 104c2 is a layer adjacent to the outermost layer 104c1. The adjacent layer resin constituting the adjacent layer 104c2 can be any resin with a melting point higher than that of the outermost resin. For example, when the outermost resin is LDPE, HDPE or PP with a melting point higher than LDPE can be used as the adjacent layer resin. In addition, as the adjacent layer resin, recycled resin obtained by recovering and reusing the flash generated in the previous production process can also be used. When the melting point of the resin forming any layer of the inner container 104 is higher than that of the outermost layer 104c1, the melting point of its recycled resin is usually also higher than that of the outermost resin.

[0037] The wall thickness of the adjacent layer 104c2 is, for example, 5 to 70% of the wall thickness of the inner container 104. Specifically, it can be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70%, or it can be a range between any two of the values shown here.

[0038] The other layer 104c3 refers to the layer located closer to the inside of the inner container 104 than the adjacent layer 104c2. The other layer 104c3 is preferably made of a resin with excellent heat resistance and rigidity. For example, it can be made of a polypropylene resin. The other layer 104c3 can be omitted when not needed. The wall thickness of the adjacent layer 104c2 is preferably 20% or more of the wall thickness of the inner container 104. In this case, the other layer 104c3 can easily improve the heat resistance or rigidity of the inner container 104. The wall thickness of the adjacent layer 104c2 is, for example, 0 to 70% of the wall thickness of the inner container 104. Specifically, it can be, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70%, or it can be a range between any two of the values shown here.

[0039] The inner container 104 is a multi-layer container of 6 layers of 5 types, for example, and its specific layer constitution is shown in the following manner. The adhesive layer is a layer made of an adhesive resin such as acid-modified polypropylene.

Table 1

[0040] As shown in Table 2, the adjacent layer 104c2 can be a recycled resin layer. Various resins constituting the outermost layer 104c1 and the other layer 104c3 are contained in the recycled resin. Since the melting point of the resin constituting the other layer 104c3 is higher than the melting point of the outermost layer resin, the melting point of the recycled resin also becomes higher than the melting point of the outermost layer resin.

Table 2

[0041] <Outer jacket 105> As Figures 2 - 3 shown, the outer jacket 105 is integrally formed 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, and is an injection molded body. The outer jacket 105 includes a cylindrical portion 105a and a bottom portion 105b. The cylindrical portion 105a and the bottom portion 105b cover the outer peripheral surface 104a and the bottom surface 104b, respectively. The outer jacket 105 covers at least the accommodating portion 107, and may or may not cover the mouth portion 108.

[0042] The resin constituting the outer jacket 105 preferably has the same monomer unit as the outermost layer resin constituting the outermost layer 104c1. In this case, peeling of the bonding surface between the outer jacket 105 and the outer peripheral surface 104a can be suppressed when dropped. For example, polyethylene can be used in the outermost layer 104c1 of the inner container 104, and an ionomer resin of ethylene·(meth)acrylic acid copolymer can be used in the outer jacket 105. In this case, both resins contain an ethylene unit.

[0043] The container body 102 can be manufactured by a method using an integral forming process for integrally forming the inner container 104 and the outer jacket 105. As Figures 7 - 8 shown, in the integral forming process, the mouth portion 108 is fixed to the fixing portion 110 having an opening portion 110a, and 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 the injection molding die 109, the support rod 111 is inserted into the inner container 104, and the support rod 111 is pressed against the inner surface of the bottom surface 104b. Thereby, displacement of the accommodating portion 107 of the inner container 104 during injection molding can be suppressed.

[0044] In this state, resin is filled into the space outside the inner container 104 in the cavity 109a of the mold 109 to form the jacket 105. At this time, it is preferable to pressurize the inside of the inner container 104 and prevent the inner container 104 from deforming due to the resin pressure. The pressurization can be performed by blowing in water or air. The resin is filled into the cavity 109a from the gate 109b. The gate 109b is preferably disposed at a position opposite to the bottom surface 104b (preferably the pinch-off portion 107c) of the inner container 104. This is because in this case, it is easy to uniformly fill the resin into the entire periphery of the inner container 104.

[0045] The resin for injection molding preferably has the 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°C, preferably 70 to 90°C. Specifically, the melting point is, for example, 60, 65, 70, 75, 80, 85, 90, 95, 100°C, and may also be in the range between any two of the values shown here.

[0046] The difference between the melting point of the resin for injection molding and the melting point of the outermost layer resin is preferably 5°C or more, more preferably 10°C or more, and further preferably 20°C or more. The difference in melting point is, for example, 5 to 50°C, specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50°C, and may also be in the range between any two of the values shown here.

[0047] The resin temperature during injection molding is preferably 180 to 230°C. If the temperature is too low, the pressure during injection will be high, and if the temperature is too high, air is likely to be mixed in during injection. Specifically, the resin temperature is, for example, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230°C, and may also be in the range between any two of the values shown here.

[0048] 2. Second Embodiment The second embodiment of the present invention will be described below. This embodiment is similar to the first embodiment, and the inner container 104 has a housing 113 and an inner bag 114 as shown, and the main difference is that the inner bag 114 shrinks as the content decreases, that is, the part constituting the laminated peelable container. The following description will focus on this difference point. Figures 11 - 12 As shown, the inner bag 114 shrinks and separates from the housing 113 as the content decreases, which is the main difference point. The following description will focus on this difference point.

[0049] In this embodiment, in the laminated peelable container, as the content decreases, the inner bag 114 separates from the housing 113 and shrinks. In this container, since external gas is not easily introduced into the inner bag 114, deterioration of the content can be suppressed.

[0050] As shown in Figure 11As shown, the outer shell 113 is composed of, for example, an outermost layer 113c1, an adjacent layer 113c2, and other layers 113c3. The inner bag 114 includes an outermost layer 114c1, an adhesive layer 114c2, and an inner surface layer 114c3. The outermost layer 113c1 and the adjacent layer 113c2 correspond to the outermost layer 104c1 and the adjacent layer 104c2 of the first embodiment, and their structures and functions are the same as those of the first embodiment.

[0051] The other layers 113c3, the outermost layer 114c1, the adhesive layer 114c2, and the inner surface layer 114c3 correspond to the other layers 104c3 of the first embodiment. The other layers 113c3 and the inner surface layer 114c3 can be composed of low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and their mixtures, etc. The outermost layer 114c1 is a layer with excellent peelability from the other layers 113c3, and is preferably composed of ethylene-vinyl alcohol copolymer (EVOH) resin, etc. The adhesive layer 114c2 is preferably composed of an adhesive resin such as acid-modified polyolefin.

[0052] As Figure 12 shown, the pinch-off portions 107c block the bottoms of the outer shell 113 and the inner bag 114 respectively. However, since the strength of the pinch-off portion 107c on the outer shell 113 is particularly weak, the pinch-off portion 107c can be opened on the outer shell 113 by applying an impact to the outer shell 113 to form an outside air introduction portion 115. External gas can also be introduced between the outer shell 113 and the inner bag 114 through the outside air introduction portion 115. The outside air introduction portion 115 can be formed by perforating the outer shell 113. The outside air introduction portion 115 can be provided in the accommodating portion 107 or in the mouth portion 108.

[0053] When the outside air introduction portion 115 of the inner container 104 is covered by the outer cover 105, external gas cannot be introduced through the outside air introduction portion 115. Therefore, the outer cover 105 is provided with a ventilation portion 105c that communicates the outside space of the accommodating container 101 with the outside air introduction portion 115. The ventilation portion 105c can be a through-hole or a groove. The ventilation portion 105c can be formed during injection molding or can be formed by post-processing after injection molding.

[0054] When the outer cover 105 does not cover the mouth portion 108, if the outside air introduction portion 115 is provided on the mouth portion 108, the ventilation portion 105c is not required.

[0055] When forming the ventilation portion 105c during injection molding, for example, a method can be adopted in which a pin is first arranged at a position corresponding to the ventilation portion 105c, and then when the container body 102 is taken out of the mold 109, the pin is pulled out from the outer cover 105.

[0056] The inner container 104 preferably peels off the inner bag 114 in advance before the integral forming process. This is because it is easy to pre-peel before integrally forming the outer jacket 105 in the inner container 104.

[0057] <Pump 112> The pump 112 is configured to discharge the content from the inner container 104. When the inner container 104 is a laminated peeling container, the pump 112 is preferably configured not to introduce external gas into the inner container 104.

[0058] As Figure 13 shown, the pump 112 includes a main body portion 112a, a piston portion 112b, a nozzle 112c, and a tube 112d. The main body portion 112a includes a cylindrical portion 112a1, a cylinder portion 112a2, and an upper wall portion 112a3. An engaging portion (internal thread portion) (not shown) that engages with the engaging portion (external thread portion) 108a is provided on the inner surface of the cylindrical portion 112a1. The cylinder portion 112a2 is inserted into the mouth portion 108. The outer diameter of the cylinder portion 112a2 is substantially the same as the inner diameter of the mouth portion 108. The cylinder portion 112a2 is cylindrical, and the piston portion 112b is slidable within the cylinder portion 112a2. The internal space of the cylinder portion 112a2 communicates with the nozzle 112c and the tube 112d. A valve mechanism composed of an elastic member and a valve is housed within the internal space of the cylinder portion 112a2. By sliding the piston portion 112b to operate the valve mechanism, the sucked-up content can be discharged from the nozzle 112c through the tube 112d.

[0059] 3. Third Embodiment Refer to Figure 14 to describe the third embodiment of the present invention. This embodiment is similar to the second embodiment, and its main distinguishing feature is that the external air introduction portion 115 is provided at the mouth portion 108 of the inner container 104. Next, the distinguishing feature will be described.

[0060] When the outer shell 113 is sealed, the external air introduction portion 115 is not provided at the pinch-off portion 107c. Preferably, a through-hole is provided in the outer shell 113 to form the external air introduction portion 115. In this case, the external air introduction portion 115 is preferably provided at a position where the inner container 104 is not covered by the outer jacket 105. In this case, the ventilation portion 105c may not be provided on the outer jacket 105.

[0061] As Figure 14 shown, the external air introduction portion 115 is preferably provided at the mouth portion 108, and particularly preferably provided at a position covered by the cylindrical portion 112a1 of the pump 112 as Figure 12 shown. In this case, in the state where the pump 112 is installed, the external air introduction portion 115 is not visible, so the appearance is beautiful. The external air introduction portion 115 can ventilate to the outside through a gas passage such as a gap between the piston portion 112b and the cylindrical portion 112a1, or a gap between the lower end of the cylindrical portion 112a1 and the inner container 104.

[0062] The outside air introduction part 115 is preferably provided in the flat part 108b provided in the mouth part 108. In this case, it is easy to form the outside air introduction part 115 using a perforating tool such as a drill bit. The flat part 108b can be provided at a position closer to the housing part 107 than the engaging part 108a, or can be provided as a divided engaging part 108a. In the latter case, there is an advantage that it is not necessary to extend the mouth part 108 in order to provide the flat part 108b.

[0063] (Second view) 1. First embodiment of the second view In this section, the structure of the double-layer container 1 according to the first embodiment will be described. Figure 15 The perspective view of the double-layer container 1 according to the first embodiment is shown. Figure 16 It shows from Figure 15 The state after removing the lid 30 from the state. Figure 17 The front view and the rear view of the double-layer container 1 according to the first embodiment are shown. Figure 18 It shows from Figure 17 The state after removing the lid 30 from the state. Figure 19 The left side view and the right side view of the double-layer container 1 according to the first embodiment are shown. Figure 20 It shows from Figure 19 The state after removing the lid 30 from the state. Figure 21 The top view and the bottom view of the double-layer container 1 according to the first embodiment are shown. Figure 22 It shows from Figure 21 The state after removing the lid 30 from the state.

[0064] 1.1 Main body 2 The double-layer container 1 is a so-called laminated and peelable container. As Figures 15 - 22 shown, the double-layer container 1 includes a main body 2 (outer shell 21 and inner bag 22) and an outside air introduction hole 52. The outer shell 21 can be pressed from the outside. It is configured such that the content accommodated in the inner bag 22 (accommodation space 26) flows out from the mouth part 3 by pressing. The inner bag 22 is configured to be pressed and contracted by the air introduced into the intermediate space 25 through the outside air introduction hole 52 when the content decreases.

[0065] The outer shell 21 and the inner bag 22 are blow-molded in a multi-layer parison manner and formed in an integrally formed state. Their usage state is that the inner bag 22 is peeled off from the outer shell 21 in advance before use, and then the content is filled until the inner bag 22 contacts the outer shell 21. The content is extruded, and the inner bag 22 contracts smoothly. Or the inner bag 22 can be joined to the outer shell 21, and then as the content is discharged, the inner bag 22 is peeled off from the outer shell 21.

[0066] The main body 2 is provided with a housing 21 and an inner bag 22 as described above. The wall thickness of the housing 21 is made thicker than that of the inner bag 22 to improve the shape recovery property.

[0067] The housing 21 is made of, for example, low-density polyethylene, linear low-density polyethylene, polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof. The housing 21 is a single-layer or multi-layer structure, and it is preferable to contain a lubricant in at least one of the innermost layer and the outermost layer. When the housing 21 is a single-layer structure, the single layer is both the innermost layer and the outermost layer, and it is sufficient to contain a lubricant in this layer. When the housing 21 is a two-layer structure, the layer on the inner surface side of the container is the innermost layer, and the layer on the outer surface side of the container is the outermost layer. A lubricant may also be contained in at least one of them. When the housing 21 is configured with three or more layers, the layer on the innermost side of the container is the innermost layer, and the layer on the outermost side of the container is the outermost layer.

[0068] The innermost layer of the housing 21 is the layer in contact with the inner bag 22. By containing a lubricant in the innermost layer of the housing 21, the peelability between the housing 21 and the inner bag 22 can be improved. The outermost layer of the housing 21 is the layer in contact with the mold during blow molding. By containing a lubricant in the outermost layer of the housing 21, the mold release property can be improved.

[0069] One or both of the innermost layer and the outermost layer of the housing 21 can be formed of a random copolymer between propylene and other monomers. Thereby, the shape recovery property, transparency, and heat resistance of the housing 21 as the housing can be improved.

[0070] The random copolymer is a copolymer in which the content of monomers other than propylene is less than 50 mol%, preferably 5 to 35 mol%. As the monomer copolymerized with propylene, any monomer can be used as long as it improves the impact resistance of the random copolymer compared to the homopolymer of polypropylene. Ethylene is particularly preferred. When it is a random copolymer of propylene and ethylene, the content of ethylene is preferably 5 to 30 mol%. The weight average molecular weight of the random copolymer is preferably 100,000 to 500,000, more preferably 100,000 to 300,000.

[0071] The tensile elastic modulus of the random copolymer is preferably 400 to 1600 MPa, more preferably 1000 to 1600 MPa. When the tensile elastic modulus is in this range, the shape recovery performance is particularly good.

[0072] When the container is too hard, the usability of the container deteriorates. Therefore, the random copolymer can be mixed with a soft material such as linear low-density polyethylene to form the housing 21. However, it is preferable that the material mixed with the random copolymer is less than 50% by weight of the entire mixture so as not to significantly impair the effective performance of the random copolymer. For example, the housing 21 can be formed by mixing the random copolymer and linear low-density polyethylene in a weight ratio of 85:15.

[0073] The inner bag 22 includes an EVOH layer provided on the outer side of the container, an inner layer provided on the inner side of the EVOH layer facing the container, and an adhesive layer provided between the EVOH layer and the inner layer. By providing the EVOH layer, the gas barrier property and the peelability from the outer shell 21 can be improved.

[0074] The EVOH layer is a layer made of ethylene-vinyl alcohol copolymer (EVOH) resin, which can be obtained by hydrolysis of ethylene and ethyl acetate copolymer. The ethylene content of the EVOH resin is, for example, 25 to 50 mol%, and from the viewpoint of oxygen barrier property, it is preferably 32 mol% or less. The lower limit of the ethylene content is not particularly limited. The less the ethylene content, the more likely the flexibility of the EVOH layer is to decrease, so it is preferably 25 mol% or more. In addition, the EVOH layer preferably contains an oxygen absorber. By containing an oxygen absorber in the EVOH layer, the oxygen barrier property of the EVOH layer can be further improved.

[0075] 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 on the outer shell 21 by a heating type hole opening device. By setting the melting point of the EVOH resin higher than the melting point of the random copolymer, when forming the outside air introduction hole 52 on the outer shell 21, it can prevent the hole from reaching the inner bag 22. From this viewpoint, the difference between (the melting point of EVOH) and (the melting point of the random copolymer layer) is preferably large, preferably 15 °C or more, particularly preferably 30 °C or more. The difference in melting point is, for example, 5 to 50 °C.

[0076] The inner layer is a layer in contact with the content of the double-layer container 1. For example, it is preferably composed of polyolefins such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer and their mixtures, or composed of low-density polyethylene or linear low-density polyethylene. The tensile elastic modulus of the resin constituting the inner layer is preferably 50 to 300 MPa, more preferably 70 to 200 MPa. When the tensile elastic modulus is in this range, the inner layer is particularly soft.

[0077] The adhesive layer is a layer having the function of bonding the EVOH layer and the inner layer. For example, it can be a polyolefin added with an acid-modified polyolefin having a carboxyl group introduced (for example, maleic anhydride acid-modified polyethylene) and ethylene-vinyl acetate copolymer (EVA) as described above. An example of the adhesive layer is a mixture of low-density polyethylene or linear low-density polyethylene and acid-modified polyethylene.

[0078] In addition, it should be noted that the main body 2 as a whole has a flat shape. This configuration can achieve the beneficial effects that it is easy for the user to press and the content is easy to be extruded.

[0079] 1.2 Check valve 6 Hereinafter, the outside air introduction hole 52 and the check valve 6 will be described. Figure 23This is a diagram showing the end face of the internal structure of the double-layer container 1 according to the first embodiment. In Figure 23 The area surrounded by the dotted line in it has a design feature. Figure 24 This shows the detailed structure of the check valve 6.

[0080] As Figure 23 shown, the outside air introduction hole 52 is provided in a specific area 51 on the bottom side of the outer shell 21. Here, the bottom side means the side away from the mouth 3 when the double-layer container 1 is bisected in the height direction. In this embodiment, the specific area 51 is a part of the side surface of the outer shell 21. Specifically, the specific area 51 is located in the recess 5 of the outer shell 21.

[0081] The outside air introduction hole 52 is configured to fit the check valve 6. The check valve 6 can be a ball valve, for example. The check valve 6 can introduce air into the intermediate space 25 inside the outer shell 21 and outside the inner bag 22 after the content flows out, so as to facilitate the restoration of the shape of the outer shell 21. That is to say, the intermediate space 25 and the external space are communicated with each other through the outside air introduction hole 52.

[0082] Thus, by providing the outside air introduction hole 52 in the specific area 51 on the bottom side of the outer shell 21, when the content is taken out, the external gas is introduced from above to below into the intermediate space 25 through the outside air introduction hole 52. That is to say, compared with the prior art, the inner bag 22 can be peeled off from the outer shell 21 more effectively.

[0083] Next, the check valve 6 fitted in the outside air introduction hole 52 will be described. As Figure 24 A to Figure 24 G shown, the check valve 6 is a ball valve composed of a cylinder body 60 and a ball 69. The cylinder body 60 has a cavity portion 6s configured to communicate the external space and the intermediate space 25. The ball 69 is movably accommodated in the cavity portion 6s in a specific direction. Specifically, the diameter of the cross section of the cavity 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 move freely in a specific direction (here, the vertical direction of the paper surface).

[0084] The cylinder body 60 has a shaft portion 61 disposed in the outside air introduction hole 52, a locking portion 62 provided on the outside space side of the shaft portion 61 to prevent the cylinder body 60 from being inserted into the intermediate space 25, and a diameter-expanded portion 63 provided on the intermediate space 25 side of the shaft portion 61 to prevent the cylinder body 60 from being pulled out from the outside of the main body 2. The shaft portion 61 is configured to have a tapered shape (conical shape) with a pointed tip toward the intermediate space 25 side. By the outer peripheral surface of the shaft portion 61 being in close contact with the edge of the outside air introduction hole 52, the cylinder body 60 is mounted on the main body 2.

[0085] A stopper portion 65 for engaging the ball 69 when the ball 69 moves from the intermediate space 25 side to the outer space side is provided on the surface 66 around the cavity portion 6s. The stopper portion 65 is formed by an annular protrusion, and when the ball 69 contacts the stopper portion 65, the air flow passing through the cavity portion 6s is blocked.

[0086] The front end of the cylindrical body 60 is a flat surface 641. An opening portion 64 communicating with the cavity portion 6s is provided on the flat surface 641, and a plurality of slit portions 642 radially extending from the opening portion 64 are provided.

[0087] As Figure 24 As shown in F, when the check valve 6 is inserted into the outside air introduction hole 52 from the enlarged diameter portion 63 side and the engaging portion 62 is pressed against the position in contact with the outer surface of the housing 21, the check valve 6 supports the housing 21 in a state where the outer peripheral surface of the shaft 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 cavity 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 portion 65, the air flow passing through the cavity portion 6s is blocked.

[0088] When the housing 21 is further compressed in this state, the pressure in the intermediate space 25 becomes higher. As a result, the inner bag 22 is compressed and the contents are discharged from the accommodation space 26 in the inner bag 22. When the compressive force applied to the housing 21 is released, the housing 21 returns to its original shape by its own elasticity. As Figure 24 As shown in G, as the housing 21 returns to its original shape, the pressure in the intermediate space 25 is reduced, and a force F toward the inner side of the container is applied to the ball 69. Thus, the ball 69 moves toward the bottom surface of the cavity portion 6s, forming the state shown in Figure 24 F, and external gas (air) is introduced into the intermediate space 25 through the gap between the ball 69 and the surface 66 and the opening portion 64.

[0089] It should be noted that the check valve 6 is a ball valve as described above, which is only an example, and the present invention is not limited thereto. Any structure that can introduce external gas into the intermediate space 25 and prevent backflow can be used.

[0090] 1.3 Mouth portion 3 and lid 30 In the main body 2, the mouth portion 3 is configured to be able to mount a lid 30 as a lid member. An external thread portion is provided on the mouth portion 3, and a lid 30 having an internal thread is mounted on the external thread portion. The lid 30 is configured such that its top surface 31 serves as a grounding surface and can be placed upside down. Of course, it can also be placed upright with the bottom surface 23 of the double-layer container 1 as the placement surface. In order to be able to stand upside down stably, in the double-layer container 1, if the area of the top surface 31 of the lid 30 is S1 and the area of the mouth portion 3 is S2, it is preferably satisfied that: S1 ≥ 1.5 × S2.

[0091] Specifically, when S1 = k × S2, k = 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, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or it can also be a range between any two values shown here. Since it can be placed in an inverted state, when viscous substances such as jam, mayonnaise, or ketchup are used as the contained material, the residue rate can also be suppressed.

[0092] Refer again to Figure 23 , the specific area 51 is configured to have an inclination angle with respect to the opening surface 53 of the defining recess 5. When the inclination angle is set as θ, in the double-layer container 1, the inclination angle θ can be 5 degrees or more and 45 degrees or less. Specifically, for example, θ = 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, or it can also be a range between any two values shown here.

[0093] Having such an inclination angle θ can more smoothly introduce external gas from above to below into the intermediate space 25. That is to say, this structure helps to effectively peel the inner bag 22 from the outer shell 21.

[0094] The wall 54 defining the concave portion 5 is configured not to be perpendicular to the opening surface 53. Let the included angle be φ. In the double-layer container 1, the angle φ can be 5 degrees or more and 75 degrees or less. Specifically, for example, φ = 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, or it can be a range between any two values shown here. In addition, it is preferably satisfied that φ ≥ θ.

[0095] With such an angle φ, when the inner bag 22 is peeled off from the outer shell 21, the situation where the inner bag 22 gets stuck in the concave portion 5 (convex from the side of the inner bag 22) can be suppressed. That is to say, this configuration helps to effectively peel off the inner bag 22 from the outer shell 21.

[0096] The double-layer container 1 further includes a groove portion 55. Specifically, the groove portion 55 is provided at a position on the outer shell 21 closer to the bottom side than the specific area 51. By providing such a groove portion 55, when drilling the outside air introduction hole 52 in the licensing process, a fixing jig (not shown) that can be accommodated in the groove portion 55 and has a convex portion is used as a positioning reference. However, the depth of the groove portion 55 is preferably shallower than the depth of the concave portion 5. When a shrink film for marking the contents, etc. is pasted on the outside of the double-layer container 1, the indentation is not obvious, so it is aesthetically pleasing from the appearance.

[0097] 2. The second embodiment related to the second aspect In this section, the double-layer container 1 related to the second embodiment is described. Figure 25 The perspective view of the double-layer container 1 related to the second embodiment is shown. Figure 26 It shows from Figure 25 The state after removing the lid 30 in the state. Figure 27 The front view and the rear view of the double-layer container 1 related to the second embodiment are shown. Figure 28 It shows from Figure 27 The state after removing the lid 30 in the state. Figure 29 The left side view and the right side view of the double-layer container 1 related to the second embodiment are shown. Figure 30 It shows from Figure 29 The state after removing the lid 30 in the state. Figure 31 The top view and the bottom view of the double-layer container 1 related to the second embodiment are shown. Figure 32It shows the state after removing the lid 30 from the Figure 31 state. Figure 33 It shows an end view of the internal structure of the double - walled container 1 according to the second embodiment. It should be noted that the area surrounded by the dotted line in Figure 33 has a design feature.

[0098] The double - walled container 1 according to the second embodiment has the same basic structure as the double - walled container 1 according to the first embodiment. As Figures 25 - 33 shown, the difference lies in the shape of the main body 2. The bottom surface 23 (above the paper surface) of the double - walled container 1 in the second embodiment has a circular shape and cannot stand when the bottom surface 23 is used as the placement surface. Therefore, the second embodiment is configured on the premise that the top surface 31 of the lid 30 is used as the placement surface.

[0099] In the double - walled container 1 according to the second embodiment, the extended surface of the specific area 51 is configured to intersect with the cut embryo 231 of the bottom surface 23. With this structure, the inner bag 22 tends to shrink with the cut embryo 231 as the fulcrum, thus having the beneficial effect of not leaving the content at the bottom side.

[0100] In the second embodiment, by providing the outside - air inlet hole 52 in the specific area 51 on the bottom side of the outer shell 21, after the content is taken out, the outside air will immediately be introduced from above to below into the intermediate space 25 through the outside - air inlet hole 52. That is to say, compared with the prior art, the inner bag 22 can be peeled off from the outer shell 21 more effectively.

[0101] 3. Conclusion As described above, according to the embodiments described so far, a double - walled container can be realized, which can more effectively peel off the inner bag from the outer shell after taking out the content. It can also be implemented in various ways as follows. In the double - walled container, the mouth part is configured to be able to mount a lid, and the lid is configured to use its top surface as the grounding surface and can be placed upside - down. In the double - walled container, let the area of the top surface of the lid be S1, and the area of the mouth part be S2, and they satisfy the following relationship: S1≥1.5×S2. In the double - walled container, the specific area is a part of the side surface of the outer shell. In the double - walled container, the specific area is located in the concave part of the outer shell and forms an inclination angle with respect to the opening surface defining the concave part. In the double - walled container, the inclination angle is 5 degrees or more and 45 degrees or less. In the double - walled container, the wall defining the concave part is configured not to be perpendicular to the opening surface. In the double - walled container, a groove part is further provided, and the groove part is provided closer to the bottom side than the specific area of the outer shell. In the double - walled container, the depth of the groove part is shallower than the depth of the concave part. In the double - walled container, the check valve is a ball valve. Of course, the present invention is not limited to this.

[0102] (Third perspective) 1. First embodiment of the third perspective As Figure 34 shown, the double-layer container 201 of the first embodiment of the present invention includes a container body 202. As Figure 36 shown in A, the container body 202 has an outer shell 203 and an inner bag 204, and the inner bag 204 shrinks as the content decreases.

[0103] As Figure 34 shown, the container body 202 includes a mouth part 205, a body part 206, and a bottom part 207. The mouth part 205 has an engaging part 205a for attaching a pump (not shown). When it is a screw-type pump, the engaging part 205a is an external thread part, and when it is a pressing-type pump, it is an annular protrusion protruding in the circumferential direction. The mouth part 205 is provided to extend from the upper end part 206a of the body part 206. The mouth part 205 is cylindrical. The outer diameter of the body part 206 is larger than that of the mouth part 205 (in this specification, when the cross-section is not circular, the so-called "outer diameter" refers to the diameter of the circumscribed circle).

[0104] The body part 206 is cylindrical, the bottom part 207 is provided at the lower end of the body part 206 and closes the lower end of the body part 206. The bottom part 207 includes a central concave part 207a provided at the center of the bottom part 207 and a peripheral part 207b surrounding the central concave part 207a.

[0105] As Figure 35 shown in A, a locking part 207a1, an external air introduction hole 207a2, an annular convex part 207a3, and a positioning concave part 207a4 are provided in the central concave part 207a. As Figure 36 shown in A, the locking part 207a1 is configured such that a locking protrusion 204a of the inner bag 204 is inserted into an insertion hole 203a provided in the outer shell 203. Through the locking part 207a1, the inner bag 204 can be prevented from detaching from the outer shell 203. The external air introduction hole 207a2 is a through hole penetrating the outer shell 203, and as the inner bag 204 shrinks, external gas can be introduced into the intermediate space between the outer shell 203 and the inner bag 204 through the external air introduction hole 207a2. The locking part 207a1 and the external air introduction hole 207a2 are arranged within the annular convex part 207a3. The positioning concave part 207a4 is used to position the container body 202 in the circumferential direction during processes such as printing on the container body 202.

[0106] A grounding portion 207b1 and a peripheral recess 207b2 are provided at the peripheral portion 207b. The grounding portion 207b1 is a portion that contacts the placement surface on which the container body 202 stands when the container body 202 stands. If the entire peripheral portion 207b is used as the grounding portion 207b1, when the container body 202 stands, a sealed space is formed between the container body 202 and the placement surface by the central recess 207a, which may cause obstruction to the introduction of external gas through the outside air introduction hole 207a2. Therefore, the peripheral recess 207b2 is provided as a gas passage to prevent the formation of a sealed space in the central recess 207a.

[0107] When discharging the contents in the inner bag 204 through a pump installed on the mouth portion 205, the inner bag 204 contracts and separates from the outer shell 203. At this time, external gas can be introduced into the space between the inner bag 204 and the outer shell 203 through the outside air introduction hole 207a2. As Figure 36 shown in FIG. A, since the radius of curvature of the peripheral portion 207b is small, it is not easy for the inner bag 204 to separate from the outer shell 203 at the peripheral portion 207b, and it is difficult to form a gas passage through which the external gas introduced from the outside air introduction hole 207a2 flows. Therefore, it is not easy to introduce external gas into the body portion 206. In this case, a problem occurs in that the outer shell 203 and the inner bag 204 contract together as the contents decrease. In the present embodiment, a spacer member 209 is disposed between the outer shell 203 and the inner bag 204. In the present embodiment, as the spacer member 209, a protrusion 203b protruding from the outer shell 203 toward the inner bag 204 is provided. When the spacer member 209 is provided, a gap 208 is formed between the outer shell 203 and the inner bag 204 at a position adjacent to the spacer member 209, and the gap 208 can form a gas passage communicating the body portion 206 and the bottom portion 207, and the external gas introduced from the outside air introduction hole 207a2 can easily be introduced into the body portion 206 through the peripheral portion 207b. The spacer member 209 is provided to radially straddle the bottom portion 207 and the body portion 206, and this structure is easy to form a gas passage straddling the bottom portion 207 and the body portion 206.

[0108] As Figures 37 - 39 shown, the container body 202 can be formed by heat and biaxial stretch blow molding of an inner preform 214 constituting the inner bag 204 and an outer preform 213 constituting the outer shell 203 in a state where the outer preform 213 is covered on the inner preform 214.

[0109] As Figure 37 shown, the inner preform 214 is a bottomed cylindrical shape and includes a mouth portion 214a, a body portion 214b, and a bottom portion 214c. A flange 214a1 is provided at the open end of the mouth portion 214a. A positioning pin 214c1 is provided at the bottom portion 214c.

[0110] As Figure 37As shown, the outer preform 213 is a bottomed cylindrical shape, and has a mouth portion 213a, a body portion 213b, and a bottom portion 213c. As Figure 38 shown, radially arranged protrusions 213c1 are provided on the inner surface of the bottom portion 213c of the outer preform 213. A positioning hole 213c2 and an outer air introduction hole 213c3 are provided in the bottom portion 213c. As Figure 39 shown in FIG. B, an annular convex portion 213c4 is provided on the outer surface of the bottom portion 213c. The positioning hole 213c2 and the outer air introduction hole 213c3 are arranged in a region inside the annular convex portion 213c4. The outer preform 213 is sized to be insertable into the inner preform 214.

[0111] The inner preform 214 and the outer preform 213 can be formed by blow molding or injection molding of thermoplastic resins such as polyester (e.g., PET) and polyolefin (e.g., polypropylene, 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 materials of the inner preform 214 and the outer preform 213 different, welding to each other during blow molding can be suppressed. In addition, when the outer preform 213 is formed by injection molding, the outer air introduction hole 213c3 can be formed during injection molding, thereby saving the time spent on post-treatment.

[0112] 2. Biaxial stretch blow molding The biaxial stretch blow molding can be carried out using the following method.

[0113] First, as Figure 39 shown, the outer preform 213 is covered 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 contacts the open end of the mouth portion 213a, and the positioning pin 214c1 is inserted into the positioning hole 213c2. Thus, the inner preform 214 and the outer preform 213 are positioned relative 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.

[0114] Then, the assembly 215 is heated and softened.

[0115] Subsequently, the component 215 is disposed in a mold for blow molding. While the mouth portion 213a and the annular convex portion 213c4 are supported by a jig, air is blown into the inner preform 214 to expand the component 215 and closely fit it to the inner surface of the cavity of the mold. At this time, the component 215 can be restrained from shaking in the mold by pressing an unillustrated support rod against the inner bottom surface of the inner preform 214. In addition, a concave portion for engaging the support rod can be provided on the inner bottom surface of the inner preform 214 so that the support rod can be easily fixed in the inner preform 214.

[0116] Through blow molding, the component 215 expands to form the container body 202 as shown in Figures 34 - 36 . The mouth portions 213a and 214a become the mouth portion 205, the body portions 213b and 214b become the body portion 206, and the bottom portions 213c and 214c become the bottom portion 207. The protrusion 213c1, the annular convex portion 213c4, and the outside air introduction hole 213c3 respectively become the protrusion 203b, the annular convex portion 207a3, and the outside air introduction hole 207a2. When blow molding, the mouth portions 213a, 214a, the annular convex portion 213c4, and the area inside thereof are hardly deformed, and the deformation mainly occurs in other portions. Since the outside air introduction hole 213c3 is disposed in the inner area of the annular convex portion 213c4, the situation of being blocked due to deformation during blow molding can be suppressed. The flange 214a1 forms a flange 204b that covers the open end of the mouth portion 205 of the container body 202 as shown in Figure 34 A.

[0117] After blow molding, the positioning hole 213c2 becomes the insertion hole 203a as shown in Figure 36 A, and the positioning pin 214c1 is inserted into the insertion hole 203a. Subsequently, the positioning pin 214c1 is deformed (i.e., flattened or bent) to form a locking protrusion 204a as shown in Figure 36 A. Thus, the locking portion 207a1 of the container body 202 is formed.

[0118] 3. Details of biaxial stretch blow molding In the above-described biaxial stretch blow molding, for example, the mold unit 220 as shown in Figures 40 - 42 can be used. The mold unit 220 includes a mouth portion support mold 221, a bottom portion support mold 222, and forming molds 223 and 224.

[0119] The mouth portion support mold 221 is configured to support the mouth portion 213a of the outer preform 213. An insertion hole 221a is provided in the mouth portion support mold 221, and a support rod 225 is inserted into the insertion hole 221a. The support rod 225 can be extended and retracted by a drive mechanism (not shown). The bottom portion support mold 222 is configured to be driven by a drive mechanism 222c and can be moved in the longitudinal extension direction ( Figure 40The forming molds 223 and 224 can be opened and closed, and have cavity surfaces 223a and 224a, respectively. The cavity surfaces 223a and 224a are closed to form a cavity having a shape corresponding to the outer shape of the container body 202.

[0120] This method includes a preform heating step, a bottom supporting step, a stretching step, and a blow molding step.

[0121] <Preform heating process> In the preform heating process, the inner preform 214 covers the outer preform 213 to form an assembly 215. Figure 40 The assembly 215 is installed on the mouth support mold 221 in the manner shown, and in this state, the assembly 215 is heated to soften it. The assembly 215 can be heated in a state where the assembly 215 is arranged between the forming molds 223 and 224, or it can be heated outside the space between the forming molds 223 and 224. In addition, before the preform heating step, the front end of the support rod 225 can also be abutted against the inner bottom surface of the inner preform 214. This can suppress the shaking of the softened assembly 215.

[0122] <Bottom support process> In the bottom support process, such as Figure 41 As shown, the bottom support mold 222 moves toward the bottom 213c of the outer preform 213, and the bottom support mold 222 supports the bottom 213c of the outer preform 213. A recess 222a that can accommodate the annular protrusion 213c4 is provided on the bottom support mold 222, and the bottom support mold 222 preferably supports the bottom 213c in a manner that the annular protrusion 213c4 is accommodated in the recess 222a. In this way, the annular protrusion 213c4 and the inner area can be prevented from being extended during the blow molding process. The recess 222a is preferably annular. The bottom support mold 222 has a recess 222b that can accommodate the positioning pin 214c1, and preferably supports the bottom 213c in a manner that the positioning pin 214c1 is accommodated in the recess 222b. In this way, the positioning pin 214c1 can be prevented from interfering with the bottom support mold 222. Although Figure 41 The figure shows the state where the forming dies 223 and 224 are closed, but the forming dies 223 and 224 only need to be closed at any time point before the blow molding process, and can also be made to be closed after the longitudinal stretching process.

[0123] <Vertical stretching process> In the longitudinal stretching process, Figures 41 - 42 As shown, the assembly 215 can be extended in the longitudinal direction ( Figure 42extends in the vertical direction (up and down in the figure). At this time, it is preferable to retract the bottom support die 222 synchronously with the extension of the support rod 225. Thereby, the assembly 215 can be stabilized and extended. It should be noted that the longitudinal extension process can be carried out without using the bottom support die 222 to support the bottom 213c, or the bottom support process can be carried out after the longitudinal extension process.

[0124] <Blow molding process> In the blow molding process, the assembly 215 can be laterally extended (i.e., inflated) and the shapes of the cavity surfaces 223a and 224a can be imparted by blowing air into the inner preform 214 in the state shown in Figure 42 . The air can be blown through the gas passage 226 between the mouth support die 221 and the support rod 225, or it can be blown by providing a gas passage in the support rod 225 and blowing air from the side of the support rod 225.

[0125] In this embodiment, since air is blown into the bottom 213c of the outer preform 213 while being supported by the bottom support die 222, the extension of the bottom 213c of the outer preform 213 can be suppressed.

[0126] It should be noted that the blow molding process can be carried out synchronously with the longitudinal extension process. That is, air can be blown into the inner preform 214 while longitudinally extending the assembly 215. In addition, the longitudinal extension process can be omitted, and after the bottom support process, the assembly 215 is not longitudinally extended and only air is blown.

[0127] 4. Other embodiments · In the above embodiment, the spacer member 209 is arranged radially, but the spacer member 209 can also be of other shapes. For example, the spacer member 209 can be configured as a discontinuous circle. In this case, a gas passage is formed at the position of the notch of the circle. It is preferable that a plurality of discontinuous circles are arranged concentrically. As Figure 43 shown, such a spacer member 209 can be formed by using an outer preform 213 having a protrusion 213c1 in the shape of a discontinuous circle. · In the above embodiment, the protrusion 203b protruding from the outer shell 203 toward the inner bag 204 is formed by providing the protrusion 213c1 on the outer preform 213, but as Figures 44 - 45 shown, it can also be formed by providing a protrusion 214c2 (for example: a radially protrusion as Figure 44 shown, or a discontinuous circle-shaped protrusion as Figure 45 shown) on the bottom 214c of the inner preform 214 to form a protrusion (spacer member) protruding from the inner bag 204 toward the outer shell 203. · The spacer member 209 can be composed of other components. The spacer member 209 between the outer shell 203 and the inner bag 204 can be configured by blow molding in a state where a component serving as the spacer member is disposed between the inner preform 214 and the outer preform 213.

[0128] 5. Inventions of Other Views When the inner preform 214 is a blow molded body (specifically, a direct blow molded body), as Figure 46 shown, a cut embryo portion 214h is formed at a position where the bottom 214g of the inner preform 214 blocks the parison. Since the strength of the cut embryo portion 214h is relatively weak, when the portion near the cut embryo portion 214h is strongly stretched during biaxial stretch blow molding, the cut embryo portion 214h may crack.

[0129] In one example, as Figure 46 shown, the inner preform 214 has a multi-layer structure and includes, in order from the inside, an innermost layer 214d, a gas barrier layer (e.g., an EVOH layer) 14e, and an outermost layer 214f. The innermost layer 214d and the outermost layer 214f can be composed of polyolefins (e.g., polyethylene, polypropylene) and PET, etc. At the cut embryo portion 214h, even if the opposed gas barrier layers 214e1 and 214e2 are connected or separated from each other, the gap G therebetween becomes very small. When the portion near the cut embryo portion 214h is strongly stretched during biaxial stretch blow molding, the gas barrier layer 214e may crack or the gap G may become larger, resulting in problems such as a deterioration in gas barrier properties.

[0130] As described in "2. Biaxial Stretch Blow Molding" and "3. Details of Biaxial Stretch Blow Molding", the above problems can be solved by expanding the assembly 215 in a state where the extension of the bottom 213c of the outer preform 213 is suppressed. Since the cut embryo portion 214h is disposed at a position opposed to the bottom 213c of the outer preform 213, when the extension of the bottom 213c is suppressed, the extension of the portion near the cut embryo portion 214h can also be suppressed, thereby solving the above problems.

[0131] In "2. Biaxial Stretch Blow Molding", by providing an annular convex portion 213c4 at the bottom 213c of the outer preform 213, the rigidity of the bottom 213c can be increased to suppress the extension of the bottom 213c. The structure provided to increase the rigidity of the bottom 213c can also be a reinforcement structure other than the annular convex portion 213c4.

[0132] In "3. Details of biaxial stretch blow molding", the bottom 213c of the outer preform 213 is supported by the bottom support die 222, and the blow molding process is performed in this state to suppress the stretching of the bottom 213c. In the above description, although the annular convex portion 213c4 is received in the concave portion 222a, even when there is no annular convex portion 213c4 in the bottom 213c, the stretching of the bottom 213c can be suppressed by supporting the bottom 213c with the bottom support die 222 and using the friction between the bottom 213c and the bottom support die 222.

[0133] When considering the above, the present invention provides a method for manufacturing a double-layer container, which includes a blow molding process. In the blow molding process, the inner preform and the outer preform are heated to soften them in a state where the inner preform covers the outer preform, and air is blown into the inner preform in this state. The inner preform is a blow molded body, and the blow molding process is performed in a state where the stretching of the bottom of the outer preform is suppressed.

[0134] Preferably, the outer preform has a reinforcing structure for suppressing the stretching of the bottom of the outer preform. Preferably, the reinforcing structure is an annular convex portion provided at the bottom of the outer preform. Preferably, the blow molding process is performed by supporting the bottom of the outer preform with a bottom support die and in a state where the stretching of the bottom is suppressed.

[0135] In addition, from another perspective, there is provided a method for manufacturing a double-layer container, which includes a blow molding process. The blow molding process is completed by heating the inner preform and the outer preform to soften them in a state where the inner preform covers the outer preform and blowing air into the inner preform. The inner preform is a blow molded body, and the outer preform has an annular convex portion at the bottom.

[0136] It should be noted that in the invention from another perspective, the position of the external air inlet hole is not limited and can be provided at any one of the mouth portion 205, the body portion 206, and the bottom portion 207 of the container body 202. In addition, the spacer member 209 for forming a gap between the outer shell 203 and the inner bag 204 is not necessary.

Embodiment

[0137] The following shows an embodiment related to the first aspect.

[0138] 1. Manufacture of the container body 102 <Embodiment 1> Using direct blow molding and the layer composition shown in Table 3, manufacture as Figure 12The inner container 104 configured as shown. The wall thickness at the center in the height direction of the housing portion 107 of the inner container 104 is 1500 μm.

Table 3

[0139] Each layer in Table 3 is made of the following materials. LDPE / LLDPE layer: A mixed resin with a mass ratio of 50:50 of LDPE (melting point 110 °C, manufactured by Asahi Kasei Corporation, model: F2206) and LLDPE (melting point 120 °C, manufactured by Japan Polyethylene Corporation, model: NF325N) PP layer: Polypropylene (manufactured by Sumitomo Chemical Company, model: FH3315) EVOH layer: EVOH (manufactured by Mitsubishi Chemical Corporation, model: SF7503B) Acid-modified PE / LDPE layer: A mixed resin with a mass ratio of 50:50 of acid-modified polyethylene (manufactured by Mitsubishi Chemical Corporation, model: L522) and LDPE (melting point 110 °C, manufactured by Asahi Kasei Corporation, model: F2206) LDPE layer: LDPE (manufactured by Asahi Kasei Corporation, model: F2206)

[0140] Next, in the method described in the first embodiment, the container body 102 was manufactured by injection molding the jacket 105 at a resin temperature of 220 °C so as to cover the outer peripheral surface and the bottom surface of the inner container 104. The injection molding used an ionomer resin of ethylene·(meth)acrylic acid copolymer (manufactured by Dow-Mitsui Polychemicals Company, model: PC2000, melting point 80 °C).

[0141] <Example 2> As the outermost layer 113c1 of the outer shell 113, the container body 102 was manufactured using the same method as in Example 1, except that the LDPE / ADH layer was used instead of the LDPE / LLDPE layer.

[0142] The LDPE / ADH layer is a mixed resin with a mass ratio of 50:50 of LDPE (melting point 110 °C, manufactured by Asahi Kasei Corporation, model: F2206) and an adhesive resin (melting point 120 °C, manufactured by Mitsubishi Chemical Corporation, model: L522), and the melting point of the mixed resin is 115 °C.

[0143] <Comparative Example 1> As the outermost layer 113c1 of the outer shell 113, the container body 102 was manufactured using the same method as in Example 1, except that the PP layer was used instead of the LDPE / LLDPE layer.

[0144] The PP layer is made of polypropylene (manufactured by Sumitomo Chemical Co., Ltd., model: FH3315), and its melting point is 140°C.

[0145] 2. Evaluation The following evaluations were conducted on the above-mentioned examples and comparative examples, and the results are shown in Table 4. As shown in Table 4, in the examples, the deformability and adhesiveness are good. In contrast, the deformability and adhesiveness of the comparative examples are poor.

[0146]

Table 4

[0147] <Deformability> Visually confirm whether the inner container 104 inside the outer casing 105 is deformed, and evaluate it according to the following criteria. ○: Not deformed ×: Deformed

[0148] <Adhesiveness> Cut the container body 102 longitudinally and confirm whether the inner container 104 can be peeled off from the outer casing 105 by hand, and evaluate it according to the following criteria. ○: It cannot be peeled off even when pulled hard by hand. △: It can be peeled off after being pulled hard by hand. ×: It can be easily peeled off by hand. (Symbol Explanation)

[0149] 1: double-layer container, 2: main body, 3: mouth, 5: recess, 6: check valve, 6s: cavity, 21: outer shell, 22: inner bag, 23: bottom surface, 25: intermediate space, 26: storage space, 30: lid, 31: top surface, 51: specific area, 52: external air introduction hole, 53: opening surface, 54: wall, 55: groove, 60: cylinder, 61: shaft, 62: stopper, 63: expansion part, 64: opening, 65: stopper, 66: surface, 69: ball, 101: storage container, 102: container main body, 103: plug opening member, 104: inner container, 104a: outer peripheral surface, 104b: bottom surface, 104c1: outermost layer, 104c2: adjacent layer, 104c3: other layers, 10 5: outer sleeve, 105a: barrel, 105b: bottom, 105c: ventilation, 107: storage, 107a: trunk, 107b: bottom, 107c: pinch-off, 108: mouth, 108a: engagement, 108b: flat, 109: mold, 109a: cavity, 109b: gate, 110: fixing, 110a: opening, 111: support rod, 112: pump, 112a: main body, 112a1: barrel, 112a2: cylinder, 112a3: upper wall, 112b: piston, 112c: nozzle, 112d: tube, 113: outer shell, 113c1: outermost layer, 113c2: adjacent layer, 113c3: other layers, 114: inner bag, 114c 1: Outermost layer, 114c2: Adhesive layer, 114c3: Inner layer, 115: External air inlet, 201: Double-layer container, 202: Container body, 203: Outer shell, 203a: Insertion hole, 203b: Protrusion, 204: Inner bag, 204a: Stopping protrusion, 204b: Flange, 205: Mouth, 205a: Locking part, 206: Body, 206a: Upper end, 207: Bottom, 207a: Central concave part, 207a1: Stopping part, 207a2: External air inlet hole, 207a3: Annular convex part, 207a4: Positioning concave part, 207b: Peripheral part, 207b1: Grounding part, 207b2: Peripheral concave part, 208: Gap, 209: Spacer, 213: External preform Blank, 213a: mouth, 213b: body, 213c: bottom, 213c1: protrusion, 213c2: positioning hole, 213c3: external air introduction hole, 213c4: annular convex portion, 214: inner preform, 214a: mouth, 214a1: flange, 214b: body, 214c: bottom, 214c1: positioning pin, 214c2: protrusion, 214d: innermost layer, 214e: gas barrier layer, 214e1: gas barrier layer, 214e2: gas barrier layer, 214f: outermost layer, 214g: bottom, 214h: blank cutting part, 215: assembly, 220: mold unit, 221: mouth support mold, 221a: insertion hole, 222: bottom support mold, 222a: recess,222b: concave part, 222c: driving mechanism, 223: forming die, 223a: cavity surface, 224: forming die, 224a: cavity surface, 225: support rod, 226: gas passage, 231: cut embryo, 641: flat surface, 642: slit part, A: area, B: area, C: area, F: force, G: gap, Tpm: melting peak temperature, θ: tilt angle, φ: angle.

Claims

1. A manufacturing method of a double-layer container, which includes a blow molding process, The blow molding process is carried out in the following manner: with the outer preform covering the inner preform, heating and softening the inner preform and the outer preform, and blowing air into the inner preform in this state, The inner preform is a blow molded body, The blow molding process is carried out in a state where the extension of the bottom of the outer preform is suppressed.

2. The manufacturing method of the double-layer container according to claim 1, wherein, The outer preform has a reinforcement structure for suppressing the extension of the bottom of the outer preform.

3. The manufacturing method of the double-layer container according to claim 2, wherein, The reinforcement structure is an annular protrusion provided at the bottom of the outer preform.

4. The manufacturing method of the double-layer container according to any one of claims 1 to 3, wherein, The blow molding process is carried out in a state where the bottom of the outer preform is supported by a bottom support mold to suppress the extension of the bottom.

5. A manufacturing method of a double-layer container, the double-layer container includes an inner bag and an outer shell, and the manufacturing method includes a blow molding process, The blow molding process is carried out in the following manner: heating and softening a preform having a part constituting the inner bag and a part constituting the outer shell, and blowing air into the preform in this state, The blow molding process is carried out in a state where the extension of the bottom of the part constituting the outer shell is suppressed.

6. The manufacturing method of the double-layer container according to claim 5, wherein, The part constituting the outer shell has a reinforcement structure for suppressing the extension of the bottom of the part constituting the outer shell.

7. The manufacturing method of the double-layer container according to claim 6, wherein, The reinforcement structure is an annular protrusion provided at the bottom of the part constituting the outer shell.

8. The manufacturing method of the double-layer container according to claim 7, wherein, An outer air inlet hole is arranged on the outer shell in the area inside the annular protrusion.

9. The manufacturing method of the double-layer container according to any one of claims 5 to 8, wherein, The blow molding process is carried out in a state where the bottom of the part constituting the outer shell is supported by a bottom support mold to suppress the extension of the bottom.

10. A double-layer container, which includes a container body, the container body has an outer shell and an inner bag and the inner bag can contract, The container body is formed by blow molding a preform having a part constituting the inner bag and a part constituting the outer shell, The blow molding process is carried out in a state where the extension of the bottom of the part constituting the outer shell is suppressed.

11. The double-layer container according to claim 10, wherein, The part constituting the outer shell has a reinforcement structure for suppressing the extension of the bottom of the part constituting the outer shell.

12. A double-layer container, which includes a container body, the container body has an outer shell and an inner bag and the inner bag can contract, The container body includes a cylindrical body portion and a bottom provided at the lower end of the body portion, An annular protrusion is provided on the outer shell at the bottom. In the region inside the annular convex portion, an outside air introduction hole is provided on the outer shell.

13. A double-layer container including a container body having an outer shell and an inner bag, the inner bag being capable of shrinking. The container body includes a cylindrical body portion and a bottom portion provided at the lower end of the body portion. The bottom portion includes a central concave portion provided at the center of the bottom portion and a peripheral portion surrounding the periphery of the central concave portion. In the central concave portion, an outside air introduction hole is provided on the outer shell. In the peripheral portion, a spacer member is provided for forming a gap between the outer shell and the inner bag.

14. The double-layer container according to claim 13, wherein the spacer member is a protrusion provided on the outer shell or the inner bag.

15. The double-layer container according to claim 13 or 14, wherein the spacer member is arranged radially.

16. The double-layer container according to claim 13 or 14, wherein the spacer member is arranged to form a discontinuous circle.

17. The double-layer container according to claim 13 or 14, wherein the container body is formed by blow molding the inner preform constituting the inner bag and the outer preform constituting the outer shell while heating them in a state where the inner preform is covered with the outer preform.

18. The double-layer container according to claim 17, wherein the inner preform has a positioning pin at the bottom of the inner preform, the outer preform has a positioning hole at the bottom of the outer preform, and the blow molding is performed with the positioning pin inserted into the positioning hole.

19. The double-layer container according to claim 13 or 14, wherein the container body is formed by blow molding a preform having a portion constituting the inner bag and a portion constituting the outer shell while heating it.

20. A double-layer container including an outer shell, an outside air introduction hole, and an inner bag. The outer shell is configured to be pressed from the outside, and the pressing causes the content accommodated in the inner bag to flow out from the mouth portion. The outside air introduction hole is provided in a specific region on the bottom side of the outer shell, where the bottom side refers to the side away from the mouth portion when the double-layer container is bisected in the height direction. And it is configured to be fitted with a check valve, and through the check valve, after the content flows out, air is introduced into the intermediate space between the inner side of the outer shell and the outer side of the inner bag to restore the shape of the outer shell. The inner bag is configured to be pressed and shrunk by the air introduced into the intermediate space when the content decreases.

21. The double-layer container according to claim 20, wherein the mouth portion is configured to be able to mount a lid, and the top surface of the lid can be placed upside down as a grounding surface.

22. The double-layer container according to claim 21, wherein the area of the top surface of the lid is S1, and the area of the mouth portion is S2, satisfying S1≥1.5×S2.

23. The double-layer container according to any one of claims 20 to 22, wherein the specific region is a part of the side surface of the outer shell.

24. The double-layer container according to any one of claims 20 to 22, wherein, The specific region is located in a concave portion of the outer shell, and is configured to have an inclination angle with respect to the opening surface defining the concave portion.

25. The double-layer container according to claim 24, wherein the inclination angle is 5 degrees or more and 45 degrees or less.

26. The double-layer container according to claim 24, wherein the wall of the recess is configured not to be perpendicular to the opening surface.

27. The double-layer container according to claim 24, wherein it further includes a groove portion, and the groove portion is provided at a position on the outer shell closer to the bottom side than the specific area.

28. The double-layer container according to claim 27, wherein the depth of the groove portion is shallower than the depth of the recess.

29. The double-layer container according to any one of claims 20 to 22, wherein the check valve is a ball valve.

Images