Double-walled aerosol container and inner bag

Abstract

To provide a double aerosol container that suppresses damage to a flange part of an inner bag during manufacturing and suppresses leakage of a content and pressurized gas.SOLUTION: A double aerosol container comprises: an outer container 11 having an end wall part 11a defining an open end, a side wall part 11c extending downward via an enlarged shoulder wall part 11b, and a bottom wall part 11d; and an inner bag 12 having: an open end part 12a with a flange part 12a1; a first trunk part 12c extending downward through a shoulder part 12b having a diameter larger than that of the flange part 12a1; a constricted part 12d connected to a lower end of the first trunk part 12c and having a smaller diameter than the first trunk part 12c; a second trunk part 12e connected to a lower end of the constricted part 12d and extending downward and having substantially the same outer diameter as the first trunk part 12c; and a bottom part 12f. When the inner bag 12 is arranged in the outer container 11, the bottom part 12f and the bottom wall part 11d are in contact with each other, and the flange part 12a1 protrudes from the end wall part 11a.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a double aerosol container and an inner bag used therefor.

Background Art

[0002] There is a double aerosol container in which a flexible plastic inner bag is housed in an outer container such as a metal can. The shape of the inner bag is designed in consideration of a gap space for housing a pressurized gas. As a general inner bag, there is one having an open end portion with a flange portion, a body portion extending axially along a portion whose diameter is larger than the outer diameter of the flange portion from the lower end of the open end portion, and a bottom portion closing the body portion (Patent Document 1). Also, when such an inner bag is inserted into an outer container, there is one in which the bottom of the inner bag abuts on the bottom wall portion of the outer container (Patent Documents 1 to 3).

[0003] At this time, the open end portion is in a state of protruding from the open end wall portion of the outer container, and the pressurized gas is filled in the gap space defined by the inner bag and the outer container. Then, by caulking the valve covering the openings of the outer container and the inner bag, a double aerosol container is obtained.

[0004] In such an inner bag, since almost no gap space can be obtained between the bottom of the inner bag and the bottom wall portion of the outer container, most of the gap space is formed by an annular portion between the body portion of the inner bag and the side wall portion of the outer container. On the other hand, the open end wall portion of the outer container is designed to match the diameter suitable for a general-purpose valve, that is, the outer diameter of the side wall portion of the mounting cup of the valve (about 25.4 mm). Also, when formed by a curled portion where the end wall portion is bent in a curled shape, the outer diameter of the side wall portion constituting the body portion of the outer container is set to a minimum outer diameter of 33 mm, which is slightly larger than the outer diameter of the curled portion.

[0005] When the outer diameter of the outer container is small, especially if the outer diameter is 40 mm or less, the required gap space may not be obtained. To obtain the required gap space, it is known that the body of the inner bag should be made slightly smaller than the inner diameter of the end wall of the outer container. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-240760 [Patent Document 2] Japanese Patent Application Publication No. 9-118380 [Patent Document 3] Japanese Patent Publication No. 2005-41547 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, in the double-walled aerosol container described in Patent Document 1, the flange portion protrudes radially beyond the outer diameter of the body, which may cause damage to the flange portion. If the gap space is wide, it becomes difficult to stabilize the position of the inner bag when it is transported in automated equipment such as a container manufacturing line. If the position of the inner bag is not stable when it is transported, it may lead to damage to the flange portion. In addition, sealing materials such as gaskets that are placed or fixed in a predetermined position at the open end may shift from their predetermined position. Such malfunctions may lead to leakage of pressurized gas.

[0008] In view of the above issues, the objective is to provide a double-walled aerosol container and an inner bag for use therein that suppress damage to the flange portion of the inner bag, thereby suppressing leakage of the contents and pressurizing agent of the double-walled aerosol container, and that the inner bag remains stable when transported alone or when transported while contained in an outer container. [Means for solving the problem]

[0009] The double-walled aerosol container 10 of the present invention comprises an outer container 11 having an end wall portion 11a defining an open end, a side wall portion 11c extending axially downward from the end wall portion 11a via an enlarged portion (shoulder wall portion 11b), and a bottom wall portion 11d closing the lower end of the side wall portion 11c; an open end portion 12a having a flange portion 12a1, a first body portion 12c extending axially downward from the lower end of the open end portion 12a via a portion (shoulder portion 12b) that is larger in diameter than the outer diameter of the flange portion 12a1, and a connection to the lower end of the first body portion 12c The invention comprises inner bags 12, 12A, and 12B, each having a constricted portion 12d that is smaller in diameter than the first body portion 12c, a second body portion 12e that extends downward and is connected to the lower end of the constricted portion 12d and has substantially the same outer diameter as the first body portion 12c, and a bottom portion 12f that closes the lower end of the second body portion 12e, wherein when the inner bags 12, 12A, and 12B are placed inside the outer container 11, the bottom portion 12f and the bottom wall portion 11d come into contact, and the flange portion 12a1 protrudes above the end wall portion 11a.

[0010] In such a double-walled aerosol container 10, it is preferable that the constricted portion 12d of the inner bags 12, 12A, and 12B has a first diameter-reducing portion 12d1 that is reduced in diameter axially downward from the first body portion 12c, and a second diameter-reducing portion 12d2 that is reduced in diameter axially upward from the second body portion 12e. It is also preferable that there is a cylindrical portion 12d3 extending axially between the first diameter-reducing portion 12d1 and the second diameter-reducing portion 12d2.

[0011] Furthermore, it is even more preferable that, when a tangent line L is drawn from an arbitrary point in the region of the inner surface of the inner bag 12 having a diameter greater than or equal to the inner diameter of the open end 12a in a longitudinal cross-sectional view passing through axis J, and the tangent line L touches the inner surface of the open end 12a on the opposite side of axis J at one point, the straight portion located axially above the tangent point extends without intersecting the inner surface of the inner bag 12, or extends along the inner surface of the inner bag 12. The inner bag 12 may also be shaped so that the entire inner surface of the inner bag 12 can be seen from the open end 12a.

[0012] Furthermore, a double-walled aerosol container 10 is preferred in which the outer diameter of the side wall portion 11c of the outer container 11 is 40 mm or less and 33 mm or more. In addition, a double-walled aerosol container is preferred in which the inner diameter of the side wall portion 11c of the outer container 11 is 2 to 10 mm larger than the outer diameter of the first body portion 12c of the inner container 12, and the outer diameter of the smallest diameter portion of the constricted portion 12d of the inner container 12 is 7 to 14 mm smaller than the outer diameter of the first body portion 12c.

[0013] The inner bags 12, 12A, and 12B of the present invention are inner bags for use in a double-walled aerosol container 10, and are characterized in that they have an open end 12a having a flange portion 12a1, a first body portion 12c extending axially downward from the lower end of the open end 12a via a portion (shoulder portion 12b) that is larger in diameter than the outer diameter of the flange portion 12a1, a constricted portion 12d connected to the lower end of the first body portion 12c and having a smaller diameter than the first body portion 12c, a second body portion 12e connected to the lower end of the constricted portion 12d and extending downward and having substantially the same outer diameter as the first body portion 12c, and a bottom portion 12f that closes the lower end of the second body portion 12e, wherein the constricted portion 12d has a first diameter reduction portion 12d1 that is smaller in diameter axially downward from the first body portion 12c, and a second diameter reduction portion 12d2 that is smaller in diameter axially upward from the second body portion 12e.

[0014] In such inner bags 12, 12A, and 12B, it is preferable that there is a cylindrical portion 12d3 extending in the axial direction between the first reduced diameter portion 12d1 and the second reduced diameter portion 12d2. Furthermore, in a longitudinal cross-sectional view passing through axis J, when a tangent line is drawn from an arbitrary point in the region of the inner surface of the inner bags 12, 12A having a diameter greater than or equal to the inner diameter of the open end 12a, with respect to axis J, and touching the inner surface of the open end 12a on the opposite side of the base point at one point, it is preferable that the straight portion located axially above the base point extends without intersecting the inner surface of the inner bags 12, 12A, or extends along the inner surface of the inner bags 12, 12A. [Effects of the Invention]

[0015] In the double-walled aerosol container of the present invention, the first body of the inner bag extends axially downward through a portion that is larger in diameter than the outer diameter of the flange, thereby suppressing damage to the flange and thus suppressing leakage of pressurized gas. Furthermore, because the inner bag has a constricted portion, a sufficiently wide gap can be formed between the outer container and the inner bag when the inner bag is inserted into the outer container. Therefore, the diameters of the first and second bodies of the inner bag do not need to be significantly smaller than the inner diameter of the outer container. Consequently, the inner bag is stable within the outer container, making it easy to transport the inner bag in automated equipment.

[0016] In such a double-walled aerosol container, if the constricted portion of the inner bag has a first diameter-reducing portion that decreases in diameter axially downward from the first body portion and a second diameter-reducing portion that decreases in diameter axially upward from the second body portion, the inner bag is more likely to collapse due to the pressurized gas filled between the outer container and the inner bag. Furthermore, if there is a cylindrical portion extending axially between the first and second diameter-reducing portions, the volume of the gap space between the outer container and the inner bag increases, allowing for a larger amount of pressurized gas to be filled.

[0017] Furthermore, in a longitudinal cross-sectional view passing through the axis, if a tangent line is drawn from an arbitrary point in the region of the inner surface of the inner bag having a diameter greater than or equal to the inner diameter of the open end, and touches the inner surface of the open end on the opposite side of the axis at one point, then if the straight portion located axially above the tangent point extends without intersecting the inner surface of the inner bag, or extends along the inner surface of the inner bag, then the inside of the inner bag is easily visible from the open end, and foreign objects such as dirt are easily detected. The same effect is achieved if the inner bag is shaped so that the entire inner surface of the inner bag is visible from the open end.

[0018] When the outer diameter of the side wall portion of the outer container is 40 mm or less and 33 mm or more, it is easier to exhibit the above-described effects. When the inner diameter of the side wall portion of the outer container is 2 to 10 mm larger than the outer diameter of the first body portion of the inner container, and the outer diameter of the minimum diameter portion of the constricted portion of the inner container is 7 to 14 mm smaller than the inner diameter of the first body portion, the inner bag housed in the outer container can be stably held, and moreover, the amount of the pressurized gas in the gap space can be increased.

[0019] The double aerosol container using the inner bag of the present invention exhibits the same effects as the above-described double aerosol container.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a cross-sectional view showing an embodiment of the double aerosol container of the present invention together with a valve assembly. [Figure 2] FIG. 2 is a cross-sectional view of the inner bag used in the double aerosol container of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view showing another embodiment of the inner bag of the present invention. [Figure 4] FIG. 4 is a cross-sectional view showing still another embodiment of the inner bag of the present invention.

Modes for Carrying Out the Invention

[0021] The double aerosol container 10 shown in FIG. 1 includes an outer container 11 and an inner bag 12 housed inside the outer container 11. FIG. 1 shows the state before the inner bag 12 is fixed to the outer container 11. In this state, the upper end of the inner bag 12 protrudes outside the upper end of the outer container 11, and a valve 13 is attached to the protruding portion. The valve 13 is in the state before being crimped to the outer container 11. The internal space S1 of the inner bag 12 is a space for filling the content (stock solution), and the gap space S2 between the outer container 11 and the inner bag 12 is a space for filling the pressurized gas.

[0022] (Embodiment 1) As shown in Figure 2, the inner bag 12 has an open end portion 12a that forms an upper opening. The open end portion 12a has an annular flange portion 12a1 extending radially outward and a neck portion 12a2 extending downward along the axial direction via a bent portion from the inner edge of the flange portion 12a1. A portion with a larger diameter than the outer diameter of the flange portion 12a1, i.e., a shoulder portion 12b, is connected to the lower end of the open end portion 12a. The shoulder portion 12b extends so as to widen downward in the axial direction. In this embodiment, the flange portion 12a1 is a flat annular shape, and the neck portion 12a2 is substantially cylindrical. The shoulder portion 12b is substantially frustoconical, and its inclination angle θ1 with respect to the axis J is about 30 to 45°. In cross-sectional shape, the shoulder portion 12b has a curved shape in which inward and outward convexities are continuous.

[0023] A first torso section 12c, extending axially downward, is connected to the outer circumferential end of the shoulder section 12b. A constricted section 12d, smaller in diameter than the first torso section 12c, is connected to the lower end of the first torso section 12c, and a second torso section 12e, substantially equal in outer diameter to the first torso section 12c, is connected to the lower end of the constricted section 12d. The lower end of the second torso section 12e is closed by a bottom section 12f. The vertical dimension of the first torso section 12c may be, for example, about 5 to 20 mm, the vertical dimension of the constricted section 12d may be about 15 to 45 mm, and the vertical dimension of the second torso section 12e may be about 5 to 20 mm. The outer diameter of the smallest diameter part of the constricted section 12d may be about 7 to 14 mm smaller than the outer diameter of the first torso section.

[0024] The ratio of the vertical dimension of the first body section 12c to the vertical dimension of the second body section 12e is set to approximately 1:1, but it may be around 1:3 to 3:1, or 1:2 to 2:1. By making them roughly the same length, the position of the inner bag 12 inside the outer container 11 is more stable. Furthermore, the ratio of [vertical dimension of the first body section 12c + vertical dimension of the second body section 12e] to [vertical dimension of the constricted section 12d] is set to approximately 2:3.

[0025] The constricted portion 12d has a first reduced diameter portion 12d1 that is reduced in diameter axially downward from the first body portion 12c, and a second reduced diameter portion 12d2 that is reduced in diameter axially upward from the second body portion 12e. In this embodiment, there is a cylindrical portion 12d3 that extends axially between the first reduced diameter portion 12d1 and the second reduced diameter portion 12d2. The cylindrical portion 12d3 can be omitted, but if the cylindrical portion 12d3 is provided, especially if the cylindrical portion 12d3 is made longer in the axial direction, the region where the outer diameter is smallest becomes larger, so the volume of the gap space (reference numeral S2 in Figure 1) can be increased. In addition, since the axial distance between the first body portion 12c and the second body portion 12e becomes longer, the posture of the inner bag 12 can be made even more stable.

[0026] In this embodiment, the first diameter-reduced portion 12d1 is generally frustoconical in shape, and its inclination angle θ2 with respect to the axis J is approximately 20 to 45°. Furthermore, the first diameter-reduced portion 12d1 includes a radially outward-convex curved portion R1 connected to the first body portion 12c, and a radially inward-convex curved portion R2 connected to the cylindrical portion 12d3. The inclination angle θ2 of the first diameter-reduced portion 12d1 can be made larger, and by increasing the inclination angle θ2, the vertical dimension of the first diameter-reduced portion 12d1 is shortened. As a result, the vertical dimension of the second diameter-reduced portion 12d2 can be made longer, and the volume of the gap space S2 can be increased. Furthermore, the inclination angle θ3 of the second diameter-reduced portion 12d2, which will be described later, can be made smaller.

[0027] The second reduced-diameter section 12d2 comprises, in order from the upper end of the second body section 12e upward in the axial direction, a bent section (hereinafter referred to as the bent section) P1 that connects to the second body section 12e, a linearly extending section (hereinafter referred to as the linear section) T1, and a curved section (hereinafter referred to as the curved section) R3. The order of the linear section T1 and the curved section R3 may be reversed. Either one of them can be omitted, and the entire section can extend in either a curved or linear manner. The linear section T1 is approximately frustoconical in shape, and its inclination angle θ3 with respect to the axis J is small, about 10 to 20°. If the inclination angle θ3 is large, the linear section T1 may not be visible when viewed from the upper end opening (see Figure 4), but because the inclination angle θ3 is small, the entire inner surface of the inner bag 12 can be seen from the upper end opening.

[0028] In the curved section R3, the inclination angle θ with the axis J gradually decreases as you move axially upward. In other words, the inclination angle of the curved section R3 changes from an angle θ3 equal to the angle of the straight section T1 to an angle that gradually approximates 0 degrees as you move axially upward. Because the change in angle is gradual and there are few curved sections with a small radius of curvature, the contents tend to deform into a flat shape after being dispensed.

[0029] Furthermore, in this embodiment, when a tangent line L is drawn from an arbitrary point in the region of the inner surface of the inner bag 12 having a diameter greater than or equal to the inner diameter of the open end 12a, in a longitudinal cross-sectional view including the axis J, and touches the inner surface of the open end 12a on the opposite side of the axis J at one point, the straight portion located axially above the base point extends without intersecting the inner surface of the inner bag 12. When the inner surface of the inner bag 12 is positioned in this way with respect to the tangent line L, it becomes easy to visually inspect the inside of the inner bag 12 from the outside of the open end 12a. In addition, it is easy to visually inspect the inside of the inner bag 12 even after it has been placed in the outer container 11. Furthermore, it is easy to clean by air blowing and disinfect by ultraviolet light.

[0030] In this embodiment, the bottom portion 12f of the inner bag 12 has a tapered portion 12f1 that narrows downward from the second body portion 12e. The tapered portion 12f1 extends in an arc shape in a longitudinal cross-sectional view, but it may also extend straight in a tapered shape. When the inner bag 12 is formed by blow molding, the bottom portion 12f may have a pinch-off portion 12f2 on the outer side, i.e., the lower surface side, which is formed by being sandwiched in the mold. The pinch-off portion 12f2 may be formed in a recess 12f3 that protrudes from the bottom portion 12f toward the second body portion 12e, and may be formed so as not to protrude from the lowest end of the bottom portion 12f. This allows the inner bag 12 to stand upright stably in the outer container 11.

[0031] The inner bag 12 can be formed in a single or multilayer structure using one or more synthetic resins such as polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, or polyamide. The thickness of the inner bag 12 may be 0.3 to 0.6 mm. The inner bag 12 is formed by blow molding or the like. The inner bag 12 has appropriate flexibility so that when it is pushed into the outer container 11 together with the valve 13 from the state shown in Figure 1, it shrinks in the vertical or radial direction, and so that it flattens as the contents of the inner bag 12 are discharged using the double aerosol container 10. If such deformation is possible, a synthetic resin film laminated with metal foil can also be used.

[0032] Returning to Figure 1, the outer container 11 has an end wall portion 11a that defines the open end, a side wall portion 11c that extends axially via an enlarged portion from the end wall portion 11a, in other words, a shoulder wall portion 11b, and a bottom wall portion 11d that closes the lower end opening of the side wall portion 11c. The side wall portion 11c is cylindrical. However, irregularities may be provided within a practical range. The outer diameter of the side wall portion 11c is usually 40 mm or less and 33 mm or more. The inner diameter of the side wall portion 11c is slightly larger than the outer diameter of the first body portion 12c and the second body portion 12e of the inner bag 12, for example, about 2 to 10 mm. As a result, the gap G1 (half the difference in diameters) between the inner surface of the side wall portion 11c and the outer surfaces of the first body portion 12c and the second body portion 12e when they are housed concentrically is about 1 to 5 mm. The gap G1 is preferably narrow enough so as not to hinder the insertion of the inner bag 12 into the outer container 11, thereby stabilizing the position of the inner bag 12 inside the outer container 11.

[0033] On the other hand, the gap G2 (half the difference in diameters) between the inner surface of the side wall portion 11c and the outer surface of the cylindrical portion 12d3 is approximately 8 to 16 mm. A larger gap G2 is preferable because it increases the volume of the gap space S2. However, ease of blow molding and the tendency to flatten after the contents are dispensed should be considered. The end wall portion 11a of the outer container 11 may be a curled portion that is bent to curl. The mounting cup 13a of the valve 13 is attached to the end wall portion 11a by clinching.

[0034] The outer container 11 may be made of a metal material such as aluminum, aluminum alloy, or steel, or a synthetic resin material such as polyethylene terephthalate. In this embodiment, the bottom wall portion 11d, the side wall portion 11c, the shoulder wall portion 11b, and the end wall portion 11a are integrally formed. For example, a bottomed cylindrical pre-molded body is made by impact molding, drawing, or the like, with the bottom wall portion 11d and the side wall portion 11c integrally formed, and a secondary molding is performed on a portion of the open side of this pre-molded body to form the shoulder wall portion 11b and the end wall portion 11a. However, the three portions above the bottom wall portion 11d, the side wall portion 11c, and the shoulder wall portion 11b may be made separately and then joined together, or two adjacent portions may be made integrally, the remainder may be made separately and then joined together.

[0035] The inner bag 12 is inserted into the outer container 11 through the opening in the end wall portion 11a of the outer container 11, and the bottom portion 12f of the inner bag 12 is brought into contact with the bottom wall portion 11d of the outer container 11 to make it stand upright. In this state, the flange portion 12a1 of the inner bag 12 protrudes axially upward from the end wall portion 11a of the outer container 11. In addition, all or part of the neck portion 12a2, which is located axially below the flange portion 12a1, may also protrude axially upward from the end wall portion 11a.

[0036] The valve 13 assembled to the inner bag 12 comprises a mounting cup 13a fixed to the end wall portion 11a of the outer container 11, and a discharge portion 13b held by the mounting cup 13a that opens and closes a passage through which the contents pass. The mounting cup 13a has a central wall portion 13c to which the discharge portion 13b is fixed, an outer wall portion 13d, an edge wall portion 13e extending radially outward from the upper end of the outer wall portion 13d, and a transverse wall portion 13f connecting the lower ends of the central wall portion 13c and the outer wall portion 13d, respectively.

[0037] The valve 13 and the inner bag 12 are temporarily fixed together when the outer wall portion 13d of the mounting cup 13a is inserted into the open end portion 12a of the inner bag 12. In this state, pressurized gas is filled into the gap space S2 between the outer container 11 and the inner bag 12 through the gap between the open end portion 12a of the inner bag 12 and the end wall portion 11a of the outer container 11 (under-cup filling). Subsequently, the valve 13 is pressed downward in the axial direction until the edge wall portion 13e of the mounting cup 13a is at a height that covers the end wall portion 11a. At this time, the sealing material 14 located below the flange portion 12a of the inner bag 12 comes into contact with the end wall portion 11a. The inner bag 12 is also compressed in the axial direction. In this state, the outer wall portion 13d is crimped so that it partially protrudes outward, and the valve 13 and the inner bag 12 are fixed to the outer container 11.

[0038] The contents to be contained in the internal space S1 of the inner bag 12 are filled into the internal space S1 before or after the valve 13 and the inner bag 12 are temporarily fixed in place. The ratio of the volume of the internal space S1 of the inner bag 12 to the volume of the gap space S2 between the inner bag 12 and the outer container 11 is set to 60:40, but it may also be 80:20 to 30:70, or 75:25 to 55:45 may be an acceptable range. With a normal inner bag, increasing the gap space would reduce the diameter of the inner bag's body, making it unstable. However, in this invention, even if the gap space is increased, the diameters of the first and second body sections can be made approximately the same as the inner diameter of the outer container, allowing for stable containment.

[0039] In this embodiment, since the outer diameter of the flange portion 12a1 of the inner bag 12 is smaller than the outer diameters of the first body portion 12c and the second body portion 12e, damage to the flange portion 12a1 is suppressed. Also, since the first body portion 12c and the second body portion 12e have substantially equal outer diameters, the posture of the inner bag 12 is stable when the inner bag 12 is transported on a container manufacturing line or the like. Furthermore, because the posture of the inner bag 12 is stable, damage to the flange portion 12a1 is suppressed. And because the inclination angle θ3 of the second reduced diameter portion 12d2 is small, there are no shaded areas when viewing the inner surface from the upper opening. Therefore, it is easy to see.

[0040] (Embodiment 2) The inner bag 12A shown in Figure 3, like the inner bag 12 in Figure 2, is housed inside the outer container 11 and used as a double aerosol container (see Figure 1). In this inner bag 12A, the shape of the constricted portion 12d differs from that of the inner bag 12 in Figure 2. Specifically, the vertical dimension and inclination angle θ2 of the first reduced diameter portion 12d1 are approximately the same as the vertical dimension and inclination angle θ3 of the second reduced diameter portion 12d2. Also, the inclination angles θ2 and θ3 of each reduced diameter portion 12d1 and 12d2 with respect to the axis J are, for example, about 10 to 20°. The vertical dimension of the cylindrical portion 12d3 is about 5 to 26 mm, which is longer than that of the inner bag 12 in Figure 2.

[0041] Furthermore, the first reduced-diameter portion 12d1 of the constricted portion 12d differs from the inner bag 12 (Embodiment 1) in that it is composed of a bent portion P2 connected to the first body portion 12c, a straight portion T2, and a bent portion P3 connected to the cylindrical portion 12d3. Also, the second reduced-diameter portion 12d2 differs from Embodiment 1 in that it does not have a curved portion (reference numeral R3 in Figure 2), and is composed of a bent portion P1 connected to the second body portion 12e, a straight portion T1, and a bent portion P4 connected to the cylindrical portion 12d3.

[0042] Furthermore, in the inner bag 12A shown in Figure 3, there is no recess in the bottom 12f (see reference numeral 12f3 in Figure 2), and the pinch-off portion 12f2 protrudes downward from the lower surface of the bottom 12f. Because this inner bag 12A has a simple mold structure, it is easy to blow mold. In other respects, it is substantially the same as the inner bag 12 shown in Figure 2.

[0043] In the inner bag 12A shown in Figure 3, the outer diameters of each body portion 12c and 12e are larger than the outer diameter of the flange portion 12a1. Therefore, similar to Embodiment 1 in Figure 2, damage to the flange portion 12a1 is suppressed, and the posture of the inner bag 12A is stabilized when the inner bag 12A is transported. Furthermore, because it has a constricted portion 12d, when it is housed in an external container, even if the gap between the external container and the body portions 12c and 12e of the inner bag 12A is small, the volume of the space between the external container and the inner bag 12A is large, allowing for a sufficiently large amount of pressurized gas to be filled.

[0044] In the inner bag 12A (Embodiment 2) shown in Figure 3, when a tangent line L is drawn in a longitudinal cross-sectional view passing through axis J, touching the upper end of the inner surface of the second reduced diameter portion 12d2 and the inner surface of the open end 12a passing through axis J, the inner surface of the second reduced diameter portion 12d2 is located on the tangent line L. Therefore, in the inner bag 12A of Figure 3, as with Embodiment 1 of Figure 2, it is easy to visually inspect the inner surfaces of the second reduced diameter portion 12d2, the second body portion 12e, and the bottom portion 12f from the outside of the open end 12a. Furthermore, if the angle θ3 of the straight portion T1 of the second reduced diameter portion 12d2 with respect to axis J is made smaller than the angle of the tangent line L with respect to axis J (see T1a), the inner surface of the inner bag 12A is easier to see. Conversely, if the angle θ3 of the straight portion T1 is made larger than the angle of the tangent line (see T1b), the inner surface of the second reduced diameter portion 12d2 cannot be seen from the open end 12a.

[0045] (Embodiment 3) In the inner bag 12B (Embodiment 3) shown in Figure 4, the first reduced diameter portion 12d1 of the constricted portion 12d does not have a curved portion that is convex radially inward, but is composed only of a curved portion R1 that is convex radially outward, and the portion that connects to the cylindrical portion 12d3 is a bent portion P3, which is different from the inner bag 12 (Embodiment 1) in Figure 2 and the inner bag 12A (Second Embodiment) in Figure 3. Similarly, the second reduced diameter portion 12d2 is composed only of a curved portion R3 that is convex radially outward, and the portion that connects to the cylindrical portion 12d3 is a bent portion P4, which is different from Embodiment 1.

[0046] In Embodiment 3 of Figure 4, the outer diameters of each body portion 12c and 12e are larger than the outer diameter of the flange portion 12a1. Therefore, similar to Embodiment 1 of Figure 2 and Embodiment 2 of Figure 3, damage to the flange portion 12a1 is suppressed, and the posture of the inner bag 12B is stabilized when the inner bag 12B is transported. In addition, because it has a constricted portion 12d, when it is housed in an external container, the volume of the gap space between the external container and the inner bag 12B is large, allowing for a sufficiently large amount of pressurized gas to be filled.

[0047] On the other hand, the inner bag 12B (Embodiment 3) in Figure 4 differs from Embodiments 1 and 2 in that it is not configured so that the entire inner surfaces of the second reduced diameter portion 12d2, the second body portion 12e, and the bottom portion 12f can be visually inspected from the outside of the open end portion 12a. That is, in Embodiment 3, when a tangent line L is drawn in a longitudinal cross-sectional view passing through axis J, touching the upper end of the inner surface of the second reduced diameter portion 12d2 and the inner surface of the open end portion 12a passing through axis J, the inner surface of the second reduced diameter portion 12d2 is located radially outward from the tangent line L. In other words, the inclination angle θ3 of the upper end of the second reduced diameter portion 12d2 with respect to axis J is greater than the angle θ4 of the tangent line L with respect to axis J.

[0048] In this case, the inner surface of the second reduced-diameter portion 12d2 and the upper part of the second body portion 12e cannot be visually inspected from the outside of the open end portion 12a. However, the effects of suppressing damage to the flange portion 12a1 and stabilizing the posture of the inner bag 12B when transporting the inner bag 12B are achieved in the same manner as in Embodiment 1 and Embodiment 2.

[0049] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be adopted. For example, in the double aerosol container 10 of Figure 1, a cylindrical flow channel member such as a dip tube is not provided at the lower end of the valve 13, but it may be provided depending on the contents. The second reduced diameter portion 12d2 of the inner bag 12 in Figure 2 extends in a straight line at the bottom, but it may be gently curved so as to be convex inward, or gently curved so as to be convex outward. [Explanation of Symbols]

[0050] 10 Double-walled aerosol container 11. Outer container 11a End wall 11b Shoulder wall 11c Side wall part 11d Bottom wall 12, 12A, 12B inner bag 12a open end 12a1 Flange section 12a2 neck 12b Shoulder 12c First hull 12d Waist area 12d1 1st reduced diameter section 12d2 2nd reduced diameter section 12d3 Cylinder part R1, R2, R3 Curved sections (parts that extend in a curved shape) P1, P2, P3, P4: Bent section (bent part) T1, T2, T1a, T1b: Straight section (part extending in a straight line: tapered section) 12e Second Fuselage 12f bottom 12f1 Narrowing section 12f2 Pinch-off section 12f3 recess S1 interior space S2 Gap Space L tangent J axis θ1 Shoulder inclination angle θ2 Inclination angle of the first reduced diameter section θ3 Inclination angle of the second reduced diameter section θ4 tangent angle 13 valves 13a Mounting Cup 13b Discharge part 13c Central wall 13d Exterior wall section 13e Edge wall section 13th floor transverse wall section 14. Sealant

Claims

1. An external container having an end wall portion that defines an open end, a side wall portion that extends axially downward through a portion that widens from the end wall portion, and a bottom wall portion that closes the lower end of the side wall portion, An inner bag having an open end with a flange portion, a first body portion extending axially downward from the lower end of the open end via a portion that is larger in diameter than the outer diameter of the flange portion, a constricted portion connected to the lower end of the first body portion and having a smaller diameter than the first body portion, a second body portion connected to the lower end of the constricted portion and extending downward, having substantially the same outer diameter as the first body portion, and a bottom portion that closes the lower end of the second body portion, It is equipped with a valve attached to the upper end of the inner bag, When the inner bag is placed inside the outer container, the bottom and the bottom wall come into contact, and the flange protrudes above the end wall. A double-walled aerosol container with a valve, characterized in that, with the valve clinched to the outer container, the inside of the inner bag is a space for filling the contents, in which the first body, the constricted portion, and the second body are in communication.

2. The double-walled aerosol container with a valve according to claim 1, characterized in that the constricted portion has a first diameter reduction portion that decreases in diameter axially downward from the first body portion, and a second diameter reduction portion that decreases in diameter axially upward from the second body portion.

3. The double-walled aerosol container with a valve according to claim 2, characterized in that it has a cylindrical portion extending in the axial direction between the first diameter-reduced portion and the second diameter-reduced portion.

4. A double-walled aerosol container with a valve according to any one of claims 1 to 3, characterized in that, when a tangent line is drawn from an arbitrary point in the region of the inner surface of the inner bag having a diameter greater than or equal to the inner diameter of the open end, with respect to the axis, and the line touches the inner surface of the open end on the opposite side of the axis at one point, the straight portion located axially above the reference point extends without intersecting the inner surface of the inner bag, or extends along the inner surface of the inner bag.

5. The double-walled aerosol container with a valve according to any one of claims 1 to 3, characterized in that the inner bag is shaped so that the entire inner surface of the inner bag can be seen from the open end.

6. A double-walled aerosol container with a valve according to any one of claims 1 to 5, wherein the outer diameter of the side wall portion of the outer container is 40 mm or less and 33 mm or more.

7. The inner diameter of the side wall portion of the outer container is 2 to 10 mm larger than the outer diameter of the first body portion of the inner bag. The outer diameter of the smallest diameter portion of the constricted part of the inner bag is 7 to 14 mm smaller than the outer diameter of the first body portion. A double-walled aerosol container with a valve according to any one of claims 1 to 6.

8. An inner bag for use in a double-walled aerosol container with a valve, It has an open end with a flange portion, a first body portion extending axially downward from the lower end of the open end via a portion that is larger in diameter than the outer diameter of the flange portion, a constricted portion connected to the lower end of the first body portion and having a smaller diameter than the first body portion, a second body portion connected to the lower end of the constricted portion and extending downward, having substantially the same outer diameter as the first body portion, and a bottom portion that closes the lower end of the second body portion. The constricted portion has a first conical, substantially frustoconical, tapered portion that tapers downward in the axial direction from the first body portion, and a second constricted portion that tapers upward in the axial direction from the second body portion. The inner bag is characterized in that the second diameter reduction portion has a straight section extending linearly with an inclination angle of 10 to 20° with respect to the axis, a curved section extending curvedly such that the inclination angle with respect to the axis gradually decreases, or both the straight section and the curved section.

9. The inner bag according to claim 8, characterized in that it has a cylindrical portion extending axially in a cylindrical shape between the first diameter reduction portion and the second diameter reduction portion.

10. The inner bag according to claim 8 or 9, characterized in that, when a tangent line is drawn with respect to the axis from an arbitrary point in the region of the inner surface of the inner bag having a diameter greater than or equal to the inner diameter of the open end, with respect to the axis, the straight portion located axially above the reference point extends without intersecting the inner surface of the inner bag, or extends along the inner surface of the inner bag.

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