Tube container and production method for tube container

Abstract

Provided is a less-expensive tube container that has excellent recyclability.　This tube container 1 has an end seal part 30 that: is formed by welding an inner circumferential surface of a rolled sheet S that has been heated with hot air and then brought together in a first direction D1; and seals another end part 14 in the axial direction DA of a cylindrical body part 10. The sheet S includes a first base material layer SL1 that constitutes the inner circumferential surface of the sheet S when the sheet S has been rolled and a reinforcing layer RL that is further to the outer circumferential side than the first base material layer SL1. The first base material layer SL1 is formed from a not-stretched film that includes a polyester resin. The reinforcing layer RL is formed from a biaxially-stretched film that includes a resin component so as to be capable of supporting the first base material layer SL1 such that the inner peripheral surface as heated by hot air to become weldable is opposite itself in the first direction D1.

Description

Tube container and method for manufacturing the tube container

[0001] The present invention relates to a tube container and a method for manufacturing the tube container.

[0002] Japanese Patent Laid-Open Publication No. 2009-190785 (Patent Document 1) discloses a multi-layer laminated tube made of polyethylene with a wall thickness of 0.36 mm. Furthermore, Patent Document 1 discloses a method of sealing a tube by melting the opening of a tube container with hot air and then pressurizing and sealing the opening with a sealing device.

[0003] JP 2009-190785 A

[0004] In order to improve the recyclability of tube containers and to facilitate the formation of the cylindrical body portion of the tube container, the use of a non-stretched film containing a polyester resin as a layer constituting the inner peripheral surface of the cylindrical body portion has been considered. As a method for forming the end seal portion of such tube containers, hot air welding as disclosed in Patent Document 1 has been considered.

[0005] However, because unstretched films containing polyester resins can be easily melted by heating with hot air, their rigidity also decreases. The decrease in sheet rigidity due to heating with hot air can cause the sheet constituting the tube container to bend inward just before the inner circumferential surfaces of the tube containers are butted together. This can result in a decrease in yield in the process of forming the end seals and an increase in the manufacturing cost of the tube container.

[0006] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a tube container that is highly recyclable and less expensive.

[0007] The tube container according to the present invention comprises a cylindrical body portion, a pouring portion, and an end seal portion. The cylindrical body portion has a band-shaped welded portion formed by curving or bending a single sheet, and overlapping and welding a first side end portion in the surface direction of the sheet and a second side end portion of the sheet opposite the first side end portion in the thickness direction of the sheet. The pouring portion is joined to one axial end of the cylindrical body portion and allows the contents contained in the cylindrical body portion to be poured. The end seal portion is formed by welding the inner circumferential surface of the sheet, which is formed into a cylindrical shape by overlapping and welding the first side end portion and the second side end portion in the thickness direction of the sheet, in a first direction perpendicular to the axial direction while heated with hot air, thereby closing the other axial end of the cylindrical body portion. The sheet includes a first base layer that forms the inner circumferential surface of the sheet when formed into a cylindrical shape, and a reinforcing layer located outer than the first base layer. The first base layer is composed of a non-stretched film containing a polyester resin. The reinforcing layer is made of a biaxially oriented film containing a resin component, and is configured to support the first base material layer so that the inner surfaces, which can be heated with hot air and welded together, face each other in the first direction.

[0008] According to the above configuration, since the reinforcing layer is made of a biaxially stretched film containing a resin component, the first base material layer SL1 is supported so that the inner circumferential surfaces, which are in a state where they can be heated and welded by hot air, face each other in the first direction. Therefore, according to the above configuration, a tube container can be provided that is excellent in recyclability because the first base material layer is made of a polyester-based resin, and is more inexpensive because the yield in the end seal formation process using hot air is increased.

[0009] According to the present invention, it is possible to provide a tube container that is highly recyclable and less expensive.

[0010] 1 is a front view of a tube container according to a first embodiment of the present invention. FIG. 1 is a perspective view of the tube container according to the first embodiment of the present invention, viewed from one side. FIG. 2 is a perspective view of the tube container with the cap removed. FIG. 3 is a perspective view of the tube container according to the first embodiment of the present invention, viewed from the other side, with the cap removed. FIG. 4 is a cross-sectional view of a portion of the tube container of FIG. 1, viewed from the direction of the arrows line V-V. FIG. 5 is a cross-sectional view of the cylindrical body of FIG. 1, viewed from the direction of the arrows line VI-VI. FIG. 6 is an exploded perspective view of a tube container according to the first embodiment of the present invention. FIG. 7 is a partial cross-sectional view of a sheet constituting the cylindrical body and end seal portion according to the first embodiment of the present invention. FIG. 8 is a partial cross-sectional view of a sheet in a modified example of an embodiment of the present invention. FIG. 9 is a partial cross-sectional view of a sheet in another modified example of an embodiment of the present invention. FIG. 10 is a partial cross-sectional view of the cylindrical body of FIG. 4, viewed from the direction of the arrows line XI-XI. FIG. 11 is a schematic cross-sectional view of the sheet immediately before the end seal portion is formed. FIG. 12 is a cross-sectional view of the sheet in FIG. 12, viewed from the direction of the arrows line XIII-XIII. FIG. 13 is a flow chart showing a method for manufacturing a tube container according to the first embodiment of the present invention. FIG. 14 is a schematic view of a sheet in a superposing step and a cylindrical body forming step. FIG. 15 is a plan view of an ultrasonic horn used in the method for manufacturing a tube container according to the first embodiment of the present invention, viewed from the side facing the anvil. 17 is a cross-sectional view of the ultrasonic horn of FIG. 16 as viewed from the direction of the arrows along line XVII-XVII. It is a plan view showing an ultrasonic horn in which convex portions of a concave-convex shape are connected to each other in the first embodiment of the present invention. It is a schematic cross-sectional view showing a mold and a cylindrical body when joining a spout portion to the cylindrical body by insert molding in a spout portion joining step. It is a schematic cross-sectional view showing a hot air device used in the end seal portion forming step, together with the cylindrical body. It is a schematic cross-sectional view showing a press device used in the end seal portion forming step, together with the cylindrical body. It is a front view of a tubular container according to the second embodiment of the present invention. It is a schematic perspective view showing a state in which the internal pressure of the storage space of the tubular container according to the second embodiment of the present invention is high. It is a cross-sectional view showing a part of a tubular container according to the third embodiment of the present invention. It is a schematic cross-sectional view showing a cooling press device used in the end seal portion forming step, together with the cylindrical body, in the third embodiment of the present invention. It is a perspective view showing a tubular container according to the fourth embodiment of the present invention.

[0011] Hereinafter, a tube container according to each embodiment of the present invention will be described. In the following description of each embodiment, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and description thereof will not be repeated.

[0012] (Embodiment 1) <Tube container> Fig. 1 is a front view showing a tube container according to embodiment 1 of the present invention. Fig. 2 is a perspective view showing the tube container according to embodiment 1 of the present invention from one side. Fig. 3 is a perspective view showing a state in which a cap is removed from the tube container. Fig. 4 is a perspective view showing a state in which a cap is removed from the tube container according to embodiment 1 of the present invention from the other side. Fig. 5 is a cross-sectional view of a part of the tube container in Fig. 1 as seen from the direction of the arrow V-V.

[0013] As shown in Figures 1 to 5, the tube container 1 according to the first embodiment of the present invention includes a cylindrical body portion 10, a pouring portion 20, an end seal portion 30, and a cap portion 40. Figure 6 is a cross-sectional view of the cylindrical body portion of Figure 1 as viewed from the direction of the arrows along line VI-VI. Note that the cap portion 40 is not shown in the tube container 1 shown in Figure 5. The cap portion 40 may also not be shown in the figures described later. The tube container 1 does not necessarily have to include the cap portion 40.

[0014] As shown in FIGS. 1 to 6 , the cylindrical body 10 has a sheet base 11 , a welded portion 12 , one end 13 , the other end 14 , a main body 15 , and a resin block 16 .

[0015] 7 is an exploded perspective view of a tube container according to the first embodiment of the present invention. As shown in FIGS. 6 and 7, the sheet base 11 is located between a first side end SE1 in the plane direction DP of one sheet S and a second side end SE2 of the sheet S located opposite the first side end SE1. The welded portion 12 is formed by curving or bending the sheet S and welding the first side end SE1 and the second side end SE2 to each other in the thickness direction of the sheet S. The thickness direction is a direction perpendicular to the plane direction DP of the sheet S.

[0016] Thus, in this embodiment, the cylindrical body 10 is made of one sheet S. First, the sheet S will be described in detail.

[0017] Before the first side end portion SE1 and the second side end portion SE2 are welded to each other, the sheet S has a rectangular outer shape when viewed in the thickness direction of the sheet S. However, the shape of the sheet S when viewed in the thickness direction is not limited as long as it can be curved or bent to form the cylindrical body portion 10.

[0018] Fig. 8 is a partial cross-sectional view of the sheet constituting the tubular body portion and end seal portion according to the first embodiment of the present invention. As shown in Fig. 8, the sheet S includes at least a first base material layer SL1 and a reinforcing layer RL. The first base material layer SL1 is located toward the center of the tubular body portion 10 in the radial direction of the tubular body portion 10. In other words, the first base material layer SL1 is the innermost layer of the tubular body portion 10.

[0019] The first base layer SL1 contains a polyester-based resin as a main component. From the viewpoint of improving recyclability, the first base layer SL1 preferably contains a polyester-based resin as a main component. The content of the polyester-based resin in the first base layer SL1 is preferably 95% by mass or more, or 99% by mass or more.

[0020] The polyester-based resin contained in the first base layer SL1 is not particularly limited as long as it can be used for the cylindrical body portion 10 of the tubular container 1. Examples of polyester-based resins include polyethylene terephthalate, polyethylene naphthalate, glycol-modified polyethylene terephthalate (PETG, polyethylene terephthalate in which part of the glycol component is modified with cyclohexanedimethanol (CHDM) or neopentyl glycol, etc.), polylactic acid, etc. It is preferable that the first base layer SL1 contains only polyester-based resin as a resin component.

[0021] From the viewpoint of recyclability of the tubular body portion 10, the polyester-based resin in the first base layer SL1 is preferably homopolyethylene terephthalate, polyethylene terephthalate such as copolymerized polyethylene terephthalate obtained by copolymerizing ethylene glycol, terephthalic acid, and a third component, or glycol-modified polyethylene terephthalate, with homopolyethylene terephthalate being more preferred. Furthermore, from the viewpoints of welding the sheets S together in the welded portion 12 with relatively low energy and of efficiently transmitting ultrasonic vibrations, the polyester-based resin in the first base layer SL1 is preferably an amorphous polyester-based resin (such as amorphous polyethylene terephthalate or glycol-modified polyethylene terephthalate). Therefore, from the viewpoints of both recyclability of the tubular body portion 10 and the adhesiveness of the sheets S in the welded portion 12 and the end seal portion 30 described below, amorphous homopolyethylene terephthalate is most preferred for the first base layer SL1. From the viewpoint of reducing the environmental load, it is preferable that the polyester-based resin in the first base layer SL1 is made from recycled materials or biomass materials, but when contents are to be stored inside the cylindrical body portion 10, it is also preferable that the polyester-based resin in the first base layer SL1 is made from virgin materials.

[0022] The first base layer SL1 may be a single-layer film or a part of a laminate film. The film (single-layer film or laminate film) constituting the first base layer SL1 is an unstretched film. This suppresses crystallization of the surface of the first base layer SL1, improving weldability with other layers when ultrasonic welding, described below, is performed to form the tubular body portion 10. Furthermore, the adhesiveness between the sheets S in the tubular body portion 10 and the end seal portion 30, described below, as well as the bond strength between the tubular body portion 10 and the spout portion 20, are improved.

[0023] The reinforcing layer RL is laminated on the first base material layer SL1. The reinforcing layer RL is located radially outward of the cylindrical body 10 as viewed from the first base material layer SL1. The sheet S may further include another layer between the first base material layer SL1 and the reinforcing layer RL. The sheet S constituting the cylindrical body 10 includes the reinforcing layer RL, which improves the strength of the tube container 1 and can prevent the tube container 1 from being damaged when dropped.

[0024] The reinforcing layer RL contains a resin component as a main component, such as a polyester resin, a polyolefin resin, or a polyamide resin. From the viewpoint of improving recyclability, the reinforcing layer RL preferably contains a polyester resin as a main component, similar to the first base layer SL1. From the viewpoint of further suppressing breakage of the tube container 1 when the tube container 1 is dropped, the reinforcing layer RL also preferably contains a polyamide resin as a main component.

[0025] The polyester resin of the reinforcing layer RL is preferably homopolyethylene terephthalate, polyethylene terephthalate such as copolymerized polyethylene terephthalate obtained by copolymerizing ethylene glycol, terephthalic acid, and a third component, glycol-modified polyethylene terephthalate, or polybutylene terephthalate (PBT). It is also preferable that the reinforcing layer RL contains only a polyester resin or polybutylene terephthalate as a resin component.

[0026] From the viewpoint of recyclability, the polyester-based resin of the reinforcing layer RL is preferably homopolyethylene terephthalate, or polyethylene terephthalate such as copolymerized polyethylene terephthalate obtained by copolymerizing ethylene glycol, terephthalic acid, and a third component, or glycol-modified polyethylene terephthalate, and more preferably homopolyethylene terephthalate. From the viewpoint of reducing the environmental load, the polyester-based resin of the reinforcing layer RL is preferably made from recycled materials or biomass materials, but from the viewpoint of reducing the manufacturing costs of the tubular body portion 10 and the end seal portion 30 described later, it is also preferable that the polyester-based resin of the reinforcing layer RL be made from virgin materials.

[0027] From the viewpoint of further preventing breakage of the tube container 1 when dropped, it is also preferable that the polyester-based resin of the reinforcing layer RL is polybutylene terephthalate. Polybutylene terephthalate has a lower melting point and glass transition temperature than polyethylene terephthalate. However, polybutylene terephthalate has higher impact strength than polyethylene terephthalate. Therefore, by using polybutylene terephthalate as the polyester-based resin of the reinforcing layer RL, the recyclability of the tube container 1 can be improved while further preventing breakage of the tube container 1 when dropped. Furthermore, films containing polybutylene terephthalate have superior refraction resistance compared to films containing polyethylene terephthalate. Therefore, by including polybutylene terephthalate as the polyester-based resin of the reinforcing layer RL, the formation of pinholes in the tube container 1 can be prevented when a fold line is formed by squeezing the tube container 1, for example. Furthermore, films containing polybutylene terephthalate have higher rigidity (specifically, tensile modulus, etc.) compared to films containing polyamide. As a result, since the reinforcing layer RL contains polybutylene terephthalate instead of polyamide resin, it is possible to prevent the cylindrical body made of the sheet S from folding inward during hot air welding to form the end seal portion 30. Hot air welding will be described later.

[0028] Examples of the polyolefin resin for the reinforcing layer RL include polyethylene, polypropylene, and cyclic olefin polymer. From the viewpoint of recyclability, the polyolefin resin for the reinforcing layer RL is preferably polypropylene. The polyolefin resin may also be polyethylene.

[0029] Examples of the polyamide resin for the reinforcing layer RL include aliphatic polyamides such as polyamide 6 (nylon 6), polyamide 66 (nylon 66), polyamide 610 (nylon 610), polyamide 10 (nylon 10), polyamide 12 (nylon 12), and polyamide 6-12 (nylon 6-12), copolymers thereof, and semi-aromatic polyamides synthesized from aromatic dicarboxylic acids and aliphatic diamines. The polyamide resin is preferably polyamide 6 (nylon 6) or polyamide 66 (nylon 66), which are relatively easy to handle.

[0030] Films containing polyamide resins such as nylon 6 and nylon 66 have higher drop strength than polyester resins such as polyethylene terephthalate. Therefore, when the reinforcing layer RL contains a polyamide resin, breakage of the tube container 1 when dropped can be further suppressed. Furthermore, films containing polyamide resins such as nylon 6 and nylon 66 have superior refraction resistance compared to films containing polyester resins such as polyethylene terephthalate. Therefore, when the reinforcing layer RL contains a polyamide resin, pinholes can be suppressed from being formed in the tube container 1 when a fold line is formed by squeezing the tube container 1, for example.

[0031] The film constituting the reinforcing layer RL is a biaxially stretched film. This allows the radial thickness of the tubular body portion 10 to be thinner while maintaining its strength. Furthermore, when the sheet S includes a barrier layer BL (described later), the film constituting the reinforcing layer RL is a biaxially stretched film, which can suppress cracking of the barrier layer BL. The reinforcing layer RL may be a single-layer film or a part of a laminated film. When the reinforcing layer RL is a part of a laminated film, the reinforcing layer RL may be configured as one layer of the laminated film together with the first base layer SL1, or may be laminated directly to the first base layer SL1 without an adhesive layer or the like. In this embodiment, the reinforcing layer RL is a biaxially stretched film, which further facilitates the formation of the end seal portion 30. This will be described later.

[0032] The reinforcing layer RL is preferably made of, for example, a biaxially oriented film containing a polyester resin as a main component, which allows the cylindrical body portion 10 to be made thinner in the radial direction while maintaining its strength, thereby improving the recyclability of the tube container 1.

[0033] The reinforcing layer RL may be a biaxially oriented film containing polyethylene terephthalate, which further improves the recyclability of the tube container 1. Furthermore, the reinforcing layer RL has a higher rigidity (specifically, tensile modulus, etc.) than a biaxially oriented film containing nylon 6 or nylon 66, which makes it easier to form the end seal portion 30.

[0034] The reinforcing layer RL may be a biaxially stretched film containing polybutylene terephthalate. This improves the drop strength of the tube container 1 and suppresses pinhole formation compared to when the reinforcing layer RL is a biaxially stretched film containing polyethylene terephthalate. Furthermore, the reinforcing layer RL has greater rigidity (specifically, tensile modulus, etc.) compared to when the reinforcing layer RL is a biaxially stretched film containing nylon 6 or nylon 66, which facilitates the formation of the end seal portion 30 and improves the recyclability of the tube container 1. From the viewpoint of recyclability, it is also more preferable that the reinforcing layer RL be a biaxially stretched film containing only polybutylene terephthalate as a resin component.

[0035] That is, by using the reinforcing layer RL as a biaxially oriented film containing polybutylene terephthalate, it is possible to improve in a balanced manner the recyclability, drop strength, and pinhole formation suppression of the tube container 1, as well as the ease of forming the end seal portion 30. Consequently, the thickness of the reinforcing layer RL can be made thinner, and the thickness of the cylindrical body portion 10 (sheet S) can also be made thinner.

[0036] It is also preferable that the reinforcing layer RL is a biaxially stretched film containing nylon 6 or nylon 66. This can improve the drop strength of the tube container 1 and suppress pinhole formation, compared to when the reinforcing layer RL is a biaxially stretched film containing polyethylene terephthalate.

[0037] The sheet S may include multiple reinforcing layers RL. For example, the sheet S may include two or more, or three or more, reinforcing layers RL. From the viewpoint of reducing the thickness of the sheet S, it is preferable that the sheet S includes one reinforcing layer RL, two reinforcing layers RL, or three reinforcing layers RL. At least one of the multiple reinforcing layers RL may be a biaxially stretched film. However, it is preferable that all of the reinforcing layers RL are biaxially stretched films. All of the multiple reinforcing layers RL contain the resin component that can be contained in the reinforcing layer RL described above. The resin components contained in the multiple reinforcing layers RL may be the same or different from each other.

[0038] In this embodiment, the sheet S further includes a barrier layer BL. The barrier layer BL is located on the first base layer SL1 side as viewed from the reinforcing layer RL, but may be located on the opposite side of the reinforcing layer RL from the first base layer SL1. Note that the sheet S does not necessarily include the barrier layer BL.

[0039] The material constituting the barrier layer BL is not particularly limited. Examples of the barrier layer BL include a ceramic barrier layer such as a silica barrier layer or an alumina barrier layer, and a metal barrier layer such as an aluminum barrier layer. The ceramic barrier layer may be a transparent vapor deposition layer. In this embodiment, the barrier layer BL is laminated on the reinforcing layer RL (specifically, the film constituting the reinforcing layer RL) by vapor deposition.

[0040] The sheet S may include multiple barrier layers BL. In this case, the sheet S may also include multiple reinforcing layers RL. The multiple barrier layers BL may be laminated on multiple reinforcing layers RL by vapor deposition, respectively. The sheet S may simultaneously include one or more reinforcing layers RL on which a barrier layer BL is vapor-deposited and one or more reinforcing layers RL on which a barrier layer BL is not vapor-deposited. For example, the sheet S may include both a ceramic barrier layer and a metal barrier layer as the multiple barrier layers BL, or may include two ceramic barrier layers.

[0041] In this embodiment, the sheet S further includes a second base material layer SL2. The second base material layer SL2 is laminated on the opposite side of the reinforcing layer RL from the first base material layer SL1. The second base material layer SL2 is located radially outward of the cylindrical body portion 10 from the first base material layer SL1 and the reinforcing layer RL. The second base material layer SL2 may be located between the first base material layer SL1 and the reinforcing layer RL.

[0042] The sheet S may further include another layer between the first base layer SL1 and the second base layer SL2. The sheet S may further include another layer between the reinforcing layer RL and the second base layer SL2. The sheet S may not include the second base layer SL2.

[0043] In this embodiment, the second substrate layer SL2 contains a resin component as its main component, and may contain, for example, a polyolefin resin or a polyester resin as its main component. The second substrate layer SL2 may contain a polyester resin, similar to the first substrate layer SL1, as its resin component, or may contain a polyester resin, polyolefin resin, or polyamide resin that can be used as a resin component of the reinforcing layer RL. When the second substrate layer SL2 is laminated on the opposite side of the first substrate layer SL1 from the reinforcing layer RL, it is preferable that the second substrate layer SL2 contain, as its main component, the same type of resin component as the main component of the first substrate layer SL1, from the viewpoint of adhesion between the sheets S at the welded portion 12. This allows the first substrate layer SL1 and the second substrate layer SL2 to be welded to each other at the welded portion 12, thereby further improving the bonding strength between the sheets S at the welded portion 12. From the viewpoint of recyclability, the second base material layer SL2 preferably contains a polyester-based resin as a main component, similar to the first base material layer SL1.

[0044] The polyester-based resin that can be used as the main component of the second base layer SL2 is preferably polyethylene terephthalate or glycol-modified polyethylene terephthalate, and more preferably homopolyethylene terephthalate. From the viewpoint of reducing the environmental impact, the polyester-based resin in the second base layer SL2 is preferably made from recycled materials or biomass materials, but from the viewpoint of reducing the manufacturing cost of the tubular body portion 10, it is also preferable that the polyester-based resin in the second base layer SL2 be made from virgin materials.

[0045] The second base layer SL2 may be a monolayer film or part of a laminate film. The film (monolayer film or laminate film) constituting the second base layer SL2 may be composed of a non-stretched film, a uniaxially stretched film, or a biaxially stretched film. From the viewpoint of the adhesiveness between the sheets S in the tubular body portion 10 (i.e., the ease of welding between the first base layer SL1 and the second base layer SL2 at the welding portion 12), the second base layer SL2 is preferably composed of a non-stretched film or a uniaxially stretched film, and more preferably a non-stretched film. If the second base layer SL2 is composed of a non-stretched film, crystallization of the surface of the second base layer SL2 is suppressed, thereby improving weldability with other layers during ultrasonic welding. It is particularly preferable that the second base layer SL2 contains a polyester resin as a main component and is composed of a non-stretched film.

[0046] The second base layer SL2 is preferably the outermost layer of the sheet S, and is preferably the outermost layer of the sheet S at least in the welded portion 12 and the end seal portion 30. Therefore, when the sheet S includes one or more reinforcing layers RL and one or more barrier layers BL, the one or more reinforcing layers RL and the one or more barrier layers BL are arranged in the sheet S between the first base layer SL1 and the second base layer SL2 in the stacking direction of the sheet S.

[0047] As shown in FIG. 8 , in this embodiment, the sheet S further includes multiple adhesive layers AL. The multiple adhesive layers AL are located between the first base layer SL1 and the barrier layer BL, and between the second base layer SL2 and the reinforcing layer RL. More specifically, each adhesive layer AL bonds the first base layer SL1 and the barrier layer BL to each other, and bonds the second base layer SL2 and the reinforcing layer RL to each other. When the barrier layer BL is not located between the first base layer SL1 and the reinforcing layer RL, the adhesive layer AL bonds the first base layer SL1 and the reinforcing layer RL to each other. While the adhesive constituting the adhesive layer AL is not particularly limited, it is preferable to use a dry lamination adhesive. Conventional dry lamination adhesives can be used.

[0048] The sheet S may further include a printed layer for improving design. The printed layer may be located between any layers as long as it is located radially outward from the first base material layer SL1, which is the innermost layer of the cylindrical body portion 10. For example, the printed layer may be located on the opposite side of the first base material layer SL1 from the reinforcing layer RL, or may be located between the first base material layer SL1 and the reinforcing layer RL, or may be located on the opposite side of the first base material layer SL1 from the reinforcing layer RL. The printed layer may be located on the opposite side of the second base material layer SL2 from the reinforcing layer RL, or may be located between the second base material layer SL2 and the reinforcing layer RL. The printed layer is preferably located on the opposite side of the second base material layer SL2 from the reinforcing layer RL.

[0049] It is also preferable that the sheet S does not include a printed layer in the welded portion 12. This prevents the printed layer from melting during welding of the welded portion 12, which would reduce the aesthetic appeal of the tube container 1. It is also preferable that the sheet S does not include a printed layer in the end seal portion 30, which will be described later. This prevents the printed layer from melting during welding of the end seal portion 30, which would reduce the aesthetic appeal of the tube container 1.

[0050] The print layer is made of, for example, ink, such as oil-based ink (including solvent-based ink using an organic solvent as a solvent), water-based ink (including water-dispersed emulsion ink), or UV-curable ink.

[0051] The sheet S may further include an anchor coat layer. The anchor coat layer is located between the printed layer and another layer. The anchor coat layer enhances adhesion between the printed layer and another layer. The anchor coat layer can be formed using a conventionally known anchor coating agent or the like.

[0052] When the sheet S includes a printed layer, a transparent protective layer may be further laminated on the printed layer. The transparent protective layer may be, for example, a resin film such as a polypropylene film, or a layer made of transparent ink.

[0053] The sheet S may further include a heat insulating layer. The heat insulating layer may be disposed between the first base layer SL1 and the second base layer SL2. This prevents heat applied to the first base layer SL1 to form the end seal portion 30 (described later) from being transferred to the second base layer SL2. The heat insulating layer may be disposed between the first base layer SL1 and the reinforcing layer RL. This prevents the heat from being transferred to the reinforcing layer RL. The heat insulating layer preferably has a thermal conductivity lower than that of the first base layer SL1. This effectively prevents the heat from being transferred to the second base layer SL2, etc., even if the heat insulating layer is relatively thin. The heat insulating layer may be a metal layer such as aluminum, but from the viewpoint of effectively suppressing heat conduction as described above, it is preferable that the heat insulating layer be made of a foam material made of a resin component such as polyethylene terephthalate.

[0054] The sheet S constituting the cylindrical body portion preferably has a polyester resin content of polyethylene terephthalate or the like of 85% by mass or more, more preferably 90% by mass or more, as a whole.

[0055] The total thickness of the sheet S is preferably, for example, 12 μm or more and 250 μm or less, from the viewpoint of forming the sheet S into a cylindrical shape and from the viewpoint of the handleability of the tube container 1. This provides the cylindrical body 10 with squeezability that allows the contents contained in the container to be poured out when the cylindrical body 10 is used as part of a container. Furthermore, since the sheet S includes the first base layer SL1 containing a polyester resin, a total thickness of the sheet S of 12 μm or more and 250 μm or less makes it easy to form fold lines extending in the axial direction DA in the cylindrical body 10. This provides even better squeezability to the cylindrical body 10. Considering the formation of the end seal portion 30 described below, the total thickness of the sheet S is preferably 100 μm or more, and more preferably 120 μm or more.

[0056] The first base layer SL1 is the innermost layer of the tubular body 10, and is preferably thicker than the reinforcing layer RL because it will necessarily be bonded to other layers during welding of the welded portion 12. This reduces the effect of the resin component contained in the reinforcing layer RL on the strength of the weld between the sheets S during welding of the welded portion 12. To further reduce this effect, the thickness of the first base layer SL1 is preferably 1.5 times or more, more preferably 3 times or more, and even more preferably 5 times or more, the thickness of the reinforcing layer RL. The first base layer SL1 may be the thickest layer in the sheet S. Note that, in this specification, the thickness of the sheet S and its constituent layers refers to the sheet S and its constituent thickness in a state before the tubular body 10 is formed, and corresponds to the radial thickness of the layer constituting the extension portion 113 (described in detail below) in the sheet base 11.

[0057] The thickness of the first base layer SL1 is preferably, for example, 10 μm to 250 μm, and more preferably 60 μm to 80 μm. When the sheet S includes a second base layer SL2, the thickness of the first base layer SL1 is preferably 10 μm to 80 μm. The thickness of the first base layer SL1 may be, for example, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

[0058] The thickness of the reinforcing layer RL is preferably, for example, 5 μm or more and 200 μm or less, and more preferably 5 μm or more and 100 μm or less. From the viewpoint of reducing the total thickness of the sheet S, the thickness of the reinforcing layer may be, for example, 5 μm or more and 25 μm or less. When the sheet S includes multiple reinforcing layers RL, the thickness of each of the multiple reinforcing layers RL is preferably 5 μm or more and 25 μm or less. When a barrier layer BL is vapor-deposited on the reinforcing layer RL, the total thickness of the reinforcing layer RL and the barrier layer BL may be 5 μm or more and 25 μm or less. The total thickness of the reinforcing layer RL and the barrier layer BL may be, for example, 12 μm or 25 μm.

[0059] The thickness of the second substrate layer SL2 is preferably, for example, 10 μm or more and 250 μm or less. The thickness of the second substrate layer SL2 is also preferably, for example, 5 μm or more and 200 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 60 μm or more and 80 μm or less. The thickness of the second substrate layer SL2 may be, for example, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm. The thickness of the second substrate layer SL2 may be the same as that of the first substrate layer SL1. This makes it possible to form the second substrate layer SL2 using the same film as that forming the first substrate layer SL1. The thickness of the second substrate layer SL2 may be different from that of the first substrate layer SL1. It is also preferable that the thickness of the second substrate layer SL2 be thicker than that of the first substrate layer SL1. When the second base layer SL2 is thicker than the first base layer SL1, the sheet S is more likely to curl concavely on the first base layer SL1 side, making it easier to form the sheet S into a cylindrical shape. The second base layer SL2 may be the thickest layer in the sheet S. The second base layer SL2 is preferably thicker than the reinforcing layer RL.

[0060] 8, when the sheet S includes one reinforcing layer RL and one barrier layer BL, it is preferable from the viewpoint of recyclability that the first base layer SL1, the reinforcing layer RL, and the second base layer SL2 all contain a polyester-based resin. More specifically, it is preferable that the first base layer SL1 and the second base layer SL2 contain polyethylene terephthalate, and the reinforcing layer RL contains polyethylene terephthalate or polybutylene terephthalate. When the sheet S includes one reinforcing layer RL and one barrier layer BL, for example, the thickness of the first base layer SL1 may be approximately 90 μm, the total thickness of the reinforcing layer RL and the barrier layer BL may be approximately 12 μm, and the thickness of the second base layer SL2 may be approximately 90 μm.

[0061] Fig. 9 is a partial cross-sectional view of a sheet according to a modified embodiment of the present invention. As shown in Fig. 8, the sheet Sa may include three reinforcing layers RL, namely, a first reinforcing layer RL1, a second reinforcing layer RL2, and a third reinforcing layer RL3. These layers are preferably all biaxially stretched films.

[0062] The first reinforcing layer RL1, the second reinforcing layer RL2, and the third reinforcing layer RL3 are arranged in this order when viewed from the first base layer SL1 toward the second base layer SL2. From the viewpoint of recyclability, it is preferable that one of the first reinforcing layer RL1, the second reinforcing layer RL2, and the third reinforcing layer RL3 is a biaxially stretched film containing a polyester-based resin, and more preferably that two of these layers are biaxially stretched films containing a polyester-based resin. For example, it is more preferable that the first reinforcing layer RL1 and the third reinforcing layer RL3 are both biaxially stretched films containing a polyester-based resin, and even more preferably that they are biaxially stretched films containing polyethylene terephthalate or polybutylene terephthalate. The second reinforcing layer RL2 is not particularly limited, but may be a biaxially stretched film containing a polyamide-based resin such as nylon 6 or nylon 66. The first reinforcing layer RL1 and the third reinforcing layer RL3 may both be biaxially stretched films containing polyethylene terephthalate, and the second reinforcing layer RL2 may be a biaxially stretched film containing polybutylene terephthalate.

[0063] The first reinforcing layer RL1 is bonded to the first base layer SL1 and the second reinforcing layer RL2 via adhesive layers AL formed on both sides of the sheet Sa in the stacking direction. The second reinforcing layer RL2 is bonded to the third reinforcing layer RL3 via an adhesive layer AL. The third reinforcing layer RL3 is bonded to the second base layer SL2 via an adhesive layer AL. For each reinforcing layer RL, if a barrier layer is vapor-deposited on the reinforcing layer RL, the reinforcing layer RL may be bonded to another layer via the vapor-deposited barrier layer and the adhesive layer AL formed on the barrier layer.

[0064] When the sheet S includes three reinforcing layers RL as in this modified example, for example, the thickness of the first base layer SL1 may be 60 μm, the thickness of the first reinforcing layer RL1 (or the total thickness of the first reinforcing layer RL1 and the barrier layer vapor-deposited thereon) may be 12 μm, the thickness of the second reinforcing layer RL2 may be 15 μm, the thickness of the third reinforcing layer RL3 (or the total thickness of the third reinforcing layer RL3 and the barrier layer vapor-deposited thereon) may be 12 μm, and the thickness of the second base layer SL2 may be 60 μm.

[0065] Figure 10 is a partial cross-sectional view of a sheet according to another modified example of the embodiment of the present invention. As shown in Figure 10, the sheet Sb may include a first reinforcing layer RL1 and a second reinforcing layer RL2 as two reinforcing layers RL. In this case, considering the formation of the end seal portion 30 described below, it is preferable that at least one of the first reinforcing layer RL1 and the second reinforcing layer RL2 be a biaxially stretched film containing polybutylene terephthalate. Considering recyclability, it is preferable that the other of the first reinforcing layer RL1 and the second reinforcing layer RL2 be a biaxially stretched film containing polyethylene terephthalate. For example, the first reinforcing layer RL1 may be a biaxially stretched film containing polybutylene terephthalate, and the second reinforcing layer RL2 may be a biaxially stretched film containing polyethylene terephthalate.

[0066] Next, the details of the seat base 11 and the welded portion 12 will be described. Figure 11 is a partial cross-sectional view of the cylindrical body portion of Figure 4, as seen from the direction of the arrows XI-XI. As shown in Figures 1 to 4, 6, and 11, the seat base 11 has a first base end portion 111, a second base end portion 112, and an extension portion 113.

[0067] The first base end portion 111 is a portion of the sheet S that is continuous with the second side end portion SE2. The second base end portion 112 is a portion of the sheet S that is continuous with the first side end portion SE1. The first base end portion 111 and the second base end portion 112 each extend from one end portion 13 to the other end portion 14 of the tubular body portion 10 along the welded portion 12 (see FIGS. 4 and 6).

[0068] The average thickness of the first base end portion 111 and the second base end portion 112 is different from the thickness of the sheet S in a state before the cylindrical body portion 10 is formed (the radial thickness of the extension portion 113).

[0069] The first base end 111 and the second base end 112 may have both thicker and thinner portions in the radial direction than the thickness of the sheet S before the cylindrical body 10 is formed, or may be composed of only thicker portions or only thinner portions. For example, in the cross-sectional view shown in Figure 11, the radial thickness of the first base end 111 is thicker than the thickness of the sheet S in the state before the cylindrical body 10 is formed (the radial thickness of the extension portion 113). In addition, the second base end 112 has a thinner portion in the radial direction than the thickness of the sheet S in the state before the cylindrical body 10 is formed (the radial thickness of the extension portion 113), and a thicker portion.

[0070] The extension portion 113 is a portion located between the first base end portion 111 and the second base end portion 112 in the planar direction DP of the sheet S (the circumferential direction DC of the cylindrical body portion 10) (see FIG. 6 ). The extension portion 113 has a substantially C-shaped outer shape when viewed in the axial direction DA of the cylindrical body portion 10. The thickness of the extension portion 113 in the radial direction of the cylindrical body portion 10 is equal to the thickness of the sheet S before the cylindrical body portion 10 is formed.

[0071] The band-shaped welded portion 12 is formed by curving or bending the sheet S, and then overlapping and welding the first side end portion SE1 and the second side end portion SE2 to each other in the thickness direction of the sheet S. In this embodiment, the outer peripheral surface of the first side end portion SE1 and the inner peripheral surface of the second side end portion SE2 are welded to each other (see FIG. 6). The welded portion 12 extends along the axial direction DA of the cylindrical body portion 10 (see FIG. 4). The welded portion 12 extends continuously from one end portion 13 to the other end portion 14.

[0072] The welded portion 12 has a first leading edge 121 , a second leading edge 122 , a welded portion outer peripheral surface 123 , and a welded portion inner peripheral surface 124 .

[0073] 11 , the first leading edge 121 is the leading edge of the first side end portion SE1 in the circumferential direction DC of the cylindrical body portion 10. The first leading edge 121 is joined to the first base end portion 111. This makes the welded area of ​​the welded portion 12 relatively large. Consequently, when peeling stress is applied to the welded portion 12, the stress is dispersed. This improves the weld strength of the welded portion 12.

[0074] In the present embodiment, there is a boundary between the first base material layer SL1 of the first side end portion SE1 and the first base material layer SL1 of the first base end portion 111 at the first tip edge 121, but this boundary need not exist. That is, the first base material layer SL1 of the first side end portion SE1 and the first base material layer SL1 of the first base end portion 111 may be fused to each other and continuous in the circumferential direction DC.

[0075] Furthermore, the first leading edge 121 is located within the thickness of the first base end 111 when viewed along the circumferential direction DC. This reduces the chance of the first leading edge 121 coming into contact with an external object. In particular, in this embodiment, the outer peripheral surface of the first side end SE1 and the inner peripheral surface of the second side end SE2 are welded to each other to form the welded portion 12 (see FIG. 6 ). Therefore, since the first leading edge 121 is located within the thickness of the first base end 111 when viewed along the circumferential direction DC, the chance of the contents of the tube container 1 coming into contact with the first leading edge 121 is reduced. In this case, it is sufficient that at least a portion of the first leading edge 121 is located within the thickness of the first base end 111 when viewed along the circumferential direction DC. However, as shown in FIG. 11 , it is most preferable that the entire first leading edge 121 is located within the thickness of the first base end 111 when viewed along the circumferential direction DC.

[0076] Furthermore, the first interlayer portion SB1 between the first base material layer SL1 and one or more reinforcing layers RL at the first side end portion SE1 contacts the first base end portion 111 within the thickness of the first base end portion 111 when viewed along the circumferential direction DC. This makes it difficult for the contents of the tube container 1 to come into contact with the first interlayer portion SB1 between the first base material layer SL1 and one or more reinforcing layers RL at the first side end portion SE1. This in turn makes it possible to suppress the occurrence of delamination between the first base material layer SL1 and one or more reinforcing layers RL due to the contents coming into contact with the first interlayer portion SB1.

[0077] 6, it is shown that a boundary surface is formed between the first side end portion SE1 and the second side end portion SE2. However, in this embodiment, as shown in FIG. 11, the second base material layer SL2 of the first side end portion SE1 and the first base material layer SL1 of the second side end portion SE2 are fused together to form an integral layer ML. Therefore, at least the first side end portion SE1 and the second side end portion SE2 do not clearly form a boundary surface along the circumferential direction DC. Details of the integral layer ML will be described later.

[0078] The first tip edge 121 extends from one end 13 to the other end 14 in the axial direction DA of the cylindrical body portion 10 (see FIG. 4).

[0079] 11 , the second leading edge 122 is the leading edge of the second side end portion SE2 in the circumferential direction DC. The second leading edge 122 is joined to the second base end portion 112. This makes the welded area of ​​the welded portion 12 relatively large. Consequently, when peeling stress is applied to the welded portion 12, this stress is dispersed.

[0080] In the present embodiment, there is a boundary between the second base material layer SL2 of the second side end portion SE2 and the second base material layer SL2 of the second base end portion 112 at the second tip edge 122, but this boundary need not exist. That is, the second base material layer SL2 of the second side end portion SE2 and the second base material layer SL2 of the second base end portion 112 may be fused to each other and continuous in the circumferential direction DC.

[0081] Furthermore, the second leading edge 122 is located within the thickness of the second base end portion 112 when viewed along the circumferential direction DC. This reduces the chance of the second leading edge 122 coming into contact with an external object. In this case, it is sufficient that at least a portion of the second leading edge 122 is located within the thickness of the second base end portion 112 when viewed along the circumferential direction DC. However, as shown in FIG. 11 , it is most preferable that the entire second leading edge 122 is located within the thickness of the second base end portion 112 when viewed along the circumferential direction DC.

[0082] Furthermore, the second interlayer portion SB2 between the one or more reinforcing layers RL and the second base layer SL2 at the second side end portion SE2 is in contact with the second base end portion 112 within the thickness of the second base end portion 112 when viewed in the circumferential direction DC. This makes it difficult for other objects located outside the tubular body portion 10 to come into contact with the second interlayer portion SB2, thereby suppressing the occurrence of delamination between the one or more reinforcing layers RL and the second base layer SL2 due to the other objects coming into contact with the second interlayer portion SB2.

[0083] The second tip edge 122 extends from one end 13 to the other end 14 in the axial direction DA of the cylindrical body portion 10 (see FIG. 4).

[0084] Next, the integrated layer ML will be described. As shown in Fig. 11, the integrated layer ML is formed as a single layer by fusing the second base layer SL2 of the first side end portion SE1 and the first base layer SL1 of the second side end portion SE2 together. Therefore, the first side end portion SE1 and the second side end portion SE2 are firmly connected to each other.

[0085] The integral layer ML is welded to the first base material layer SL1 of the first base end 111. Specifically, the integral layer ML does not form a boundary with the first base material layer SL1 of the first base end 111, and is continuous with the first base material layer SL1 of the first base end 111 in the circumferential direction DC. This allows the integral layer ML to be firmly connected to the first base material layer SL1 of the first base end 111. The integral layer ML is also welded to the second base material layer SL2 of the second base end 112. Specifically, the integral layer ML does not form a boundary with the second base material layer SL2 of the second base end 112, and is continuous with the second base material layer SL2 of the second base end 112 in the circumferential direction DC. This allows the integral layer ML and the second base material layer SL2 of the second base end 112 to be firmly connected to each other.

[0086] As shown in Figure 11, the welded portion outer peripheral surface 123 faces radially outward from the cylindrical body portion 10. The welded portion outer peripheral surface 123 is configured as the second side end portion SE2. The welded portion outer peripheral surface 123 is uneven. That is, the second side end portion SE2 has unevenness formed on the radially outer side. The unevenness formed on the welded portion outer peripheral surface 123 not only improves tactile identification but also makes the cylindrical body portion 10 less likely to slip off when gripped.

[0087] In the welded portion 12, unevenness is formed over the entire circumferential direction DC of the welded portion outer peripheral surface 123 from one end 13 to the other end 14 of the tubular body portion 10 (see FIGS. 4 and 11 ). In the welded portion 12 (second side end portion SE2), the second interlayer portion SB2 between one or more reinforcing layers RL and the second base material layer SL2 extends so as to follow the uneven shape of the welded portion outer peripheral surface 123 (see FIG. 11 ).

[0088] In this embodiment, the convex portions 125 of the unevenness formed on the welded portion outer peripheral surface 123 are formed in a lattice pattern when viewed from the radial direction of the cylindrical body portion 10 (see FIG. 4 ). However, the shape of the convex portions 125 when viewed from the radial direction of the cylindrical body portion 10 is not particularly limited. Recesses may be formed in a lattice pattern on the welded portion outer peripheral surface 123. By forming the convex portions 125 or recesses of the unevenness formed on the welded portion outer peripheral surface 123 in a lattice pattern, the welding area between the first side end portion SE1 and the second side end portion SE2 can be increased in both the circumferential direction DC and the axial direction DA of the cylindrical body portion 10.

[0089] The protrusions 125 or recesses may be formed in the form of multiple dots or multiple parallel lines when viewed radially of the cylindrical body portion 10. The height of the protrusions 125 in the irregularities formed on the outer peripheral surface 123 of the welded portion is greater than the thickness of the sheet S (thickness of 113) before the cylindrical body portion 10 is formed. The height of the protrusions 125 in the irregularities formed on the outer peripheral surface 123 of the welded portion is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.5 times or more, of the thickness of the sheet S (thickness of the extending portion 113) before the cylindrical body portion 10 is formed. The greater the height of the protrusions 125, the longer the length of the second interlayer portion SB2 extending along the irregularities in the circumferential direction DC. This distributes the peel stress acting on the welded portion 12 and improves the strength of the welded portion 12.

[0090] On the other hand, the inner peripheral surface 124 of the welded portion faces radially inward of the cylindrical body portion 10. The inner peripheral surface 124 of the welded portion is smooth along the circumferential direction DC.

[0091] Because the welded portion outer peripheral surface 123 and the welded portion inner peripheral surface 124 are as described above, the welded portion 12 has a portion with a relatively thick radial thickness (the portion where the protrusion 125 is located) and a portion with a relatively thin radial thickness. The radial thickness dimension of the thickest radial portion of the welded portion 12 is, for example, more than 1.5 times and not more than 3 times the radial thickness dimension of the extension 113 of the sheet base 11 (i.e., the thickness dimension of the sheet S before the first side end SE1 and the second side end SE2 are welded to each other). The radial thickness dimension of the thinnest radial portion of the welded portion 12 is, for example, not less than 0.3 times and not more than 1.5 times the radial thickness dimension of the extension 113 of the sheet base 11 (i.e., the thickness dimension of the sheet S before the first side end SE1 and the second side end SE2 are welded to each other).

[0092] In this embodiment, the uneven shape is formed on the welded portion outer peripheral surface 123, but the uneven shape may also be formed on the welded portion inner peripheral surface 124. When the uneven shape is formed on the welded portion inner peripheral surface 124, the convex portions of the uneven shape may have a configuration similar to the convex portions 125 described above. In this case, in the welded portion 12 (first side end portion SE1), the first interlayer portion SB1 between the first base material layer SL1 and one or more reinforcing layers RL may extend so as to follow the uneven shape of the welded portion inner peripheral surface 124. Furthermore, in this case, the welded portion outer peripheral surface 123 may be smooth so as to follow the circumferential direction DC.

[0093] 1 to 5 , one end 13 is joined to the pouring portion 20 in the axial direction DA of the cylindrical body 10. By being joined to the pouring portion 20, one end 13 is not flexible and is configured to be able to maintain its outer shape. One end 13 has an annular outer shape when viewed in the axial direction DA of the cylindrical body 10. One end 13 may also have an elliptical or polygonal annular outer shape when viewed in the axial direction DA of the cylindrical body 10.

[0094] One end 13 of the cylindrical body 10 in the axial direction DA consists of one end of the sheet base 11 in the axial direction DA and one end of the welded portion 12. At one end 13, too, the first leading edge 121 is preferably located within the thickness of the first base end 111 when viewed in the circumferential direction DC. This makes the inner surface of the cylindrical body 10 relatively smooth near the first leading edge 121 of one end 13, making it easy to join the inner surface of the cylindrical body 10 to the pouring portion 20.

[0095] It is also preferable that the second tip edge 122 (see FIG. 11 ) at one end 13 is located within the thickness of the second base end 112 when viewed in the circumferential direction DC. This makes the outer surface of the cylindrical body 10 relatively smooth near the second tip edge 122 at one end 13, and when joining at least a portion of the pouring portion 20 to the outer periphery of the cylindrical body 10, the outer surface of the cylindrical body 10 can be easily joined to the pouring portion 20.

[0096] In this embodiment, the inner peripheral surface 124 of the welded portion (see FIG. 11 ) is also smooth along the circumferential direction DC at one end 13. This makes it easy to join the inner peripheral surface of the cylindrical body 10 and the spout 20 at one end 13.

[0097] The other end 14 is located on the opposite side of the one end 13. The other end 14 in the axial direction DA of the cylindrical body 10 extends along a direction perpendicular to the axial direction DA (specifically, a second direction described below). The other end 14 is closed by an end seal portion 30. The other end 14 extends along the end seal portion 30.

[0098] Main body 15 is a portion of cylindrical body 10 located between one end 13 and the other end 14. When main body 15 is deformed into a substantially cylindrical shape, the inner diameter of main body 15 may be, for example, 25 mm or more and 60 mm or less.

[0099] The resin block portion 16 is arranged to extend from the other end portion 14 toward the storage space of the cylindrical body portion 10. The resin block portion 16 is arranged to contact the main body portion 15 of the cylindrical body portion 10. By arranging the resin block portion 16 as described above, it is possible to prevent the internal pressure of the tube container 1 from being directly applied to the other end portion 14 and the end seal portion 30. The resin block portion 16 may be made of the same resin material as the resin material contained in the first base material layer SL1. It is noted that the cylindrical body portion 10 does not necessarily have to have the resin block portion 16.

[0100] 1 to 5 , the pouring portion 20 is joined to one end 13 in the axial direction DA of the cylindrical body portion 10. This enables the pouring portion 20 to pour out the contents accommodated in the cylindrical body portion 10. In this embodiment, the pouring portion 20 also has a shape that allows the contents to be accommodated, and the tube container 1 can accommodate the contents in the accommodation space formed by the cylindrical body portion 10 and the pouring portion 20.

[0101] Specifically, the spout 20 is located radially inside the one end 13 of the cylindrical body 10. The spout 20 may be located radially outside the one end 13 of the cylindrical body 10. The spout 20 may be located both radially outside and inside the one end 13 of the cylindrical body 10.

[0102] The pouring portion 20 has a pouring outlet 21 and a shoulder portion 22. The pouring outlet 21 is provided on the side opposite the cylindrical body portion 10 side to pour out the contents. In other words, the pouring outlet 21 connects the inside and outside of the tube container 1 when the cap portion 40 is removed. The pouring outlet 21 extends along the axial direction DA of the cylindrical body portion 10 and has a generally cylindrical outer shape.

[0103] Shoulder portion 22 extends radially from spout 21 with spout 21 as the center when viewed in axial direction DA, extends away from spout 21 in axial direction DA, and is joined to one end 13 of cylindrical body 10. In this embodiment, shoulder portion 22 has a circular outer shape when viewed in axial direction DA, but may also have an elliptical or polygonal shape.

[0104] The pouring portion 20 is preferably composed of a resin composition containing a polyester-based resin as a main component. The polyester-based resin in the pouring portion 20 can be the same as the polyester-based resin in the first base layer SL1. From the viewpoint of the recyclability of the tube container 1, the polyester-based resin in the pouring portion 20 is preferably homopolyethylene terephthalate, polyethylene terephthalate such as copolymerized polyethylene terephthalate obtained by copolymerizing ethylene glycol, terephthalic acid, and a third component, or glycol-modified polyethylene terephthalate, and more preferably homopolyethylene terephthalate. Furthermore, from the viewpoint of the moldability of the pouring portion 20, the polyester-based resin in the pouring portion 20 is preferably an amorphous polyester-based resin (such as amorphous polyethylene terephthalate or glycol-modified polyethylene terephthalate). The polyester-based resin in the pouring portion 20 may also be a crystalline polyester-based resin (for example, crystalline polyethylene terephthalate). From the viewpoint of the recyclability of the tube container 1, the resin composition constituting the pouring portion 20 preferably contains only polyester-based resin as a resin component. The resin composition constituting the pouring portion 20 may further contain conventionally known additives. From the viewpoint of reducing the environmental load, the polyester-based resin in the resin composition is preferably made from recycled materials or raw materials derived from biomass, but from the viewpoint of reducing the manufacturing cost of the pouring portion 20, it is also preferable that the polyester-based resin in the resin composition is made from virgin raw materials.

[0105] In this embodiment, pouring portion 20 is an injection-molded product of a resin composition. Details of the molding method of pouring portion 20 will be described later. The intrinsic viscosity (IV) value of the polyester-based resin material used to mold pouring portion 20 may be, for example, 0.60 or more and 0.90 or less when measured in accordance with JIS standard (K7390-1:2015). If the IV value is 0.60 or more and 0.90 or less, pouring portion 20 can be easily molded.

[0106] Next, the end seal portion 30 will be described. The end seal portion 30 closes the other end 14 of the tubular body portion 10 in the axial direction DA. In this embodiment, the end seal portion 30 extends approximately parallel to the second direction D2. The second direction D2 is a direction perpendicular to both the axial direction DA and the first direction D1. The first direction D1 is a direction perpendicular to the axial direction DA. The end seal portion 30 has a flattened outer shape.

[0107] Fig. 12 is a schematic cross-sectional view showing the state of the sheet immediately before the end seal portion is formed. Fig. 12 shows a cross-sectional view that is roughly the same as Fig. 6. Fig. 13 is a cross-sectional view of the sheet of Fig. 12 as seen in the direction of the arrows XIII-XIII.

[0108] As shown in Figures 1 to 5, 12 and 13, the end seal portion 30 is formed by overlapping and welding the first side end portion SE1 and the second side end portion SE2 in the thickness direction of the sheet S to form a cylindrical shape, i.e., the inner surface of the cylindrical body CB (see particularly Figures 12 and 13), in the first direction D1 and further welding them together.

[0109] As shown in FIG. 12 , the first base layer SL1 constitutes the inner peripheral surface of the sheet S when the sheet S is formed into a cylindrical shape. In other words, the first base layer SL1 constitutes the inner peripheral surface of the cylindrical body CB. The reinforcing layer RL is located on the outer peripheral side of the first base layer SL1 and on the inner peripheral side of the second base layer SL2 in the sheet S when the sheet S is formed into a cylindrical shape. In other words, the reinforcing layer RL is located on the outer peripheral side of the first base layer SL1 and on the inner peripheral side of the second base layer SL2 in the cylindrical body CB. The second base layer SL2 constitutes the outer peripheral surface of the sheet S when the sheet S is formed into a cylindrical shape. In other words, the second base layer SL2 constitutes the outer peripheral surface of the cylindrical body CB. The integral layer ML is sandwiched between the reinforcing layers RL from both the outer peripheral side and the inner peripheral side of the sheet S when the sheet S is formed into a cylindrical shape. The integral layer ML is not exposed to the inner and outer peripheral sides of the cylindrical body CB.

[0110] The end seal portion 30 is formed by welding the inner peripheral surfaces of the cylindrically formed sheet S in a first direction D1 perpendicular to the axial direction DA while heated with hot air. The reinforcing layer RL is made of a biaxially oriented film containing a resin component, and is therefore configured to support the first base layer SL1 so that the inner peripheral surfaces, which are heated with hot air and ready to be welded, face each other in the first direction D1.

[0111] Because the first base layer SL1 is made of a non-stretched film containing a polyester resin, it becomes weldable at a relatively low temperature when heated with hot air. However, the rigidity of the first base layer SL1 decreases when heated with hot air. This causes the portion of the cylindrically formed sheet S intended to form the end seal portion 30 to easily collapse toward the inner periphery (see arrow A in Figure 13). Here, because the reinforcing layer RL is made of a biaxially stretched film containing a resin component, the first base layer SL1 is supported so that the inner periphery surfaces, which are weldable when heated with hot air, face each other in the first direction D1. Therefore, with this configuration, a tube container 1 can be provided that is highly recyclable because the first base layer SL1 is made of a polyester resin, and is more affordable because the yield in the end seal portion 30 formation process using hot air is increased.

[0112] Furthermore, in this embodiment, the thickness of the sheet S is 100 μm or more and 250 μm or less.

[0113] When the thickness of the sheet S is 250 μm or less, the portion of the cylindrically formed sheet S intended to form the end seal portion 30 tends to collapse inward due to the heating of the first base layer SL1 with hot air during the formation of the end seal portion 30. However, the configuration of the reinforcing layer RL supports the first base layer SL1 so that the inner circumferential surfaces, which are heated with hot air and ready for welding, face each other in the first direction D1. Therefore, when the thickness of the sheet S is 100 μm or more and 250 μm or less, the tube container 1 is provided with appropriate elasticity, making it easier to squeeze the tube container 1, and the configuration of the reinforcing layer RL prevents a decrease in yield in the process of forming the end seal portion 30.

[0114] Furthermore, in this embodiment, the sheet S further includes a second base material layer SL2 that forms the outer peripheral surface when the sheet S is formed into a cylindrical shape. The first base material layer SL1 and the second base material layer SL2 are welded to each other at a welded portion 12 of the cylindrical body portion 10. The second base material layer SL2 is made of a non-stretched film containing a polyester resin.

[0115] This facilitates welding of the second base material layer SL2 with the above-described configuration to the first base material layer SL1 at the welding portion 12 of the cylindrical body portion 10. Meanwhile, in the cylindrically formed sheet S, heating the first base material layer SL1 with hot air also reduces the rigidity of the second base material layer SL2. This heating tends to cause the portion intended to form the end seal portion 30 to collapse toward the inner periphery. However, with the above-described configuration of the reinforcing layer RL, the first base material layer SL1 is supported so that the inner periphery surfaces, which are heated with hot air and ready for welding, face each other in the first direction D1. Therefore, while facilitating the formation of the welding portion 12, the above-described configuration of the reinforcing layer RL can suppress a decrease in yield in the end seal portion 30 formation process.

[0116] Furthermore, in this embodiment, the reinforcing layer RL contains polybutylene terephthalate.

[0117] As described above, the reinforcing layer RL containing polybutylene terephthalate increases the impact strength and improves refraction resistance of the reinforcing layer RL compared to when the reinforcing layer RL contains polyethylene terephthalate. Furthermore, the reinforcing layer RL containing polybutylene terephthalate increases rigidity compared to when the reinforcing layer RL contains a polyamide such as nylon. Therefore, even if the rigidity of the reinforcing layer RL decreases due to heating of the first base layer SL1 with hot air, the reinforcing layer RL can more firmly support the first base layer SL1 during the end seal portion 30 formation process. Therefore, by forming the reinforcing layer RL from a biaxially stretched film containing polybutylene terephthalate, it is possible to simultaneously improve the drop strength of the tube container 1, suppress pinhole formation, and suppress a decrease in yield during the end seal portion 30 formation process.

[0118] As shown in FIGS. 1 to 4, the cap portion 40 is detachably attached to the spout portion 20.

[0119] In the tube container 1 according to the first embodiment of the present invention, the cap portion 40 is made of a resin composition. The cap portion 40 is preferably made of a resin composition containing a polyester-based resin as a main component from the viewpoint of recyclability of the tube container 1. When the tube container 1 includes the cap portion 40, the tube container 1 as a whole preferably has a polyester-based resin content of 95% by mass or more, such as polyethylene terephthalate.

[0120] The polyester-based resin in the cap portion 40 can be the same as the polyester-based resin in the first base layer SL1. From the viewpoint of recyclability of the tube container 1, the polyester-based resin in the cap portion 40 is preferably homopolyethylene terephthalate, polyethylene terephthalate such as copolymerized polyethylene terephthalate obtained by copolymerizing ethylene glycol, terephthalic acid, and a third component, or glycol-modified polyethylene terephthalate, and more preferably homopolyethylene terephthalate. Furthermore, from the viewpoint of moldability of the cap portion 40, the polyester-based resin in the cap portion 40 is preferably an amorphous polyester-based resin (such as amorphous polyethylene terephthalate or glycol-modified polyethylene terephthalate).

[0121] <Tube Container with Content> The tube container with content includes a tube container 1 and a content contained in the tube container 1 (cylindrical body portion 10 and spout portion 20). The content is not particularly limited, and may be a content contained in a conventionally known tube container. Examples of the content include cosmetics, food, pharmaceuticals, and oral compositions. The content may contain at least one of an oil-soluble compound adsorbable to a polyolefin resin, an oily component, a volatile oily component, a flavoring, or a sweetener, or a surfactant.

[0122] In the tube container 1 according to this embodiment, the resin (first base layer SL1) that comes into direct contact with the contents is a polyester resin, which relatively prevents the components adsorbable to polyolefin resins from being adsorbed onto the tube container 1 and prevents the tube container 1 from absorbing these components and swelling. In addition, since the welded parts 12 are firmly joined, it is possible to prevent the surfactant from leaking out of the welded parts 12.

[0123] Examples of oil-soluble compounds include tocopherols such as DL-α-tocopherol, D-δ-tocopherol, DL-α-tocopherol acetate, DL-α-tocopherol succinate, DL-α-tocopherol nicotinate, and DL-α-tocopherol linoleate; 3-methyl-4-isopropylphenol (also known as isopropylmethylphenol); and the like. The oil-soluble compound is contained in the contents, for example, when the contents are pharmaceuticals, foods, or cosmetics. The tocopherols are known as vitamin E and its derivatives, and are incorporated into the contents in the hopes of anti-aging effects, peripheral vasodilating effects, and blood circulation promoting effects. 3-methyl-4-isopropylphenol is incorporated as a disinfectant and preservative in cosmetics such as acne cosmetics and pharmaceuticals.

[0124] Examples of oily components include triacylglycerol; diacylglycerol; natural oils and fats such as rapeseed oil, canola oil, sesame oil, sunflower oil, corn oil, rice oil, grape oil, camellia oil, macadamia nut oil, olive oil, castor oil, safflower oil, soybean oil, tea seed oil, cocoa butter, coconut oil, hardened coconut oil, palm oil, Japan wax, hardened castor oil, beeswax, candelilla wax, carnauba wax, lanolin, liquid lanolin, jojoba wax, hard lanolin, polyoxyethylene lanolin alcohol ether, and polyoxyethylene cholesterol ether; hydrocarbon oils and fats such as liquid paraffin, ozokerite, squalene, paraffin, ceresin, petrolatum, and microcrystalline wax; hydrocarbon oils and fats such as liquid paraffin, ozokerite, squalene, paraffin, ceresin, petrolatum, and microcrystalline wax; and isomyristate. Examples of suitable oil-based ingredients include synthetic oil components such as propyl ester, octyldodecyl myristate, isopropyl palmitate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexylate, dipentaerythritol fatty acid ester, pentaerythritol tetra-2-ethylhexylate, glycerin tri-2-ethylhexylate, trimethylolpropane triisostearate, cetyl-2-ethylhexanoate, and castor oil fatty acid methyl ester; and linear polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane; cyclic polysiloxanes such as decamethylpolysiloxane, dodecamethylpolysiloxane, and tetramethyltetrahydrogenpolysiloxane; silicone resins capable of forming a three-dimensional network structure; and silicones such as silicone rubber. These oil-based ingredients are contained in the contents, for example, when the contents are foods such as mayonnaise or cosmetics.

[0125] Examples of volatile oily components include relatively low molecular weight silicone oils, relatively low molecular weight hydrocarbon oils, ether oils, etc. Silicone oils include linear silicones and cyclic silicones. Specific examples of silicone oils include linear dimethylpolysiloxanes and cyclic dimethylpolysiloxanes. The linear dimethylpolysiloxanes may be either linear or branched, and linear ones include dimethylpolysiloxane (1.5cs), dimethylpolysiloxane (2cs), etc., while branched ones include methyltrimethicone, tris(trimethylsilyl)methylsilane, tetrakis(trimethylsilyl)silane, etc. Cyclic dimethylpolysiloxanes include octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, etc. Examples of hydrocarbons include isododecane, isotridecane, isohexadecane, light isoparaffin, light liquid isoparaffin, etc. Examples of ether oils include ethyl perfluorobutyl ether, etc. These volatile oily components are mainly contained in the contents when the contents are cosmetics such as sunscreen oil-in-water emulsion cosmetics.

[0126] Examples of fragrances include peppermint oil, spearmint oil, anise oil, eucalyptus oil, wintergreen oil, cassia oil, clove oil, thyme oil, sage oil, lemon oil, orange oil, mint oil, cardamom oil, coriander oil, mandarin oil, lime oil, lavender oil, rosemary oil, laurel oil, chamomile oil, caraway oil, marjoram oil, bay oil, lemongrass oil, origanum oil, pine needle oil, neroli oil, rose oil, jasmine oil, grapefruit oil, sweetie oil, yuzu oil, cinnamon bark oil, perilla oil, wintergreen oil, clove oil, and pi Natural fragrances such as menthol oil, tea tree oil, taban oil, star anise oil, fennel oil, diatomaceous oil, basil oil, iris concrete, peppermint absolute, rose absolute, orange flower, and nutmeg, or fragrances obtained by processing these natural fragrances (such as front-end cutting, back-end cutting, fractional distillation, liquid-liquid extraction, essence preparation, and powdered fragrance preparation); camphor, menthol, carvone, benzyl succinate, anethole, cineole, methyl salicylate, cinnamic aldehyde, eugenol, methyleugenol, 3-l-menthoxy Propane-1,2-diol, thymol, linalool, linalyl acetate, limonene, menthone, menthyl acetate, N-substituted-paramenthan-3-carboxamide, pinene, octyl aldehyde, citral, pulegone, carbeth acetate, anisaldehyde, ethyl acetate, ethyl butyrate, allyl cyclohexane propionate, methyl anthranilate, ethyl methylphenylglycidate, vanillin, undecalactone, hexanal, butanol, isoamyl alcohol, hexenol, dimethyl sulf Examples of flavorings include single flavorings such as methyl acrylate, cyclotene, furfural, trimethylpyrazine, ethyl lactate, ethyl thioacetate, ocimene, n-decyl alcohol, methyl acetate, citronenyl acetate, ethyl linalool, vanillin, and benzaldehyde; and compound flavorings such as strawberry flavor, apple flavor, banana flavor, pineapple flavor, grape flavor, mango flavor, butter flavor, milk flavor, fruit mix flavor, and tropical fruit flavor.These flavors are contained in the contents when the contents are oral compositions, for example.Flavors may also be contained in the contents as food aroma components such as wasabi, mustard, and the like.

[0127] Examples of sweeteners include saccharin, saccharin sodium, acesulfame potassium, stevia extract, stevioside, neohesperidyl dihydrochalcone, glycyrrhizin, perillartine, thaumatin, aspartylphenylalanine methyl ester, methoxycinnamic aldehyde, palatinose, palatinit, erythritol, maltitol, xylitol, lactitol, etc. These sweeteners are contained in the contents when the contents are, for example, an oral composition.

[0128] Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Examples of anionic surfactants include fatty acid soaps, higher alkyl sulfates, alkyl ether sulfates, N-acylsarcosinic acid, higher fatty acid amide sulfonates, phosphate salts, sulfosuccinates, alkylbenzene sulfonates, higher fatty acid ester sulfates, N-acylglutamates, sulfated oils, POE-alkyl ether carboxylic acids, POE-alkyl allyl ether carboxylates, α-olefin sulfonates, higher fatty acid ester sulfonates, secondary alcohol sulfates, higher fatty acid alkylolamide sulfates, sodium lauroyl monoethanolamide succinate, N-palmitoyl aspartic acid ditriethanolamine, and sodium caseinate. Examples of cationic surfactants include alkyltrimethylammonium salts, alkylpyridinium salts, distearyldimethylammonium chloride, dialkyldimethylammonium salts, poly(N,N'-dimethyl-3,5-methylenepiperidinium) chloride, alkyl quaternary ammonium salts, alkyldimethylbenzylammonium salts, alkylisoquinolinium salts, dialkylmorphonium salts, POE-alkylamines, alkylamine salts, polyamine fatty acid derivatives, amyl alcohol fatty acid derivatives, benzalkonium chloride, and benzethonium chloride. Examples of amphoteric surfactants include imidazoline-based amphoteric surfactants and betaine-based surfactants. Examples of nonionic surfactants include polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ethers, sucrose fatty acid esters, alkyl glycosides, polyoxyethylene-polyoxypropylene block copolymers, polyoxyethylene ethers of glycerin esters, fatty acid alkylolamides, and glycerin fatty acid esters.

[0129] <Method for manufacturing tube container> Next, a method for manufacturing the tube container 1 according to the first embodiment of the present invention will be described. Fig. 14 is a flow diagram showing the method for manufacturing the tube container according to the first embodiment of the present invention. The method for manufacturing the tube container 1 according to this embodiment includes a sheet preparation step S1, a stacking step S2, a cylindrical body formation step S3, a spout portion joining step S4, a cap portion attachment step S5, and an end seal portion formation step S6.

[0130] In the sheet preparation step S1, a sheet S is prepared by laminating multiple layers together. For example, the sheet S may be prepared by dry laminating a first substrate layer SL1 made of a single-layer film and a reinforcing layer RL on which a barrier layer BL is vapor-deposited with an adhesive layer AL, and then dry laminating the reinforcing layer RL and a second substrate layer SL2 made of a single-layer film with an adhesive layer AL. A commercially available laminated film including the first substrate layer SL1, the reinforcing layer RL, and the second substrate layer SL2 may also be prepared. When the sheet S includes multiple reinforcing layers RL, these multiple reinforcing layers may be dry-laminated with an adhesive layer AL.

[0131] Fig. 15 is a schematic diagram showing the sheet S in the overlapping step and the cylindrical body forming step. Fig. 15 shows the sheet S from a direction corresponding to the cross-sectional view direction of Fig. 6. As shown in Fig. 15, in the overlapping step S2, the prepared sheet S is formed into a cylindrical shape, and the first side end SE1 and the second side end SE2 are overlapped with each other.

[0132] In the cylindrical body forming step S3, the first side end portion SE1 and the second side end portion SE2 are sandwiched between an ultrasonic horn 5 positioned on one of the radially inner and outer sides of the cylindrically formed sheet S and an anvil 6 positioned on the other of the radially inner and outer sides, and ultrasonically welded together to form a cylindrical body. In the cylindrical body forming step S3, a welded portion 12 is formed (see FIGS. 4 and 6).

[0133] In this specification and the drawings, the same or corresponding parts of the cylindrical body as those of the cylindrical body portion 10 are denoted by the same reference numerals.

[0134] 15 , the first side edge SE1 and the second side edge SE2 are vibrated by ultrasonic waves from the ultrasonic horn 5 and are pressed in the thickness direction of the sheet S by the ultrasonic horn 5 and the anvil 6. In this embodiment, the ultrasonic horn 5 is located on the radially outer side of the sheet S, and the anvil 6 is located on the radially inner side of the sheet S. Alternatively, the ultrasonic horn 5 may be located on the radially inner side of the sheet S, and the anvil 6 may be located on the radially outer side of the sheet S.

[0135] At least one of the ultrasonic horn 5 and the anvil 6 has an uneven shape 51 for pressing against the sheet S when sandwiching the sheet S. In this embodiment, only the ultrasonic horn 5 has the uneven shape 51. Note that both the ultrasonic horn 5 and the anvil 6 may have the uneven shape, or only the anvil 6 may have the uneven shape.

[0136] In this embodiment, the ultrasonic horn 5 having the uneven shape 51 is located on the radially outer side of the cylindrically formed sheet S, and the anvil 6 is located on the radially inner side of the cylindrically formed sheet S. Therefore, unevenness is formed on the outer peripheral surface 123 of the weld portion so as to follow the uneven shape 51 of the ultrasonic horn 5 (see FIG. 11 ). Note that the ultrasonic horn 5 having the uneven shape 51 may be located on the radially inner side of the sheet S, and the anvil 6 may be located on the radially outer side of the sheet S.

[0137] In this embodiment, the convex portions 511 of the concave-convex shape 51 locally press the second end portion SE2 into the first end portion SE1 at multiple locations. This makes it easier for the resin components of the first end portion SE1 and the second end portion SE2 to fuse together at the welded portion 12 (see FIGS. 6 and 11 ). As a result, the first end portion SE1 and the second end portion SE2 are firmly welded to each other. More specifically, an integral layer ML is easily formed at the welded portion 12.

[0138] 15 , the uneven shape 51 is positioned so as to overlap the entire first side end portion SE1 and the entire second side end portion SE2 when viewed in the radial direction of the cylindrically formed sheet S. As a result, in this embodiment, unevenness is formed over the entire circumferential direction DC in the welded portion 12.

[0139] Furthermore, when viewed from the radial direction of the cylindrically formed sheet S, the width dimension of the concave-convex shape 51 in the circumferential direction of the cylindrically formed sheet S is preferably larger than the width dimension of the region where the first side end portion SE1 and the second side end portion SE2 overlap each other in the sheet S. This makes it possible to more reliably weld the first side end portion SE1 and the second side end portion SE2 to each other even if the width length of the region where the first side end portion SE1 and the second side end portion SE2 overlap each other changes from the designed dimension or if the ultrasonic horn 5 and the anvil 6 are misaligned.

[0140] Fig. 16 is a plan view of the ultrasonic horn used in the method for manufacturing a tube container according to the first embodiment of the present invention, seen from the side facing the anvil. Fig. 17 is a cross-sectional view of the ultrasonic horn of Fig. 16, seen from the direction of the arrows along line XVII-XVII.

[0141] 16 and 17, the height dimension DH of the convex portions 511 of the uneven shape 51 is preferably greater than the thickness dimension of the sheet S. The height dimension DH is more preferably 1.1 times or more the thickness dimension of the sheet S, even more preferably 1.2 times or more, and most preferably 1.5 times or more.

[0142] By locally applying pressure to the overlapping portion of the first side end portion SE1 and the second side end portion SE2 with the convex portion 511, frictional heat due to ultrasonic waves is easily applied to the overlapping surface of the first side end portion SE1 and the second side end portion SE2. Furthermore, if the height dimension DH is greater than the thickness of the sheet S, the resin component of the molten sheet S flows between the convex portions 511, and high stress can be applied to the portion of the sheet S that abuts the convex portions 511. Therefore, the first side end portion SE1 and the second side end portion SE2 can be firmly welded to each other. Furthermore, in this embodiment, the integral layer ML can be easily formed.

[0143] Furthermore, the height dimension DH is preferably three times or less the thickness of the sheet S. If the height dimension DH is three times or less, it is possible to prevent the protrusions 511 from penetrating the sheet S. The height dimension DH is, for example, about 300 μm.

[0144] Although there are no particular limitations on the shape of each of the plurality of protrusions 511, it is preferable that the shape be, for example, a substantially quadrangular pyramid shape. Furthermore, the plurality of protrusions 511 are positioned so as to be aligned along one direction and a direction perpendicular to the one direction when viewed from the opposing direction of the ultrasonic horn 5 and the anvil 6. As a result, the protrusions 125 of the weld portion 12 are formed in a lattice pattern.

[0145] The dimension DW of the separation distance between the vertices of the multiple protrusions 511 is preferably 0.4 mm or more and 2.0 mm or less. If the dimension DW of the separation distance is 0.4 mm or more, the resin components of the sheet S can flow in more easily. If the dimension DW of the separation distance is 2.0 mm or less, the resin components of the sheet S that have flowed between the protrusions 511 can be prevented from leaking out of the uneven shape 51. Note that the uneven shape 51 does not have to be formed so as to overlap the entire first side end portion SE1 and the second side end portion SE2, but is preferably formed so as to overlap these entirely.

[0146] The uneven shape 51 is not limited to the above-described shape. FIG. 18 is a plan view showing an ultrasonic horn in which the convex portions of the uneven shape are connected to each other in the first embodiment of the present invention. As shown in FIG. 18 , when viewed from the opposing direction, each of the multiple convex portions 511 may be connected to the convex portion 511 located closest to it. That is, the convex portions 511 may be formed in a lattice pattern extending across the entire uneven shape 51. In this case, it is preferable that the intersections 511C of the lattice formed by the convex portions 511 in the uneven shape 51 are arranged at intervals of 0.4 mm or more and 2.0 mm or less. This allows the resin component of the sheet S to more easily flow into the concave portions of the uneven shape 51.

[0147] In the spout portion joining step S4, the spout portion 20 is joined to the cylindrical body CB. In this embodiment, the spout portion 20 is joined to the cylindrical body CB by so-called insert molding. As shown in Fig. 14, the spout portion joining step S4 includes a cylindrical body arrangement step S41 and an injection molding step S42.

[0148] 19 is a schematic cross-sectional view showing a mold and a cylindrical body when joining the pouring portion to the cylindrical body by insert molding in the pouring portion joining step. As shown in Fig. 19, in a cylindrical body placement step S41, a cylindrical body CB is placed inside a mold 7. Specifically, at least one end 13 of the cylindrical body CB is placed inside the mold 7. In an injection molding step S42, with one end 13 of the cylindrical body CB placed inside the mold 7, a molten resin composition is filled onto (one end 13 of) the cylindrical body CB in the mold 7, thereby injection-molding pouring portion 20 onto the cylindrical body CB.

[0149] In addition, in the spout portion joining step S4, the spout portion 20 may be joined to the cylindrical body CB by compression molding or ultrasonic welding instead of the insert molding described above.

[0150] In the cap part attachment step S5, a pre-formed cap part 40 is attached to the pouring part 20. The cap part 40 can be formed by a conventionally known method such as injection molding or compression molding. If the tube container 1 does not have the cap part 40, the tube container manufacturing method does not need to include the cap part attachment step S5.

[0151] Next, the end seal forming step S6 will be described. As shown in Fig. 14, the end seal forming step S6 includes a step S61 of melting the inner peripheral surface and a pressing step S62.

[0152] FIG. 20 is a schematic cross-sectional view showing the hot air device used in the end seal portion forming step together with the cylindrical body. As shown in FIG. 20 , in step S61 of the end seal portion forming step S6, the inner circumferential surface of the cylindrical body CB, i.e., the cylindrically formed sheet S, is heated with hot air. More specifically, the inner circumferential surface of the end of the cylindrical body CB opposite the spout 20 is heated with hot air. This melts at least a portion of the inner circumferential surface of the cylindrical body CB, making the inner circumferential surfaces weldable to each other. Hot air is blown toward the cylindrical body CB from a hot air device 91 inserted into the cylindrical body CB. The hot air device 91 may be a heater that heats the air on the inner circumferential surface of the cylindrical body CB. After the inner circumferential surfaces are weldable to each other, the hot air device 91 is withdrawn from the cylindrical body CB.

[0153] In the pressing step S62, the inner circumferential surfaces of the sheets S (cylindrical bodies CB) that have been heated with hot air and become weldable to each other are butted against each other in the first direction and welded together (see FIGS. 12 and 13).

[0154] FIG. 21 is a schematic cross-sectional view showing the press machine used in the end seal portion forming process together with the cylindrical body. In the pressing process S62, the cylindrical body CB is sandwiched between a pair of heated plates 92 arranged in the first direction D1, at least at the portion heated in process S61. This causes at least a portion of the inner circumferential surface of the sheet S (cylindrical body) that is weldable to each other. The welded portions of the inner circumferential surfaces of the sheet S are then cooled and solidified, forming the end seal portion 30 and forming a cylindrical body 10 with its other end 14 closed. Specifically, when sandwiched between the pair of plates 92, the first base layer SL1, which is a portion of the sheet S and forms the inner circumferential surface of the cylindrical body CB, is welded to each other (see FIGS. 12 and 13 ). At this time, a portion of the molten first base layer SL1 leaks into the storage space of the cylindrical body 10 and solidifies. This forms the resin block portion 16. In addition, the first base material layers SL1 constituting the inner circumferential surface of the cylindrical body CB may be welded together so that the resin block portion 16 is not formed.

[0155] The tube container 1 according to this embodiment is manufactured as described above. The manufacturing method for the tube container 1 according to this embodiment includes the cap attachment step S5 and the end seal portion forming step S6 in this order, but this order may be reversed. When manufacturing a tube container containing contents, for example, the contents may be filled into the cylindrical body CB from the other end 14 after the spout portion joining step S4 or the cap attachment step S5 and before the end seal portion forming step S6. When manufacturing a tube container containing contents, the contents may be filled into the cylindrical body CB from the spout portion 20 after the end seal portion forming step S6.

[0156] The tube container 1 according to the first embodiment described above has excellent recyclability because the sheet S constituting the cylindrical body portion 10 can contain a polyester-based resin as a primary component. Furthermore, the recyclability of the tube container 1 can be further improved by the cylindrical body portion 10, the pouring portion 20, and the end seal portion 30 as a whole containing a polyester-based resin as a primary component. Furthermore, the recyclability of the tube container 1 can be further improved by the tube container 1 as a whole containing a polyester-based resin as a primary component. Therefore, the tube container 1 according to the first embodiment of the present invention is in line with the sustainable circular economy sought by the SDGs (Sustainable Development Goals) and can significantly contribute to reducing plastic waste. In this specification, a component containing a polyester-based resin as a primary component can mean that the polyester-based resin content in the component is 85% by mass or more, 90% by mass or more, 95% by mass or more, or 99% by mass or more.

[0157] (Embodiment 2) A tube container according to embodiment 2 of the present invention will be described below. The shape of the end seal portion of the tube container according to embodiment 2 of the present invention is different from that of the tube container 1 according to embodiment 1 of the present invention. Therefore, in the following description, the same configuration and effects as those of the tube container 1 according to embodiment 1 will not be described repeatedly.

[0158] Fig. 22 is a front view showing a tube container according to embodiment 2 of the present invention. As shown in Fig. 22, in the tube container 1A according to embodiment 2 of the present invention, the other end 14A of the cylindrical body 10 is bent or curved in a convex shape toward the pouring portion 20. Specifically, the central portion of the other end 14A in the second direction D2 is bent in a convex shape toward the pouring portion 20.

[0159] The end seal portion 30A has a protruding portion 31. The protruding portion 31 is positioned along the other end portion 14A of the cylindrical body portion 10. The protruding portion 31 protrudes toward the pouring portion 20. The protruding portion 31 is positioned at the center of the end seal portion 30A in the second direction D2. The edge of the protruding portion 31 is bent. The edge of the protruding portion 31 may be curved.

[0160] FIG. 23 is a schematic perspective view showing a state in which the internal pressure of the storage space of a tube container according to embodiment 2 of the present invention is high. As shown in FIG. 23 , in this embodiment, the other end 14A of the cylindrical body 10 is bent or curved convexly toward the pouring portion 20. In other words, the end seal portion 30A has a protrusion 31 that protrudes toward the pouring portion 20. As a result, when the internal pressure of the tube container 1A increases, the surface 151 on one side of the portion of the main body 15 adjacent to the bent or curved portion (or protrusion 31) at the other end 14A faces away from the pouring portion 20. The end seal portion 30A is inclined so as to be continuous with the surface 151. This prevents pressure from being applied to the end seal portion 30A when the internal pressure of the storage space of the tube container 1A is high. This in turn prevents the sheets S welded to each other at the end seal portion 30A from peeling off.

[0161] (Embodiment 3) A tube container according to Embodiment 3 of the present invention will be described below. The cross-sectional shape of the end seal portion of the tube container according to Embodiment 3 of the present invention is different from that of the tube container according to Embodiment 1 of the present invention. Therefore, in the following description, the same configuration and effects as those of the tube container 1 according to Embodiment 1 will not be described repeatedly.

[0162] Fig. 24 is a cross-sectional view showing a portion of a tube container according to embodiment 3 of the present invention. Fig. 24 illustrates a cross-sectional view corresponding to Fig. 5 of embodiment 1. As shown in Fig. 24, the end seal portion 30B includes a first wide portion 32 and a second wide portion 33. The first wide portion 32 and the second wide portion 33 are portions of the end seal portion 30B that are thicker in the first direction D1 than other portions.

[0163] The first wide portion 32 contacts the other end 14B of the cylindrical body 10. The first wide portion 32 contacts the resin block portion 16. The first wide portion 32 has a pair of first surface portions 321 and a pair of second surface portions 322.

[0164] The pair of first surface portions 321 respectively face one side and the other side in the first direction D1. The pair of first surface portions 321 are inclined with respect to the axial direction DA. The pair of first surface portions 321 are inclined so as to face the side opposite to the pouring portion 20 side.

[0165] The pair of second surface portions 322 respectively face one side and the other side in the first direction D1. The pair of second surface portions 322 extend approximately parallel to the axial direction DA. The pair of second surface portions 322 may be inclined with respect to the axial direction DA. The inclination angle of the pair of second surface portions 322 with respect to the axial direction DA is smaller than the inclination angle of the pair of first surface portions 321 with respect to the axial direction DA. The pair of second surface portions 322 are respectively continuous with the pair of first surface portions 321. The pair of second surface portions 322 are respectively located on the pouring portion 20 side as viewed from the pair of first surface portions 321. The first wide portion 32 does not necessarily have a pair of second surface portions 322.

[0166] The second wide portion 33 is located on the opposite side to the pouring portion 20 side when viewed from the first wide portion 32. The second wide portion 33 is spaced apart from the first wide portion 32.

[0167] Next, a method for manufacturing a tube container 1B according to a third embodiment of the present invention will be described. The method for manufacturing a tube container according to the third embodiment of the present invention differs from the method for manufacturing a tube container in the above-described embodiments in that the shape of the pair of plate portions used in the pressing step S62 is different.

[0168] 25 is a schematic cross-sectional view showing a cooling press apparatus used in the end seal portion forming step together with a cylindrical body in embodiment 3 of the present invention. In this embodiment, the pair of plate portions 92 each have a pair of tapered portions 921 and a pair of recessed portions 922.

[0169] The pair of tapered portions 921 are aligned in the first direction D1. The pair of tapered portions 921 extend so that the distance between them increases toward the other end 14 of the cylindrical body 10. This allows the resin of the end seal portion 30B sandwiched between the pair of tapered portions 921 to easily leak from the end seal portion 30B into the storage space. When this resin solidifies, it can easily form a resin block portion 16. The pair of tapered portions 921 are positioned to correspond to the pair of first surfaces 321 of the tube container 1.

[0170] The pair of recesses 922 are aligned in the first direction D1. The pair of recesses 922 are located on the opposite side of the pair of tapered portions 921 from the cylindrical body portion 10. The resin of the end seal portion 30B sandwiched between the pair of recesses 922 is prevented from being stretched in the axial direction DA.

[0171] (Embodiment 4) A tube container according to embodiment 4 of the present invention will be described below. The tube container according to embodiment 4 of the present invention differs from the tube container 1 according to embodiment 1 of the present invention mainly in the configuration of the main body of the cylindrical body. Therefore, the same configuration and effects as those of the tube container according to embodiment 1 of the present invention will not be described repeatedly.

[0172] Fig. 26 is a perspective view showing a tube container according to a fourth embodiment of the present invention. As shown in Fig. 26, in a tube container 1C according to the fourth embodiment of the present invention, the dimension of the cylindrical body portion 10 in the second direction D2 extends so as to be substantially constant from one end 13 to the other end 14C. When viewed from the first direction D1, the tube container 1C according to the fourth embodiment has an outer shape that extends straight along the axial direction DA. This tube container 1C can be easily transported. Furthermore, the tube container 1C can have improved design when viewed from the first direction D1.

[0173] In this embodiment, the main body portion 15C of the cylindrical body 10 has at least one pressed region 152. The pressed region 152 is a region of the main body portion 15C that is pressed toward the storage space of the tube container 1C by folding the main body portion 15C in a mountain fold when viewed from the outside. The at least one pressed region 152 is located along the other end portion 14C and adjacent to the end seal portion 30C. The positioning of the pressed region as described above prevents the main body portion 15C from expanding in the second direction D2 near the end seal portion 30C of the main body portion 15C. Consequently, the dimension of the main body portion 15C in the second direction D2 can be extended so that it is approximately constant from the one end portion 13 to the other end portion 14C.

[0174] The other end 14C of the cylindrical body 10 is curved when viewed in the axial direction DA. The end seal portion 30C is curved along the other end 14C when viewed in the axial direction DA. The end seal portion 30C extends in a substantially semicircular shape.

[0175] (Additional Notes) As described above, the embodiments of the present invention include the following disclosures.

[0176] <Configuration 1> A cylindrical body portion having a band-like welded portion formed by curving or bending a sheet, and overlapping and welding a first side end portion in a surface direction of the sheet and a second side end portion of the sheet opposite the first side end portion in the thickness direction of the sheet; a pouring portion joined to one end portion in the axial direction of the cylindrical body portion and capable of pouring out contents accommodated in the cylindrical body portion; and an end seal portion formed by overlapping and welding the first side end portion and the second side end portion in the thickness direction of the sheet, and then welding the inner peripheral surface of the sheet to each other in a first direction perpendicular to the axial direction while heated with hot air, the end seal portion closing the other end portion in the axial direction of the cylindrical body portion; the sheet includes a first base material layer that constitutes the inner peripheral surface of the sheet when the sheet is formed into a cylindrical shape, and a reinforcing layer located outer than the first base material layer; the first base material layer is made of a non-oriented film containing a polyester-based resin; The reinforcing layer is made of a biaxially oriented film containing a resin component, and is therefore configured to support the first base material layer so that the inner surfaces, which are in a state that can be heated with hot air to be welded, face each other in the first direction.

[0177] <Configuration 2> The tube container according to <Configuration 1>, wherein the thickness of the sheet is 100 μm or more and 250 μm or less.

[0178] <Configuration 3> The tube container according to <Configuration 1> or <Configuration 2>, wherein the sheet further includes a second base material layer that forms an outer peripheral surface when the sheet is formed into a cylindrical shape, the first base material layer and the second base material layer are welded to each other at the welded portion of the cylindrical body portion, and the second base material layer is made of an unstretched film containing a polyester-based resin.

[0179] <Configuration 4> The tube container according to any one of <Configuration 1> to <Configuration 3>, wherein the reinforcing layer contains polybutylene terephthalate.

[0180] <Configuration 5> A method for manufacturing the tubular container according to any one of <Configuration 1> to <Configuration 4>, comprising the steps of: preparing the sheet; overlapping the first side end portion and the second side end portion of the prepared sheet while forming the sheet into a cylindrical shape; sandwiching the first side end portion and the second side end portion between an ultrasonic horn positioned on one of the radially inner side and the radially outer side of the tubularly formed sheet and an anvil positioned on the other of the radially inner side and the radially outer side, and ultrasonically welding them together to form a tubular body; joining the spout portion to the tubular body; and forming the end seal portion, wherein the end seal portion forming step includes the steps of: heating an inner circumferential surface of the tubular body with hot air to melt the inner circumferential surface of the tubular body; and pressing the tubular body to butt the melted inner circumferential surfaces together in the first direction and weld them together.

[0181] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0182] REFERENCE SIGNS LIST 1, 1A, 1B, 1C Tube container, 5 Ultrasonic horn, 6 Anvil, 7 Mold, 10 Cylindrical body portion, 11 Sheet base portion, 111 First base end portion, 112 Second base end portion, 113 Extension portion, 12 Welded portion, 121 First tip edge, 122 Second tip edge, 123 Outer circumferential surface of welded portion, 124 Inner circumferential surface of welded portion, 13 One end portion, 14, 14A, 14B, 14C Other end portion, 15, 15B, 15C Main body portion, 151 Surface, 152 Pressed region, 16 Resin block portion, 20 Spout portion, 21 Spout outlet, 22 Shoulder portion, 30, 30A, 30B, 30C End seal portion, 31 Protruding portion, 32 First wide portion, 321 First surface portion, 322 Second surface portion, 33 Second wide portion, 40 Cap portion, 51 uneven shape, 91 hot air device, 92 plate portion, 921 tapered portion, 922 recess, AL adhesive layer, BL barrier layer, CB cylindrical body, ML integrated layer, RL reinforcing layer, RL1 first reinforcing layer, RL2 second reinforcing layer, RL3 third reinforcing layer, S, Sa, Sb sheet, SB1 first interlayer portion, SB2 second interlayer portion, SE1 first side end portion, SE2 second side end portion, SL1 first base material layer, SL2 second base material layer.

Claims

1. A cylindrical body having a band-shaped welded portion formed by curving or bending a sheet, and overlapping and welding a first side end in a plane direction of the sheet and a second side end of the sheet opposite the first side end in the thickness direction of the sheet; a pouring portion joined to one end in the axial direction of the cylindrical body and capable of pouring out contents contained in the cylindrical body; and an end seal portion formed by overlapping and welding the first side end and the second side end in the thickness direction of the sheet to each other, and by aligning and welding the inner peripheral surface of the sheet in a first direction perpendicular to the axial direction while being heated with hot air, and closing the other end in the axial direction of the cylindrical body; the sheet includes a first base layer that constitutes the inner peripheral surface of the sheet when the sheet is formed into a cylindrical shape, and a reinforcing layer that is located on the outer periphery side of the first base layer, and the first base layer is made of a non-oriented film containing a polyester-based resin, The reinforcing layer is made of a biaxially oriented film containing a resin component, and is configured to support the first base material layer so that the inner surfaces, which are in a state capable of being heated with hot air and welded, face each other in the first direction.

2. The tube container according to claim 1, wherein the thickness of the sheet is 100 μm or more and 250 μm or less.

3. A tube container as described in claim 1, wherein the sheet further includes a second base material layer that constitutes the outer peripheral surface when the sheet is formed into a cylindrical shape, the first base material layer and the second base material layer are welded to each other at the welded portion of the cylindrical body, and the second base material layer is composed of a non-oriented film containing a polyester-based resin.

4. The tube container according to claim 1, wherein the reinforcing layer comprises polybutylene terephthalate.

5. A method for producing the tube container according to any one of claims 1 to 4, comprising the steps of: preparing the sheet; overlapping the first side end and the second side end of the prepared sheet while forming the sheet into a cylindrical shape; sandwiching the first side end and the second side end between an ultrasonic horn positioned on one of the radially inner and outer sides of the cylindrically formed sheet and an anvil positioned on the other of the radially inner and outer sides and ultrasonically welding them together to form a cylindrical body; joining the pouring portion to the cylindrical body; and forming the end seal portion, wherein the end seal portion forming step includes the steps of heating an inner circumferential surface of the cylindrical body with hot air to melt the inner circumferential surface of the cylindrical body; and pressing the cylindrical body to butt the melted inner circumferential surfaces together in the first direction and weld them together.

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