Tube containers and tube containers with caps

Abstract

To provide a tube container and a tube container with a cap capable of having a sufficient bond strength at a bonding part.SOLUTION: A tube container 10 includes a body tube 50 having a bonding portion 52 in which opposing end portions of a laminated body sheet 55 are overlapped and bonded each other, and a head portion member 40 bonded to one end 51 of the body tube 50. In the bonding portion 52, a first sealant layer 56a of a laminated body sheet 55a positioned outside melts to cover a first end face 58a of a base layer 58 and adhere to a first sealant layer 56b of a laminated body sheet 55b positioned inside, and a second sealant layer 59b of the laminated body sheet 55b positioned inside melts to cover a second end face 58b of the base layer 58 and adhere a second sealant layer 59a of the laminated body sheet 55a positioned outside.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a tube container and a tube container with a cap. [Background technology]

[0002] Conventionally, laminated tube containers have been known as tube containers. Generally, laminated tube containers are composed of a body tube (laminated tube) and a head member including a mouth. The manufacturing process of laminated tube containers consists of a process of forming a body tube made of laminate layers into a cylinder and a process of molding a head member onto the body tube.

[0003] In the process of manufacturing a body tube made of laminated layers, the laminated material is rolled up, and the outermost resin layer (sealant layer) surface and the innermost resin layer (sealant layer) surface at both ends of the laminated material are overlapped, and the overlapped parts are welded to form a welded part (joint), thereby manufacturing the body tube (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-281094 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional tube containers, poor bonding between sealant layers may occur at the joint, which can lead to peeling of the joined laminated materials at the joint.

[0006] The present disclosure has been made in consideration of these points, and aims to provide a tube container and a tube container with a cap that can have sufficient bonding strength at the joint. [Means for solving the problem]

[0007] A tube container according to one embodiment comprises a body tube having a joint formed by overlapping and joining opposing ends of a laminate sheet, the laminate sheet including a first sealant layer, a base material layer, and a second sealant layer from the outside, and a head member joined to one end of the body tube, wherein at the joint, the first sealant layer of the outer laminate sheet melts to cover a first end face of the base material layer of the outer laminate sheet and adhere to the first sealant layer of the inner laminate sheet, and the second sealant layer of the inner laminate sheet melts to cover a second end face of the base material layer of the inner laminate sheet and adhere to the second sealant layer of the outer laminate sheet.

[0008] In one embodiment of a tube container, the first sealant layer of the laminate sheet located on the inside may be melted in a direction from the first end face of the base material layer to the second end face, more than the second end face of the base material layer, and the second sealant layer of the laminate sheet located on the outside may be melted in a direction from the second end face of the base material layer to the first end face, more than the first end face of the base material layer.

[0009] In the tube container according to one embodiment, the thickness of the first sealant layer may be thinner than the thickness of the second sealant layer.

[0010] In one embodiment of the tubular container, the laminate sheet may have a thickness of 330 μm or more and 350 μm or less.

[0011] In one embodiment of the tube container, the base layer may include polyethylene terephthalate.

[0012] A tube container with a cap according to one embodiment comprises a tube container according to the present disclosure and a cap attached to the head member. [Effects of the Invention]

[0013] According to the present invention, sufficient adhesive strength can be achieved at the joints of the tube container. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a side view showing a tube container with a cap according to this embodiment, with the cap in a closed state. [Figure 2] FIG. 2 is a side view showing the capped tube container according to this embodiment, with the cap in an open state. [Figure 3] FIG. 3 is a partial vertical cross-sectional view showing a tube container with a cap according to this embodiment. [Figure 4A] FIG. 4A is a cross-sectional view showing an example of the layer structure of the laminate sheet of the body tube of the capped tube container according to the present embodiment. [Figure 4B] FIG. 4B is a cross-sectional view showing another example of the layer structure of the laminate sheet of the body tube of the capped tube container according to the present embodiment. [Figure 5] FIG. 5 is a horizontal cross-sectional view (cross-sectional view taken along line VV in FIG. 1) showing the joint portion of the body tube of the capped tube container according to this embodiment. [Figure 6] 6(a) to 6(e) are schematic diagrams showing a method for manufacturing a tube container according to this embodiment. [Figure 7] 7(a) and 7(b) are schematic diagrams showing a method for manufacturing a tube container according to this embodiment. [Figure 8] FIG. 8 is a horizontal cross-sectional view showing an example of a joint where a joint defect occurs in an example. [Figure 9] FIG. 9 is a horizontal cross-sectional view showing another example of a joint where a joint failure occurs in the example. [Figure 10]FIG. 10 is a horizontal cross-sectional view showing still another example of a joint where a joint failure occurs in the example. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of a capped tube container according to the present invention will be described below with reference to Figures 1 to 7. Figures 1 to 7 are views showing a capped tube container according to an embodiment of the present invention. Figures 1 to 7 show an empty capped tube container 10A that has not yet been bottom-sealed after being filled with contents.

[0016] As shown in FIGS. 1 to 3, a capped tube container 10A according to this embodiment includes a tube container 10 and a cap 20 attached to the tube container 10.

[0017] Of these, the tube container 10 comprises a body tube 50 which is a laminated molded tube, and a head member 40 having a shoulder portion 12 joined to one end 51 of the body tube 50 .

[0018] First, the head member 40 of the tube container 10 will be described.

[0019] As shown in FIG. 3, the head member 40 has a mouth portion 11 and a shoulder portion 12 provided below the mouth portion 11.

[0020] The mouth portion 11 has a threaded portion 14 to which an inner cylindrical portion 28 (described later) of the cap 20 is screwed. The shape of the mouth portion 11 may be any conventionally known shape.

[0021] The shoulder portion 12 has a shape in which the diameter gradually increases from the mouth portion 11 side toward the body tube 50 side. The shoulder portion 12 has a circular horizontal cross section.

[0022] As will be described later, the head member 40 is formed by, for example, compression molding, and is made of, for example, a resin material such as high density polyethylene (HDPE).

[0023] Next, the body tube 50 of the tube container 10 will be described. The body tube 50 shown in FIGS. 1 to 3 has a generally cylindrical shape. The body tube 50 is made of a laminated laminate sheet 55 (see FIGS. 4A and 4B). The laminate sheet 55 is rolled into a cylindrical shape, and opposing ends are overlapped and joined together, for example, by heat sealing. Therefore, the body tube 50 has a joint 52 (see FIGS. 1, 2, and 5) along its longitudinal direction, where the laminate sheets 55 are joined together. The thickness T1 (see FIG. 4A) of the body tube 50 is preferably, for example, 330 μm or more and 350 μm or less. Having a thickness T1 of 330 μm or more allows the body tube 50 to maintain a predetermined strength. This allows the body tube 50 to maintain its self-supporting and shape-retaining properties when the tube container 10 is placed upside down. Furthermore, by making the thickness T1 of the body tube 50 350 μm or less, the manufacturing cost of the body tube 50 can be reduced, and as will be described later, moldability can be ensured when molding the head member 40 by compression molding.

[0024] Next, a description will be given of the layer structure of the laminate sheet 55. Figures 4A and 4B show an example of the layer structure of the laminate sheet 55 that constitutes the trunk tube 50.

[0025] 4A, laminate sheet 55 has, arranged in this order from the outside to the inside, a first sealant layer 56, a first adhesive layer 57a, a base layer 58, a second adhesive layer 57b, and a second sealant layer 59. In this case, for example, a printed layer may be provided on the inside of base layer 58 by reverse printing.

[0026] 4B, the base material layer 58 may have a first base material layer 581 and a second base material layer 582, and a third adhesive layer 57c may be provided between the first base material layer 581 and the second base material layer 582. In this case, a barrier layer 60 may be provided on the inner side of the second base material layer 582, for example.

[0027] Each layer of the laminate sheet 55 will be described below.

[0028] First Sealant Layer The first sealant layer 56 is a layer for bonding the laminate sheets 55 together, and any material that melts and fuses when heated can be used for the first sealant layer 56. For example, a polyolefin film can be used for the first sealant layer 56. More specifically, the first sealant layer 56 can be made of one or more of the following resins: low-density polyethylene film (LDPE), medium-density polyethylene film (MDPE), high-density polyethylene film (HDPE), linear low-density polyethylene film (LLDPE), polypropylene film, acid-modified polyolefin resin film obtained by modifying a polyolefin resin such as polyethylene or polypropylene with acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, or other unsaturated carboxylic acid; polyvinyl acetate resin film; polyester resin film; polystyrene resin film; polyacrylonitrile; saturated polyester; polyvinyl alcohol; and other resins. In the present embodiment, the heat-sealable film can be prepared, for example, by preparing a resin composition using one or more of the above-mentioned resins as the main component, optionally adding desired additives thereto, and then using the resin composition prepared above, for example, by a T-die method, an inflation method, or other molding method to form a film or sheet. The material for the first sealant layer 56 may contain, for example, an antiblocking agent, a lubricant (fatty acid amide, etc.), a flame retardant, an inorganic or organic filler, or the like.

[0029] In this embodiment, the thickness T2 of the first sealant layer 56 is thinner than the thickness T3 of the second sealant layer 59. This ensures that when the second sealant layer 59a of the inner laminate sheet 55b (see FIG. 5) melts, it can reliably cover the second end surface 58b of the base layer 58 of the inner laminate sheet 55b and the first sealant layer 56b, which melts in the second direction D2 (see FIG. 5) beyond the second end surface 58b of the base layer 58. This increases the bonding strength between the inner laminate sheet 55b and the outer laminate sheet 55a. Furthermore, heat from an inner seal member 82a (see FIG. 6(a)), which will be described later, can be effectively transferred to the first sealant layer 56b and the second sealant layer 59b of the inner laminate sheet 55b (see FIG. 5). Furthermore, heat from the outer seal member 82b (see FIG. 6(a)), which will be described later, can be effectively transferred to the first sealant layer 56a and the second sealant layer 59a of the outer laminate sheet 55a (see FIG. 5). This allows the transferred heat to be efficiently transferred between the layers, preventing a problem of reduced bonding between the laminate sheets 55 at the joint 52. Furthermore, by not making the thickness T2 of the first sealant layer 56 too large, a problem of reduced visibility of a printed layer formed on the inside of the base layer 58 by reverse printing can be prevented. This prevents a reduction in the design of the body tube 50.

[0030] Base material layer The base layer 58 is a layer that supports, for example, the first sealant layer 56 and the second sealant layer 59 and increases the strength of the entire laminate sheet 55. Materials that can be used to form the base layer 58 include, for example, films or sheets of polyester resins, polyamide resins, polyaramid resins, polyolefin resins, polycarbonate resins, polyacetal resins, fluorine-based resins, and other tough resins. As an example, the base layer 58 may contain polyethylene terephthalate. Examples of polyolefin resins that can be used include films of extruded low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene. The resin film or sheet may be an unstretched film, a uniaxially or biaxially stretched film, etc. Among these, a biaxially stretched polyester resin film is preferred in the present embodiment because of its excellent printability. In this embodiment, the thickness of the base material layer 58 is preferably 10 μm or more and 25 μm or less.

[0031] Second Sealant Layer The second sealant layer 59 is a layer for bonding the laminate sheets 55 together, and the material constituting the second sealant layer 59 can be, for example, the same material as that of the first sealant layer 56 described above.

[0032] In the present embodiment, increasing the thickness T3 of the second sealant layer 59 increases the amount of melting of the second sealant layer 59b of the laminate sheet 55b (see FIG. 5) located on the inner side at the joint 52. This increases the amount of the second sealant layer 59b of the laminate sheet 55b located on the inner side that melts and adheres to the second sealant layer 59a of the laminate sheet 55a (see FIG. 5) located on the outer side at the joint 52. This prevents a decrease in the bonding strength between the laminate sheets 55 at the joint 52. Furthermore, not increasing the thickness T3 of the second sealant layer 59 allows heat from an inner seal member 82a (see FIG. 6(a)), which will be described later, to be effectively transferred throughout the entire thickness direction of the second sealant layer 59b of the laminate sheet 55b located on the inner side when the laminate sheets 55 are joined together by heat sealing. This heat can also be transferred to the first sealant layer 56b of the laminate sheet 55b located on the inner side. In particular, when joining the laminate sheets 55 together by heat sealing, even if there is a limit to the output of the power source 81 (described later) when supplying power to the inner seal member 82a in the heat-sealing device 80 (see FIG. 6(a)) used, heat from the inner seal member 82a can be effectively transferred to the second sealant layer 59b and the first sealant layer 56b of the laminate sheet 55b located on the inside. This ensures that the first sealant layer 56b and the second sealant layer 59b of the laminate sheet 55b located on the inside can be melted reliably at the joint 52. This prevents a problem of reduced bonding strength between the laminate sheets 55 at the joint 52.

[0033] adhesive layer Adhesive layers such as first adhesive layer 57a, second adhesive layer 57b, and third adhesive layer 57c are layers for adhering first sealant layer 56, base material layer 58, second sealant layer 59, etc. These adhesive layers can be appropriately selected depending on the resins that make up the layers to be adhered. For example, anchor coating agents such as isocyanate-based (urethane-based), polyethyleneimine-based, polybutadiene-based, and organic titanium-based anchor coating agents, or anchor coating agents and laminating adhesives such as polyurethane-based, polyacrylic-based, polyester-based, epoxy-based, polyvinyl acetate-based, cellulose-based, and other laminating adhesives can be used as desired. Suitable adhesive layers include, for example, polyethylene, polypropylene, linear low-density polyethylene, ethylene-vinyl alcohol, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ionomer, and maleic anhydride-modified polyolefin resin. In this embodiment, the thickness of the adhesive layer is preferably 3 μm or more and 60 μm or less.

[0034] The first sealant layer 56, the base layer 58, the second sealant layer 59, etc. may be laminated by any method, such as wet lamination, dry lamination, solventless dry lamination, extrusion lamination, T-die coextrusion molding, coextrusion lamination, inflation, or any other method. When laminating as described above, the film may be subjected to pretreatment such as corona treatment or ozone treatment, if necessary.

[0035] Barrier layer The barrier layer is a layer for suppressing the permeation of oxygen gas, water vapor, etc. As the barrier layer, for example, a gas barrier material against oxygen gas, water vapor, etc., a light-shielding material against sunlight, etc., or a material having aroma retention properties for the contents can be used. Specifically, as the barrier layer, for example, aluminum foil, tin, lead, copper, iron, nickel, or alloys thereof, or a resin film or sheet having a vapor-deposited thin film of aluminum, etc. can be used. When aluminum foil is used as the barrier layer, the thickness of the barrier layer can be approximately 5 μm or more and 20 μm or less.

[0036] Furthermore, when a resin film or sheet having a vapor-deposited thin film of aluminum or the like is used as a barrier layer, a resin film or sheet having a vapor-deposited thin film of metal such as aluminum formed on the resin film can be used, for example, by using a physical vapor deposition method (PVD method) such as vacuum deposition, sputtering, ion plating, or cluster ion beam method. When a resin film having a vapor-deposited thin film of aluminum is used as the barrier layer, the thickness of the barrier layer is typically preferably about 50 Å to 3000 Å, and particularly preferably about 100 Å to 2000 Å. Examples of resin films that can be used to support the vapor-deposited thin film of aluminum include polyester films, polyamide films, polyolefin films, polyvinyl chloride films, polycarbonate films, polyvinylidene chloride films, polyvinyl alcohol films, and saponified ethylene-vinyl acetate copolymer films. The surface of the resin film can be coated in advance with, for example, a vapor deposition primer to enhance the adhesion of the vapor-deposited film, and other required pretreatments can also be applied.

[0037] printing layer As described above, a printed layer having a pattern or the like printed thereon may be formed on the base layer 58. The printed layer may be an ink composition obtained by adjusting the ink composition by adding one or more of ordinary ink vehicles as the main component, optionally adding one or more of plasticizers, stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, and other additives as needed, and further adding a colorant such as a dye or pigment, and thoroughly kneading the mixture with a solvent, diluent, etc. Examples of such ink vehicles include linseed oil, tung oil, soybean oil, hydrocarbon oil, rosin, rosin ester, rosin-modified resin, shellac, alkyd resin, phenolic resin, maleic acid resin, natural resin, hydrocarbon resin, polyvinyl chloride resin, polyacetic acid resin, polystyrene resin, polyvinyl butyral resin, acrylic or methacrylic resin, polyamide resin, polyester resin, polyurethane resin, epoxy resin, urea resin, melamine resin, aminoalkyd resin, nitrocellulose, ethyl cellulose, chlorinated rubber, cyclized rubber, and others, and one or more of these may be used in combination. The printing method may be gravure printing, letterpress printing, screen printing, transfer printing, flexographic printing, or other printing methods.

[0038] Furthermore, the laminate sheet 55 may be provided with an intermediate layer, if necessary. The intermediate layer is provided to adjust the thickness of the laminate sheet 55. An olefin resin can be used for the intermediate layer. More specifically, it is preferable to use a polyethylene film such as low-density polyethylene, linear low-density polyethylene, or medium-density polyethylene as the intermediate layer. These polyethylene films may be transparent or may be colored, for example, as in a milky white polyethylene film. The use of a milky white polyethylene film as the intermediate layer can enhance the glossiness of the laminate sheet 55. The thickness of the intermediate layer is preferably, for example, 50 μm to 200 μm.

[0039] Furthermore, the head member 40 and the body tube 50 of the tube container 10 according to this embodiment are joined by thermal welding when the head member 40 is molded by compression molding, as will be described later. However, this is not limitative, and the head member 40 and the body tube 50 of the tube container 10 may also be joined by injection molding.

[0040] As shown in FIG. 5 , in this embodiment, at the joint 52, the first sealant layer 56a of the laminate sheet 55a located on the radially outer side of the body tube 50 (hereinafter simply referred to as the outer side) melts and covers the first end surface 58a of the base material layer 58 of the outer laminate sheet 55a, while adhering to the first sealant layer 56b of the laminate sheet 55b located on the radially inner side of the body tube 50 (hereinafter simply referred to as the inner side). This increases the bonding strength between the outer laminate sheet 55a and the inner laminate sheet 55b. This prevents the outer laminate sheet 55a from peeling off from the inner laminate sheet 55b. Note that the first adhesive layer 57a and the second adhesive layer 57b are omitted from FIG. 5 for clarity.

[0041] In this case, the length L1 along the first direction D1 of the first sealant layer 56a of the outer laminate sheet 55a that has melted in the first direction D1 (the direction from the second end face 58b of the base layer 58 to the first end face 58a) further than the first end face 58a of the base layer 58 can be, for example, approximately 0.40 mm or more and 0.80 mm or less.

[0042] Furthermore, at the joint 52, the second sealant layer 59b of the inner laminate sheet 55b melts and covers the second end surface 58b of the base material layer 58 of the inner laminate sheet 55b, and is adhered to the second sealant layer 59a of the outer laminate sheet 55a. This increases the bonding strength between the inner laminate sheet 55b and the outer laminate sheet 55a. This prevents the inner laminate sheet 55b from peeling off from the outer laminate sheet 55a.

[0043] In this case, the length L2 along the second direction D2 of the second sealant layer 59b of the laminate sheet 55b located on the inner side, which is melted in the second direction D2 (the direction from the first end face 58a of the base layer 58 to the second end face 58b) D2 further than the second end face 58b of the base layer 58, can be, for example, approximately 0.40 mm or more and 0.80 mm or less.

[0044] Furthermore, the first sealant layer 56b of the inner laminate sheet 55b melts in the second direction D2 more than the second end surface 58b of the base layer 58. This further increases the bonding strength between the inner laminate sheet 55b and the outer laminate sheet 55a. Furthermore, since the first sealant layer 56b melts in the second direction D2 more than the second end surface 58b of the base layer 58, the thickness of the inner laminate sheet 55b can be gradually reduced in the second direction D2. This prevents a large local force from acting on the edge 55c of the inner laminate sheet 55b, even when the joint 52 is folded along the longitudinal direction. Therefore, even when the joint 52 is folded along the longitudinal direction, it is possible to prevent the formation of a portion at the joint 52 that could cause the inner laminate sheet 55b to peel from the outer laminate sheet 55a. As a result, it is possible to effectively prevent the inner laminate sheet 55b from peeling off from the outer laminate sheet 55a.

[0045] In this case, the length L3 along the second direction D2 of the first sealant layer 56b of the laminate sheet 55b located on the inner side, which is melted in the second direction D2 further than the second end face 58b of the base material layer 58, can be, for example, approximately 0.10 mm or more and 0.50 mm or less.

[0046] Furthermore, the second sealant layer 59a of the outer laminate sheet 55a melts in the first direction D1 more than the first end surface 58a of the base layer 58. This further increases the bonding strength between the outer laminate sheet 55a and the inner laminate sheet 55b. Furthermore, since the second sealant layer 59a melts in the first direction D1 more than the first end surface 58a of the base layer 58, the thickness of the outer laminate sheet 55a can be gradually reduced in the first direction D1. This prevents a large local force from acting on the edge 55d of the outer laminate sheet 55a even when the joint 52 is folded along the longitudinal direction. Therefore, even when the joint 52 is folded along the longitudinal direction, it is possible to prevent the formation of a portion at the joint 52 that could cause the outer laminate sheet 55a to peel from the inner laminate sheet 55b. As a result, it is possible to effectively prevent the outer laminate sheet 55a from peeling off from the inner laminate sheet 55b.

[0047] In this case, the length L4 along the first direction D1 of the second sealant layer 59a of the outer laminate sheet 55a that has melted in the first direction D1 further than the first end face 58a of the base material layer 58 can be, for example, approximately 0.10 mm or more and 0.50 mm or less.

[0048] Furthermore, in the above-mentioned joint 52, the length L5 along the second direction D2 of the area where the base material layer 58 of the laminate sheet 55a located on the outside and the base material layer 58 of the laminate sheet 55b located on the inside overlap can be, for example, approximately 1.0 mm or more and 1.5 mm or less.

[0049] 5, the laminate sheets 55a and 55b are shown flat, but in reality they are rolled into an arc shape. Therefore, the above-mentioned lengths L1 to L5 refer to lengths along the circumferential direction of the trunk tube 50.

[0050] Next, the cap 20 will be described.

[0051] 1 to 3, the cap 20 has a head 21 and a cover 22 connected to the head 21. The head 21 and the cover 22 are connected to each other via a pair of connectors 23 each having a hinge 25 at its center. This allows the cover 22 to freely rotate relative to the head 21 around the hinge 25 of the connector 23 as an axis, and serves as a lid that covers the top surface of the head 21. The head 21, the cover 22, and the pair of connectors 23 are integrally formed from injected resin, as will be described later.

[0052] The head 21 includes an inner tube 28 attached to the tube container 10, an outer tube 27 positioned radially outward of the inner tube 28, and an upper plate 29 disposed above the inner and outer tubes 28 and having a spout 26 formed therein. As shown in FIG. 3 , the inner tube 28 is attached to the mouth 11 of the head member 40. The upper plate 29, outer tube 27, and inner tube 28 are integrally formed from an injection molded resin. The upper plate 29 is flat and generally circular in plan view. A downwardly protruding annular undercut 29a is provided at the approximate center of the upper plate 29, ensuring a more complete fit with the mouth 11 of the head member 40. The spout 26 is eccentrically positioned away from the connector 23 to facilitate ease of use during spouting and to facilitate fitting with the plug 34 (described below) of the cover 22. The spout 26 may alternatively be provided at the approximate center of the upper plate 29.

[0053] The cover 22 has a flat lid plate 32 and a substantially cylindrical side wall 33 formed to surround the periphery of the lid plate 32. As shown in Figure 3, the lid plate 32 has a downwardly protruding annular undercut 35, which more completely fits with a fitting portion 36 on the inner wall of the spout 26. A protrusion 37 is formed on the inside edge of the side wall 33 of the cover 22 at the portion with the largest radius of rotation. This protrusion 37 fits into a recess 38 formed in the upper surface of the top plate 29 of the head 21, thereby reliably locking the cover 22 onto the top plate 29. In addition, a protruding piece 39 that makes it easier to open the cover 22 is provided at the portion with the largest radius of rotation about the hinge 25 of the lid plate 32 as the rotation axis.

[0054] As shown in Figures 1 to 3, the surface of the cover 22 (the surface of the closed lid plate 32) is molded flat, so that the product produced by filling the tube container 10 with contents can stand upright (stand upright when top-down) and can be placed upside down when displayed in a store or when not in use. Furthermore, by making the center of the lid plate 32 slightly concave, the product can be made to stand upright more stably. To facilitate fingertip opening of the cover 22, a protruding piece 39 is provided on the cover 22, and a portion of the outer tube 27 below the protruding piece 39 when the cap 20 is closed is carved inward to form a recess 31, making it easier for a finger to grip the protruding piece 39.

[0055] Next, a method for manufacturing the above-described tube container 10 using a compression molding method will be described with reference to FIGS. 6(a)-(e) and 7(a)-(b).

[0056] First, a heat-sealing device 80 is prepared as shown in FIG. 6(a). As shown in FIG. 6(a), the heat-sealing device 80 includes a power source 81 and a sealing member 82 connected to the power source 81. The sealing member 82 includes a cylindrical inner sealing member 82a and an outer sealing member 82b that sandwiches the object to be joined (the laminate sheet 55) together with the inner sealing member 82a. In this heat-sealing device 80, the output of the power source 81 can be adjusted to achieve a desired joining state for the object to be joined. Note that power is supplied to the inner sealing member 82a and the outer sealing member 82b independently from the power source 81. In this case, the output of the power source 81 when supplying power to the inner sealing member 82a and the output of the power source 81 when supplying power to the outer sealing member 82b can be adjusted independently.

[0057] 6(b), a laminate sheet 55 is prepared. In this case, a sheet material is produced by laminating a first sealant layer 56, a first adhesive layer 57a, a base layer 58, a second adhesive layer 57b, and a second sealant layer 59 together, and the sheet material is then cut to a predetermined size to obtain the laminate sheet 55.

[0058] Next, the laminate sheet 55 is rolled up and the opposing ends are joined together, for example, by heat sealing, to form a cylindrical tube, thereby producing the body tube 50. In this process, first, as shown in Fig. 6(c), the laminate sheet 55 is wrapped around the outer surface of the cylindrical inner seal member 82a, and the opposing ends of the laminate sheet 55 are overlapped.

[0059] Next, as shown in Figure 6(d), the outer seal member 82b is pressed against the portion where the opposing ends of the laminate sheet 55 are overlapped, and the portion where the opposing ends of the laminate sheet 55 are overlapped is sandwiched between the inner seal member 82a and the outer seal member 82b.

[0060] Next, as shown in Fig. 6(e), the overlapping portions of the opposing ends of the laminate sheet 55 are heat-sealed. At this time, power is supplied from a power source 81 to the inner seal member 82a and the outer seal member 82b, causing the inner seal member 82a and the outer seal member 82b to generate heat. The heat is then transferred to the laminate sheet 55, joining the ends of the laminate sheet 55 to form the joint 52. In this manner, the body tube 50 is produced.

[0061] At this time, at the joint 52, the first sealant layer 56a of the laminate sheet 55a located on the outside melts, covering the first end surface 58a of the base material layer 58 of the laminate sheet 55a located on the outside, and adhering to the first sealant layer 56b of the laminate sheet 55b located on the inside (see FIG. 5). Also, at the joint 52, the second sealant layer 59b of the laminate sheet 55b located on the inside melts, covering the second end surface 58b of the base material layer 58 of the laminate sheet 55b located on the inside, and adhering to the second sealant layer 59a of the laminate sheet 55a located on the outside (see FIG. 5).

[0062] At this time, the first sealant layer 56b of the laminate sheet 55b located on the inside melts in the second direction D2 more than the second end surface 58b of the base material layer 58, and the second sealant layer 59a of the laminate sheet 55a located on the outside melts in the first direction D1 more than the first end surface 58a of the base material layer 58 (see Figure 5).

[0063] 7(a), this cylindrical laminate sheet 55 (body tube 50) is wound around a mandrel 72, and a mold 71 for compression molding the head member 40 is attached to one end of the mandrel 72. That is, the laminate sheet 55 (body tube 50), which has been previously molded into a cylindrical shape, is inserted into the mandrel 72, whose tip serves as a core for compression molding the head member 40, and then is advanced to a predetermined position into the cavity of the mold 71 for molding the head member 40.

[0064] Next, molten resin is supplied from a resin supply device (not shown) into the mold 71 to compression-mold the head member 40. In this case, one end 51 of the body tube 50 is inserted into the mold 71 to mold the head member 40, and at the same time, the body tube 50 is fused integrally to the head member 40. Thereafter, the integrated head member 40 and body tube 50 are removed from the mold 71 and mandrel 72 to obtain the tube container 10 (see FIG. 7(b)).

[0065] When manufacturing the capped tube container 10A, the cap 20 is prepared in parallel with the production of the tube container 10. In this case, the cap 20 is produced by injection molding using, for example, an injection molding machine (not shown). The cap 20 is then screwed onto the opening of the head member 40 of the tube container 10, thereby obtaining the capped tube container 10A shown in FIG.

[0066] Thereafter, the contents are filled into the body tube 50 of the capped tube container 10A from the bottom side, and the bottom of the body tube 50 is sealed, thereby obtaining the capped tube container 10A filled with the contents as a product.

[0067] As described above, according to this embodiment, at the joint 52, the first sealant layer 56a of the outer laminate sheet 55a melts and covers the first end surface 58a of the base material layer 58 of the outer laminate sheet 55a, and is adhered to the first sealant layer 56b of the inner laminate sheet 55b. This increases the bonding strength between the outer laminate sheet 55a and the inner laminate sheet 55b. This prevents the outer laminate sheet 55a from peeling off from the inner laminate sheet 55b.

[0068] Furthermore, at the joint 52, the second sealant layer 59b of the inner laminate sheet 55b melts and covers the second end surface 58b of the base material layer 58 of the inner laminate sheet 55b, and is adhered to the second sealant layer 59a of the outer laminate sheet 55a. This increases the bonding strength between the inner laminate sheet 55b and the outer laminate sheet 55a. This prevents the inner laminate sheet 55b from peeling off from the outer laminate sheet 55a.

[0069] Furthermore, according to this embodiment, the first sealant layer 56b of the inner laminate sheet 55b melts in the second direction D2 (the direction from the first end surface 58a to the second end surface 58b of the base layer 58) more than the second end surface 58b of the base layer 58. This further increases the bonding strength between the inner laminate sheet 55b and the outer laminate sheet 55a. Furthermore, since the first sealant layer 56b melts in the second direction D2 more than the second end surface 58b of the base layer 58, the thickness of the inner laminate sheet 55b can be gradually reduced in the second direction D2. This prevents a large local force from acting on the edge 55c of the inner laminate sheet 55b, even when the joint 52 is folded along the longitudinal direction. Therefore, even when the joint portion 52 is folded along the longitudinal direction, it is possible to prevent the formation of a portion that could cause the inner laminate sheet 55b to peel from the outer laminate sheet 55a at the joint portion 52. As a result, it is possible to effectively prevent the inner laminate sheet 55b from peeling from the outer laminate sheet 55a.

[0070] Furthermore, the second sealant layer 59a of the outer laminate sheet 55a is melted in the first direction D1 (the direction from the second end surface 58b of the base layer 58 to the first end surface 58a) more than the first end surface 58a of the base layer 58. This further increases the bonding strength between the outer laminate sheet 55a and the inner laminate sheet 55b. Furthermore, since the second sealant layer 59a is melted in the first direction D1 more than the first end surface 58a of the base layer 58, the thickness of the outer laminate sheet 55a can be gradually reduced in the first direction D1. This prevents a large local force from acting on the edge 55d of the outer laminate sheet 55a even when the joint 52 is folded along the longitudinal direction. Therefore, even when the joint 52 is folded along the longitudinal direction, it is possible to prevent the formation of a portion at the joint 52 that could cause the outer laminate sheet 55a to peel from the inner laminate sheet 55b. Therefore, it is possible to effectively prevent the outer laminate sheet 55a from peeling off from the inner laminate sheet 55b. [Example]

[0071] Next, a specific example of the above embodiment will be described.

[0072] Example 1 A tube container 10 (Example 1) shown in Fig. 1 was produced. In this case, first, a laminate sheet 55 having a thickness of 340 µm as shown in Fig. 4B was produced. In this case, the thickness T2 of the first sealant layer 56 was set to 130 µm, the thicknesses of the first base material layer 581 and the second base material layer 582 were each set to 12 µm, and the thickness T3 of the second sealant layer 59 was set to 180 µm. The layer structure of this laminate sheet 55 is as follows: (Outside) Polyethylene film / DL / Polyethylene terephthalate / DL / Polyethylene terephthalate / Vapor-deposited film / DL / Polyethylene film (Inside)

[0073] In the above, "DL" stands for two-component curing urethane adhesive (base: polyester resin, curing agent: aliphatic polyisocyanate, dry mass 3.5 g / m 2 ) refers to the adhesive layer formed by the dry lamination method.

[0074] Next, this laminate sheet 55 was formed into a cylindrical shape to produce body tube 50. At this time, laminate sheet 55 was joined by heat sealing using inner seal member 82a and outer seal member 82b. In this case, the output of power source 81 when supplying power to inner seal member 82a was set to 200 W, 250 W, 280 W, and 300 W, and the output of power source 81 when supplying power to outer seal member 82b was set to 300 W, 350 W, 380 W, 400 W, and 460 W, and 10 body tubes 50 were produced for each output power.

[0075] Thereafter, the body tube 50 was wound around a mandrel 72, and the head member 40 was integrally molded onto the body tube 50 by compression molding to obtain the tube container 10 (Example 1). The head member 40 was made of high-density polyethylene (HDPE).

[0076] In this way, the tube container 10 was produced.

[0077] Example 2 A tube container was produced in the same manner as in Example 1, except that the thickness T2 of the first sealant layer 56 was 100 μm and the thickness T3 of the second sealant layer 59 was 210 μm.

[0078] Next, the joints 52 of these tube containers 10 (Examples 1 and 2) were folded along the longitudinal direction, and it was confirmed whether or not the laminate sheets 55 had peeled apart at the joints 52. The joints 52 were also cut, and the horizontal cross-sectional shapes of the joints 52 were observed and evaluated for appearance. The results are shown in Tables 1 and 2.

[0079] [Table 1]

[0080] [Table 2]

[0081] In Tables 1 and 2, the evaluation "x" means that the laminate sheets 55 were peeled from each other at the joint 52. For example, an "x" in the "outside" column means that the laminate sheet 55a located on the outside was peeled from the laminate sheet 55b located on the inside, and an "x" in the "inside" column means that the laminate sheet 55b located on the inside was peeled from the laminate sheet 55a located on the outside. Furthermore, an evaluation "o" means that the laminate sheets 55 were not peeled from each other at the joint 52.

[0082] As a result, in the tube container 10 of Example 1, peeling between the laminate sheets 55 was more effectively suppressed than in the tube container 10 of Example 2. That is, by setting the thickness of the first sealant layer 56 in the tube container 10 to 130 μm or more as in Example 1, peeling of the outer laminate sheet 55a from the inner laminate sheet 55b was more effectively suppressed under various manufacturing conditions than in the tube container 10 in which the thickness of the first sealant layer 56 is less than 130 μm as in Example 2. This is thought to be because, by setting the thickness T2 of the first sealant layer 56 to 130 μm or more, the amount of the first sealant layer 56a adhering to the first sealant layer 56b of the inner laminate sheet 55b at the joint 52 increases, improving the bonding strength between the laminate sheets 55 at the joint 52.

[0083] Furthermore, in the tube container 10 of Example 1, the thickness of the second sealant layer 59 was set to 180 μm or less, which prevented the inner laminate sheet 55b from peeling from the outer laminate sheet 55a under various manufacturing conditions, compared to the tube container 10 of Example 2, in which the second sealant layer 59 was thicker than 180 μm. This is thought to be because, by setting the thickness T3 of the second sealant layer 59 to 180 μm or less, heat from the inner seal member 82a was effectively transferred to the second sealant layer 59b and the first sealant layer 56b of the inner laminate sheet 55b when joining the laminate sheets 55 together. This heat melted the first sealant layer 56b and the second sealant layer 59b, which then bonded them to the second sealant layer 59a of the outer laminate sheet 55a, which is thought to improve the bonding strength between the laminate sheets 55 at the joint 52.

[0084] As described above, it was found that the bonding strength between the laminate sheets 55 can be increased under various manufacturing conditions in the tube container 10 according to Example 1. Therefore, it is possible to manufacture a tube container 10 having sufficient bonding strength at the joint 52 without having to review the manufacturing conditions depending on the season or room temperature.

[0085] In addition, the horizontal cross-sectional shape of the joint 52 was observed and an appearance evaluation was performed. In the tube containers 10 marked with an "x" in the "outside" column and an "o" in the "inside" column in Tables 1 and 2, the first sealant layer 56a of the outer laminate sheet 55a at the joint 52 did not cover the first end surface 58a of the base layer 58 of the outer laminate sheet 55a, nor was it adhered to the first sealant layer 56b of the inner laminate sheet 55b, as shown in Fig. 8. In the tube containers 10 marked with an "x" in the "inside" column and an "o" in the "outside" column in Tables 1 and 2, the second sealant layer 59b of the inner laminate sheet 55b at the joint 52 did not cover the second end surface 58b of the base layer 58 of the inner laminate sheet 55b, nor was it adhered to the second sealant layer 59a of the outer laminate sheet 55a, as shown in Fig. 9. Furthermore, in the tube containers 10 marked with an "X" in the "Outside" and "Inside" columns in Tables 1 and 2, as shown in FIG. 10, at the joint 52, the first sealant layer 56a of the outer laminate sheet 55a did not cover the first end surface 58a of the base layer 58 of the outer laminate sheet 55a, nor was it adhered to the first sealant layer 56b of the inner laminate sheet 55b. Also, at the joint 52, the second sealant layer 59b of the inner laminate sheet 55b did not cover the second end surface 58b of the base layer 58 of the inner laminate sheet 55b, nor was it adhered to the second sealant layer 59a of the outer laminate sheet 55a. Therefore, it is believed that the bonding strength between the laminate sheets 55 in these tube containers was insufficient, causing the laminate sheets 55 to peel off from each other. In these cases, when joint portion 52 is folded along the longitudinal direction, it is believed that a large force acts locally on edge 55d of laminate sheet 55a shown in Fig. 8, edge 55c of laminate sheet 55b shown in Fig. 9, and edge 55c of laminate sheet 55b and edge 55d of laminate sheet 55a located on the outside shown in Fig. 10, forming a portion that triggers peeling of laminate sheets 55. It is believed that laminate sheets 55 then peeled from the trigger portion.

[0086] On the other hand, in the tube containers 10 marked with a circle in the "outside" and "inside" columns in Tables 1 and 2, as shown in FIG. 5, at the joint 52, the first sealant layer 56a of the outer laminate sheet 55a melted, covering the first end surface 58a of the base layer 58 of the outer laminate sheet 55a and adhering to the first sealant layer 56b of the inner laminate sheet 55b. Also, at the joint 52, the second sealant layer 59b of the inner laminate sheet 55b melted, covering the second end surface 58b of the base layer 58 of the inner laminate sheet 55b and adhering to the second sealant layer 59a of the outer laminate sheet 55a. This is thought to have increased the bonding strength between the laminate sheets 55 and prevented peeling between the laminate sheets 55. Thus, according to this embodiment, the bonding strength between the laminate sheets 55 can be increased and peeling between the laminate sheets 55 can be prevented.

[0087] It is also possible to combine the multiple components disclosed in the above embodiments as needed, or to delete some of the components disclosed in the above embodiments. [Explanation of symbols]

[0088] 10 tube containers 10A Tube with Cap 20 caps 40 Head member 50 Body tube 51 one end 52 Joint 55 Laminated sheet 55a Laminated sheet 55b Laminated sheet 56 First sealant layer 56a First sealant layer 56b First sealant layer 58 Base material layer 58a 1st end face 58b 2nd end face 59 Second sealant layer 59a Second sealant layer 59b Second sealant layer

Claims

1. In a tube container, a trunk tube having a joint portion where opposing ends of a laminate sheet including a first sealant layer, a base material layer, and a second sealant layer are overlapped and joined together from the outside; a head member joined to one end of the body tube, At the joint, the first sealant layer of the laminate sheet located on the outside melts to cover the first end surface of the base material layer of the laminate sheet located on the outside and the second sealant layer of the laminate sheet located on the outside, and is adhered to the first sealant layer of the laminate sheet located on the inside, At the joint, the second sealant layer of the laminate sheet located on the inner side melts to cover the second end surface of the base material layer of the laminate sheet located on the inner side and the first sealant layer of the laminate sheet located on the inner side, and is adhered to the second sealant layer of the laminate sheet located on the outer side, the first end surface and the second end surface are end surfaces in a circumferential direction, the first sealant layer and the second sealant layer are each made of polyethylene; The thickness of the first sealant layer is smaller than the thickness of the second sealant layer, The thickness of the first sealant layer is 130 μm or more, A tube container, wherein the second sealant layer has a thickness of 180 μm or less.

2. 2. The tube container according to claim 1, wherein the first sealant layer of the laminate sheet located on the inside is melted in a direction from the first end face of the base material layer to the second end face, more than the second end face of the base material layer, and the second sealant layer of the laminate sheet located on the outside is melted in a direction from the second end face of the base material layer to the first end face, more than the first end face of the base material layer.

3. 3. The tube container according to claim 1, wherein the thickness of the laminate sheet is 330 μm or more and 350 μm or less.

4. The tube container according to claim 1 , wherein the base layer comprises polyethylene terephthalate.

5. In a tube container with a cap, The tube container according to any one of claims 1 to 4, a cap attached to the head member.

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