Lid, container body, airtight container, method of manufacturing lid, method of manufacturing container body

Abstract

To provide a lid body which can be engaged detachably with a container body and can be formed at low cost without any complicated processing, the container body, a closed container, a method of manufacturing the lid body, and a method of manufacturing the container body.SOLUTION: There is provided a cylindrical lid body which detachably covers a cylindrical mouth part formed on an opening end side of a container body, wherein a lid body projection part to engage with a container projection part formed on an outer peripheral surface of the mouth part is formed on an inner peripheral surface of the lid body facing the outer peripheral surface of the mouth part, and the lid projection part is formed of a first resin layer formed by uniting a plurality of resin films including photopolymerizable material through photopolymerization.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a lid, a container body, a sealed container, a method for manufacturing a lid, and a method for manufacturing a container body. [Background technology]

[0002] For example, a bottle can body is known as a can body in which contents such as beverages are filled and sealed. The bottle can body has a can body (wall) and a can bottom (bottom), and a shoulder portion with a reduced diameter on the opening side. A mouth portion is formed at the tip of the shoulder portion of such a bottle can body for attaching a cap that seals the opening. For example, Patent Document 1 describes a screw cap that is screwed onto a thread groove formed in the mouth portion as a cap that seals the bottle can body.

[0003] Patent document 2 also describes a container cap that has a curled portion that is wound outward from the lower edge of a cylindrical portion that extends downward from the periphery of the top plate portion, and a plurality of lugs that are provided on this curled portion and protrude inwardly to engage with a plurality of engaging threads that extend approximately horizontally along the outer periphery of the mouth of the container. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4908544 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-002343 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the inventions disclosed in Patent Documents 1 and 2, thread grooves and lugs are formed on a cap made of metal by pressing and bending, which makes the manufacturing process complicated and raises concerns that the metal may crack or break during processing.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a lid body, a container body, a sealed container, a method for manufacturing a lid body, and a method for manufacturing a container body, which can be freely engaged with each other and can be formed at low cost without complex processing. [Means for solving the problem]

[0007] In order to solve the above problems, the lid, container body, sealed container, lid manufacturing method, and container body manufacturing method of one embodiment of the present invention propose the following means. In other words, the lid body of the present invention is a cylindrical lid body that can be easily attached and detached to cover a cylindrical mouth portion formed on the open end side of a container body, and is characterized in that a lid body convex portion that engages with a container convex portion formed on the outer peripheral surface of the mouth portion is formed on the inner peripheral surface of the lid body that faces the outer peripheral surface of the mouth portion, and the lid body convex portion is made of a first resin layer formed by integrating multiple resin films containing a photopolymerizable material by photopolymerization.

[0008] According to the lid of the present invention, by forming a first resin layer on the inner peripheral surface of the lid by integrating multiple resin films by photopolymerization, the lid can be processed more easily and at lower cost than when protrusions are formed on the lid itself by pressing, etc. Furthermore, because protrusions are not formed on the lid itself by pressing, etc., there are fewer bent portions, which reduces the possibility of cracking or cutting due to pressing.

[0009] In the present invention, the lid protrusions may be formed intermittently along the circumferential direction on the inner peripheral surface of the lid.

[0010] In addition, in the present invention, the area of ​​one side of at least one of the multiple resin films that constitute the first resin layer, which is located above the lowest resin film near the inner surface of the lid body, may be larger than the area of ​​one side of the lowest resin film.

[0011] The container body of the present invention has a cylindrical mouth portion which is covered with a lid body that can be attached and detached freely, and is characterized in that a container protrusion is formed on the outer surface of the mouth portion opposite the inner surface of the lid body, which engages with a lid body protrusion formed on the inner surface of the lid body, and the container protrusion is made of a second resin layer formed by integrating multiple resin films containing a photopolymerizable material by photopolymerization.

[0012] According to the container body of the present invention, by forming a second resin layer on the outer peripheral surface of the mouth portion by integrating multiple resin films by photopolymerization, the container body can be processed more easily and formed at lower cost than when a convex portion is formed on the mouth portion of the container body by pressing with a mold, etc. Furthermore, because a convex portion is not formed on the mouth portion of the container body by pressing, etc., the number of bent portions on the mouth portion is reduced, thereby reducing the possibility of cracking or cutting due to pressing.

[0013] In the present invention, the container protrusions may be formed intermittently along the circumferential direction on the outer circumferential surface of the mouth.

[0014] In addition, in the present invention, the area of ​​one side of at least one of the multiple resin films that constitute the second resin layer, which is located above the lowest resin film closer to the outer peripheral surface of the mouth portion, may be larger than the area of ​​one side of the lowest resin film.

[0015] The sealed container of the present invention is a sealed container having a container body with a cylindrical mouth and a cylindrical lid that covers the mouth in a removable manner, wherein a container convex portion is formed on the outer surface of the mouth that faces the inner surface of the lid, and a lid convex portion that engages with the container convex portion is formed on the inner surface of the lid, and the lid convex portion is made of a first resin layer formed by integrating multiple resin films containing a photopolymerizable material through photopolymerization, and the container convex portion is made of a second resin layer formed by integrating multiple resin films containing a photopolymerizable material through photopolymerization.

[0016] In addition, in the present invention, the lid body convex portion may be formed intermittently along the circumferential direction on the inner surface of the lid body, and the container convex portion may be formed intermittently along the circumferential direction on the outer surface of the mouth portion.

[0017] The method for manufacturing a lid body of the present invention is a method for manufacturing a lid body described in each of the above paragraphs, and includes a first resin layer formation process for forming the first resin layer on the inner surface of the lid body, and is characterized in that the first resin layer formation process involves photopolymerizing adjacent resin films when a resin liquid containing a photopolymerizable material is ejected by a droplet ejection device to form multiple overlapping resin films.

[0018] The method for manufacturing a container body of the present invention is a method for manufacturing a container body described in each of the above paragraphs, and includes a second resin layer formation process for forming the second resin layer on the outer peripheral surface of the container body, and is characterized in that the second resin layer formation process photopolymerizes adjacent resin films when a resin liquid containing a photopolymerizable material is ejected by a droplet ejection device to form multiple overlapping resin films. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a lid body, a container body, a sealed container, a method for manufacturing a lid body, and a method for manufacturing a container body, which can be freely engaged with each other and can be formed at low cost without complex processing. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a partially cutaway view showing a cover according to a first embodiment of the present invention. [Figure 2] FIG. 3 is an enlarged cross-sectional view of a main part of a first resin layer (lid projection) in this embodiment. [Figure 3] FIG. 6 is a partially cutaway view showing a cover according to a second embodiment of the present invention. [Figure 4] FIG. 3 is an enlarged cross-sectional view of a main part of a first resin layer (lid projection) in this embodiment. [Figure 5] FIG. 2 is a partially cutaway view showing a container body according to an embodiment of the present invention. [Figure 6] FIG. 2 is an enlarged cross-sectional view of a main part of a second resin layer (container protrusion) of the container body. [Figure 7] 1 is an enlarged cross-sectional view of a main part of a bottle can body (sealed container) with a cap according to one embodiment. [Figure 8] FIG. 10 is an enlarged cross-sectional view of a main part showing a modified example of a bottle can body (sealed container) with a cap. [Figure 9] FIG. 2 is a schematic diagram showing an example of an inkjet printer used in a first resin layer forming step and a second resin layer forming step. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, a lid, a container body, a sealed container, a method for manufacturing a lid, and a method for manufacturing a container body, which are embodiments of the present invention, will be described with reference to the drawings. Note that the embodiments shown below are specifically described to provide a better understanding of the gist of the invention, and do not limit the present invention unless otherwise specified. Furthermore, the drawings used in the following description may show essential parts enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional proportions of each component may not necessarily be the same as those in reality.

[0022] (Lid: First embodiment) A lid according to one embodiment of the present invention will now be described. The lid of this embodiment will be described as a cap that is attached to the mouth of a bottle can (container body) that contains a beverage and closes the bottle can. Fig. 1 is a partially cutaway view showing a lid according to a first embodiment of the present invention, and Fig. 2 is an enlarged cross-sectional view of a main part of a first resin layer (lid projection) in this embodiment.

[0023] The cap (lid) 10 of this embodiment has a cap body 1 formed integrally with a disk-shaped top plate 2 and a peripheral wall 3 extending cylindrically from the periphery of the top plate 2 toward the lower end (lower side in FIG. 1) about the cap center line O, and a first resin layer 13 that is a lid body protrusion formed on the inner circumferential surface of the cap 10, i.e., the inner surface of the peripheral wall 3. In this embodiment, the first resin layer 13 is an engagement lug that engages with an engagement thread F formed on the container body.

[0024] A disk-shaped resin liner 4 is disposed on the inner surface (lower surface) 2a of the top plate 2 of the cap 10. This liner 4 has a multilayer structure including a large-diameter sliding layer 4a made of a hard resin, such as polyethylene or polypropylene, and disposed on the top plate 2 side in a non-adhered state with respect to the inner surface 2a, and a smaller-diameter sealing layer 4b made of an elastomer resin and softer than the sliding layer 4a, and disposed on the opposite side of the top plate 2 from the sliding layer 4a, either directly or via an intermediate layer such as a barrier layer.

[0025] The sliding layer 4a is flat and has a substantially uniform thickness, while the sealing layer 4b has a thick outer peripheral edge and a thin inner peripheral portion that is recessed toward the top plate portion 2, and the step portion between the inner peripheral portion and the outer peripheral edge is tapered toward the top plate portion 2 as it approaches the inner peripheral side.

[0026] In addition, the peripheral wall portion 3 of the cap body 1 is formed with a knurl portion 5 at the upper end side near the top plate portion 2, which bulges radially outward relative to the cap center line O toward the lower end, and a groove 6 connected to the lower end of this knurl portion 5 and recessed inward, so as to circle the peripheral wall portion 3 around the cap center line O.

[0027] Furthermore, on the lower end side of the peripheral wall portion 3 opposite the top plate portion 2, there are formed, in order from the upper end side to the lower end side, a bead 7 that also bulges outward, a breakable portion 8 that has a smaller outer diameter than this bead 7, and a cylindrical flare (open end) 9 that has a larger outer diameter than this breakable portion 8 and extends to the lower end of the cap body 1.

[0028] The fragile portion 8 is formed with a plurality of slits 8a at equal intervals in the circumferential direction, extending in a side view and recessed radially inward relative to the cap center line O, and the portion between these slits 8a is formed as a bridge portion 8b. A slit 8c penetrating the peripheral wall portion 3 is formed on the long side of the upper end of each slit 8a. In addition, when the cap 10 is attached to the mouth of a bottle can body, which will be described later, the flare 9 is wrapped around the lower end of a bulge formed on the lower end side of the male thread portion of the mouth.

[0029] The portion between the groove 6 on the upper end side of the peripheral wall portion 3 and the bead 7 on the lower end side is an engagement portion 12 on the inner surface of which a first resin layer (lid body protrusion) 13 is formed. The outer diameter of this engagement portion 12 is a substantially constant diameter that is larger than the outer diameter of the groove 6 and smaller than the outer diameter of the bead 7.

[0030] In the knurl portion 5, in the part of the knurl portion 5 closer to the top plate portion 2, the peripheral wall portion 3 of the cap body 1 is formed to be recessed inward, and a liner engagement portion 11 is formed which protrudes radially inward relative to the cap center line O, but does not penetrate the peripheral wall portion 3.

[0031] The radius of the cylindrical surface inscribed in this liner locking portion 11 and centered on the cap center line O is smaller than the radius of the outer peripheral edge of the liner 4 (the outer peripheral edge of the sliding layer 4a) but larger than the radius of the outer peripheral edge of the sealing layer 4b, and the liner 4 is locked by this liner locking portion 11 at the outer peripheral edge of the sliding layer 4a to prevent it from coming off, and is held between the liner 4 and the inner surface 2a of the top plate portion 2. Of the knurl portion 5 that bulges in two steps in this way, the width of the step on the lower end side of the peripheral wall portion 3 in the direction of the cap center line O is formed to be larger than the width of the step on the upper end side in the direction of the cap center line O.

[0032] A plurality of first resin layers (lid body protrusions) 13 of this embodiment are formed intermittently along the circumferential direction of the peripheral wall 3 on the inner surface of the cap 10 so as to protrude from the inner surface side of the engaging portion 12. Each first resin layer 13 is formed in a rectangular parallelepiped shape with its long side extending in a direction inclined at a predetermined angle with respect to the circumferential direction of the peripheral wall 3. The distance between adjacent first resin layers 13 may be set to a size that allows an engaging thread (container protrusion) F formed intermittently on a bottle-can body (container body) B to be closed using the cap 10 of this embodiment to pass through along the cap center line O.

[0033] The first resin layer (lid body convex portion) 13 is formed by forming a resin film 14 made of a resin that is entirely composed of a polymerizable compound or that contains a polymerizable compound in part, such as a photo-radical polymerization type ultraviolet curing resin, on the surface of the peripheral wall portion 3 of the cap body 1 using a droplet ejection device, such as an inkjet printer, and then stacking the layers one by one while curing each layer through a photopolymerization reaction caused by UV irradiation, or by integrating multiple stacked resin films 14, 14... through a photopolymerization reaction.

[0034] When UV light is irradiated onto each layer during the formation of the resin film 14, if the reaction is suppressed to a certain rate by reducing the irradiation intensity of the UV light or shortening the irradiation time, a photopolymerization reaction can be carried out on the next resin film 14 to be stacked, and all of the stacked resin films 14 can be integrated to form the first resin layer 13.

[0035] The resin film 14 before polymerization (resin liquid ejected from the droplet ejecting device) for forming the first resin layer 13 contains a photopolymerizable material. Examples of the photopolymerizable material contained in the resin film 14 before polymerization include at least one monomer or oligomer of acrylic resin (including methacrylic resin), epoxy resin, urethane resin, vinyl resin (including vinyl chloride resin, polyvinyl alcohol resin, and vinyl acetate resin), polyester resin, polyester amino resin, silicone resin, and polyolefin resin.

[0036] More specifically, the photopolymerizable material contained in the pre-polymerized resin film 14 can be monofunctional to oligofunctional prepolymers such as acrylic monomers, methacrylic monomers, and vinyl compounds. In addition, the photopolymerizable oligomer can be, for example, epoxy acrylate, aliphatic and aromatic urethane acrylate, polyester acrylate, acrylic oligomer, etc.

[0037] Furthermore, by integrating multiple resin films 14 by photopolymerization using a photopolymerizable material to form the first resin layer 13, it is possible to prevent shrinkage due to evaporation of solvent when drying, such as in water-based paints or oil-based paints.

[0038] The first resin layer 13 of this embodiment is formed so that the area of ​​one side of at least one of the multiple resin films 14, 14... that is located above the lowest resin film 14a in contact with the surface of the peripheral wall portion 3 is smaller than the area of ​​one side of the lowest resin film 14.

[0039] That is, in this embodiment, the multiple resin films 14, 14... are formed so that the area of ​​one surface of each resin film 14 gradually decreases from the lowest resin film 14a closest to the peripheral wall portion 3 to the highest resin film 14n. As a result, the first resin layer 13 is formed in a trapezoidal shape with inclined sides.

[0040] The thickness of the first resin layer 13 protruding from the inner surface of the peripheral wall 3 of the cap (lid) 10 may be, for example, 0.03 mm or more and 1 mm or less. If the protruding thickness of the first resin layer 13 is less than 0.03 mm, there is a concern that the anti-slip performance may be reduced. Furthermore, if the protruding thickness of the first resin layer 13 exceeds 1 mm, there is a concern that partial peeling of the first resin layer 13 may occur.

[0041] A base layer (not shown) may be formed on the surfaces (outer and inner surfaces) of the cap body 1. The base layer may be, for example, a thin film formed of an epoxy resin or a thermosetting acrylic resin. More specifically, the epoxy resin may be any epoxy resin commonly used for paints, without any particular limitations. Examples of such epoxy resins include various epoxy resins that are commonly available commercially, such as epi-bis, novolac, β-methylepicro, cyclic oxirane, glycidyl ether, glycidyl ester, polyglycol ether, glycol ether, epoxidized fatty acid ester, polycarboxylic acid ester, aminoglycidyl, and resorcinol.

[0042] Such an underlayer may be formed to have a thickness of, for example, about 3 μm to 10 μm. The underlayer may be formed by applying the above-mentioned resin with a roll coater, for example.

[0043] When forming the underlayer, if the underlayer is formed from a resin paint containing 0.1% to 2% of a polymerizable oligomer of a polyester resin that has good adhesive compatibility with the first resin layer 13, the interface between the first resin layer 13 formed on top of this underlayer can be bonded by photopolymerization, for example, photoradical polymerization or photocationic polymerization. This makes it possible to prevent the first resin layer 13 from peeling off from the underlayer even when external stress is applied to the first resin layer 13.

[0044] The cap (lid) 10 of this embodiment configured as described above can close a bottle can body (container body) B by engaging the first resin layer (engagement lugs) 13 formed on the inner surface of the peripheral wall portion 3 with the engagement threads (container protrusions) F formed intermittently so as to protrude from the outer circumferential surface of the mouth portion (mouth part) of the bottle can body (container body) B. That is, by placing the cap 10 on the mouth portion (mouth part) of the bottle can body B so that the engagement threads (container protrusions) F pass between the first resin layers (engagement lugs) 13, and then rotating the cap 10 in the circumferential direction, the first resin layers (engagement lugs) 13 and the engagement threads (container protrusions) F come into close contact with each other, and the bottle can body B can be closed.

[0045] Thus, according to the cap (lid) 10 of this embodiment, by intermittently forming the first resin layer 13 consisting of a plurality of resin films 14, 14... on the peripheral wall portion 3, processing of the cap (lid) 10 is easier and the cap 10 can be formed at low cost compared to when lugs (lid protrusions) are formed on the cap body itself by pressing or the like. Furthermore, because the lugs are not formed on the cap body itself by pressing or the like, there are fewer bent portions, which reduces the possibility of cracking or cutting due to pressing.

[0046] (Lid: Second embodiment) A lid according to a second embodiment of the present invention will now be described. The same components as those of the cover of the first embodiment are given the same numbers, and redundant explanations will be omitted. Fig. 3 is a partially cutaway view showing a lid according to a second embodiment of the present invention, and Fig. 4 is an enlarged cross-sectional view of a main part of the first resin layer (lid projection) in this embodiment. The cap (lid) 20 of this embodiment has a cap body 1 formed integrally with a disk-shaped top plate 2 and a peripheral wall 3 extending cylindrically from the periphery of the top plate 2 toward the lower end (lower side in FIG. 4) centered on the cap center line O, and a first resin layer 23 that is a lid body protrusion formed on the inner circumferential surface of the cap 20, i.e., the inner surface of the peripheral wall 3. The first resin layer 23 of this embodiment forms an engaging lug that engages with an engaging thread formed on the container body, which will be described later.

[0047] A plurality of first resin layers (lid body protrusions) 23 of this embodiment are formed intermittently along the circumferential direction of the peripheral wall portion 3 on the inner surface of the cap 10 so as to protrude from the inner surface side of the engaging portion 12. Each first resin layer 23 is formed in a rectangular parallelepiped shape with its long side extending along the circumferential direction of the peripheral wall portion 3. The distance between adjacent first resin layers 23 may be set to a size that allows an engaging thread (container protrusion) F formed intermittently on a bottle-can body (container body) B to be closed using the cap 20 of this embodiment to pass through along the cap center line O.

[0048] The first resin layer 23 of this embodiment is formed so that the area of ​​one side of at least one of the multiple resin films 24, 24... that is located above the lowest resin film 24a that contacts the inner surface of the cap (lid) 20 is larger than the area of ​​one side of the lowest resin film 24.

[0049] That is, in this embodiment, the plurality of resin films 24, 24... are formed so that the area of ​​one surface of each resin film 24 gradually increases from the lowest resin film 24a near the inner circumferential surface of the peripheral wall portion 3 of the cap (lid body) 20 toward the highest resin film 24n. As a result, each first resin layer 23 is formed in an inverted trapezoid shape with an inclined side surface.

[0050] The cap (lid) 20 of this embodiment configured as described above can close a bottle can body (container body) B by engaging the first resin layer (engagement lugs) 23 formed on the inner surface of the peripheral wall portion 3 with the engagement threads (container protrusions) F formed intermittently so as to protrude from the outer circumferential surface of the mouth portion (mouth part) of the bottle can body (container body) B. That is, by placing the cap 20 on the mouth portion (mouth part) of the bottle can body B so that the engagement threads (container protrusions) F pass between the first resin layers (engagement lugs) 23, and then rotating the cap 20 in the circumferential direction, the first resin layers (engagement lugs) 23 and the engagement threads (container protrusions) F come into close contact with each other, and the bottle can body B can be closed.

[0051] At this time, by forming the engaging thread (container protrusion) F into an inverted trapezoidal shape, it engages with the first resin layer (engaging lug) 23 formed into an inverted trapezoidal shape so that they partially overlap in the thickness direction. Therefore, the cap (lid body) 20 of this embodiment can seal the bottle-can body B more firmly than the first embodiment.

[0052] (Container body) A container body according to one embodiment of the present invention will now be described. The container body of this embodiment will be described taking a bottle can body for containing a beverage as an example. Fig. 5 is a partially cutaway view showing a container body according to one embodiment of the present invention, and Fig. 6 is an enlarged cross-sectional view of a main part of the second resin layer (container protrusion) of the container body.

[0053] The bottle can body (container body) 30 of this embodiment is formed in a roughly multi-stage, bottomed cylindrical shape centered on a can axis C, and includes a bottom 32 that closes one end of a cylindrical body 35, and an outer peripheral portion 33 that is formed integrally with the bottom 32 and extends from the outer peripheral edge of the bottom 32 to the upper end side (upward in Figure 6).

[0054] The bottom 32 has a dome portion 32a in the center that is recessed inward in the direction of the can axis C (toward the upper end of the bottle can body 30) and has an approximately arc-shaped cross section. At the outer periphery of this dome portion 32a, an annular protrusion 32b is formed continuously in the circumferential direction around the can axis C, protruding outward in the direction of the can axis C (toward the lower end of the bottle can body 30).

[0055] The outer periphery 33 is formed, in this order from the bottom 32 toward the opening 34 at the upper end of the bottle can body 30, with a cylindrical body 35 centered on the can axis C, a truncated conical shoulder portion 36 that gradually reduces in diameter from the other end of the body 35 toward the upper end at a constant incline, a cylindrical neck 37 that extends further toward the upper end from the shoulder portion 36, and a mouth portion (jam) 38 that includes: a bulge 38a that protrudes outward from the upper end of the neck 37; a locking portion 38b; a reduced diameter portion 38c that gradually reduces in diameter from the upper end of the locking portion 38b toward the upper end; and a curled portion 38d formed by folding the upper part of the reduced diameter portion 38c toward the outer periphery and then back toward the lower end.

[0056] A plurality of second resin layers 43, 43... serving as container protrusions are formed on the outer peripheral surface of the locking portion 38b constituting the mouth portion (neck portion) 38 of the bottle can body (container body) 30. In this embodiment, the second resin layers (container protrusions) 43 are engaging lugs that engage with engaging threads F formed on the container body.

[0057] A plurality of second resin layers (container protrusions) 43 of this embodiment are formed intermittently along the circumferential direction of the mouth portion (mouth portion) 38 so as to protrude from the outer peripheral surface side of the mouth portion 38. Each second resin layer 43 is formed in a shape that extends from one end in the circumferential direction of the mouth portion 38 and is bent in a direction inclined at a predetermined angle in the circumferential direction midway. The interval between adjacent second resin layers 43 may be set to a size that allows the passage of engaging lugs R formed intermittently on the lid body Q for closing the bottle-can body 30 of this embodiment.

[0058] The second resin layer 43 is formed by forming a resin film 44 made of a resin that is either entirely composed of a polymerizable compound or that contains a polymerizable compound in part, such as a photo-radical polymerization type ultraviolet curing resin, on the outer surface of the locking portion 38b that constitutes the nozzle portion (mouth portion) 38 using a droplet ejection device, such as an inkjet printer, and stacking the layers one by one while hardening each layer through a photopolymerization reaction caused by UV irradiation, or by integrating multiple stacked resin films 44, 44... through a photopolymerization reaction.

[0059] When UV light is irradiated onto each layer during the formation of the resin film 44, if the reaction is suppressed to a certain rate by reducing the irradiation intensity of the UV light or shortening the irradiation time, a photopolymerization reaction can be carried out on the next resin film 44 to be stacked, and all of the stacked resin films 44 can be integrated to form the second resin layer 43.

[0060] The resin film 44 before polymerization (resin liquid ejected from the droplet ejecting device) for forming the second resin layer 43 contains a photopolymerizable material. Examples of the photopolymerizable material contained in the resin film 44 before polymerization include at least one monomer or oligomer of acrylic resin (including methacrylic resin), epoxy resin, urethane resin, vinyl resin (including vinyl chloride resin, polyvinyl alcohol resin, and vinyl acetate resin), polyester resin, polyester amino resin, silicone resin, and polyolefin resin.

[0061] More specifically, the photopolymerizable material contained in the pre-polymerized resin film 44 can be monofunctional to oligofunctional prepolymers such as acrylic monomers, methacrylic monomers, and vinyl compounds. In addition, the photopolymerizable oligomer can be, for example, epoxy acrylate, aliphatic and aromatic urethane acrylate, polyester acrylate, acrylic oligomer, etc.

[0062] Furthermore, by integrating multiple resin films 44 by photopolymerization using a photopolymerizable material to form the second resin layer 43, it is possible to prevent shrinkage due to evaporation of solvent when drying, such as in water-based paints or oil-based paints.

[0063] The second resin layer 43 of this embodiment is formed so that the area of ​​one side of at least one of the multiple resin films 44, 44... that is located above the lowest resin film 44a that contacts the outer surface 35a of the body 35 is smaller than the area of ​​one side of the lowest resin film 44.

[0064] That is, in this embodiment, the plurality of resin films 44, 44... are formed so that the area of ​​one surface of each resin film 44 gradually decreases from the lowest resin film 44a near the outer circumferential surface of the locking portion 38b constituting the mouth portion (mouth portion) 38 to the highest resin film 44n. As a result, each second resin layer 43 is formed in a trapezoidal shape with side surfaces sloping in a stepped manner.

[0065] The thickness of the second resin layer 43 protruding from the outer peripheral surface of the locking portion 38b constituting the mouth portion 38 may be, for example, 0.03 mm or more and 1 mm or less. If the protruding thickness of the second resin layer 43 is less than 0.03 mm, there is a concern that the engagement characteristics with the engagement thread F formed on the container body may be reduced. Furthermore, if the protruding thickness of the second resin layer 43 exceeds 1 mm, there is a concern that partial peeling of the second resin layer 43 may occur.

[0066] In addition to the shape shown in Figure 6, the second resin layer 43 may be formed in an inverted trapezoid shape, for example, as shown in Figure 4, so that the area of ​​one side of each resin film gradually decreases from the bottom resin film to the top resin film.

[0067] A base layer (not shown) may be formed on the outer surface of the bottle can body 30. The base layer may be, for example, a thin film formed of an epoxy resin or a thermosetting acrylic resin. More specifically, the epoxy resin may be any epoxy resin commonly used for paints, without any particular restrictions. Examples of such epoxy resins include various epoxy resins that are commonly available commercially, such as epi-bis type, novolac type, β-methylepicro type, cyclic oxirane type, glycidyl ether type, glycidyl ester type, polyglycol ether type, glycol ether type, epoxidized fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type, and resorcinol type.

[0068] Such an underlayer may be formed to have a thickness of, for example, about 3 μm to 10 μm. The underlayer may be formed by applying the above-mentioned resin with a roll coater, for example.

[0069] When forming a base layer, if the resin film 44 constituting the second resin layer 43 is formed using a resin paint containing 0.1% to 2% of a polymerizable oligomer of a polyester-based resin that has good adhesion compatibility with the base layer, the base layer and the second resin layer 43 can be firmly bonded by photopolymerization.

[0070] The bottle can body (container body) 30 of this embodiment configured as described above can be closed by engaging the second resin layer (engagement thread) 43 formed on the outer peripheral surface of the locking portion 38b constituting the nozzle portion (mouth portion) 38 of the bottle can body (container body) 30 with the engaging lugs R formed intermittently on the lid body Q. That is, by placing the lid body Q over the nozzle portion (mouth portion) 38 of the bottle can body 30 so that the second resin layer (engagement thread) 43 passes between the engaging lugs R, and then rotating the lid body Q in the circumferential direction, the second resin layer (engagement thread) 43 and the engaging lugs R of the lid body Q come into close contact with each other, and the bottle can body 30 can be closed.

[0071] Thus, according to the bottle can body (container body) 30 of this embodiment, by intermittently forming the second resin layer 43 consisting of a plurality of resin films 44, 44... on the outer peripheral surface of the locking portion 38b that constitutes the mouth portion (neck portion) 38, processing of the bottle can body 30 becomes easier and the bottle can body 30 can be formed at low cost compared to when an engaging thread is formed by pressing the mouth portion (neck portion) 38 of the bottle can body 30 with a mold or the like. Also, because an engaging thread is not formed on the neck portion of the bottle can body by pressing or the like, there are fewer bending portions on the neck portion, reducing the possibility of cracking or cutting due to pressing.

[0072] (sealed container) As an example of the sealed container of this embodiment, a bottle can body with a cap in which the cap (lid body) of the second embodiment is attached to the mouth portion (mouth portion) of the bottle can body (container body) of the above-mentioned embodiment is exemplified. FIG. 7 is an enlarged cross-sectional view of a main part of a bottle can (sealed container) with a cap according to one embodiment. The capped bottle can body 50 of this embodiment is formed by, for example, attaching the cap 20 of the second embodiment to the mouth portion 38 of the bottle can body 30 of the above-described embodiment.

[0073] In the capped bottle can body 50 of this embodiment having such a configuration, a first resin layer (lid body convex portion) 23 made by laminating and integrating a plurality of resin films 24, 24... (see FIG. 4) is formed on the inner surface of the peripheral wall portion 3 of the cap (lid body) 20. Also, a second resin layer (container convex portion) 43 made by laminating and integrating a plurality of resin films 44, 44... (see FIG. 6) is formed on the outer peripheral surface of the mouth portion (neck portion) 38 of the bottle can body (container main body) 30.

[0074] With the capped bottle can body 50 configured in this way, it is not necessary to form thread grooves in the cap (lid body) 10 and the bottle can body (container body) 30 by pressing with a mold or the like to allow them to be detachably engaged with each other, which makes it easier to mold the capped bottle can body 50 and also reduces the number of bent portions, making it possible to prevent cracking or cutting due to pressing even when using a thin metal plate, for example, and to realize a lightweight capped bottle can body 50.

[0075] In the capped bottle can body 50 of the above-described embodiment, the first resin layer (lid body convex portion) 23 and the second resin layer (container convex portion) 43 are intermittently formed in one line along the circumferential direction on each of the cap (lid body) 20 and the bottle can body (container body) 30, but these first resin layer (lid body convex portion) 23 and second resin layer (container convex portion) 43 can also be formed in two or more lines.

[0076] For example, in the embodiment (modification) shown in Fig. 8, two first resin layers (lid body protrusions) 13 are formed on the inner surface side of the peripheral wall portion 3 of the cap (lid body) 10. With this configuration, it is possible to realize a capped bottle can body (sealed container) 50 that can more firmly seal the cap (lid body) 10 and the bottle can body (container body) 30.

[0077] (Lid manufacturing method, container body manufacturing method) A method for manufacturing a cap according to one embodiment of the present invention will now be described. For example, when manufacturing the above-mentioned cap (lid body) 10 or bottle can body (container body) 30, a cap body 1 or bottle can body formed by pressing an aluminum alloy plate is prepared, and a droplet ejection device, for example, an inkjet printer, is used to laminate multiple resin films 14, 44 on the inner surface of the peripheral wall portion 3 of the cap (lid body) 10 and the outer peripheral surface of the nozzle portion (mouth portion) 38 of the bottle can body (container body) 30, thereby forming a first resin layer (lid body convex portion) 13 and a second resin layer (container convex portion) 43 (first resin layer formation process, second resin layer formation process).

[0078] When forming the first resin layer 13 and the second resin layer 43, a droplet ejection device capable of ejecting a resin liquid for forming the resin films 14, 44, such as an inkjet printer having an inkjet head, may be used. The resin liquid to be applied contains an ultraviolet curable resin.

[0079] In this embodiment, an inkjet printer P (droplet ejection device) with six inkjet heads is used as shown in Fig. 9, but the number of inkjet heads used is limited to improve productivity. For example, of the C, M, Y, and K heads used for color printing, only the M (magenta) head is used, and two heads V are allocated to further laminate a transparent resin film (varnish).

[0080] In this way, by limiting the number of colors, the time required to form the first resin layer 13 and the second resin layer 43 can be shortened, thereby improving the productivity of the caps 10 and the bottle can bodies 30. Furthermore, by using two heads to laminate the transparent resin film (varnish) to increase the thickness of the first resin layer 13 and the second resin layer 43 and increasing the amount of resin liquid discharged, it is possible to form the first resin layer 13 and the second resin layer 43 that are thick and have excellent anti-slip properties in a short time, thereby improving the productivity of the caps 10 and the bottle can bodies 30.

[0081] Then, while rotating a cap (lid body) 10 or a bottle can body 30 (container body) near each head, a resin liquid containing a photopolymerizable material is ejected from each head to form a pre-polymerized resin film 14a (lowest layer) to a resin film 14n (uppermost layer) and a pre-polymerized resin film 44a (lowest layer) to a resin film 44n (uppermost layer).

[0082] Thereafter, for example, ultraviolet light is irradiated from ultraviolet irradiation units UV formed at positions opposite each head to photopolymerize the unpolymerized resin films 14a-14n, 44a-44n ejected by each head, and adjacent underlying resin films 14 are bonded together by photopolymerization. This forms a first resin layer 13 in which the resin films 14a-14n are firmly bonded together by photopolymerization, and a second resin layer 43 in which the resin films 44a-44n are firmly bonded together by photopolymerization.

[0083] In forming the first resin layer 13 and the second resin layer 43, as described above, an ultraviolet irradiation unit UV may be arranged corresponding to each inkjet head, and each time a resin film 14 is formed, it may be polymerized with the underlying resin film 14, 44, or all of the unpolymerized resin films 14, 44 may be stacked and then polymerized all at once.

[0084] Furthermore, when forming a base layer on the cap 10, a resin paint containing 0.1% to 2% polymerizable oligomer of polyester-based resin, which has good adhesive properties, is used as a resin liquid and ejected from an inkjet head to laminate multiple resin films 14, thereby photopolymerizing the bottommost resin film 14a and the base layer to form a resin layer 13 that is firmly adhered to the base layer.

[0085] Similarly, when forming a base layer on the outer peripheral surface of the locking portion 38b that constitutes the nozzle portion (mouth portion) 38 of the bottle can body (container body) 30, a resin paint containing 0.1% to 2% polymerizable oligomer of polyester-based resin, which has good adhesive properties, is used as a resin liquid and ejected from an inkjet head to laminate multiple resin films 44, thereby photopolymerizing the bottom-most resin film 44a and the base layer to form a resin layer 43 that is firmly adhered to the base layer.

[0086] When forming the first resin layer 13 on the cap (lid) 10, an inkjet printer P having a small inkjet head that can fit inside the concave cap 10 may be used.

[0087] The first resin layer 13 and the second resin layer 43 may be formed by placing an ultraviolet irradiation device between each inkjet head and curing each layer of the resin liquid coating with ultraviolet light to form the resin films 14, 44, or alternatively, the resin liquid coatings may be stacked in an uncured state, and then in a subsequent process, the uncured resin liquid coatings stacked together may be cured with ultraviolet light to form the first resin layer 13 and the second resin layer 43 in which multiple resin films 14, 44 are integrated.

[0088] In the first resin layer forming process and the second resin layer forming process, a resin paint containing a polymerizable unsaturated compound can be used as the resin liquid for forming the resin films 14, 44. For example, by ejecting an ultraviolet-curable resin paint containing a polymerizable unsaturated compound as the resin liquid from an inkjet head, laminating multiple resin films 14, 44, and irradiating them with ultraviolet light, the first resin layer 13 and the second resin layer 43 can be formed in which the multiple resin films 14, 44 are polymerized and integrated without shrinking each other.

[0089] Monofunctional to oligofunctional prepolymers of acrylic monomers, methacrylic monomers, and vinyl compounds can be used as polymerizable unsaturated compounds used in the resin liquid for forming the resin films 14, 44. In addition, polymerizable oligomers such as epoxy acrylates, aliphatic and aromatic urethane acrylates, polyester acrylates, and acrylic oligomers can be used.

[0090] Although one embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0091] 1...Cap body 2...Top plate 3...Peripheral wall part 4. Liner 5...Nar Department 10...Cap (lid) 12...Engagement portion 13...First resin layer 14...Resin film 30...Bottle can body (container body) 32...Bottom 33...Outer periphery 35...Torso 36...Shoulder part 38...Mouth part (mouth part) 38b…Locking part 43... Second resin layer (container protrusion) 50...Bottle can with cap (sealed container)

Claims

1. A cylindrical lid that detachably covers a cylindrical opening formed on the open end side of the container body, a lid protrusion that engages with a container protrusion formed on the outer peripheral surface of the mouth portion is formed on an inner peripheral surface of the lid body that faces the outer peripheral surface of the mouth portion; The lid body is characterized in that the lid body protrusion portion is made of a first resin layer formed by integrating a plurality of resin films containing a photopolymerizable material by photopolymerization.

2. The lid body according to claim 1 , wherein the lid body protrusions are formed intermittently along the circumferential direction on the inner peripheral surface of the lid body.

3. A lid body as described in claim 1 or 2, characterized in that, among the multiple resin films that constitute the first resin layer, the area of ​​one side of at least one resin film that is located above the lowest resin film near the inner surface of the lid body is larger than the area of ​​one side of the lowest resin film.

4. A container body having a cylindrical mouth portion, the mouth portion being detachably covered with a lid body, a container projection that engages with a lid projection formed on the inner peripheral surface of the lid is formed on an outer peripheral surface of the opening that faces the inner peripheral surface of the lid; The container body is characterized in that the container protrusion is made of a second resin layer formed by integrating a plurality of resin films containing a photopolymerizable material by photopolymerization.

5. 5. The container body according to claim 4, wherein the container protrusions are formed intermittently along the circumferential direction on the outer peripheral surface of the mouth portion.

6. A container body as described in claim 4 or 5, characterized in that the area of ​​one side of at least one of the multiple resin films that constitute the second resin layer, which is located above the lowest resin film near the outer peripheral surface of the mouth portion, is larger than the area of ​​one side of the lowest resin film.

7. A sealed container having a container body with a cylindrical mouth and a cylindrical lid that detachably covers the mouth, a container protrusion is formed on an outer peripheral surface of the opening portion that faces an inner peripheral surface of the lid body; a lid protrusion that engages with the container protrusion is formed on the inner peripheral surface of the lid; the lid protrusion is made of a first resin layer formed by integrating a plurality of resin films containing a photopolymerizable material by photopolymerization; The hermetically sealed container is characterized in that the container convex portion is made of a second resin layer formed by integrating a plurality of resin films containing a photopolymerizable material by photopolymerization.

8. The sealed container according to claim 7, characterized in that the lid body protrusions are formed intermittently along the circumferential direction on the inner peripheral surface of the lid body, and the container protrusions are formed intermittently along the circumferential direction on the outer peripheral surface of the mouth portion.

9. A method for manufacturing the lid body according to any one of claims 1 to 3, comprising the steps of: a first resin layer forming step of forming the first resin layer on an inner circumferential surface of the lid body, The first resin layer forming process is a method for manufacturing a lid body, characterized in that when a resin liquid containing a photopolymerizable material is ejected by a droplet ejection device to form multiple overlapping resin films, adjacent resin films are photopolymerized together.

10. A method for manufacturing the container body according to any one of claims 4 to 6, comprising the steps of: a second resin layer forming step of forming the second resin layer on the outer peripheral surface of the container body, The second resin layer forming process is a method for manufacturing a container body, characterized in that when a resin liquid containing a photopolymerizable material is ejected by a droplet ejection device to form multiple overlapping resin films, adjacent resin films are photopolymerized together.

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