Method for manufacturing metal container and metal container

Abstract

SOLUTION: There is provided a method for manufacturing a metal container which includes: a first radiation curable type resin layer formation step of forming a first radiation curable type resin layer on at least a part of a surface of a resin film layer coating at least a part of a container body having an opening, a side wall part and a bottom part; and a surface modification treatment step of subjecting at least a part of at least either of the resin film layer and the first radiation curable resin layer to surface modification treatment. There is also provided a metal container which includes: a container body having an opening, a side wall part and a bottom part; a resin film layer coating at least a part of the container body; and a first radiation curable type resin layer formed on at least a part of a surface of the resin film layer. Therein surface free energy of the surface of the resin film layer is 44 mN / m or more, or surface free energy of the surface of the first radiation curable resin layer is 20 mN / m or more.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a metal container and a metal container. [Background technology]

[0002] Patent Document 1 describes a stackable metal cup having a hollow shape that is open at the top, a body portion having an inner diameter or outer diameter that tapers downward so that the inner diameter at the upper end is larger than the outer diameter at the lower end, and a bottom portion having a grounding portion connected to the lower end of the body portion via a curvature portion, wherein in a stacked state, a region P where the angle of the body portion with respect to the horizontal plane is in the range of 85 to 90 degrees and a region Q where the angle is in a range smaller than region P are alternately continuous in the height direction so that a gap t of 0.5 mm or more is formed between the inner diameter of the body portion of the lower metal cup and the outer diameter of the body portion of the upper metal cup.'' [Prior art document] [Patent documents] [Patent Document 1] JP 2023-46747 A Summary of the Invention

[0003] In a first aspect of the present invention, there is provided a method for manufacturing a metal container, comprising a first radiation-cured resin layer forming step and a surface modification step. In the first radiation-cured resin layer forming step, a first radiation-cured resin layer is formed on at least a portion of the surface of a resin film layer that covers at least a portion of a container body having an opening, a sidewall, and a bottom. In the surface modification step, a surface modification treatment is performed to modify at least a portion of the surface of at least one of the resin film layer and the first radiation-cured resin layer.

[0004] The surface modification treatment may include a flame treatment in which a flame is brought into contact with at least a portion of the surface of at least one of the resin film layer and the first radiation curable resin layer to modify the surface.

[0005] The surface modification treatment step may include a resin film layer modification treatment step, in which at least a part of the surface of the resin film layer may be subjected to a surface modification treatment prior to the first radiation cured resin layer forming step.

[0006] The surface free energy of the surface of the resin film layer after the resin film layer modification treatment step may be 44 mN / m or more and less than 60 mN / m.

[0007] The resin film layer modification treatment step may include a flame treatment in which a flame is brought into contact with at least a part of the surface of the resin film layer to modify the surface. The ratio of fuel gas to combustion air used to generate the flame may be 1:10 to 1:30.

[0008] In the resin film layer modification treatment process, the amount of fuel gas and combustion air used to generate the flame and / or the ratio of fuel gas to combustion air may be adjusted depending on the treatment time during which the flame is in contact with at least a portion of the surface of the resin film layer.

[0009] The first radiation curable resin layer forming step may include a step of applying a first radiation curable resin. The step of applying a first radiation curable resin may be to apply the first radiation curable resin to at least a part of the surface of the resin film layer after the resin film layer modification treatment step by plate printing or inkjet printing.

[0010] The surface modification step may include a first radiation-cured resin layer modification step, which may involve performing a surface modification treatment on at least a portion of the surface of the first radiation-cured resin layer after the first radiation-cured resin layer formation step.

[0011] The surface free energy of the first radiation cured resin layer after the first radiation cured resin layer modifying treatment step may be 20 mN / m or more.

[0012] The first radiation curable resin layer forming step may include a first radiation curable resin applying step, in which the first radiation curable resin is applied to at least a portion of the surface of the resin film layer by plate printing or inkjet printing.

[0013] In the above, the method for manufacturing a metal container may further include a second radiation-cured resin layer forming step, which may form a second radiation-cured resin layer on at least a portion of the surface of the first radiation-cured resin layer after the first radiation-cured resin layer modifying treatment step.

[0014] The second radiation curable resin layer may have a pencil hardness of HB or greater.

[0015] An image may be formed on at least one of the first radiation curable resin layer and the second radiation curable resin layer.

[0016] The first radiation curable resin layer may include a white ink.

[0017] The second radiation curable resin layer may include a clear ink.

[0018] The first radiation-curable resin layer may include a first ultraviolet-curable resin. The first radiation-curable resin layer forming step may include a first ultraviolet-curable resin curing step of curing the first ultraviolet-curable resin by using ultraviolet light.

[0019] The second radiation-curable resin layer may include a second ultraviolet-curable resin. The second radiation-curable resin layer forming step may include a second ultraviolet-curable resin curing step of curing the second ultraviolet-curable resin using ultraviolet light.

[0020] The container body may be made of aluminum or an aluminum alloy. The resin film layer may include a polyester resin.

[0021] The container body may be made of a plate-shaped material made of aluminum or an aluminum alloy, and a resin film layer may be formed on both sides of the plate-shaped material.

[0022] In a second aspect of the present invention, there is provided a metal container comprising a container body, a resin film layer, and a first radiation cured resin layer. The container body has an opening, a side wall, and a bottom. The resin film layer covers at least a portion of the container body. The first radiation cured resin layer is formed on at least a portion of the surface of the resin film layer. In the metal container, at least one of the surface free energy of the resin film layer is 44 mN / m or more, and the surface free energy of the first radiation cured resin layer is 20 mN / m or more.

[0023] The surface free energy of the surface of the resin film layer may be 44 mN / m or more and less than 60 mN / m.

[0024] The surface free energy of the first radiation curable resin layer may be 20 mN / m or more.

[0025] The metal container may further include a second radiation curable resin layer. The second radiation curable resin layer may be formed on at least a portion of the surface of the first radiation curable resin layer.

[0026] The second radiation curable resin layer may have a pencil hardness of HB or greater.

[0027] The first radiation curable resin layer may include a first ultraviolet curable resin.

[0028] The second radiation curable resin layer may include a second ultraviolet curable resin.

[0029] The container body may be made of aluminum or an aluminum alloy. The resin film layer may include a polyester resin.

[0030] The container body may be made of a plate-shaped material made of aluminum or an aluminum alloy, and may have resin film layers formed on both sides of the plate-shaped material.

[0031] The above summary of the invention does not list all of the features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0032] [Figure 1] An example of a metal container 100 according to this embodiment is shown. [Diagram 2] In the metal container 100 of this embodiment, an example of the layer structure 200 in the case where the resin film layer 220 is subjected to a surface modification treatment is shown. [Diagram 3] In the metal container 100 of this embodiment, an example of a layer structure 300 in which the first radiation cured resin layer 330 is subjected to a surface modification treatment is shown. [Figure 4] An example of a manufacturing system 1000 for carrying out the manufacturing method of the metal container 100 of this embodiment is shown. [Diagram 5] Specific examples of the radiation curable resin layer forming apparatus 1300 and the surface modification treatment apparatus 1400 are shown below. [Figure 6] An example of a flow of a method for manufacturing the metal container 100 of this embodiment will be described. [Figure 7] An example of a sub-flow of S20 is shown below. [Figure 8] An example of a flow of a method for manufacturing the metal container 100 of this embodiment will be described. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0034] FIG. 1 shows an example of the metal container 100 of the present embodiment. The metal container 100 is a metal container capable of holding contents. The metal container 100 may be used for the purpose of holding beverages and / or for the purpose of holding foods.

[0035] The metal container 100 includes a container body having an opening 110, a side wall portion 120, and a bottom portion 130.

[0036] As shown in FIG. 1, the opening 110 may be a ring-shaped portion where an opening is formed in the container body. The side wall portion 120 forms the side wall of the container body and may have a cylindrical shape. The bottom portion 130 serves as the bottom of the container body and may hold the contents from below. In the metal container 100, the container body may have a cup-like shape that is used in a state where the opening 110 is open. The container body may have a shape in which the inner diameter of the opening 110 is the largest and the diameter gradually decreases toward the bottom portion 130. This enables the metal containers 100 to be stacked, and enables a plurality of metal containers 100 to be stacked for storage and transportation.

[0037] As shown in FIG. 1, the container body may include a curl portion 140 at the periphery of the opening 110, where the end of the container body is curved outward in the radial direction of the container. The side wall portion 120 may have a shape that gradually decreases in diameter uniformly from the opening 110 toward the bottom portion 130 or in a stepped shape. In addition to this, the side wall portion 120 may have a shape in which a curve and a straight line are combined in the cross-sectional shape. For example, the side wall portion 120 may have a shape including a bulging portion 150 that bulges outward. By having the bulging portion 150 in the container body, it is possible to easily separate the metal containers 100 from each other when stacked. The bottom portion 130 of the container body may have a dome-shaped shape that protrudes toward the opening 110 side.

[0038] The metal container 100 may be a cylindrical can container to which a lid is attached to the opening 110. The can container may have a cylindrical shape with a shape that decreases in diameter from the bottom portion 130 toward the opening 110 at the upper part of the side wall portion 120. The can container may also have a bottle-like shape in which the opening 110 is provided at a narrow-diameter mouth portion.

[0039] In the metal container 100, the container body may be made of aluminum or an aluminum alloy. The container body may be made of stainless steel or steel. The container body may be made of a plate-shaped material. The plate-shaped material may be made of aluminum or an aluminum alloy. Alternatively, the plate-shaped material may be made of stainless steel or steel. The thickness of the plate-shaped material may vary depending on the application of the metal container 100. For example, the average thickness of the side wall portion 120 of the metal container 100 may be 0.08 to 0.22 mm. Within this range, it is possible to achieve both appropriate flexibility and strength. Furthermore, it is possible to combine the convenience of a paper cup with the luxurious feel of a metal cup.

[0040] 2 shows an example of a layer structure 200 in the case where the metal container 100 of this embodiment includes a resin film layer 220 that has been subjected to a surface modification treatment. The metal container 100 includes a resin film layer 220 that covers at least a portion of the container body, and a first radiation cured resin layer 230 that is formed on at least a portion of the surface of the resin film layer 220.

[0041] The resin film layer 220 covers at least a part of the surface of the container body, and has the role of improving the slipperiness of the metal container 100 when the metal container 100 is subjected to diameter reduction drawing. The resin film layer 220 may be a film made of a thermoplastic resin. The resin film layer 220 may contain a polyester resin and / or a polyolefin resin. The polyester resin may be, for example, polyethylene terephthalate. The resin film layer 220 may be formed in a single layer or multiple layers. The resin film layer 220 may be a coating film made of a thermosetting resin and / or a thermoplastic resin. Examples of paints that can form a coating film include polyester-based, acrylic-based, urethane-based, silicone-based, and fluorine-based paints.

[0042] The resin film layer 220 may be formed on the inner surface 212 and / or the outer surface 214 of the container body. In the metal container 100 shown in Fig. 2, a surface modification treatment is applied to at least a part of the surface of the resin film layer 220. The details of the surface modification treatment will be described later.

[0043] In the example of the layer structure 200 shown in FIG. 2, the surface free energy of the surface of the resin film layer 220 that has been subjected to the surface modification treatment may be 44 mN / m or more and less than 60 mN / m. The surface free energy may be 46 mN / m or more and less than 57 mN / m. When the surface free energy of the surface of the resin film layer 220 is 44 mN / m or more or 46 mN / m or more, the adhesion between the resin film layer 220 and the first radiation cured resin layer 230 is improved. When the surface free energy of the surface of the resin film layer 220 is less than 60 mN / m or less than 57 mN / m, the penetration of water between the resin film layer 220 and the first radiation cured resin layer 230 is suppressed. This makes it possible to improve the water resistance, scratch resistance, and peel resistance of the first radiation cured resin layer 230 formed on the surface of the resin film layer 220.

[0044] A first radiation cured resin layer 230 is formed on at least a portion of the surface of the resin film layer 220 that has been subjected to the surface modification treatment. The first radiation cured resin layer 230 imparts an aesthetic appearance to the metal container 100.

[0045] The first radiation curable resin layer 230 may be formed on the surface of the resin film layer 220 formed on the outer surface 214 of the container body, as shown in Fig. 2. The first radiation curable resin layer 230 may be formed on the surface of the resin film layer 220 formed on the inner surface 212 of the container body. The first radiation curable resin layer 230 may be formed on the side wall portion 120 and / or the bottom portion 130 of the container body in the metal container 100 shown in Fig. 1. The first radiation curable resin layer 230 may be formed as a single layer or multiple layers.

[0046] The first radiation cured resin layer 230 contains a resin that is cured by irradiation with radiation. The first radiation cured resin layer 230 may contain a first ultraviolet cured resin, or may contain an electron beam cured resin. The first ultraviolet cured resin may be, for example, an ultraviolet curable acrylic resin, an epoxy resin, a polyester resin, or a polyurethane resin. The first radiation cured resin layer 230 is formed by applying the first radiation cured resin to at least a part of the surface of the resin film layer 220 and then curing the resin by irradiating it with radiation.

[0047] An image may be formed on the first radiation cured resin layer 230. The image may include a pattern such as a design, a picture, a character, a symbol, or a color. The first radiation cured resin layer 230 may be formed as a printed layer including an image. In the metal container 100, by forming a printed layer on the surface of the resin film layer 220 that has been subjected to a surface modification treatment, the water resistance, scratch resistance, and peel resistance of the printed layer can be improved.

[0048] Other layers, such as a protective layer, may be further formed on the surface of the first radiation cured resin layer 230. By forming the protective layer, the water resistance, etc., of the printed layer formed on the surface of the resin film layer 220 can be further improved.

[0049] 3 shows an example of a layer structure 300 in which the metal container 100 is provided with a first radiation cured resin layer 330 that has been subjected to a surface modification treatment. The metal container 100 is provided with a resin film layer 320 that covers at least a portion of the container body, and a first radiation cured resin layer 330 formed on at least a portion of the surface of the resin film layer 320. In the example of the layer structure 300, the metal container 100 further includes a second radiation cured resin layer 340 formed on at least a portion of the surface of the first radiation cured resin layer 330.

[0050] The resin film layer 320 covers at least a part of the surface of the container body and serves to improve the slidability of the metal container 100 when performing diameter reduction drawing on the metal container 100. The description of the resin forming the resin film layer 320 may be directly applied as described above. The resin film layer 320 may be formed on the inner surface 312 and / or the outer surface 314 of the metal container 100. The resin film layer 320 may be formed as a single layer or multiple layers.

[0051] In the example of the layer configuration 300 shown in FIG. 3, a first radiation-curable resin layer 330 is formed on at least a part of the surface of the resin film layer 320. As shown in FIG. 3, the first radiation-curable resin layer 330 may be formed on the surface of the resin film layer 320 formed on the outer surface 314 of the container body and / or on the surface of the resin film layer 320 formed on the inner surface 312 of the container body. The first radiation-curable resin layer 330 may be formed on the side wall portion 120 and / or the bottom portion 130 of the metal container 100 shown in FIG. 1.

[0052] The description of the resin forming the first radiation-curable resin layer 330 may be directly applied as described above.

[0053] An image may be formed on the first radiation-curable resin layer 330. The image may include patterns such as patterns, pictures, characters, symbols, colors, etc. The first radiation-curable resin layer 330 may be formed as a printed layer including the image.

[0054] The first radiation-curable resin layer 330 may include a base coat layer such as a white solid printing layer or an anchor coat layer. At this time, the first radiation-curable resin layer 330 may include white ink. By the first radiation-curable resin layer 330 including white ink, it is possible to reduce the influence of the color of the container body on the image formed on the metal container 100. At this time, the first radiation-curable resin layer 330 can be used as an underlayer, and a second radiation-curable resin layer 340 formed on the surface of the first radiation-curable resin layer 330 can be used as a printed layer including an image.

[0055] The surface free energy of the surface of the first radiation cured resin layer 330 that has been subjected to the surface modification treatment may be 20 mN / m or more. The surface free energy may be 22 mN / m or more. When the surface free energy of the surface of the first radiation cured resin layer 330 is within this range, the adhesion between the first radiation cured resin layer 330 and the second radiation cured resin layer 340 is improved.

[0056] The second radiation cured resin layer 340 is formed on at least a part of the surface of the first radiation cured resin layer 330 after the first radiation cured resin layer 330 has been subjected to a surface modification treatment.

[0057] The second radiation cured resin layer 340 imparts an aesthetic appearance to the metal container 100 and / or functions as a protective layer for the first radiation cured resin layer 330. The second radiation cured resin layer 340 is formed by applying a second radiation cured resin to at least a portion of the surface of the first radiation cured resin layer 330 and then curing the applied resin by irradiating it with radiation.

[0058] The second radiation curable resin layer 340 contains a resin that is cured by irradiation with radiation. The second radiation curable resin layer 340 may contain a second ultraviolet curable resin, or may contain an electron beam curable resin. The second ultraviolet curable resin may be, for example, an acrylic resin, an epoxy resin, a polyester resin, or a polyurethane resin. The second ultraviolet curable resin may be formed as a single layer or multiple layers.

[0059] The second radiation cured resin layer 340 may be formed on the surface of the first radiation cured resin layer 330 formed on the outer surface 314 side of the container body and / or on the surface of the first radiation cured resin layer 330 formed on the inner surface 312 side of the container body, as shown in Fig. 3. The second radiation cured resin layer 340 may be formed on the side wall portion 120 and / or the bottom portion 130 of the container body in the metal container 100 shown in Fig. 1.

[0060] The pencil hardness of the second radiation-curable resin layer 340 may be HB or higher. The pencil hardness may also be H or higher. By subjecting the first radiation-curable resin layer 330 to a surface modification treatment, the adhesion of the second radiation-curable resin layer 340 to the first radiation-curable resin layer 330 is improved, and the hardness of the second radiation-curable resin layer 340 is improved. Thereby, the scratch resistance and peel resistance of the second radiation-curable resin layer 340 can be improved.

[0061] An image may be formed on the second radiation-curable resin layer 340. The image may include patterns such as patterns, pictures, characters, symbols, colors, etc.

[0062] The second radiation-curable resin layer 340 may be formed on the surface of the first radiation-curable resin layer 330 as a protective layer for protecting the first radiation-curable resin layer 330. At this time, the second radiation-curable resin layer 340 may contain a transparent ink.

[0063] The second radiation-curable resin layer 340 may be formed in multiple layers. For example, a protective layer containing a transparent resin may be further formed on the layer containing the image. Also, the second radiation-curable resin layer 340 may be formed including a base coat layer such as a white solid printing layer or an anchor coat layer and a layer containing an image.

[0064] In the metal container 100 of the present embodiment, by subjecting the first radiation-curable resin layer 330 to a surface modification treatment, the peel resistance and hardness of the second radiation-curable resin layer 340 formed on the surface of the first radiation-curable resin layer 330 can be improved. In the metal container 100, when a printing layer is superposed on the container body, the hardness of the overlying printing layer is improved, and the scratch resistance and peel resistance of the printing layer can be improved.

[0065] Next, a manufacturing system for manufacturing the metal container 100 will be described. Fig. 4 shows an example of a manufacturing system 1000 for carrying out the manufacturing method for the metal container 100 of this embodiment. The manufacturing system 1000 for the metal container 100 includes a resin film layer forming device 1100, a metal container molding device 1200, a radiation cured resin layer forming device 1300, and a surface modification treatment device 1400.

[0066] The resin film layer forming apparatus 1100 forms the resin film layers 220, 320 on the container body in the metal container 100. The resin film layer forming apparatus 1100 may form the resin film layers 220, 320 on a plate-shaped material before the container body is molded. The resin film layer forming apparatus 1100 may form the resin film layers 220, 320 on the plate-shaped material by an extrusion coating method, a cast film thermal bonding method, a biaxially stretched film thermal bonding method, or the like.

[0067] The metal container molding apparatus 1200 molds a container body having an opening 110, a side wall 120, and a bottom 130 from the material of the container body. The metal container molding apparatus 1200 may perform punching, drawing and / or ironing, trimming, tip reduction, curling, or flanging of a plate-shaped material to mold the container body from the plate-shaped material on which the resin film layers 220, 320 are formed.

[0068] The radiation cured resin layer forming apparatus 1300 forms the first radiation cured resin layer 230, 330 and / or the second radiation cured resin layer 340 in the metal container 100. The radiation cured resin layer forming apparatus 1300 may apply an ink containing a radiation cured resin to the surface of the resin film layer 220, 320 and / or the first radiation cured resin layer 330 in the metal container 100 and cure the applied ink to form the first radiation cured resin layer 230, 330 and / or the second radiation cured resin layer 340. The radiation cured resin layer forming apparatus 1300 may include a printing device that applies radiation cured resin by plate printing or inkjet printing, and a curing device that cures the applied radiation cured resin by radiation.

[0069] The surface modification processing device 1400 performs a surface modification process to modify at least a part of the surface of the resin film layer 220 and / or the first radiation cured resin layer 330. The surface modification processing device 1400 may perform the surface modification by a flame treatment in which a flame is brought into contact with the surface of the resin film layer 220 and / or the first radiation cured resin layer 330 to modify the surface. The surface modification processing device 1400 may perform the surface modification by a corona treatment or an atmospheric pressure plasma treatment.

[0070] 5 shows specific examples of a radiation curable resin layer forming apparatus 1300 and a surface modification treatment apparatus 1400. The radiation curable resin layer forming apparatus 1300 shown in Fig. 5 is an offset printing machine that applies radiation curable resin to the surface of the resin film layer 220 and / or the first radiation curable resin layer 330 by offset printing, and has an inking unit 1310, a blanket 1320, a blanket wheel 1330, a mandrel 1340, and a mandrel wheel 1350.

[0071] The inking unit 1310 has an ink supply section 1312 that stores ink containing a radiation curable resin, and a plate cylinder 1316 on which a printing plate 1314 corresponding to the ink in the ink supply section 1312 is mounted. The inking unit 1310 may be made up of a plurality of inking units 1310 each different for each ink color. These plurality of inking units 1310 are each arranged along the outer circumferential surface of a blanket wheel 1330.

[0072] The mandrel 1340 is provided so as to be rotatable around the central axis of the mandrel 1340 while holding the metal container 100. The mandrel wheel 1350 includes a plurality of mandrels 1340 protruding in a direction intersecting the mandrel wheel 1350, and supports the mandrels 1340 on the outer periphery of the mandrel wheel 1350. The mandrel wheel 1350 is provided so as to be rotatable around its central axis. The metal container 100 is transported by the rotation of the mandrel wheel 1350 to a region in contact with the blanket 1320 and a region in contact with the flame of the surface modification treatment device 1400.

[0073] In the radiation-curable resin layer forming apparatus 1300, ink is supplied from the ink supply unit 1312 to the printing plate 1314 mounted on the plate cylinder 1316 and adheres thereto, so that the image lines of the printing plate 1314 are transferred to the blanket 1320. When the metal container 100 is conveyed by the mandrel wheel 1350 and conveyed to the region where it contacts the blanket 1320, the rotation of the mandrel wheel 1350 stops. The metal container 100 contacts the blanket 1320 as the mandrel 1340 rotates at the stopped position. Then, the image lines are transferred from the blanket 1320 to the outer peripheral surface of the metal container 100 held by the mandrel 1340, and an image is printed on the surface of the resin film layer 220 or the first radiation-curable resin layer 330.

[0074] The metal container 100 to which the ink has been transferred is carried out by the mandrel wheel 1350 and conveyed to a radiation irradiation device such as an ultraviolet irradiation device or an electron beam irradiation device. The radiation irradiation device irradiates the printed ink with radiation to cure the ink. Thereby, the first radiation-curable resin layer 230, 330 and / or the second radiation-curable resin layer 340 is formed.

[0075] The surface modification treatment device 1400 performs a flame treatment for modifying the surface by bringing a flame into contact with the surface of the resin film layer 220 and / or the first radiation-curable resin layer 330. When the metal container 100 is conveyed by the mandrel wheel 1350 and conveyed to the region where it contacts the flame, the rotation of the mandrel wheel 1350 stops. The metal container 100 contacts the flame while the mandrel 1340 rotates at the stopped position. The surface modification treatment device 1400 brings a flame into contact with the metal container 100 mounted and rotationally held on the mandrel 1340 to perform a flame treatment on the surface of the resin film layer 220 and / or the first radiation-curable resin layer 330.

[0076] 5, the metal container 100 that has been subjected to surface modification treatment by the surface modification treatment device 1400 is transported to the radiation cured resin layer forming device 1300 while being held by the mandrel 1340, so that the treatment by the surface modification treatment device 1400 and the treatment by the radiation cured resin layer forming device 1300 can be performed consecutively. For example, after the surface modification treatment is performed on the resin film layer 220, the first radiation cured resin layer 230 can be formed on the surface of the resin film layer 220 consecutively, and after the surface modification treatment is performed on the first radiation cured resin layer 330, the second radiation cured resin layer 340 can be formed on the surface of the first radiation cured resin layer 330 consecutively.

[0077] Next, a method for manufacturing the metal container 100 of this embodiment will be described. Fig. 6 shows an example of a flow of the method for manufacturing the metal container 100 of this embodiment. By executing the flow from S10 to S40 in Fig. 6, the manufacturing system 1000 for the metal container 100 performs a method for manufacturing a metal container, which includes a first radiation-cured resin layer forming step of forming a first radiation-cured resin layer on at least a part of the surface of a resin film layer covering at least a part of a container body having an opening, a side wall, and a bottom, and a surface modification treatment step of performing a surface modification treatment to modify at least a part of the surface of the resin film layer.

[0078] For ease of explanation, the processes from S10 to S40 will be explained in order. However, at least some of these processes may be executed in parallel, or the steps may be interchanged and executed without departing from the spirit of the present invention. Some steps may be omitted and executed without departing from the spirit of the present invention.

[0079] In the manufacturing method flow shown in Fig. 6, a manufacturing system 1000 for the metal container 100 executes a resin film layer forming step S10, a container body molding step S20, a surface modification treatment step S30, and a first radiation cured resin layer forming step S40. By this manufacturing method flow, a metal container 100 having the layer structure 200 shown in Fig. 2 may be formed.

[0080] First, in S10, the resin film layer forming device 1100 forms the resin film layer 220 on the plate-shaped material 210 that forms the container body of the metal container 100. The plate-shaped material may be formed by cutting a plate material wound in a coil shape. The above-mentioned explanation may be applied to the materials of the container body, the plate-shaped material, and the resin film layer 220. In S10, the resin film layer forming device 1100 may form the resin film layer 220 on the surface of the plate-shaped material 210 that will become the inner surface 212 and / or the outer surface 214 of the container body after the manufacturing of the metal container 100. In S10, the resin film layer forming device 1100 may form the resin film layer 220 on the plate-shaped material by an extrusion coating method, a cast film heat bonding method, a biaxially stretched film heat bonding method, or the like. The resin film layer 220 may be formed to have a thickness in the range of 2 to 30 μm.

[0081] Next, in S20, the metal container molding apparatus 1200 molds a container body having an opening 110, a side wall 120, and a bottom 130 from the plate material 210 on which the resin film layer 220 has been formed in S10. The metal container molding apparatus 1200 may mold the container body by a known molding method according to the shape of the container body. The above description may be applied as is to the container body.

[0082] Fig. 7 shows an example of a subflow of S20. When the container body has a cup-like shape in which the inner diameter of the opening 110 is the largest and the diameter decreases toward the bottom 130 as shown in Fig. 1, the metal container molding apparatus 1200 may mold a cup-like container body by executing S210 to S250 in Fig. 7.

[0083] First, in S210, the metal container molding apparatus 1200 punches out the plate material on which the resin film layer has been formed in S10, and applies drawing and / or ironing to mold a cup-shaped bottomed cup. In S210, the drawing and / or ironing may be performed multiple times depending on the shape of the container body.

[0084] Next, in S220, the tip of the bottomed cup formed in S210 is trimmed. In S220, the tip height of the bottomed cup, which has become uneven due to drawing and / or ironing processes, is cut evenly around the central axis to make the tip height of the bottomed cup after trimming uniform.

[0085] Next, in S230, the trimmed tip of the bottomed cup is subjected to tip diameter reduction processing. In S230, as the diameter reduction processing for the tip, the tip opening of the bottomed cup is gradually reduced in diameter toward the tip.

[0086] Next, in S240, the tip opening of the bottomed cup is curled or flanged to form an opening 110.

[0087] Next, in S250, the diameter is gradually reduced from the tip end portion reduced in S230 toward the bottom portion 130, thereby forming the side wall portion 120 having an overall tapered contour.

[0088] By the subflow shown in Fig. 7, a container body having a cup-like shape is formed as shown in Fig. 1. After the steps according to the subflow are completed, the process proceeds to S30 or S50 described later.

[0089] In S30, the surface modification treatment device 1400 performs a surface modification treatment to modify at least a part of the surface of the resin film layer 220 of the container body molded in S20. In an example of the flow of the manufacturing method shown in Fig. 6, at least a part of the surface of the resin film layer 220 is subjected to a surface modification treatment before the first radiation cured resin layer 230 is formed in S40 described below.

[0090] The surface modification treatment may include a flame treatment in which a flame is brought into contact with at least a part of the surface of the resin film layer 220 to modify the surface. The surface modification treatment may include a corona treatment or an atmospheric pressure plasma treatment.

[0091] In S30, the surface free energy of the resin film layer 220 after the surface modification treatment may be 44 mN / m or more and less than 60 mN / m. The surface free energy of the resin film layer 220 may be 46 mN / m or more and less than 57 mN / m. By performing the surface modification treatment so that the surface free energy of the resin film layer 220 is within this range, the adhesion between the first radiation cured resin layer 230 formed in S40 described below and the resin film layer 220 is improved, and the water resistance of the first radiation cured resin layer 230 can be improved.

[0092] In S30, when the surface modification treatment of the resin film layer 220 includes a flame treatment, the ratio of fuel gas to combustion air used to generate the flame to be brought into contact with the surface of the resin film layer 220 may be 1:10 to 1:30. The ratio of fuel gas to combustion air may be 1:10 to 1:20. The ratio of fuel gas to combustion air may be 1:12 to 1:13.

[0093] In S30, the flame treatment on the surface of the resin film layer 220 may be performed by adjusting the amounts of fuel gas and combustion air used to generate the flame and / or the ratio of fuel gas and combustion air according to the treatment time during which the flame is in contact with at least a part of the surface of the resin film layer 220. By adjusting the amounts of fuel gas and combustion air used to generate the flame and the ratio of fuel gas and combustion air according to the treatment time during which the flame is in contact with the surface of the resin film layer 220, the surface free energy of the surface of the resin film layer 220 after the surface modification treatment can be adjusted to be within the above range.

[0094] Table 1 shows a specific example in which the resin film layer 220 formed on the cup-shaped container body was subjected to frame treatment using the surface modification treatment apparatus 1400 shown in FIG.

[0095] [Table 1]

[0096] In Table 1, "air / gas" in the condition column refers to the amount of combustion air (air) and fuel gas (gas) used to generate the flame, and the ratio of combustion air to fuel gas. "Surface free energy" refers to the surface free energy measured on the surface of the resin film layer 220 after flame treatment. The surface free energy was measured by the OWRK method using a KRUSS double drop handy contact angle / surface free energy analyzer. Here, "surface treatment start part" refers to the part of the container body that the flame contacted when the flame treatment started, and "other than the surface treatment start part" refers to the overall average of the surface of the resin film layer 220 other than the above-mentioned surface treatment start part.

[0097] In the surface modification treatment device 1400 shown in Fig. 5, the metal container 100 mounted on the mandrel 1340 is transported by the mandrel wheel 1350 to a region of the surface modification treatment device 1400 that comes into contact with the flame, and then the mandrel 1340 starts rotating and flame treatment is performed on the rotating container body. At this time, the rotation speed of the mandrel 1340 is not uniform, the initial rotation is relatively slow, the time that the flame contacts the portion (surface treatment start portion) that is subjected to the flame treatment at the start of rotation in the surface modification treatment device 1400 is relatively long, and when the flame treatment is performed multiple times on the rotating container body, there is an area in the surface treatment start portion where the number of times the flame treatment is performed is greater than in other portions. For these reasons, there may be a difference in the treatment time that the flame contacts the surface treatment start portion and other portions (other than the surface treatment start portion) in the metal container 100.

[0098] The surface modification treatment apparatus 1400 shown in FIG. 5 may adjust the amount of fuel gas and combustion air and / or the ratio of fuel gas and combustion air depending on the treatment time for which the flame is in contact with the surface of the resin film layer 220, as shown in Table 1.

[0099] As shown in Table 1, by adjusting the amount of fuel gas and combustion air and / or the ratio of fuel gas to combustion air depending on the processing time for which the flame is in contact with the surface of the resin film layer 220 to be subjected to the frame processing, the surface free energy of the resin film layer 220 after the frame processing can be adjusted to a range of 44 mN / m or more and less than 60 mN / m or less throughout the entire resin film layer 220 to which the frame processing has been applied.

[0100] Next, in S40, the radiation cured resin layer forming apparatus 1300 forms a first radiation cured resin layer 230 on at least a portion of the surface of the resin film layer 220 that has been subjected to the surface modification treatment in S30. The description above may be applied to the first radiation cured resin layer 230 as is.

[0101] In S40, the radiation curable resin layer forming apparatus 1300 first applies a first radiation curable resin to at least a portion of the surface of the resin film layer 220 that has been subjected to the surface modification treatment in S30.

[0102] In S40, the first radiation curable resin may be applied to the surface of the resin film layer 220 by printing. Alternatively, the first radiation curable resin may be applied by a roller or a spray. The first radiation curable resin may be applied by plate printing or inkjet printing. Plate printing may be offset printing, screen printing, flexographic printing, or gravure printing using a gravure roller.

[0103] In S40, an image may be formed by plate printing or inkjet printing on the first radiation curable resin layer 230. The image may include a pattern such as a design, a picture, a character, a symbol, or a color.

[0104] In S40, the radiation cured resin layer forming apparatus 1300 irradiates the first radiation cured resin with radiation to cure it. If the first radiation cured resin layer 230 contains a first ultraviolet cured resin, the first ultraviolet cured resin is cured by irradiating it with ultraviolet light in S40. This forms the first radiation cured resin layer 230.

[0105] In S40, the radiation cured resin layer forming apparatus 1300 may form the first radiation cured resin layer 230 in a single layer or in multiple layers. When forming the first radiation cured resin layer 230 in multiple layers, for example, a printed layer including an image may first be applied and cured to form the layer, and a protective layer including a transparent resin may be further formed thereon. Alternatively, a base coat layer such as a white solid printed layer or an anchor coat layer may be formed, and a printed layer including an image may be further formed thereon to form the first radiation cured resin layer 230.

[0106] Table 2 shows the results of a peel test of the first radiation cured resin layer 230 in the metal container 100 manufactured according to the flow of Fig. 6. The peel test was performed by evaluating the peelability of the first radiation cured resin layer 230 when cellophane tape was attached to the surface of the first radiation cured resin layer 230 and then peeled off without immersion in water and after immersing the metal container 100 in water. [Table 2]

[0107] In Table 2, "air / gas" refers to the amount of combustion air (air) and fuel gas (gas) used to generate the flame, and the ratio of combustion air to fuel gas. "Surface free energy" refers to the surface free energy measured on the surface of the first resin film layer 220 after flame treatment. The surface free energy was measured by the OWRK method using a KRUSS double drop handy contact angle / surface free energy analyzer. "Immersion time" refers to the length of time the metal container 100 was immersed in water at 25°C. In Table 2, the peelability was expressed by the following indexes. ◯: No peeling. ×: Peeling occurred.

[0108] As shown in Table 2, when the surface free energy of the resin film layer 220 is in the range of 44 mN / m or more and 60 mN / m or less, the peel resistance and water resistance of the first radiation cured resin layer 230 relative to the resin film layer 220 are improved compared to resin film layers 220 outside this range.

[0109] The flow of the manufacturing method for the metal container 100 of this embodiment improves adhesion between the resin film layer 220 and the first radiation cured resin layer 230 in the metal container 100, and also suppresses the penetration of water between the resin film layer 220 and the first radiation cured resin layer 230, thereby improving the water resistance, scratch resistance and peel resistance of the first radiation cured resin layer 230. This makes it possible to provide a metal container 100 having a printed layer that is excellent in water resistance, scratch resistance and peel resistance.

[0110] Fig. 8 shows an example of a flow of the method for manufacturing a metal container of this embodiment. By executing the flows of S10 and S20 and S50 to S70 in Fig. 8, the manufacturing system 1000 for metal containers 100 performs a method for manufacturing a metal container including a first radiation-cured resin layer forming step of forming a first radiation-cured resin layer on at least a part of the surface of a resin film layer covering at least a part of a container body having an opening, a side wall, and a bottom, and a surface modification treatment step of performing a surface modification treatment to modify at least a part of the surface of the first radiation-cured resin layer.

[0111] For ease of explanation, the processes of S10, S20, and S50 to S70 will be explained in order. However, at least some of these processes may be executed in parallel, or the steps may be interchanged and executed without departing from the spirit of the present invention. Some steps may be omitted and executed without departing from the spirit of the present invention.

[0112] In the manufacturing method flow shown in Fig. 8, a manufacturing system 1000 for a metal container 100 executes a resin film layer forming step S10, a container body molding step S20, a first radiation cured resin layer forming step S50, a surface modification treatment step S60, and a second radiation cured resin layer forming step S70. By this manufacturing method flow, a metal container 100 having the layer structure 300 shown in Fig. 3 may be formed.

[0113] First, in S10, the resin film layer forming apparatus 1100 forms a resin film layer 320 on a plate-shaped material 310 that forms the container body of the metal container 100. In S10, the resin film layer forming apparatus 1100 may form a resin film layer 320 on a surface of the plate-shaped material 310 that will become the inner surface 312 and / or the outer surface 314 of the container body after the metal container 100 is manufactured. The above-mentioned descriptions of the container body, the plate-shaped material 310, and the resin film layer 320 may be applied as they are.

[0114] Next, in S20, the metal container molding apparatus 1200 molds a container body having an opening 110, a side wall 120, and a bottom 130 from the plate material 310 on which the resin film layer 320 has been formed in S10. The metal container molding apparatus 1200 may mold the container body by a known molding method according to the shape of the container body. The above description may be applied as is to the container body. When molding a cup-shaped container body in the manufacturing method flow shown in FIG. 8, the subflow of S20 shown in FIG. 7 may be applied as is.

[0115] Next, in S50, the radiation cured resin layer forming apparatus 1300 forms a first radiation cured resin layer 330 on at least a portion of the surface of the resin film layer 320 of the container body molded in S20. The above description of the first radiation cured resin layer 330 may be applied as is.

[0116] In S50, the radiation curable resin layer forming apparatus 1300 first applies a first radiation curable resin to at least a portion of the surface of the resin film layer 320 of the container body molded in S20. The first radiation curable resin may be applied to the surface of the resin film layer 320 by printing. Alternatively, the first radiation curable resin may be applied by a roller or spray. In S50, the first radiation curable resin may be applied by plate printing or inkjet printing. The plate printing may be offset printing, screen printing, flexographic printing, or gravure printing using a gravure roller.

[0117] In S50, an image may be formed by plate printing or inkjet printing on the first radiation curable resin layer 330. The image may include a pattern such as a design, a picture, a character, a symbol, or a color.

[0118] In S50, the radiation cured resin layer forming apparatus 1300 may form the first radiation cured resin layer 330 as a base coat layer such as a white solid print layer or an anchor coat layer. In this case, the first radiation cured resin layer 330 may contain white ink. By making the first radiation cured resin layer 330 contain white ink, it is possible to reduce the influence of the color of the container body on the image formed on the metal container 100.

[0119] The first radiation curable resin layer 330 may be formed as a single layer or multiple layers. For example, a printed layer containing an image may be applied and cured to form the layer, and a protective layer containing a transparent resin may be further formed thereon. In addition, a base coat layer such as a white solid printed layer and an anchor coat layer may be applied and cured multiple times.

[0120] In S50, the radiation cured resin layer forming apparatus 1300 irradiates the first radiation cured resin with radiation to cure it. If the first radiation cured resin layer 330 contains a first ultraviolet cured resin, the first ultraviolet cured resin is cured using ultraviolet light in S50. This forms the first radiation cured resin layer 330.

[0121] Next, in S60, after S50, a surface modification treatment is performed on at least a part of the surface of the first radiation cured resin layer 330 formed in S50.

[0122] The surface modification treatment may include a flame treatment in which a flame is brought into contact with at least a part of the surface of the first radiation curable resin layer 330 to modify the surface. The surface modification treatment may include a corona treatment or an atmospheric pressure plasma treatment.

[0123] In S60, when the surface modification treatment of the first radiation cured resin layer 330 includes a flame treatment, the ratio of fuel gas to combustion air used to generate the flame to be brought into contact with the surface of the resin film layer 320 may be 1:10 to 1:30. The ratio of fuel gas to combustion air may be 1:10 to 1:20. The ratio of fuel gas to combustion air may be 1:12 to 1:13.

[0124] In S60, the flame treatment of the surface of the first radiation cured resin layer 330 may be performed in the same manner as the flame treatment in S30 of the flow shown in FIG. 6, by adjusting the treatment time for which the first radiation cured resin layer 330 is in contact with the flame, the amounts of fuel gas and combustion air used to generate the flame, and / or the ratio of fuel gas to combustion air.

[0125] The surface free energy of the first radiation cured resin layer 330 after the surface modification treatment in S60 may be 20 mN / m or more. The surface free energy of the first radiation cured resin layer 330 may be 22 mN / m or more. When the surface free energy is in this range, the adhesion of the second radiation cured resin layer 340 to the first radiation cured resin layer 330 is improved, and the peel resistance of the second radiation cured resin layer 340 is improved.

[0126] Table 3 shows the results of measuring the surface free energy when frame treatment was performed on the first radiation cured resin layer 330 formed by offset printing according to the flow shown in FIG. [Table 3]

[0127] In Table 3, the column for flame treatment conditions indicates the amount of combustion air and fuel gas used to generate the flame. The surface free energy indicates the surface free energy of the first radiation cured resin layer 330, and shows the surface free energy values ​​for the case without surface modification treatment (No. 1) and the cases with surface modification treatment (Nos. 2 to 6). The surface free energy was measured by the OWRK method using a double drop handy contact angle / surface free energy analyzer manufactured by KRUSS. By carrying out the surface modification treatment, the surface free energy of the first radiation cured resin layer 330 can be increased.

[0128] Next, in S70, the radiation cured resin layer forming apparatus 1300 forms a second radiation cured resin layer 340 on at least a portion of the surface of the first radiation cured resin layer 330 that has been subjected to the surface modification treatment in S60. The description above may be applied as is to the second radiation cured resin layer.

[0129] In S70, the radiation cured resin layer forming apparatus 1300 first applies a second radiation cured resin to at least a portion of the surface of the first radiation cured resin layer 330 that has been subjected to the surface modification treatment in S60.

[0130] The second radiation curable resin may be applied to the surface of the first radiation curable resin layer 330 by printing. Alternatively, the second radiation curable resin may be applied by a roller or a spray. In S70, the second radiation curable resin may be applied by plate printing or inkjet printing. Plate printing may be offset printing, screen printing, flexographic printing, or gravure printing using a gravure roller.

[0131] In S70, an image may be formed by plate printing or inkjet printing on the second radiation curable resin layer 340. The image may include a pattern such as a design, a picture, a character, a symbol, or a color.

[0132] In S70, the radiation cured resin layer forming apparatus 1300 may form the second radiation cured resin layer 340 as a protective layer for the first radiation cured resin layer 330. At this time, an ink containing a transparent ink may be used as the second radiation cured resin, and the second radiation cured resin layer 340 may be formed so as to contain the transparent ink.

[0133] In S70, the radiation cured resin layer forming apparatus 1300 irradiates the second radiation cured resin with radiation to cure it. If the second radiation cured resin layer 340 contains a second ultraviolet cured resin, the second ultraviolet cured resin is cured using ultraviolet light in S70. This forms the second radiation cured resin layer 340.

[0134] In S70, the radiation cured resin layer forming apparatus 1300 may form the second radiation cured resin layer 340 in a single layer or in multiple layers. When forming the second radiation cured resin layer 340 in multiple layers, for example, a printed layer including an image may first be applied and cured to form the layer, and a protective layer including a transparent resin may be further formed thereon. Alternatively, a base coat layer such as a white solid printed layer or an anchor coat layer may be formed, and a printed layer including an image may be further formed thereon to form the second radiation cured resin layer 340.

[0135] The pencil hardness of the second radiation cured resin layer 340 formed in S70 may be HB or higher. The pencil hardness may be H or higher. By subjecting the first radiation cured resin layer 330 to a surface modification treatment, the adhesion of the second radiation cured resin layer 340 to the first radiation cured resin layer 330 is improved, and the hardness of the second radiation cured resin layer 340 is improved. Therefore, when a printed layer is formed on the metal container 100, the scratch resistance and peel resistance of the overlying printed layer can be improved.

[0136] Table 4 shows the evaluation results of the pencil hardness of the second radiation cured resin layer 340 of the metal container 100 shown in Table 3, and the adhesion between the first radiation cured resin layer 330 and the second radiation cured resin layer 340. The pencil hardness was evaluated in accordance with JIS K5600. The adhesion between the first radiation cured resin layer 330 and the second radiation cured resin layer 340 was evaluated by evaluating the peelability from the first radiation cured resin layer 330 when cellophane tape was attached to the surface of the second radiation cured resin layer 340 and then peeled off.

[0137] [Table 4]

[0138] In Table 4, the column for flame treatment conditions indicates the amount of combustion air and fuel gas used to generate the flame. The surface free energy indicates the surface free energy of the first radiation cured resin layer 330, and shows the surface free energy values ​​for the case where no surface modification treatment was performed (No. 1) and the cases where surface modification treatment was performed (Nos. 2 to 6). In Table 4, the releasability of the second radiation cured resin layer 340 is expressed by the following index. ◯: No peeling. ×: Peeling occurred.

[0139] As shown in Table 4, by subjecting the first radiation cured resin layer 330 to a surface modification treatment, the surface free energy of the surface of the first radiation cured resin layer 330 is improved. As the surface free energy of the surface of the first radiation cured resin layer 330 is improved, the pencil hardness of the second radiation cured resin layer 340 is improved, and a hardness of HB or higher or H or higher can be achieved. In addition, the peel resistance of the second radiation cured resin layer 340 can be improved.

[0140] In the flow shown in FIG. 8, before S50, at least a part of the surface of the resin film layer 320 of the container body formed in S20 may be subjected to a surface modification treatment. At this time, the surface modification treatment described for S30 in the flow shown in FIG. 6 may be executed. Thereby, the adhesion between the first radiation-curable resin layer 330 and the resin film layer 320 and the water resistance of the first radiation-curable resin layer 330 can also be improved.

[0141] According to the flow of the manufacturing method of the metal container 100 of the present embodiment, in the metal container 100, the adhesion between the first radiation-curable resin layer 330 and the second radiation-curable resin layer 340 is improved, and the hardness of the second radiation-curable resin layer 340 is improved. Thereby, when a printing layer is formed by overlapping it on the metal container 100, the stain resistance and peeling resistance of the overlying printing layer can be improved.

[0142] In the above description, the present embodiment has been described by limiting it to the metal container 100. However, the manufacturing method of the present embodiment may be applied to containers other than those made of metal. For example, for a resin cup-shaped container, the first radiation-curable resin layer forming step of forming the above-described first radiation-curable resin layer and the surface modification treatment step of performing a surface modification treatment for modifying at least a part of at least one of the resin surface of the container and the surface of the first radiation-curable resin layer may be applied.

[0143] As described above, the present invention has been described using embodiments. However, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

[0144] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. [Explanation of symbols]

[0145] 100 metal containers 110 Opening 120 Side wall 130 Bottom 140 Curl section 150 Bulge 200 layer configuration 210 Plate material 212 Inner surface 214 Outer surface 220 Resin film layer 230 First radiation curable resin layer 300 layer configuration 310 Plate material 312 Inner surface 314 Outer surface 320 Resin film layer 330 First radiation curable resin layer 340 Second radiation curable resin layer 1000 Manufacturing Systems 1100 Resin film layer forming device 1200 Metal container molding equipment 1300 Radiation curing resin layer forming equipment 1310 Inking Unit 1312 Ink supply section 1314 Print Edition 1316 Print cylinder 1320 Blanket 1330 Blanket Wheel 1340 Mandrel 1350 Mandrel Wheel 1400 Surface modification treatment equipment

Claims

1. a first radiation-curable resin layer forming step of forming a first radiation-curable resin layer on at least a portion of a surface of a resin film layer covering at least a portion of a container body having an opening, a side wall, and a bottom; a surface modification treatment step of performing a surface modification treatment to modify at least a portion of the surface of at least one of the resin film layer and the first radiation cured resin layer; A method for manufacturing a metal container comprising the steps of:

2. The surface modification treatment includes a flame treatment in which a flame is brought into contact with at least a part of a surface of at least one of the resin film layer and the first radiation curable resin layer to modify the surface. The method for manufacturing a metal container according to claim 1 .

3. The surface modification treatment step includes a resin film layer modification treatment step of performing the surface modification treatment on at least a part of the surface of the resin film layer before the first radiation cured resin layer forming step. The method for manufacturing a metal container according to claim 1 .

4. The surface free energy of the surface of the resin film layer after the resin film layer modification treatment step is 44 mN / m or more and less than 60 mN / m; The method for manufacturing a metal container according to claim 3.

5. The resin film layer modification treatment step includes a flame treatment for modifying at least a part of a surface of the resin film layer by bringing a flame into contact with the surface, The ratio of fuel gas to combustion air used to generate the flame is 1:10 to 1:

30. The method for manufacturing a metal container according to claim 3.

6. The resin film layer modification treatment step includes: adjusting the amounts of the fuel gas and the combustion air used to generate the flame and / or the ratio of the fuel gas and the combustion air depending on the treatment time during which the flame is in contact with at least a portion of the surface of the resin film layer; The method for manufacturing a metal container according to claim 5 .

7. The first radiation curable resin layer forming step includes a step of applying a first radiation curable resin to at least a part of the surface of the resin film layer after the resin film layer modifying treatment step by plate printing or inkjet printing. The method for manufacturing a metal container according to claim 3.

8. the surface modification treatment step includes a first radiation cured resin layer modification treatment step of subjecting at least a part of a surface of the first radiation cured resin layer to the surface modification treatment after the first radiation cured resin layer formation step, The method for manufacturing a metal container according to claim 1 .

9. the surface free energy of the first radiation-cured resin layer after the first radiation-cured resin layer modification treatment step is 20 mN / m or more; The method for manufacturing a metal container according to claim 8.

10. the first radiation curable resin layer forming step includes a first radiation curable resin applying step of applying a first radiation curable resin to at least a part of a surface of the resin film layer by plate printing or inkjet printing; The method for manufacturing a metal container according to claim 8.

11. The method further includes a second radiation-cured resin layer forming step of forming a second radiation-cured resin layer on at least a part of the surface of the first radiation-cured resin layer after the first radiation-cured resin layer modifying treatment step. The method for manufacturing a metal container according to claim 8.

12. The pencil hardness of the second radiation cured resin layer is HB or more. The method for manufacturing a metal container according to claim 11.

13. an image is formed on at least one of the first radiation curable resin layer and the second radiation curable resin layer; The method for manufacturing a metal container according to claim 11.

14. the first radiation curable resin layer contains a white ink; The method for manufacturing a metal container according to claim 13.

15. the second radiation curable resin layer comprises a transparent ink; The method for manufacturing a metal container according to claim 13.

16. the first radiation curable resin layer includes a first ultraviolet curable resin, the first radiation curable resin layer forming step includes a first ultraviolet curable resin curing step of curing the first ultraviolet curable resin by using ultraviolet light; The method for manufacturing a metal container according to claim 1 .

17. the second radiation curable resin layer includes a second ultraviolet curable resin, the second radiation curable resin layer forming step includes a second ultraviolet curable resin curing step of curing the second ultraviolet curable resin by using ultraviolet light; The method for manufacturing a metal container according to claim 11.

18. The container body is made of aluminum or an aluminum alloy, and the resin film layer contains a polyester resin. The method for manufacturing a metal container according to claim 1 .

19. The container body is made of a plate-shaped material made of aluminum or an aluminum alloy, and the resin film layer is formed on both sides of the plate-shaped material. The method for manufacturing a metal container according to claim 17.

20. a container body having an opening, a sidewall and a bottom; a resin film layer covering at least a portion of the container body; a first radiation-curable resin layer formed on at least a portion of a surface of the resin film layer; Equipped with the surface free energy of the surface of the resin film layer is 44 mN / m or more, or the surface free energy of the surface of the first radiation cured resin layer is 20 mN / m or more; metal container.

21. The surface free energy of the surface of the resin film layer is 44 mN / m or more and less than 60 mN / m.

21. The metal container of claim 20.

22. the surface free energy of the first radiation cured resin layer is 20 mN / m or more; 21. The metal container of claim 20.

23. Further comprising a second radiation-curable resin layer formed on at least a portion of the surface of the first radiation-curable resin layer.

21. The metal container of claim 20.

24. The pencil hardness of the second radiation cured resin layer is HB or more.

24. The metal container of claim 23.

25. The first radiation curable resin layer contains a first ultraviolet curable resin.

21. The metal container of claim 20.

26. the second radiation curable resin layer includes a second ultraviolet curable resin; 24. The metal container of claim 23.

27. The container body is made of aluminum or an aluminum alloy, and the resin film layer contains a polyester resin.

21. The metal container of claim 20.

28. The container body is made of a plate-shaped material made of aluminum or an aluminum alloy, and has the resin film layer formed on both sides of the plate-shaped material.

21. The metal container of claim 20.

Images