Packaging materials, packaging bodies, methods for manufacturing packaging bodies

Abstract

We provide novel packaging materials. [Solution] A packaging material having a laminated structure including multiple layers, A packaging material in which a layer different from the layer containing the bonding surface that joins with other packaging materials contains an electromagnetic wave absorbing material.

Description

[Technical Field]

[0001] This invention relates to packaging materials, packaging bodies, and methods for manufacturing packaging bodies. [Background technology]

[0002] Patent Document 1 discloses a pouch with a spout. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-73048 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] As disclosed in Patent Document 1, conventional packaging materials such as pouches, which are made by joining multiple packaging materials together, have been manufactured.

[0005] Traditionally, packaging materials have been manufactured by joining multiple pieces of packaging material together to form a bag or similar shape that can hold the contents. In recent years, various materials have been considered for packaging, and the structure of packaging materials has also become more diverse.

[0006] Therefore, there is a need for new manufacturing methods that differ from conventional methods, including joining multiple packaging materials to produce a package, and there is also a need for packaging materials that can accommodate these new packaging manufacturing methods.

[0007] One aspect of the present invention aims to provide a novel packaging material. [Means for solving the problem]

[0008] A packaging material according to one aspect of the present invention is a packaging material having a laminated structure including a plurality of layers, A layer distinct from the layer containing the bonding surface that joins with other packaging materials contains electromagnetic wave absorbing material. [Effects of the Invention]

[0009] According to one aspect of the present invention, a novel packaging material can be provided. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an explanatory diagram of the layered structure of the packaging material. [Figure 2] Figure 2 is an explanatory diagram of the configuration when electromagnetic wave absorbing material is unevenly distributed within the layer. [Figure 3] Figure 3 is an explanatory diagram illustrating an example of the arrangement of electromagnetic wave absorbing materials in packaging materials. [Figure 4] Figure 4 is an explanatory diagram of one example of the packaging structure. [Figure 5] Figure 5 is a schematic diagram of a packaging manufacturing apparatus according to one aspect of the present disclosure. [Figure 6] Figure 6 is a schematic diagram of a packaging manufacturing apparatus according to one aspect of the present disclosure. [Figure 7] Figure 7 is a schematic diagram of a packaging manufacturing apparatus according to one aspect of the present disclosure. [Figure 8] Figure 8 is an explanatory diagram showing the case where a shielding member is placed on a laminate of packaging materials. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below. However, the present invention is not limited to these examples, and is intended to include all modifications within the meaning and scope of the claims, as indicated by the claims.

[0012] To facilitate understanding of the explanations, the same reference numeral is used for identical components in each drawing, and redundant explanations are omitted. Furthermore, since the drawings are schematic diagrams for explanatory purposes, the scale of each component may differ from the actual scale. [Packaging materials] A packaging material according to an embodiment of the present invention (hereinafter sometimes simply referred to as "the present embodiment") will be described.

[0013] In a conventional method for manufacturing a package, a packaging material laminate formed by laminating a plurality of film-like packaging materials is joined by heating a joining region using resistance heating and applying pressure as needed, thereby forming a bag shape or the like. The inventor of the present invention focused on using electromagnetic waves instead of resistance heating as a heating means, and completed the present invention.

[0014] In the present specification, examples of electromagnetic waves include high frequency waves and microwaves. High frequency means an electromagnetic wave having a frequency of 1 MHz or more and 300 MHz or less. The frequency of the high frequency wave used may be, among others, 10 MHz or more and 100 MHz or less, 20 MHz or more and 50 MHz or less, or 20 MHz or more and 30 MHz or less.

[0015] Microwave means an electromagnetic wave having a frequency of 0.3 GHz or more and 300 GHz or less. Therefore, as the electromagnetic wave, an electromagnetic wave having a frequency of 1 MHz or more and 300 GHz or less may be used.

[0016] In the conventional heating method using resistance heating, the portion in contact with the heat source of resistance heating and the vicinity thereof are heated by heat transfer, and it has been difficult to perform selective heating depending on the shape of the region to be heated. In addition, since heating is performed by heat transfer from the heat source, it is sometimes difficult to control the temperature profile when heating the joining region.

[0017] In contrast, with electromagnetic wave heating, for example, by selecting the irradiation area of ​​the electromagnetic waves, it is possible to select which parts are heated and which are not. Furthermore, by changing the output of the electromagnetic waves, the heating temperature and temperature profile can be set to desired conditions. For example, by irradiating with high-output electromagnetic waves, it is possible to rapidly raise the temperature in a short time. Also, since the ambient temperature can be sufficiently lowered when electromagnetic waves are irradiated, it is possible to stop heating and rapidly cool by stopping the irradiation of the electromagnetic waves. Therefore, with electromagnetic wave heating, it is easy to selectively heat a desired area to achieve a desired temperature profile.

[0018] However, conventional packaging materials were made from materials that absorb very little electromagnetic radiation, and therefore could not be applied to the manufacturing method of packaging using electromagnetic heating.

[0019] The inventors of this invention have found that by including an electromagnetic wave absorbing material in the packaging material, the electromagnetic wave absorbing material can absorb electromagnetic waves and heat the packaging material. Therefore, the packaging material of this embodiment can include an electromagnetic wave absorbing material. (1) Regarding the layers contained in the packaging material The following describes the layers that the packaging material of this embodiment can contain and the materials they are made of.

[0020] Figures 1(A), 1(B), 1(C), 1(D), and 1(E) show cross-sectional views of the packaging material along the layering direction.

[0021] The packaging material of this embodiment may have a laminated structure including multiple layers, as shown in the packaging material 100 in Figure 1(A). The packaging material of this embodiment may have, for example, a base layer 11 and a sealant layer 12. That is, the packaging material 100 may have a structure in which the base layer 11 and the sealant layer 12 are laminated. (1-1) Base material layer The base layer 11 can provide rigidity to the packaging material or the packaging body manufactured using the packaging material, and can also have barrier properties to prevent the permeation of gases and liquids.

[0022] The base material layer 11 may contain one or more resins selected from, for example, polyolefins and polyesters.

[0023] As the polyolefin, one or more types selected from, for example, polyethylene, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene and the like can be used. As the polyester, for example, polyethylene terephthalate can be used.

[0024] The density ranges of types such as ultra-low density polyethylene in the present specification will be described. The density of ultra-low density polyethylene is 0.900 g / cm 3 or less. The density of low density polyethylene is 0.900 g / cm 3 or more and less than 0.925 g / cm 3 . The density of linear low density polyethylene is 0.900 g / cm 3 or more and less than 0.925 g / cm 3 . The density of medium density polyethylene is 0.925 g / cm 3 or more and less than 0.945 g / cm 3 . The density of high density polyethylene is 0.945 g / cm 3 or more, or 0.945 g / cm 3 or more and 0.980 g / cm 3 or less.

[0025] The resin used in the packaging material of the present embodiment is not limited to those derived from petroleum, and part or all of the resin may be a bio-derived resin material. Taking a polyethylene resin as an example, examples of bio-derived resin materials include biomass polyethylene that uses biomass-derived ethylene as a raw material. A method for producing biomass-derived polyethylene is disclosed, for example, in Japanese National Publication of International Patent Application No. 2010-511634. The polyethylene resin may include commercially available biomass polyethylene (such as Green PE manufactured by Braskem). Resins other than polyethylene may also be biomass resins as described above.

[0026] The resin used in the packaging material of this embodiment may include mechanically recycled resin made from used resin products or so-called waste resin generated during the manufacturing process of resin products. Furthermore, the resin used in the packaging material of this embodiment may also include chemically recycled resin in place of, or in addition to, mechanically recycled resin.

[0027] The above explanation regarding the resin also applies to layers other than the base layer 11.

[0028] The base layer 11 may further contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, lubricants, colorants, antiblocking agents, antioxidants, flame retardants, inorganic fillers, organic fillers, dyes, pigments, and compatibilizers. Other layers described below may also contain the above additives other than resin. (1-2) Sealant layer The sealant layer 12 is a layer that can be melted by heat and welded to other components. In other words, the sealant layer 12 is a heat-sealable layer. For this reason, when packaging materials are laminated and subjected to a heating process as a laminate of packaging materials, the sealant layers may be arranged to face each other in the joining region of the packaging materials to be joined.

[0029] The sealant layer 12 may contain one or more resins selected from, for example, polyolefins, ethylene-acrylic copolymers, ethylene glycol-methacrylic acid copolymers, ethylene-vinyl acetate copolymers, and the like.

[0030] Examples of polyolefins include one or more selected from polyethylene, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, polypropylene, ionomer polyethylene, and the like.

[0031] The sealant layer 12 may also include multiple sealant layers. For example, as shown in the packaging material 103 in Figure 1(D), the sealant layer 12 may have two or more layers, such as a first sealant layer 121 and a second sealant layer 122. (1-3) Adhesive layer For example, as shown in Figure 1(B), the packaging material 101 may also have an adhesive layer 13 between the base layer 11 and the sealant layer 12.

[0032] The adhesive layer 13 can bond together each layer of the packaging material.

[0033] Regarding the adhesive layer 13, a polyurethane-based adhesive can be used as the adhesive, from the viewpoint of providing a layer with excellent flexibility and bendability. The adhesive layer 13 may include an adhesive whose main component is one or more selected from, for example, polyether polyurethane resin, polyester polyurethane resin, and polyacrylate polyurethane resin.

[0034] The packaging material may be manufactured by a known lamination method, such as a dry lamination method, in which a sealant film and a base film are bonded together via an adhesive layer. The dry lamination method may be a non-solvent dry lamination method using a solvent-free adhesive. However, the packaging material may also be manufactured by a method in which the sealant film is directly extruded onto the base material and laminated.

[0035] Furthermore, from the viewpoint of improving recyclability, the resins in each layer of the packaging material may be polyolefin-based, and the adhesive layer 13 may also be a polyolefin-based adhesive resin. Examples of polyolefin-based adhesive resins include acid-modified polypropylene resins and acid-modified polyethylene resins.

[0036] Examples of acid-modified polypropylene resins include maleic anhydride graft-modified polypropylene resins. Maleic anhydride graft-modified polypropylene resins are resins in which polypropylene resins are graft-modified with maleic anhydride.

[0037] Examples of polypropylene resins include homopolypropylene, block polypropylene, random polypropylene, and propylene-α-olefin copolymers. Examples of α-olefins include ethylene and 1-butene.

[0038] Examples of acid-modified polyethylene resins include maleic anhydride graft-modified polyethylene resins. Maleic anhydride graft-modified polyethylene resins are resins in which polyethylene resins are graft-modified with maleic anhydride.

[0039] Polyethylene resins include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene obtained by copolymerizing ethylene and α-olefins. Examples of α-olefins include ethylene, 1-butene, and 1-hexane. (1-4) Gas barrier film For example, as shown in Figure 1(C), the packaging material 102 may also have a gas barrier film 14. The gas barrier film 14 can be bonded to the substrate layer 11 or the sealant layer 12 by an adhesive layer 13.

[0040] The gas barrier film 14 may have, for example, a barrier substrate layer 141 and a barrier layer 142.

[0041] The barrier substrate layer 141 may contain the materials described in the substrate layer 11.

[0042] The barrier layer 142 has the function of reducing the permeation of oxygen and water vapor, thereby improving the storage stability of the contents. The barrier layer 142 may contain, for example, an inorganic oxide, or one or more selected from aluminum oxide and silicon oxide.

[0043] The barrier layer 142 may be, for example, a vapor-deposited layer of an inorganic oxide. That is, the barrier layer 142 may be formed on the surface of the barrier substrate layer 141 by a vapor deposition method such as physical vapor deposition or chemical vapor deposition.

[0044] Furthermore, the barrier layer 142 may contain a metal instead of, or in addition to, the inorganic oxide. As the metal, one or more types selected from aluminum, stainless steel, etc., can be used. The barrier layer 142 may also have a layer of inorganic oxide and a layer of metal.

[0045] The barrier layer 142 may include a barrier-type overcoat layer formed by coating methods such as roll coating, gravure roll coating, kiss coating, etc., or printing methods such as gravure printing, offset printing, transfer printing, etc. As the overcoat layer, a gas barrier coating film containing a resin composition of a metal alkoxide and a water-soluble polymer may be used. Alternatively, as the overcoat layer, a silane coupling agent may be added to a mixture of a metal alkoxide and a water-soluble polymer to form a gas barrier coating film containing these resin compositions. (1-5) Printing layer The packaging material may also have additional printing layers between the base layer 11 and the sealant layer 12, or on the surface of the base layer 11 opposite to the surface facing the sealant layer 12. The packaging material may also have multiple printing layers.

[0046] The printed layer includes images consisting of characters, patterns, symbols, and combinations thereof. The printed layer can be formed using printing methods such as gravure printing, offset printing, and flexographic printing.

[0047] The packaging material used in the packaging manufacturing method of this embodiment may also have any additional layers, such as a heat-resistant layer, a coating layer, or an anchor coating layer, in addition to the base layer, sealant layer, adhesive layer, gas barrier film, and printing layer described above.

[0048] Furthermore, the packaging material can be configured to have multiple layers of each layer, such as the sealant layer 12 and the adhesive layer 13, depending on the required properties. For example, it may have two or more layers of sealant layer 12.

[0049] The packaging material of this embodiment may contain only polyolefin resin as the resin material. By containing only polyolefin resin as the resin material of the packaging material of this embodiment, it is possible to improve recyclability by eliminating the need to separate the resin during recycling.

[0050] Furthermore, when the packaging material contains only polyolefin resin as the resin material, the difference in softening and melting points between the layers of the packaging material is small, making bonding difficult with conventional bonding methods using resistance heating. In contrast, with the packaging material of this embodiment, selective heating can be performed by electromagnetic wave heating, making bonding easy even when the difference in softening points between the layers of the packaging material is small. (1-6) Electromagnetic wave absorbing materials The packaging material contains electromagnetic wave absorbing material, which absorbs electromagnetic waves and generates heat. (Regarding the arrangement of electromagnetic wave absorbing materials) The electromagnetic wave absorbing material may be present in particulate form in any of the layers of the packaging material. In this case, the electromagnetic wave absorbing material may be present in only one layer of the packaging material, or in multiple layers. For example, the sealant layer 12, which is required to reach a particularly high temperature than other layers when irradiated with electromagnetic waves, or a layer adjacent to the sealant layer 12, may contain the electromagnetic wave absorbing material.

[0051] Furthermore, the electromagnetic wave absorbing material may be arranged in the form of a film. Specifically, for example, a film-like body of the electromagnetic wave absorbing material may be placed on the surface of the substrate layer 11 facing the sealant layer 12.

[0052] However, depending on the type of electromagnetic wave absorbing material and the contents of the package manufactured using the packaging material, it may be necessary to avoid contact between the contents and the electromagnetic wave absorbing material.

[0053] As described above, the packaging material 10 of this embodiment is a packaging material having a laminated structure including multiple layers. Furthermore, the packaging material 10 of this embodiment may contain an electromagnetic wave absorbing material in a layer other than the layer containing the bonding surface 10A that is joined to other packaging materials.

[0054] In the packaging material of this embodiment, if the electromagnetic wave absorbing material is not placed in the layer closest to the contents, which includes the bonding surface 10A that is joined to other packaging materials, the electromagnetic wave absorbing material will have its surface covered by at least the layer including the bonding surface 10A. Therefore, when it is formed into a package, contact with the contents of the package can be particularly prevented. Furthermore, in the sealed portion of the bonding surface 10A, the proportion of the electromagnetic wave absorbing material component, which is less likely to melt due to heat than other materials, can be reduced, thereby stabilizing the seal strength and improving heat seal performance.

[0055] For example, in the case of the packaging material 100 shown in Figure 1(A), the sealant layer 12 including the bonding surface 10A may not contain an electromagnetic wave absorbing material, while the base layer 11 may contain an electromagnetic wave absorbing material.

[0056] Furthermore, in the case of the packaging material 101 shown in Figure 1(B), the sealant layer 12 including the bonding surface 10A does not contain an electromagnetic wave absorbing material, but one or more layers selected from the base layer 11 and the adhesive layer 13 may contain an electromagnetic wave absorbing material.

[0057] In the case of the packaging material 102 shown in Figure 1(C), the sealant layer 12 including the bonding surface 10A does not contain an electromagnetic wave absorbing material, but one or more layers selected from the base layer 11, adhesive layer 13, and gas barrier film 14 may contain an electromagnetic wave absorbing material.

[0058] In the case of the packaging material 103 shown in Figure 1(D), the sealant layer 12 includes multiple sealant layers, starting from the position closest to the joint surface 10A, such as the first sealant layer 121 and the second sealant layer 122. The sealant layer 12 may also have three or more layers.

[0059] In the packaging material 103 shown in Figure 1(D), the first sealant layer 121 including the bonding surface 10A does not contain an electromagnetic wave absorbing material, but one or more layers selected from the base layer 11 and the second sealant layer 122 may contain an electromagnetic wave absorbing material. In the case of the packaging material 103 shown in Figure 1(D), the second sealant layer 122 may contain an electromagnetic wave absorbing material. By placing an electromagnetic wave absorbing material within the sealant layer 12, the sealant layer 12 itself, which will be melted or otherwise directly bonded when bonding with other packaging materials, becomes easier to melt, thereby increasing the bonding strength.

[0060] If the electromagnetic wave absorbing material contains a resin that absorbs electromagnetic waves, the resin that absorbs electromagnetic waves can also be used in packaging materials, and therefore may come into contact with the contents of the package when it is made into a package. For this reason, in the packaging material of this embodiment, the resin that absorbs electromagnetic waves may be placed in any layer, or it may be placed in the layer closest to the contents, which includes a bonding surface 10A that is joined with other packaging materials.

[0061] In this case, for example, as shown in the packaging material 104(10) in Figure 1(E), a layer 15 containing an electromagnetic wave absorbing material may be laminated on the sealant layer 12. The layer 15 containing the electromagnetic wave absorbing material may also be a layer that includes a bonding surface 10A that is joined to other packaging materials. The sealant layer 12 and the layer 15 containing the electromagnetic wave absorbing material may be formed by co-extrusion, bonded together with an adhesive layer, or formed by coating the sealant layer 12 with the layer 15 containing the electromagnetic wave absorbing material.

[0062] Furthermore, if the electromagnetic wave absorbing material is a material commonly used in adhesives, such as polyurethane, the layer 15 containing the electromagnetic wave absorbing material in the packaging material 104(10) shown in Figure 1(E) may be an adhesive layer.

[0063] The electromagnetic wave absorbing material can be placed in one or more selected layers among the multiple layers contained in the packaging material 10. In this case, the electromagnetic wave absorbing material may be uniformly contained throughout the selected layer, or it may be unevenly distributed in a part of the selected layer, for example, distributed only in a part of the layer.

[0064] When manufacturing a package using packaging materials, it is required that the packaging materials be joined only in designated joining areas, and not in non-jointed areas outside of those areas. Therefore, it is required that the packaging materials be selectively heated only in the joining areas and their vicinity, and that areas outside of the joining areas are hardly heated at all.

[0065] Figure 2(A) shows a view of the packaging material 10 of this embodiment, as seen from the joining surface 10A, which is the surface that joins with other packaging materials. As shown in Figure 2(A), in the packaging material 10 of this embodiment, the area that joins with other packaging materials is designated as the joining area 22, and the area other than the joining area 22 is designated as the non-joining area 23.

[0066] A single sheet of packaging material can be folded along a fold line so that at least a portion overlaps, i.e., multiple sheets of packaging material are stacked, and the unconnected portions can be joined together to form a bag-like packaging body. For this reason, one packaging material and the other packaging material joined to that one packaging material may be contained within a single continuous packaging material. Alternatively, one packaging material and the other packaging material joined to that one packaging material may be separate and distinct packaging materials.

[0067] The joining region 22 refers to the region on the joining surface 10A, which is the surface of the packaging material 10 that joins with other packaging materials, as shown in Figures 2(A), 3(A), etc., and includes the portion that is joined with other packaging materials. It refers to the entire region of the joining portion of the packaging material 10 in the thickness direction. The non-joining region 23 is the portion other than the joining region 22.

[0068] The arrangement of the joining area 22 is not particularly limited and can be selected according to the shape of the package manufactured using the packaging material 10 of this embodiment. For example, the joining area 22 may be arranged in at least a portion along the outer circumference of the packaging material 10. Arranging the joining area 22 in at least a portion along the outer circumference of the packaging material 10 means that the joining area can be arranged in at least a portion along the outer circumference of the packaging material 10 so as to be able to seal the portion that contains the contents, in accordance with the shape of the package manufactured.

[0069] Furthermore, as shown in Figure 2(A), for example, the joining region 22 may be arranged in a ring along the outer circumference of the packaging material 10. By arranging the joining region 22 in a ring along the outer circumference of the packaging material 10, the entire outer circumference of the packaging material can be joined with other packaging materials, making it easy to manufacture a bag-shaped package. The packaging material 10 of this embodiment can also be used to manufacture various pouches such as three-side seal pouches, and packaging bodies such as pillow packaging. For the packaging materials used in these packaging bodies, the joining region 22 may be arranged in at least a portion along the outer circumference of the packaging material 10, or it may be arranged in a ring along the outer circumference. The joining region can then be joined so that the packaging body has a desired shape. For example, it may be joined along the outer edge other than the folded portion of the packaging material to produce various pouches, pillow packaging, etc.

[0070] In the packaging material 10 of this embodiment, the distribution of electromagnetic wave absorbing material can also be selected. In the packaging material 10, the electromagnetic wave absorbing material may be distributed such that when electromagnetic waves are irradiated onto the packaging material, the amount of electromagnetic wave absorption per unit area in the junction region 22 is greater than the amount of electromagnetic wave absorption per unit area in the non-junction region 23.

[0071] The electromagnetic wave absorbing material is distributed such that the amount of electromagnetic wave absorption per unit area is greater in the bonded region 22 than in the non-bonded region 23. As a result, when the packaging material 10 is irradiated with electromagnetic waves, the bonded region 22 can be heated to a higher temperature than the non-bonded region 23. Therefore, the bonded region 22 can be selectively heated.

[0072] The above-mentioned amount of electromagnetic wave absorption per unit area refers to the amount of electromagnetic wave absorption per unit area at the junction surface 10A.

[0073] Specifically, for example, in the packaging material 10 of this embodiment, the electromagnetic wave absorbing material may be distributed such that its concentration in the bonding region 22 is higher than its concentration in the non-bonding region 23.

[0074] The electromagnetic wave absorbing material is distributed such that its concentration in the bonding region 22 is higher than its concentration in the non-bonding region 23. This allows the amount of electromagnetic wave absorbed per unit area in the bonding region 22 to be greater than that in the non-bonding region 23 when the packaging material 10 is irradiated with electromagnetic waves. Therefore, when the packaging material of this embodiment is irradiated with electromagnetic waves, the bonding region 22 can be heated to a higher temperature than the non-bonding region 23, allowing for selective heating of the bonding region 22.

[0075] When measuring the concentration of electromagnetic wave absorbing material in the bonded region 22 and the non-bonded region 23, for example, the packaging material 20 can be divided into a bonded region 22 and a non-bonded region 23. Then, after measuring the weight of the bonded region 22, resin components other than the electromagnetic wave absorbing material can be removed by heat treatment or the like, separating only the electromagnetic wave absorbing material, determining the weight of the electromagnetic wave absorbing material, and calculating the concentration, which is the ratio of the weight of the contained electromagnetic wave absorbing material to the weight of the bonded region 22. The same procedure can be used to calculate the concentration in the non-bonded region 23, except that the measurement target is the non-bonded region 23.

[0076] The method for calculating the concentration of electromagnetic wave absorbing material in the bonded region 22 and the concentration of electromagnetic wave absorbing material in the non-bonded region 23 is not limited to the above procedure. For example, it may be calculated from the amount of electromagnetic wave absorbing material placed in each region during manufacturing.

[0077] For example, as shown in Figure 2(A), in the packaging material 10 of this embodiment, the electromagnetic wave absorbing material 21 may be distributed only within the bonding region 22. In this case, the electromagnetic wave absorbing material 21 does not need to be distributed within the non-bonding region 23.

[0078] Since the electromagnetic wave absorbing material 21 is distributed only within the junction region 22, it is possible to selectively heat only the junction region 22 and prevent the non-junction region 23 from being heated.

[0079] Furthermore, as shown in Figure 2(B), for example, in the packaging material 10 of this embodiment, the electromagnetic wave absorbing material 21 may be distributed not only in the bonding region 22 but also in a portion of the non-bonding region 23 near the bonding region 22. By distributing the electromagnetic wave absorbing material 21 to the non-bonding region 23 near the bonding region 22, the bonding region 22 can be reliably heated to the desired temperature and bonded with other packaging materials. In this case, for example, by using a shielding member described later, the entire bonding region 22 can be reliably heated while reducing the absorption of electromagnetic waves into the non-bonding region 23 and the heating associated with the absorption of electromagnetic waves.

[0080] The distribution of the electromagnetic wave absorbing material in the packaging material 10 of this embodiment may be other than the configuration shown in Figures 2(A) and 2(B). For example, a small amount of electromagnetic wave absorbing material 21 may be included in the non-bonding region 23. In this case, when the packaging material 10 is irradiated with electromagnetic waves sufficient to raise the bonding region 22 to a temperature sufficient for bonding, the non-bonding region 23 may contain enough electromagnetic wave absorbing material 21 to keep the packaging material 10 at a temperature that does not melt.

[0081] Furthermore, as previously mentioned, the electromagnetic wave absorbing material may be uniformly distributed throughout the selected layer.

[0082] An example of the arrangement of an electromagnetic wave absorbing material in a packaging material having the laminated structure shown in Figure 1(A) and containing the electromagnetic wave absorbing material 21 within the bonding region 22 as shown in Figure 2(A) will be explained using Figures 3(A) and 3(B). Figures 3(A) and 3(B) correspond to the cross-sectional view along line AA in Figure 2(A). Both Figures 3(A) and 3(B) use as examples the case of a packaging material having a base layer 11 and a sealant layer 12 placed on the base layer 11, as shown in Figures 1(A) and 1(D), but other layers such as an adhesive layer 13 may also be included.

[0083] In the packaging material of this embodiment, the electromagnetic wave absorbing material 21 may be placed within the sealant layer 12, for example, as shown in the packaging material 300 in Figure 3(A) and the packaging material 301 in Figure 3(B). It may also be placed within the second sealant layer 122. Furthermore, the electromagnetic wave absorbing material 21 may be placed in the portion of the second sealant layer 122 corresponding to the bonding region 22. The electromagnetic wave absorbing material 21 may also be partially distributed within the non-bonding region 23. For example, it may be placed within the non-bonding region 23 such that the thickness of the area where the electromagnetic wave absorbing material 21 is distributed is thinner than that of the bonding region 22.

[0084] As shown in Figure 3(B), the sealant layer 12 may also have a third sealant layer 123. In the case of the packaging material 301 shown in Figure 3(B), the sealant layer 12 has, in order from the position closest to the joint surface 10A, a first sealant layer 121, a second sealant layer 122, and a third sealant layer 123. In this case, the electromagnetic wave absorbing material 21 can be placed in one or more layers selected from the second sealant layer 122 and the third sealant layer 123.

[0085] In this case, the electromagnetic wave absorbing material 21 may be uniformly arranged within one or more selected layers, or, as shown in Figure 3(B), it may be unevenly distributed in the parts corresponding to the junction region 22 within the second sealant layer 122 or the third sealant layer 123.

[0086] As shown in Figures 3(A) and 3(B), when the electromagnetic wave absorbing material 21 is configured to be unevenly distributed within the layer, the desired distribution can be achieved by dispersing the electromagnetic wave absorbing material 21 in a dispersion medium such as water-based ink or alcohol to form a slurry, and then printing.

[0087] Therefore, if the packaging material has a printed layer, the electromagnetic wave absorbing material 21 may be printed at the same time as printing the design on the printed layer, and the electromagnetic wave absorbing material 21 may be placed within the printed layer. Alternatively, the electromagnetic wave absorbing material 21 may be placed in a substrate layer 11 other than the printed layer, or in an adhesive layer, etc.

[0088] However, the electromagnetic wave absorbing material 21 generates heat when irradiated with electromagnetic waves, causing it to melt a portion of the sealant layer 12 located at the joint surface 10A. For this reason, it is preferable that the electromagnetic wave absorbing material 21 be located within the second sealant layer 122 or positioned such that the distance to the sealant layer 12 is short. (Regarding electromagnetic wave absorbing materials) The electromagnetic wave absorbing material can be selected according to the frequency of the electromagnetic waves used, the temperature at which the bonding area of ​​the packaging material is heated, etc., and is not particularly limited. As the electromagnetic wave absorbing material, one or more types selected from, for example, zinc oxide, silicon carbide, titanium oxide, barium titanate, barium zirconate titanate, lead titanate, potassium niobate, hydrated aluminum silicate, inorganic materials having crystal water such as alkali metal hydrated aluminosilicate, inorganic materials having crystal water such as alkaline earth metal hydrated aluminosilicate, and resins that absorb electromagnetic waves can be used.

[0089] The crystal structure of titanium dioxide is not particularly limited; for example, it may be anatase or rutile.

[0090] In this specification, alkali metals include one or more selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Alkaline earth metals are used in a broad sense and include one or more selected from beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

[0091] Examples of resins that absorb electromagnetic waves include polyvinyl chloride (PVC), polyurethane (PU), polyamide (nylon) (PA), polyvinylidene chloride (PVDC), acrylonitrile butadiene styrene (ABS), and thermosetting resins. Examples of thermosetting resins include phenol, epoxy, and melamine.

[0092] Resins that absorb electromagnetic waves may not absorb microwaves well, so they may be used when high frequencies are used as electromagnetic waves. Since they can efficiently absorb high frequencies, one or more types selected from polyvinyl chloride, polyurethane, and polyamide may be used as the resin that absorbs electromagnetic waves. Since polyolefin may be used in the sealant layer of the packaging material of this embodiment, one or more types selected from polyurethane and polyamide may be used as the resin that absorbs electromagnetic waves, considering compatibility with polyolefin. When using a resin that absorbs electromagnetic waves as an electromagnetic wave absorbing material and placing it in a layer of the packaging material, a compatibilizer may be added to the layer in which the electromagnetic wave absorbing resin is placed, if necessary. Conventionally, laminated films made by laminating a layer containing polyamide and a layer containing polyolefin have been known, and polyolefins obtained by mechanically recycling such laminated films often contain polyamide. For this reason, a mechanically recycled laminated film made by laminating a layer containing polyamide and a layer containing polyolefin may be used as the material for the layer of the packaging material of this embodiment, and this layer may contain an electromagnetic wave absorbing material. [Packaging] As shown in Figure 4, the packaging 41 of this embodiment may have multiple pieces of packaging material 401 and packaging material 402 according to one aspect of this disclosure. The packaging material 401 and packaging material 402 are joined together in a joining region 22. The packaging material 401 and packaging material 402 are not joined in a non-joining region 23, and can form a bag-shaped packaging that can contain contents 42. The packaging material 401 and packaging material 402 may be formed by folding a single piece of packaging material along a fold line and overlapping them. That is, the packaging material 401 and packaging material 402 may be contained within a single continuous piece of packaging material. Alternatively, the packaging material 401 and packaging material 402 may be separate pieces of packaging material.

[0093] The packaging is not limited to the example shown in Figure 4, and may include three or more packaging materials.

[0094] The contents 42 can be placed inside the packaging 41 to form a packaged product 40. Figure 4 is a cross-sectional view of the packaged product 40 along a plane passing through its center.

[0095] By joining multiple pieces of packaging material according to one aspect of this disclosure at a joining region, a packaging body can be formed, such as a sachet, gusset, various pouches such as three-sided pouches, four-sided pouches, standing pouches, and retort pouches, tubes such as laminated tubes, and pillow packaging. The packaging body of this embodiment may further have a spout or a zipper.

[0096] The shape of the packaging in this embodiment is not limited to the form shown in Figure 4, and can have any shape depending on the application. The contents to be filled into the packaging can include food, liquids, pharmaceuticals, electronic components, and the like. [Manufacturing method for packaging] The method for manufacturing the packaging of this embodiment will now be described. Note that, as the packaging material, a packaging material according to one aspect of this disclosure may also be used; therefore, matters already described will be omitted from further explanation.

[0097] The packaging manufacturing method of this embodiment may include a heating step of irradiating a laminate of packaging materials, which is formed by stacking multiple sheets of packaging material so that their joining surfaces face each other, with electromagnetic waves to heat the joining regions of the packaging materials.

[0098] The manufacturing method of the packaging according to this embodiment will be described step by step below. (1)Heating process In the heating process, electromagnetic waves can be irradiated onto a laminate of packaging materials, which is formed by stacking multiple sheets of packaging material with their joint surfaces facing each other. The irradiation conditions for electromagnetic waves in the heating process are not particularly limited, and the irradiation can be performed to achieve a desired temperature profile depending on the material of the laminate of packaging materials used.

[0099] The packaging material used in the packaging manufacturing method of this embodiment has a laminated structure including multiple layers, and a layer different from the layer including the bonding surface 10A that joins with other packaging materials may contain an electromagnetic wave absorbing material. The electromagnetic wave absorbing material can be contained in one or more selected layers from among the multiple layers contained in the packaging material 10.

[0100] In the packaging material of this embodiment, if the electromagnetic wave absorbing material is not placed in the layer closest to the contents, including the bonding surface that is joined with other packaging materials, the electromagnetic wave absorbing material will have its surface covered by at least the layer including the bonding surface. Therefore, when it is formed into a package, contact with the contents of the package can be particularly prevented. Furthermore, in the sealed portion of the bonding surface 10A, the proportion of the electromagnetic wave absorbing material component, which is less likely to melt due to heat than other materials, can be reduced, thereby stabilizing the seal strength and improving heat seal performance.

[0101] If the electromagnetic wave absorbing material contains a resin that absorbs electromagnetic waves, the resin that absorbs electromagnetic waves may be placed in any layer, or it may be placed in a layer that includes a bonding surface 10A that is bonded to other packaging materials.

[0102] When manufacturing a package, the packaging materials can be joined together by selectively heating the joining regions of the laminated packaging material, thereby softening or melting a portion of the packaging material. When manufacturing a package, it is preferable not to heat the non-joining regions, which are areas where the packaging materials are not joined.

[0103] The packaging material used in the packaging manufacturing method of this embodiment contains an electromagnetic wave absorbing material. Therefore, by irradiating a laminate of packaging materials with electromagnetic waves, the packaging materials and the laminate of packaging materials can be heated.

[0104] In the packaging material 10 used in the packaging manufacturing method of this embodiment, the distribution of the electromagnetic wave absorbing material 21 can also be selected. In the packaging material 10, the electromagnetic wave absorbing material 21 may be distributed such that, when electromagnetic waves are irradiated onto the packaging material, the amount of electromagnetic wave absorption per unit area in the bonding region 22 is greater than the amount of electromagnetic wave absorption per unit area in the non-bonding region 23.

[0105] Therefore, by irradiating a laminate of packaging materials containing packaging materials with electromagnetic waves, the bonding region can be selectively heated, and the temperature of the bonding region can be raised to the temperature necessary for bonding the packaging materials together.

[0106] In the packaging material 10, the electromagnetic wave absorbing material may be distributed such that its concentration in the bonding region is higher than its concentration in the non-bonding region. In this case, by irradiating the laminate of packaging materials containing the packaging materials with electromagnetic waves, the bonding region can be selectively heated, and the temperature of the bonding region can be raised to the temperature necessary to bond the packaging materials together.

[0107] The heating process may be carried out with a shielding member 61 that can reduce the transmission of electromagnetic waves positioned to cover at least a portion of the non-bonded areas 23 of the packaging material laminate 400 other than the bonded areas 22, as shown in Figure 8. Figure 8 is a view of the packaging material laminate 400 and the shielding member 61 along the lamination direction after the shielding member 61 has been positioned on the packaging material laminate 400.

[0108] By placing the shielding member 61 in at least a portion of the non-jointed area 23, the amount of electromagnetic waves irradiated to the non-jointed area 23 can be reduced, thereby selectively heating the joined area 22 while preventing the non-jointed area 23 from being heated. For this reason, even if the shielding member 61 is uniformly contained throughout the selected layer among the multiple layers contained in the packaging material 401 and packaging material 402, the joined area 22 can be selectively heated by using the shielding member 61. Furthermore, because the area irradiated with electromagnetic waves can be precisely controlled, the accuracy of the position and shape of the boundary line between the joined and unjointed parts of the packaging material in the package obtained after the heating process can be improved.

[0109] The shielding member can reduce the transmission of electromagnetic waves, for example, by reflecting them. Reducing the transmission of electromagnetic waves means that the amount of electromagnetic waves irradiated onto the surface of the packaging material laminate 400 is reduced compared to when the shielding member 61 is not installed.

[0110] Figure 8 shows an example in which two packaging materials, packaging material 401 and packaging material 402, are laminated together as a packaging material laminate 400, but the configuration is not limited to this. The packaging material laminate subjected to the heating process may, for example, contain three or more packaging materials according to the shape of the package being manufactured.

[0111] The shielding member 61 can be placed on the surface of the packaging material laminate 400 that is irradiated with electromagnetic waves. The shielding member 61 may be placed in direct contact with the packaging material laminate 400. Alternatively, the shielding member 61 may be placed away from the packaging material laminate 400 so that a gap is created between the shielding member 61 and the packaging material laminate 400. However, it is preferable to select a distance between the shielding member 61 and the packaging material laminate 400 that creates a gap so that the irradiated electromagnetic waves do not enter the gap between the shielding member 61 and the packaging material laminate 400. The distance between the shielding member 61 and the packaging material laminate 400 may be constant or may vary depending on the location.

[0112] The shielding member 61 may cover the entire non-jointed region 23, or it may cover only a part of the non-jointed region 23. For example, when electromagnetic waves are irradiated, parts of the non-jointed region 23 that can be controlled to a temperature such that they do not join the packaging material 401 and the packaging material 402, even if they are not covered by the shielding member 61, do not need to be covered by the shielding member 61. In addition, the shielding member 61 may be provided with through holes of a size that does not allow electromagnetic waves to pass through, and the non-jointed region 23 does not need to be covered in the areas where such through holes are provided.

[0113] The heating step in the packaging manufacturing method of this embodiment can also be performed to join the remaining joined area after filling the contents into the packaging material laminate 400, which is partially joined. For this reason, the shielding member 61 may have a recess on the surface facing the packaging material laminate 400 that corresponds to the bulge caused by the contents filled into the packaging material laminate 400. (1-1) Regarding shielding members (Regarding thickness) The thickness of the shielding member 61 can be selected according to the material of the shielding member 61, the frequency of the electromagnetic waves, the shape of the packaging material laminate 400, etc. For this reason, the shielding member 61 may be as thin as a film, only a few millimeters thick, or it may be a plate material, i.e., a plate-like body, with a thickness of several centimeters.

[0114] Within the shielding member 61, the thickness of the shielding member 61 does not need to be constant; it may vary depending on the location in order to control the amount of electromagnetic wave transmission, etc. (Regarding shape) The shielding member 61 is provided to reduce the amount of electromagnetic waves irradiated to the non-jointed region 23 and to irradiate the jointed region 22 with electromagnetic waves. For this reason, the shielding member 61 can have a shape that matches the jointed region 22 and the non-jointed region 23.

[0115] Figure 8 shows an example in which a bonding region 22 is provided along sides 400A, 400B, and 400C of a packaging material laminate 400, which is formed by stacking two packaging materials 401 and 402. Therefore, in Figure 8, the bonding region 22 along sides 400A, 400B, and 400C is exposed, while the shielding member 61 is rectangular so that the other non-bonding region 23 can be covered.

[0116] For example, the packaging manufacturing method of this embodiment can also be used when joining the packaging material laminate 400 along the edge 400D after the contents have been placed inside the packaging. In this case, the shape of the shielding member 61 can be selected so that the joining area can be set along the edge 400D.

[0117] The width of the joining area 22 is not particularly limited and can be selected according to the required strength of the packaging and the materials of the packaging materials 401 and 402. Furthermore, the width of the joining area 22 can be selected according to the specifications of the packaging being manufactured; it may be constant or vary depending on the location.

[0118] The shielding member 61 can be made of, for example, a metal plate. If the shielding member 61 is made of a metal plate, the corners 610 of the plate may be chamfered, as shown in Figure 8.

[0119] When electromagnetic waves are irradiated onto a metal material, electrons may concentrate at sharp edges or corners, causing sparks to form. On the other hand, chamfering the edges and reducing the number of sharp points can prevent sparks from forming.

[0120] The shielding member 61 may be shaped to cover a portion of the joining area 22. In this case, the shielding member 61 may be installed so as to cover a portion of the joining area 22 during the heating process.

[0121] If the shielding member 61 covers a portion of the joint area 22, the portion of the shielding member 61 that covers the joint area 22 may be made transparent to allow electromagnetic waves to pass through.

[0122] Specifically, for example, the portion of the shielding member 61 that covers the joint area 22 may be provided with multiple through-holes that allow electromagnetic waves to pass through.

[0123] Furthermore, the material of the part of the shielding member 61 that covers the joint area 22 may be a material with high electromagnetic wave transmittance, such as resin or glass.

[0124] By positioning the shielding member 61 to cover a portion of the joining area 22, it becomes possible to press the packaging material laminate 400 with the shielding member 61. Therefore, when heated in the heating process, the packaging material 401 and the packaging material 402 contained in the packaging material laminate 400 can be brought closer together in the joining area 22, and pressure can be applied simultaneously, resulting in a particularly strong bond after the heating process.

[0125] When through holes are provided in the portion of the shielding member 61 that covers the joint area 22, the size of the through holes, such as the inner diameter, is not particularly limited and can be selected according to the thickness of the shielding member 61 and the frequency of the electromagnetic waves, so that electromagnetic waves can pass through. By selecting the inner diameter of the through holes and the density in which the through holes are arranged, the degree to which electromagnetic waves pass through the shielding member 61 can be selected, and the degree to which the joint area 22 is heated can also be selected.

[0126] Through-holes may also be provided in the portion of the shielding member 61 that covers the non-jointed region 23. However, it is preferable to select the size and density of the through-holes provided in the non-jointed region 23 so that electromagnetic waves do not pass through or pass through to a reduced extent. By providing through-holes in the non-jointed region 23, the weight of the shielding member 61 can be reduced, improving workability during packaging manufacturing.

[0127] If the shielding member 61 covers at least a portion of the joint area 22, and the material of the part covering the joint area 22 and the part covering the non-joint area 23 are different, the part covering the joint area 22 may be separable from the part covering the non-joint area 23. Alternatively, the part covering the joint area 22 may be made of a separate material from the shielding member 61, and the material covering the joint area 22 and the shielding member 61 may be able to move or otherwise operate independently.

[0128] The shielding member 61 can also have its surface properties selected to enhance its electromagnetic wave reflection characteristics. For example, it can be mirror-polished. Alternatively, a coating layer can be applied to its surface. The coating layer may be applied to all surfaces of the shielding member 61, or only to some surfaces. Depending on the function of the coating layer, the surfaces of the shielding member 61 to which the coating layer is applied can be selected. (Regarding the materials for shielding members) The shielding member 61 is installed on the surface of the packaging material laminate 400, and it is sufficient if it reduces the electromagnetic waves irradiated onto the surface of the packaging material laminate 400. Therefore, the material of the shielding member 61 can be any material that can reduce the transmission of electromagnetic waves. The shielding member 61 may absorb electromagnetic waves or reflect them. In particular, it is preferable that the shielding member 61 can reflect electromagnetic waves. This is because by reflecting electromagnetic waves, the shielding member 61 can reduce the heating of the non-jointed area 23 of the packaging material laminate 400 caused by the shielding member 61 absorbing electromagnetic waves and heating, and it is particularly effective in preventing partial melting or welding. For this reason, as already explained, the shielding member 61 may be a metal plate. Metal materials have excellent electromagnetic wave reflection characteristics, so by making the shielding member 61 a metal plate, the transmission of electromagnetic waves can be particularly reduced. In addition, by making the shielding member 61 a metal plate, it is possible to make a highly durable member that can prevent damage even with repeated use.

[0129] The shielding member 61 may include one or more materials selected from, for example, iron, stainless steel, aluminum, aluminum alloy, copper, copper alloy, etc.

[0130] The shielding member may also have a coating layer on its surface. The coating layer may include one or more materials selected from, for example, resin, ceramic, carbon, and metal.

[0131] As the resin, one or more types selected from fluororesins such as polytetrafluoroethylene (PTFE) and fluoroethylene propylene (FEP), as well as silicone rubber, silicone resin, polyimide, and polysulfone, can be used.

[0132] As for the ceramic, one or more types selected from aluminum oxide, zirconium oxide, silicon oxide, etc., can be used.

[0133] As for the carbon (carbon material), one or more types selected from carbon nanotubes, graphite, diamond-like carbon, etc., can be used.

[0134] The coating layer may contain multiple types of materials, such as a composite of polyimide, polysulfone, and ceramic particles.

[0135] By having a coating layer on its surface, the shielding member 61 can be made more durable and given new functions such as heat resistance and chemical resistance.

[0136] For example, the coating layer can be made to include fluororesin or ceramic to enhance heat resistance and chemical resistance. The coating layer can also be made to include silicone rubber or silicone resin to enhance durability and heat resistance, and to reduce friction with the packaging material laminate 400.

[0137] The coating layer may be arranged to cover the entire surface of the shielding member 61, or it may be arranged only on a part of the surface of the shielding member 61, such as the surface of the shielding member 61 that is irradiated with electromagnetic waves. Depending on the material and function of the coating layer 61, the portion of the shielding member 61 on which the coating layer is placed can be selected. (1-2) Regarding support members As shown in Figures 6 and 7, during the heating process, the support member 62 may be placed on the side of the packaging material laminate 400 opposite to the side on which the shielding member 61 is placed. The packaging material laminate 400 can also be sandwiched between the shielding member 61 and the support member 62.

[0138] The support member 62 can be any member capable of supporting the packaging material laminate 400 or the shielding member 61, and its material is not particularly limited. For example, the support member 62 may have the same configuration as the shielding member 61 already described. In this case, the support member 62 may cover at least a portion of the non-joined region 23 of the packaging material laminate 400.

[0139] Since the support member 62 has the same configuration as the shielding member 61, it is possible to prevent electromagnetic waves reflected from the surface of a chamber or the like for irradiating electromagnetic waves from being irradiated from the opposite side of the packaging material laminate 400 from the side on which the shielding member 61 is placed. In particular, by having the support member 62 cover at least a part of the non-jointed region 23, the electromagnetic waves irradiated from the side on which the support member 62 is placed to the non-jointed region 23 can be particularly reduced.

[0140] The shape and size of the support member 62 are not particularly limited and can be selected to support the packaging material laminate 400. The shape and size of the support member 62 may be selected to cover, for example, at least a portion of the non-joined area 23, or to cover, for example, the entire surface of the packaging material laminate 400 opposite to the surface on which the shielding member 61 is placed.

[0141] By performing the above heating process, the bonding region of the packaging material laminate 400 is heated, and the packaging material 401 and packaging material 402 contained in the packaging material laminate 400 can be bonded together.

[0142] During the heating process, while electromagnetic waves are being irradiated onto the packaging material laminate 400, non-jointed areas 23 and the like of the packaging material laminate 400 other than the jointed areas 22 may be cooled as needed. The method of cooling the non-jointed areas 23 and the like is not particularly limited; the non-jointed areas 23 may be cooled by bringing a pipe circulating cooling water into contact with them, or by blowing cold air onto the non-jointed areas 23.

[0143] When manufacturing packaging, the heating process can be carried out in multiple stages. Specifically, for example, the heating process may be carried out to join only a portion of the joining area of ​​the packaging, then the contents may be filled into the packaging, and then the heating process may be carried out again to join the remaining joining area. In other words, the heating process can be carried out multiple times in the method of manufacturing packaging. (2) Other processes The packaging manufacturing method of this embodiment may also include any other steps besides the heating step, such as a pressurizing step or a placement step. (2-1) Pressurization process The packaging manufacturing method of this embodiment may further include a pressurizing step of pressurizing the packaging material laminate with respect to the joining region.

[0144] By performing a pressurizing process, the packaging material 401 and the packaging material 402 contained in the packaging material laminate 400 can be brought into close contact at the joining region 22 and firmly joined.

[0145] The timing of the pressurization process is not particularly limited; the timing and duration can be selected to ensure sufficient bonding strength in the bonded area. The pressurization process may be performed so as to overlap with the heating process in some way, or it may be performed after the heating process. For example, the pressurization process may be started before the heating process begins, continued during the heating process, and ended after the heating process is completed.

[0146] In the pressurizing process, the packaging material laminate 400 can be pressurized along the lamination direction of the packaging materials contained within it. In the pressurizing process, the packaging material laminate 400 may also be pressurized, including the non-joined areas. The method of pressurizing the packaging material laminate 400 in the pressurizing process is not particularly limited; for example, it may be pressurized by passing the packaging material laminate between rollers. In addition, in the pressurizing process, the packaging material laminate 400 may be pressurized by a shielding member 61, or it may be pressurized while heating the packaging material laminate 400 with a heat sealing bar. In the pressurizing process, the packaging material laminate 400 may be pressurized by multiple means; for example, the means of pressurizing may be changed midway through the pressurizing process.

[0147] If a pressurizing step is performed after a heating step, the packaging material laminate 400 may be heated again during the pressurizing step. In this case, since the pressurizing step is performed immediately after heating in the heating step, there is no need to heat it to an excessively high temperature, so for example, the pressurizing step may be performed by resistance heating. (2-2) Placement process In the placement step, the shielding member 61 can be placed on the packaging material laminate 400 so as to cover at least a portion of the non-bonded area 23. The placement step can be performed before the heating step.

[0148] The specific method of the placement process is not particularly limited, but for example, the shielding member 61 may be supplied along the transport path in which the packaging material laminate 400 is being transported, and placed so as to cover the non-joined area 23 of the packaging material laminate 400.

[0149] Alternatively, the shielding member 61 can be fixed in advance inside a chamber or the like that irradiates electromagnetic waves along the transport path of the packaging material laminate 400. The shielding member 61 may be positioned on the packaging material laminate 400 when the packaging material laminate 400 passes below the shielding member 61 or when the transport of the packaging material laminate 400 is stopped below the shielding member 61, when viewed along the direction of electromagnetic wave irradiation. In this case, when the packaging material laminate 400 reaches a predetermined position relative to the shielding member 61, the transport of the packaging material laminate 400 may be temporarily stopped and the heating process may be carried out by irradiating it with electromagnetic waves.

[0150] During the arrangement process, the distance between the shielding member 61 and the packaging material laminate 400 may be varied.

[0151] During the placement process, the support member 62 may also be placed on the packaging material laminate 400. [Packaging manufacturing equipment] An example of the configuration of the packaging manufacturing apparatus of this embodiment will be described with reference to Figures 5, 6, and 7. Since Figures 6 and 7 are modified examples of the packaging manufacturing apparatus, the explanation will mainly use Figure 5, and use Figures 6 and 7 as needed. The packaging manufacturing apparatus of this embodiment can be used to carry out a packaging manufacturing method according to one aspect of this disclosure. For this reason, some explanations of matters already described will be omitted.

[0152] As shown in Figure 5, the packaging manufacturing apparatus 50 of this embodiment may have a heating device 500 that includes an oscillator 53 that emits electromagnetic waves.

[0153] The following describes each device. (1)Heating device The heating device 500 can heat the bonding areas of the packaging material laminate 400 by irradiating it with electromagnetic waves, thereby heating the packaging material laminate 400, which is made up of multiple layers of packaging material, namely packaging material 401 and packaging material 402.

[0154] The heating device 500 may include a chamber 51, an oscillator 53 that emits electromagnetic waves, and a waveguide 52 that transmits the electromagnetic waves emitted by the oscillator 53 to the chamber 51.

[0155] The chamber 51 may have an opening 510 for loading and unloading the packaging material laminate 400. The size of the opening 510 is preferably selected to prevent electromagnetic waves transmitted into the chamber 51 from leaking to the outside.

[0156] The shape and material of the chamber 51 are not particularly limited. Furthermore, if the end of the waveguide 52 and the packaging material laminate 400 are in close proximity to prevent leakage of electromagnetic waves to the outside, the heating device 500 does not need to have a chamber 51.

[0157] Therefore, as shown in Figures 6 and 7, for example, the packaging manufacturing apparatus 60 and packaging manufacturing apparatus 70, the heating device 600 does not need to have a chamber 51. In this case, the heating device 600 can have an oscillator 53 and a waveguide 52.

[0158] Furthermore, a chamber or the like may be provided to cover the entire packaging manufacturing apparatus. In this case, the chamber or the like may have an opening for loading and unloading the packaging material laminate 400, and the heating device 600 may have an oscillator 53 and a waveguide 52, and may also be equipped with a known horn antenna.

[0159] The waveguide 52 only needs to be able to transmit electromagnetic waves, and can be made of materials such as metal. If the waveguide 52 is a metal tube, a ceramic window that can transmit electromagnetic waves may be provided at the end of the waveguide 52 as needed to prevent foreign matter from entering the waveguide. Electrical wires such as coaxial cables may be used for part or all of the waveguide 52.

[0160] The oscillator 53 can be selected according to the frequency of the electromagnetic wave used, but for example, one or more types selected from a gyrotron, magnetron, klystron, traveling wave tube, etc. may be used. The oscillator 53 may be equipped with a control device (not shown) to control the frequency of the electromagnetic wave and the output. (2) Shielding member installation device The packaging manufacturing apparatus of this embodiment may also include a shielding member installation device. The shielding member installation device can install a shielding member 61 that reduces the transmission of electromagnetic waves so as to cover at least a portion of the non-jointed area 23 other than the jointed area 22 of the packaging material laminate 400.

[0161] The shielding member installation device only needs to be able to install the shielding member 61 so as to cover at least a portion of the non-jointed areas of the packaging material laminate 400 other than the jointed areas when electromagnetic waves are irradiated, and its configuration is not particularly limited.

[0162] The shielding member installation device can, for example, install the shielding member 61 on the packaging material laminate 400 upstream of the chamber 51, which is the area irradiated with electromagnetic waves, or within the chamber 51, in the transport direction of the packaging material laminate 400. The shielding member installation device may also recover the shielding member 61 downstream of the chamber 51, which is the area irradiated with electromagnetic waves, in the transport direction of the packaging material laminate 400, and reuse it.

[0163] The shielding member installation device may simply involve placing the shielding member 61 on the packaging material laminate 400, or it may involve sandwiching the packaging material laminate 400 between the support member 62 and the shielding member 61, thereby installing the shielding member 61 on the packaging material laminate 400.

[0164] Furthermore, the shielding member installation device may have a shielding member 61 fixed in the area to be irradiated with electromagnetic waves. By fixing the shielding member 61 within the area to be irradiated with electromagnetic waves, the shielding member 61 can be installed so as the packaging material laminate 400 passes below the shielding member 61, it covers at least a portion of the non-jointed area.

[0165] Furthermore, as shown in the packaging manufacturing apparatus 60 in Figure 6, the shielding member installation device 65 may be configured to allow the shielding member 61 to move along the double-headed arrow B in the area irradiated with electromagnetic waves. By moving the shielding member 61 along the double-headed arrow B, the distance between the shielding member 61 and the packaging material laminate 400 can be increased while the packaging material laminate 400 is being transported, preventing the shielding member 61 from coming into contact with the packaging material laminate 400 and causing damage. After a predetermined area of ​​the packaging material laminate 400 reaches the area irradiated with electromagnetic waves and the transport of the packaging material laminate 400 is stopped, the shielding member installation device 65 can move the shielding member 61 to shorten the distance between the shielding member 61 and the packaging material laminate 400. This allows a portion of the packaging material laminate 400 to be covered by the shielding member 61, reducing the electromagnetic waves irradiated onto the surface of the packaging material laminate 400. After irradiating with electromagnetic waves and heating, the shielding member installation device 65 may move the shielding member 61 to increase the distance between the shielding member 61 and the packaging material laminate 400.

[0166] As shown in Figure 6, the packaging manufacturing apparatus 60 may be configured such that a support member 62 is placed on the side of the packaging material laminate 400 opposite to the side on which the shielding member 61 is placed, and the shielding member installation device 65 moves the support member 62 together with the shielding member 61. The shielding member installation device 65 can move the support member 62 along, for example, the double arrow C.

[0167] As shown in Figure 6, while the packaging material laminate 400 is being transported, the shielding member installation device 65 may increase the distance between the shielding member 61 and the support member 62 and the packaging material laminate 400. This prevents the shielding member 61 and the support member 62 from coming into contact with the packaging material laminate 400 and being damaged. After a predetermined area of ​​the packaging material laminate 400 reaches the area irradiated with electromagnetic waves and the transport of the packaging material laminate 400 is stopped, the shielding member installation device 65 can move the shielding member 61 and the support member 62. In this case, the distance between the shielding member 61 and the support member 62 may be shortened to sandwich the packaging material laminate 400. This covers a portion of the upper and lower surfaces of the packaging material laminate 400 with the shielding member 61 and the support member 62, reducing the electromagnetic waves irradiated to the non-jointed areas of the packaging material laminate 400. After irradiating with electromagnetic waves and heating, the shielding member installation device 65 may move the shielding member 61 and the support member 62 to increase the distance between the shielding member 61 and the support member 62 and the packaging material laminate 400.

[0168] If the packaging manufacturing apparatus 60 has a support member 62, the support member 62 may be driven by a device other than the shielding member installation device 65.

[0169] The configuration of the shielding member installation device 65 is not particularly limited, but it may include, for example, a motor or cylinder or other drive device for linearly moving the shielding member 61 and the support member 62. The shielding member installation device 65 may also have guides as needed.

[0170] Since the shielding member 61 and the support member 62 have already been explained, their explanation will be omitted here.

[0171] The heating device may, if necessary, include a cooling device for cooling non-jointed areas other than the jointed area in the electromagnetic wave irradiation area, such as inside the chamber 51. The cooling device may consist of piping that circulates cooling water in contact with the non-jointed area 23, etc., or it may be designed to blow cold air. It may also be designed to cool the temperature inside the chamber 51 and the electromagnetic wave irradiation area. (3) Pressurizing device The packaging manufacturing apparatus of this embodiment may further include a pressurizing device 54 for pressurizing the packaging material laminate 400 in the joining region.

[0172] By applying pressure to the joining area with the pressurizing device 54, the packaging material 401 and the packaging material 402 contained in the packaging material laminate 400 can be brought into close contact at the joining area and firmly joined.

[0173] The pressurizing device 54 may, for example, be configured to pressurize the packaging material laminate 400 by passing it between rollers, as shown in Figure 5. The pressurizing device 54 may also have a heating device to heat the packaging material laminate 400 as needed.

[0174] Furthermore, as shown in Figure 6, for example, a heat seal bar can be used as the pressurizing device 64. A heat seal bar, also known as a heat sealer, is a device that can pressurize and heat the joining region of the packaging material laminate 400 using upper and lower seal bars. By using a heat seal bar, it is possible to easily pressurize along the joining region of the packaging material laminate 400 and heat it at the same time.

[0175] Furthermore, as shown in the packaging manufacturing apparatus 70 in Figure 7, the pressurizing device 74 may be installed within the area irradiated with electromagnetic waves. In this case, the pressurizing device 74 may have a pair of plate-like bodies 741 and a drive device 742 that changes the distance between the pair of plate-like bodies 741. When pressurizing is performed by the pressurizing device 74, the drive device 742 shortens the distance between the pair of plate-like bodies 841, allowing the laminated packaging material 400 to be sandwiched and pressurized. After pressurizing is complete, the pressurizing device 74 uses the drive device 742 to increase the distance between the pair of plate-like bodies 741, making it possible to transport the laminated packaging material 400.

[0176] The configuration of the drive unit 742 is not particularly limited, but it may include, for example, a motor or cylinder for linearly moving a pair of plate-shaped bodies 741. The drive unit 742 may also have guides as needed.

[0177] The pair of plate-like bodies 741 can be formed from, for example, a resin or a material that can transmit electromagnetic waves, such as glass. Alternatively, the pair of plate-like bodies 741 may be formed from metal and have through holes that can transmit electromagnetic waves.

[0178] Therefore, by applying pressure to the packaging material laminate 400 with a pair of plate-like bodies 741 and then irradiating it with electromagnetic waves, it is possible to simultaneously apply pressure and heat to the bonding region of the packaging material laminate 400.

[0179] In the packaging manufacturing apparatus 70 shown in Figure 7, the pair of plate-shaped bodies 741 in the pressurizing device 74 may be integrated with a shielding member 61 and a support member 62, and pressurization may be performed by the shielding member 61 and the support member 62. In Figure 7, due to paper width limitations, an example of a single pressurizing device 74 is shown, but multiple pressurizing devices 74 may be installed depending on the range of the joining area, etc. Furthermore, the packaging manufacturing apparatus 70 shown in Figure 7 may also have additional pressurizing devices 54 and 64, as shown in Figures 5 and 6, outside the area irradiated with electromagnetic waves, and pressurization may be performed in multiple stages.

[0180] Examples of embodiments of the present disclosure are as follows: <1> A packaging material having a laminated structure including multiple layers, A packaging material in which a layer different from the layer containing the bonding surface that joins with other packaging materials contains an electromagnetic wave absorbing material. <2> A base layer and a sealant layer are laminated together. The sealant layer includes, in order from the position closest to the joint surface, a first sealant layer and a second sealant layer. The second sealant layer contains the electromagnetic wave absorbing material. <1> The packaging materials listed. <3> It contains only polyolefin resins as the resin material. <1> or <2> The packaging materials listed. <4> When the area that is joined to other packaging materials is designated as the joining area, and the area other than the joining area is designated as the non-joining area, The electromagnetic wave absorbing material is distributed such that, when electromagnetic waves are irradiated onto the packaging material, the amount of electromagnetic wave absorption per unit area in the junction region is greater than the amount of electromagnetic wave absorption per unit area in the non-junction region. <1> ~ <3> Packaging materials as described in any of the following. <5> The joining region is located in at least a portion of the outer circumference, <4> The packaging materials listed. <6> <1> ~ <5> It contains multiple pieces of packaging material as described in any of the following: A package in which the aforementioned packaging materials are joined at the joining region. <7> The process includes a heating step in which an electromagnetic wave is irradiated onto a laminate of packaging materials, which is formed by stacking multiple sheets of packaging material so that their joining surfaces face each other, thereby heating the joining regions of the packaging materials. The aforementioned packaging material has a laminated structure comprising multiple layers, A method for manufacturing a package, wherein a layer different from the layer including the aforementioned bonding surface contains an electromagnetic wave absorbing material. <8> The heating step is carried out with a shielding member installed to reduce the transmission of electromagnetic waves, so as to cover at least a portion of the non-bonded areas of the packaging material laminate other than the bonded areas. <7> A method for manufacturing the packaging described above. <9> The shielding member is a metal plate. <8> A method for manufacturing the packaging described above. <10> The bonding region further comprises a pressing step of pressing the packaging material laminate, <7> ~ <9> A method for manufacturing a package as described in any of the following. [Explanation of Symbols]

[0181] 10 Packaging materials 10A joint surface 100 Packaging materials 101 Packaging materials 102 Packaging materials 103 Packaging materials 104 Packaging materials 11 Base material layer 12. Sealant layer 121 First sealant layer 122 Second sealant layer 123 Third sealant layer 13 Adhesive layer 14 Gas barrier film 141 Barrier substrate layer 142 Barrier layer 15 Layer containing electromagnetic wave absorbing material 21 Electromagnetic wave absorbing materials 22 Joint area 23 Non-bonded area 300 Packaging materials 301 Packaging materials 40 Packaging products 41 Packaging 400 Packaging Material Laminate 400A side 400B side 400C side 400D side 401 Packaging materials 402 Packaging materials 42 Contents 50 Packaging manufacturing equipment 500 Heating device 51 Chamber (heating device) 510 Opening 52 Waveguide (heating device) 53 Oscillator (heating device) 54 Pressurizing device 60 Packaging manufacturing equipment 600 Heating device 61 Shielding member 610 corner 62 Support member 64 Pressurizing device 65 Shielding Member Installation Device 70 Packaging manufacturing equipment 74 Pressurizing device 741 Plate-like body 742 Drive unit B Double arrow C Double arrow

Claims

1. A packaging material having a laminated structure including multiple layers, A packaging material in which a layer different from the layer containing the bonding surface that joins with other packaging materials contains an electromagnetic wave absorbing material.

2. A base layer and a sealant layer are laminated together. The sealant layer includes, in order from the position closest to the joint surface, a first sealant layer and a second sealant layer. The packaging material according to claim 1, wherein the second sealant layer contains the electromagnetic wave absorbing material.

3. The packaging material according to claim 1 or claim 2, wherein the resin material contains only a polyolefin resin.

4. When the area that is joined to other packaging materials is designated as the joining area, and the area other than the joining area is designated as the non-joining area, The packaging material according to claim 1 or claim 2, wherein the electromagnetic wave absorbing material is distributed such that when electromagnetic waves are irradiated onto the packaging material, the amount of electromagnetic wave absorption per unit area in the bonding region is greater than the amount of electromagnetic wave absorption per unit area in the non-bonding region.

5. The packaging material according to claim 4, wherein the bonding region is located in at least a portion of the outer circumference.

6. A plurality of sheets of the packaging material according to claim 1 or claim 2, A package in which the aforementioned packaging materials are joined at the joining region.

7. The process includes a heating step in which an electromagnetic wave is irradiated onto a laminate of packaging materials, which is formed by stacking multiple sheets of packaging material so that their joining surfaces face each other, thereby heating the joining regions of the packaging materials. The aforementioned packaging material has a laminated structure comprising multiple layers, A method for manufacturing a package, wherein a layer different from the layer including the aforementioned bonding surface contains an electromagnetic wave absorbing material.

8. The method for manufacturing a package according to claim 7, wherein the heating step is carried out with a shielding member that reduces the transmission of electromagnetic waves installed so as to cover at least a portion of the non-bonded areas of the laminated packaging material other than the bonded areas.

9. The method for manufacturing a package according to claim 8, wherein the shielding member is a metal plate.

10. A method for manufacturing a package according to claim 7 or claim 8, further comprising a pressurizing step of pressurizing the laminate of the packaging material with respect to the bonding region.

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