Lid material and method for manufacturing the lid material

Abstract

To provide a lid material and a method for manufacturing a lid material that can improve mass production while suppressing the damage of variable information contained in the variable information printing layer. [Solution] The lid material for sealing the opening of the container comprises a paper base layer, a coating layer located on the surface of the base layer, an aluminum layer located on the back surface of the base layer, a base layer located on the aluminum layer and containing a first medium, and a variable information printing layer that is inkjet printed on the base layer, wherein the coating layer contains a second medium different from the first medium and a matting agent dispersed in the second medium.

Description

[Technical Field]

[0001] This disclosure relates to a lid material and a method for manufacturing a lid material. [Background technology]

[0002] From the viewpoint of ensuring the airtightness of a container that holds its contents, the container may be sealed with a lid. Conventionally, information such as campaign details has been printed on the back of the lid. In recent years, this information may include variable information such as QR codes (registered trademarks) that differ for each lid. For example, Patent Document 1 below discloses a packaging material in which a base layer with a printed layer on its back surface, a concealing layer, and a heat-adhesive resin layer that forms the innermost layer are sequentially laminated. In this packaging material, an ink-receiving layer and a variable information printing layer printed using an inkjet method are formed on the heat-adhesive resin layer side of the concealing layer. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 5428492 [Overview of the project] [Problems that the invention aims to solve]

[0004] From the standpoint of mass production and manufacturing costs, the lid material disclosed in Patent Document 1 may be manufactured using a roll-to-roll method. However, when the lid material disclosed in Patent Document 1 is manufactured using a roll-to-roll method, the variable information printing layer may peel off and adhere to the base material layer, or a portion of the base material layer may peel off and adhere to the variable information printing layer. In these cases, a problem occurs in which the variable information contained in the variable information printing layer is damaged. This problem is more likely to occur as the roll feed speed increases. In other words, avoiding the occurrence of the above problem leads to a decrease in mass production efficiency and, consequently, an increase in costs.

[0005] One aspect of this disclosure is to provide a lid material and a method for manufacturing the lid material that can improve mass productivity while suppressing damage to the variable information contained in the variable information printing layer. [Means for solving the problem]

[0006] A lid material relating to one aspect of this disclosure is a lid material for sealing the opening of a container, comprising: a paper base layer; a coating layer located on the surface of the base layer; an aluminum layer located on the back surface of the base layer; a base layer located on the aluminum layer and containing a first medium; and a variable information printing layer that is inkjet printed on the base layer, wherein the coating layer comprises a second medium different from the first medium and a matting agent dispersed in the second medium.

[0007] When a lid material relating to one aspect of this disclosure is manufactured by a roll-to-roll method, after the variable information printing layer is inkjet printed onto a substrate layer containing a first medium, the substrate layer on which the variable information printing layer is provided is wound onto a roll. At this time, the variable information printing layer comes into contact with a coating layer located on the surface of the substrate layer. As a result, contact between the variable information printing layer and the substrate layer is prevented by the coating layer, so that a part of the substrate layer does not peel off and adhere to the variable information printing layer. Here, the coating layer contains a second medium different from the first medium, as well as a matting agent dispersed in the second medium. Therefore, adhesion between the variable information printing layer and the coating layer is also well suppressed. Thus, it is possible to provide a lid material that can improve mass productivity while suppressing damage to the variable information contained in the variable information printing layer.

[0008] A printed layer is provided on the surface of the substrate layer, which is covered by a coating layer. The content of the matting agent in the coating layer may be 0.5% by mass or more and 5% by mass or less. In this case, adhesion between the variable information printed layer and the coating layer is suppressed more effectively while maintaining mass productivity. Alternatively, the content of the matting agent in the coating layer may be 0.5% by mass or more and 2% by mass or less. In this case, adhesion between the variable information printed layer and the coating layer is suppressed effectively while the matting of the printed layer is suppressed.

[0009] The matting agent may also be inorganic particles. In this case, adhesion between the variable information printing layer and the coating layer is more effectively suppressed.

[0010] The first medium may contain acrylic resin, and the second medium may contain nitrocellulose. In this case, the adhesion between the coating layer and the variable information printing layer is reduced, while the substrate layer and the variable information printing layer adhere well. Therefore, it is possible to effectively suppress the peeling of the variable information printing layer and its adhesion to the coating layer, as well as the peeling of parts of the coating layer and substrate layer and their adhesion to the variable information printing layer.

[0011] The lid material may further include a sealant layer that is located in the base layer and welded to the container.

[0012] The above-mentioned lid material may also be a lid material for food containers. In this case, it is possible to provide a lid material that can prevent adverse effects on the food contained in the container, improve mass production efficiency, and suppress damage to the variable information contained in the variable information printing layer.

[0013] A method for manufacturing a lid material relating to another aspect of the present disclosure is a method for manufacturing a lid material for sealing the opening of a container, comprising: a first step of attaching an aluminum layer to the back surface of a paper base layer; a second step of sequentially forming a printed layer and a coated layer on the surface of the base layer and forming a base layer containing a first medium on the aluminum layer; and a third step of inkjet printing a variable information printed layer onto the base layer after the second step, wherein in the second step, a mixture containing a second medium different from the first medium and a matting agent dispersed in the second medium is applied to the surface of the base layer so as to cover the printed layer to form a coated layer, and in the third step, the base layer on which the variable information printed layer has been formed is wound up.

[0014] According to this manufacturing method, in the third step, after the variable information printing layer is inkjet printed on the base layer, the base material layer on which the variable information printing layer is formed is wound up. Here, a coating layer is provided on the surface of the base material layer. Therefore, after the base material layer is wound up, the variable information printing layer comes into contact with the coating layer. Thereby, the contact between the variable information printing layer and the base material layer is prevented by the coating layer. In addition, the coating layer is formed by applying a mixture containing a second medium different from the first medium and a matting agent dispersed in the second medium onto the surface of the base material layer so as to cover the printing layer. By including the matting agent in the coating layer in this way, the adhesion between the variable information printing layer and the coating layer is favorably suppressed. Therefore, by implementing the above manufacturing method, it is possible to provide a lid material that can suppress the damage of the variable information contained in the variable information printing layer while improving mass productivity.

[0015] The content of the matting agent contained in the mixture may be 0.5% by mass or more and 5% by mass or less. In this case, the adhesion between the variable information printing layer and the coating layer is more favorably suppressed.

Effects of the Invention

[0016] According to one aspect of the present disclosure, it is possible to provide a lid material and a method for manufacturing the lid material that can suppress the damage of the variable information contained in the variable information printing layer while improving mass productivity.

Brief Description of the Drawings

[0017] [Figure 1] FIG. (1) is a schematic diagram of the usage state of the lid material according to the embodiment. [Figure 2] FIG. (2) is a schematic cross-sectional view of a part of the lid material. [Figure 3] FIG. (3) is a schematic diagram for explaining the third step.

Modes for Carrying Out the Invention

[0018] Preferred embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. Furthermore, the dimensional ratios in the drawings are not limited to those shown.

[0019] Figure 1 is a schematic diagram of the lid material in use according to this embodiment. Figure 1 discloses a side view showing the lid material in use. In Figure 1, a portion of the container 2 and the lid material 10 are cut out. As shown in Figure 1, the lid material 10 included in the container with a lid 100 is a member for sealing the container 2 in which the contents 1 are contained, and seals the opening 2a of the container 2. The contents 1 are not particularly limited and may include, for example, food and beverages, pharmaceuticals, cosmetics, chemicals, electronic equipment, tools, stationery, etc. The contents 1 are not limited to solids, and may also be liquids or gases. In this embodiment, instant food (for example, instant noodles) that is cooked by adding hot water is contained in the container 2 as the contents 1. Therefore, in this embodiment, the container 2 is a food container, and the lid material 10 is a lid material for a food container. When the lid material 10 is in use, the lid material 10 is attached to the container 2 so as to seal the container 2.

[0020] The container 2, which is sealed by the lid material 10, has a bottomed cylindrical shape. In this embodiment, the container 2 has a circular shape when viewed from the thickness direction of the bottom wall, but is not limited to this. The open end 2b on the opposite side of the bottom wall of the container 2 is bent outward, and a part of the open end 2b forms a flange portion. When the container 2 is sealed by the lid material 10, the lid material 10 is in close contact with the open end 2b.

[0021] The lid material 10 is a sheet-like member that can possess the required performance (e.g., gas barrier properties, light shielding properties, temperature and humidity resistance, mechanical strength, etc.). Gas barrier properties refer to the ability to prevent or suppress the permeation of gases such as oxygen and water vapor. The lid material 10 may also be a member to which an identification mark for paper containers and packaging is attached in accordance with Japan's Law for Promotion of Effective Utilization of Resources. In this case, the main component of the lid material 10 can be said to be paper. When the lid material 10 is in use, the entire outer surface 10a of the lid material 10 corresponds to a part of the outer surface of the container with a lid 100, and at least a part of the inner surface 10b of the lid material 10 corresponds to a part of the inner surface of the container with a lid 100. When the main component of the lid material 10 is paper, the mass of paper accounts for 51% or more of the total mass of the lid material 10. The lid material 10 has a main body part 11 and a handle part 12.

[0022] The main body portion 11 is the part that closes the opening 2a of the container 2 when the lid material 10 is in use. The main body portion 11 overlaps at least the entire opening end 2b in the thickness direction of the lid material 10. In this embodiment, the edge of the main body portion 11 extends along the opening end 2b, and the center of the main body portion 11 coincides with the center of the opening end 2b. The diameter of the main body portion 11 depends on the size of the container 2 and may be 20 mm or more and 200 mm or less, or 50 mm or more and 180 mm or less. Specific examples include diameters of 96.5 mm, 80.5 mm, and 166 mm.

[0023] The tab portion 12 is a part that protrudes from the edge of the main body portion 11, and is, for example, a tab. As shown in Figure 1, when the lid material 10 is in use, the tab portion 12 is a free end located outside the opening end 2b. Therefore, the tab portion 12 can be used as the starting point for opening the container 2 when the user opens the container 2 closed with the lid material 10. In addition, the tab portion 12 is also used as a locking device to secure the lid material 10 to the container 2 when closing the opening 2a of the container 2 with the lid material 10 again.

[0024] FIG. 2 is a schematic cross-sectional view of a part of the lid material. As shown in FIG. 2, the lid material 10 includes a base material layer 21, a printing layer 22 and a coating layer 23 located on the surface 21a of the base material layer 21, and an aluminum layer 24, an underlayer 25, a variable information printing layer 26 and a sealant layer 27 located on the back surface 21b of the base material layer 21. In the present embodiment, in the thickness direction of the lid material 10, the coating layer 23, the printing layer 22, the base material layer 21, the aluminum layer 24, the underlayer 25, the variable information printing layer 26 and the sealant layer 27 are laminated in this order.

[0025] The base material layer 21 is a film-like member formed from paper made by papermaking (that is, a paper-made member). When the lid material 10 is in use, the surface 21a of the base material layer 21 is located on the outer surface 10a side of the lid material 10, and the back surface 21b of the base material layer 21 is located on the inner surface 10b side of the lid material 10. The paper constituting the base material layer 21 is, for example, high-quality paper, special high-quality paper, coated paper, art paper, cast-coated paper, Japanese paper, imitation paper, kraft paper, etc. In the present embodiment, the base material layer 21 is art paper, but is not limited thereto.

[0026] The basis weight of the base material layer 21 is, for example, 10 g / m 2 or more and 200 g / m 2 or less. Therefore, the base material layer 21 is so-called thin paper and exhibits flexibility. The lower limit value of the basis weight of the base material layer 21 may be, for example, 10 g / m 2 or 40 g / m 2 or 60 g / m 2 or 80 g / m 2 or 100 g / m 2 or 150 g / m 2 or 120 g / m 2 or 100 g / m 2 or 80 g / m 2 or 60 g / m 2 or 40 g / m 2 or 20 g / m 2The following is also acceptable. In this embodiment, the mass of the base layer 21 is 51% or more of the total mass of the base layer 21, the printing layer 22, the coating layer 23, the aluminum layer 24, the underlayment layer 25, the variable information printing layer 26, and the sealant layer 27.

[0027] The printed layer 22 corresponds to the printed portion of the lid material 10, is located on the surface 21a of the base material layer 21, and is covered by the coating layer 23. The printed layer 22 provides characters, patterns, figures, symbols, etc., on the surface 21a of the base material layer 21. The printed layer 22 is a portion printed with, for example, water-based or oil-based ink, and is attached to the base material layer 21. At least a portion of the ink contained in the printed layer 22 may seep into the base material layer 21. Multiple inks may be mixed in the printed layer 22, or multiple inks may be layered. From the viewpoint of printability and cost, the thickness of the printed layer 22 is, for example, 0.1 μm or more and 2 μm or less. In this embodiment, the average thickness of the printed layer 22 is about 1 μm. The printed layer 22 can be formed by, for example, gravure printing, offset printing, flexographic printing, letterpress printing, silkscreen printing, and other conventional printing methods.

[0028] The coating layer 23 is a layer that improves the water resistance of the lid material 10, and coats the entire surface 21a of the base layer 21 and covers the printing layer 22. The presence of the coating layer 23 prevents peeling of the printing layer 22. In addition, the coating layer 23 is also a layer that suppresses damage to the variable information printing layer 26 during the manufacturing of the lid material 10. From the viewpoint of the visibility of the printing layer 22, the coating layer 23 is transparent. When the lid material 10 is formed, the coating layer 23 is located outside the base layer 21. The thickness of the coating layer 23 is, for example, 3 μm or more and 25 μm or less. By having a thickness of 3 μm or more of the coating layer 23, it is possible to fill in the irregularities formed on the surface 21a of the base layer 21. This makes the outer surface 23a of the coating layer 23 a smooth surface. Also, by having a thickness of 25 μm or less of the coating layer 23, the coating layer 23 becomes less prone to cracking. The lower limit of the thickness of the coating layer 23 may be, for example, 5 μm or 10 μm. The upper limit of the thickness of the coating layer 23 may be, for example, 20 μm or 15 μm.

[0029] The coating layer 23 is formed by drying a coating solution obtained by diluting a mixture containing a medium (second medium, medium ink) and a matting agent dispersed in the medium. In the formation of the coating layer 23, the solvent contained in the coating solution is removed by drying, but most of the solvent contained in the medium is not removed. Therefore, it can be said that the coating layer 23 is ultimately formed from only the above mixture. The medium contained in the coating layer 23 is an ink that exhibits good adhesion to the substrate layer 21 and is transparent, and includes, for example, nitrocellulose, acrylic resin, urethane resin, vinyl chloride vinyl acetate copolymer, epoxy resin, etc. From the viewpoint of adhesion to the substrate layer 21, the medium may also contain nitrocellulose. The solvent contained in the coating solution and used to dilute the above mixture is, for example, water, or an organic solvent such as ethyl acetate, alcohol, or acetone, or a mixture thereof.

[0030] The matting agent consists of particles different from the pigments of the medium that form the coating layer 23, and suppresses the gloss of the coating layer 23. The matting agent may be a synthetic resin wax or may be formed from an inorganic material. From the viewpoint of the antiblocking properties of the coating layer 23, the matting agent may be inorganic particles (inorganic fragments). Examples of inorganic particles include silica, alumina, barium sulfate, and titanium oxide. The average particle size of the inorganic particles is not particularly limited, but is, for example, 0.01 μm or more and 20 μm or less. The average particle size of the inorganic particles is measured by known methods such as laser diffraction. The shape of the inorganic particles is not particularly limited. The content of the matting agent in the coating layer 23 is, for example, 0.5% by mass or more and 5% by mass or less. By having a content of 0.5% by mass or more, after the coating layer 23 and the variable information printing layer 26 come into contact, the peeling of the variable information printing layer 26 and its adhesion to the coating layer 23, and the peeling of part of the coating layer 23 and the substrate layer 21 and their adhesion to the variable information printing layer 26 are well suppressed. By having a content of 5% by mass or less, defects during the manufacturing of the lid material 10 are less likely to occur. From the viewpoint of suppressing adhesion and developing the color of the printed layer 22, the content may be 2% by mass or less. Therefore, the content may be 0.5% by mass or more and 2% by mass or less, 1% by mass or more and 2% by mass or less, or 1% by mass or more and 1.5% by mass or less. In this embodiment, the content of the matting agent contained in the coating layer 23 is the same as or substantially the same as the content of the matting agent contained in the above mixture that forms the coating layer 23. The difference between the content of the matting agent contained in the coating layer 23 and the content of the matting agent contained in the above mixture is, for example, about a few percent. Defects during the manufacturing of the lid material 10 include, for example, roll winding defects and defects in the die-cutting process of the lid material 10.

[0031] In addition to the medium and matting agent, the coating layer 23 may appropriately contain additives such as release agents, lubricants, slip agents, and defoaming agents.

[0032] The aluminum layer 24 is a layer that provides gas barrier properties to the lid material 10 and is fixed on the back surface 21b of the base layer 21. By providing the aluminum layer 24 on the lid material 10, the printed layer 22 can be prevented from showing through to the back surface 21b of the base layer 21. The aluminum layer 24 may be aluminum foil or a film with aluminum vapor deposition. The film is, for example, a known plastic film such as polyethylene terephthalate film. The thickness of the aluminum layer 24 may be, for example, 3 μm to 30 μm or 5 μm to 20 μm. The aluminum layer 24 and the base layer 21 are fixed to each other via, for example, a known adhesive (not shown). The adhesive is, for example, a thermoplastic adhesive containing linear low-density polyethylene (LLD-PE), polyurethane, polypropylene, ethylene-unsaturated ester copolymer resin, or polyester copolymer resin, but is not limited thereto. In one example, the base layer 21 and the aluminum layer 24 are fixed to each other by extruding the adhesive between them using a T-die or the like (extrusion lamination method).

[0033] The base layer 25 is a layer for receiving the ink contained in the variable information printing layer 26 and is located on the aluminum layer 24. The base layer 25 coats at least a portion of the aluminum layer 24. In one example, the base layer 25 is formed in the region where the aluminum layer 24 and the variable information printing layer 26 overlap and its periphery, but is not limited to this. For example, the base layer 25 may coat the entire surface of one of the aluminum layers 24. From the viewpoint of preventing the lid material 10 from peeling off from the container 2, the portion of the aluminum layer 24 that overlaps with the opening end 2b of the container 2 does not need to be coated by the base layer 25. In other words, when the lid material 10 is sealed in the container 2, the base layer 25 does not need to be provided between the container 2 and the aluminum layer 24. The base layer 25 contains at least a medium different from the medium contained in the coating layer 23 (first medium, medium ink). The medium contained in the base layer 25 is an ink that exhibits good adhesion to the aluminum layer 24 and is transparent, and includes, for example, polyester resin, polyamide resin, polyurethane resin, epoxy resin, phenolic resin, (meth)acrylic resin, polyvinyl acetate resin, polyolefin resin, etc. From the viewpoint of adhesion to the aluminum layer 24, the medium contained in the base layer 25 includes acrylic resin. The thickness of the base layer 25 may be, for example, 3 μm to 30 μm or 5 μm to 20 μm.

[0034] The variable information printing layer 26 is an inkjet-printed layer on the base layer 25 and overlaps a portion of the base layer 25. The variable information printing layer 26 includes variable information such as a two-dimensional code encoding a large amount of information, such as an access URL to a campaign site, an explanatory text for the two-dimensional code, and product information. In this embodiment, a different variable information printing layer 26 is formed for each lid material 10. Because the variable information printing layer 26 is formed on the base layer 25, the variable information is accurately printed even when the variable information printing layer 26 is formed at high speed. In addition, the variable information printing layer 26 can adhere firmly to the base layer 25. The ink used for the variable information printing layer 26 may have properties that are easily accepted by the base layer 25 and that do not affect food.

[0035] The sealant layer 27 is located on the base layer 25 and is welded to the container 2, covering the variable information printing layer 26. When the lid material 10 is in use, the sealant layer 27 is welded to the open end 2b of the container 2. The thickness of the sealant layer 27 is, for example, 5 μm or more and 70 μm or less. The lower limit of the thickness of the sealant layer 27 may be 10 μm or 15 μm. The upper limit of the thickness of the sealant layer 27 may be 45 μm or 40 μm. The sealant layer 27 is transparent. This makes the variable information printing layer 26 visible and readable by a camera or the like.

[0036] The resin film contained in the sealant layer 27 is, for example, a flexible polymer film. Flexible polymer films include, for example, polyolefin films such as polyethylene film, polypropylene film, and ethylene-vinyl acetate copolymer film, as well as films composed of ionomer resins, EAA resins, EMAA resins, EMA resins, EMMA resins, biodegradable resins, etc. The sealant layer 27 may have a single-layer structure or a multi-layer structure. The sealant layer 27 can be formed, for example, by an extrusion lamination method, a co-extrusion method, or the like.

[0037] The following describes an example of a method for manufacturing the lid material 10 according to this embodiment. First, an aluminum layer 24 is attached to the back surface 21b of a paper base material layer 21 (first step). In the first step, for example, the adhesive described above is extruded onto the base material layer 21 or the aluminum layer 24 by an extrusion lamination method, and the base material layer 21 and the aluminum layer 24 are bonded to each other. In this embodiment, the base material layer 21 with the aluminum layer 24 attached is wound onto a roll. Although not shown, at least the base material layer 21 is unwound from the roll. That is, a roll-to-roll method is implemented in the first step. The roll feed speed and winding speed (line speed) are, for example, 100 m / min or more and 200 m / min or less. From the viewpoint of mass production, the line speed may be 150 m / min or more.

[0038] Next, a printing layer 22 and a coating layer 23 are formed sequentially on the surface 21a of the base layer 21, and a base layer 25 containing the first medium is formed on the aluminum layer 24 (second step). In one example, the formation of the printing layer 22, coating layer 23, and base layer 25 in the second step is carried out in the same printing apparatus. In this case, after the printing layer 22 and coating layer 23 are formed sequentially, the base layer 21 is inverted in the printing apparatus. Then, the base layer 25 is formed.

[0039] In the second step, first, a printed layer 22 is formed on the surface 21a. For example, the surface 21a is printed using a normal printing method. Subsequently, a coating layer 23 is formed by coating the surface 21a of the substrate layer 21 with a mixture containing a second medium different from the first medium and a matting agent dispersed in the second medium, so as to cover the printed layer 22. Specifically, a coating solution obtained by diluting the above mixture with a solvent is applied to the surface 21a so as to cover the printed layer 22. Subsequently, the coating layer 23 is formed by the removal of the solvent as the coating solution dries. The application of the coating solution is carried out by well-known methods such as offset printing, gravure printing, roll coating, air knife method, or doctor blade method. Subsequently, a coating solution containing the first medium is prepared. Subsequently, the pre-prepared coating solution containing the first medium is selectively applied to at least a portion of the aluminum layer 24. Subsequently, a base layer 25 is formed by drying the coating solution on the aluminum layer 24. In this embodiment, the amount of coating solution applied after drying is, for example, 3 g / m². 2 More than 25g / m 2 The process is as follows: For example, the coating liquid is applied to the aluminum layer 24 by a well-known method such as offset printing, gravure printing, roll coating, air knife method, doctor blade method, or inkjet method. Similar to the first step, a roll-to-roll method is used in the second step. In one example, the substrate layer 21 to which the aluminum layer 24 is attached is unwound from the roll, and the substrate layer 21 with the printed layer 22, coating layer 23, and undercoat layer 25 formed on it is wound onto the roll. The line speed in the second step is, for example, about the same as in the first step.

[0040] Next, as shown in Figure 3, after the second step, a variable information printing layer 26 is inkjet printed onto the base layer 25 using a roll-to-roll method (third step). In the third step, first, the base layer 21 on which the base layer 25 (not shown) is formed is unwound from the roll 101. Subsequently, ink 111 discharged from the inkjet printer 110 adheres to the base layer 25 on the base layer 21 unwound from the roll 101. This forms the variable information printing layer 26 on the base layer 21. In the third step, the information contained in each variable information printing layer 26 formed on the base layer 21 is different. In other words, the shape of each variable information printing layer 26 formed on the base layer 21 is different. Then, the base layer 21 on which the variable information printing layer 26 is formed is wound onto the roll 102. On the roll 102, the variable information printing layer 26 comes into contact with and is pressed against the coating layer 23. The line speed in the third step is, for example, about the same as in the first step. In other words, the roll feed speed and winding speed in the third process are, for example, 100 m / min to 200 m / min and 150 m / min to 200 m / min. As described above, by the adhesion of ink 111 to the base layer 25, the print quality of each variable information printing layer 26 formed on the base layer 21 can be maintained well even if the line speed in the third process is within the above range (i.e., high speed).

[0041] Next, a sealant layer 27 is formed on the base layer 25 and covering the variable information printing layer 26 (fourth step). In the fourth step, for example, the sealant layer 27 formed by the extrusion lamination method is extruded onto the base layer 25 and the sealant layer 27 is attached to the base layer 25. Similar to the first step, a roll-to-roll method may be used in the fourth step. In one example, the base layer 21 to which the variable information printing layer 26 is attached is unwound from the roll, and the base layer 21 to which the sealant layer 27 is attached is wound onto the roll.

[0042] Next, the base layer 21 with the sealant layer 27 attached is molded (5th step). For example, the sealant layer 27 is attached to the base layer 25 so as to cover the variable information printing layer 26. After the 5th step, a lid material 10 having a main body 11 and a handle 12 as shown in Figure 1 is manufactured by, for example, die-cutting.

[0043] In the manufacturing method of the lid material 10 according to the embodiment described above, in the third step, after the variable information printing layer 26 is inkjet printed on the base layer 25, the base layer 21 on which the variable information printing layer 26 is formed is wound onto the roll 102. At this time, the variable information printing layer 26 comes into contact with the coating layer 23 located on the surface 21a of the base layer 21. As a result, contact between the variable information printing layer 26 and the base layer 21 is prevented by the coating layer 23, so that a part of the base layer 21 peels off and does not easily adhere to the variable information printing layer 26. Here, the coating layer 23 contains a second medium different from the first medium, as well as a matting agent dispersed in the second medium. Therefore, adhesion between the variable information printing layer 26 and the coating layer 23 is also well suppressed. Thus, even if the roll feed speed and winding speed are 150 m / min or more, for example, adhesion between the variable information printing layer 26 and the coating layer 23 can be well suppressed. Therefore, the lid material 10 manufactured by the above manufacturing method makes it possible to improve mass production while suppressing damage to the variable information contained in the variable information printing layer 26.

[0044] In this embodiment, the surface 21a of the base layer 21 is provided with a printing layer 22 that is covered by a coating layer 23, and the content of the matting agent in the coating layer 23 may be 0.5% by mass or more and 5% by mass or less. In this case, adhesion between the variable information printing layer 26 and the coating layer 23 is suppressed more effectively. Alternatively, the content of the matting agent in the coating layer 23 may be 0.5% by mass or more and 2% by mass or less. In this case, adhesion between the variable information printing layer 26 and the coating layer 23 is suppressed effectively, while the matting of the printing layer 22 is suppressed.

[0045] In this embodiment, the matting agent may be inorganic particles. In this case, adhesion between the variable information printing layer 26 and the coating layer 23 is more effectively suppressed.

[0046] In this embodiment, the first medium may contain an acrylic resin, and the second medium may contain nitrocellulose. In this case, the adhesion between the coating layer 23 and the variable information printing layer 26 is reduced, while the base layer 25 and the variable information printing layer 26 adhere well. Therefore, it is possible to effectively suppress the peeling of the variable information printing layer 26 and its adhesion to the coating layer 23, and the peeling of a portion of the coating layer 23 and a portion of the base layer 21 and its adhesion to the variable information printing layer 26.

[0047] In this embodiment, the lid material 10 may be a lid material for a food container. In this case, it is possible to provide a lid material 10 that can prevent adverse effects on the food contained in the container 2, improve mass production efficiency, and suppress damage to the variable information contained in the variable information printing layer 26.

[0048] A lid material and a method for manufacturing the lid material relating to one aspect of this disclosure are described, for example, in [1] to [9] below, and these have been described in detail based on the above embodiments. [1] A lid material for sealing the opening of a container, A paper-based substrate layer, A coating layer located on the surface of the substrate layer, An aluminum layer located on the back surface of the aforementioned base material layer, A base layer located on the aforementioned aluminum layer and containing a first medium, A variable information printing layer that is inkjet printed on the aforementioned base layer, Equipped with, The coating layer comprises a second medium different from the first medium and a matting agent dispersed in the second medium. Lid material. [2] The surface of the substrate layer is provided with a printed layer which is covered by the coating layer, The lid material according to [1], wherein the content of the matting agent in the coating layer is 0.5% by mass or more and 5% by mass or less. [3] The lid material according to [2], wherein the content of the matting agent in the coating layer is 0.5% by mass or more and 2% by mass or less. [4] The matting agent is inorganic particles, the lid material according to any one of [1] to [3]. [5] The first medium comprises an acrylic resin, The second medium is a lid material according to any one of [1] to [4], comprising nitrocellulose. [6] A lid material according to any one of [1] to [5], further comprising a sealant layer located in the base layer and welded to the container. [7] A lid material for food containers, as described in any of [1] to [6]. [8] A method for manufacturing a lid material for sealing the opening of a container, The first step involves attaching an aluminum layer to the back of a paper-based substrate layer, A second step involves sequentially forming a printed layer and a coating layer on the surface of the substrate layer, and forming a base layer containing a first medium on the aluminum layer. After the second step, a third step is performed in which a variable information printing layer is inkjet printed onto the base layer, Equipped with, In the second step, a mixture comprising a second medium different from the first medium and a matting agent dispersed in the second medium is applied onto the surface of the substrate layer so as to cover the printing layer, thereby forming the coating layer. In the third step, the substrate layer on which the variable information printing layer is formed is wound up. A method for manufacturing lid material. [9] The method for producing a lid according to [8], wherein the content of the matting agent in the mixture is 0.5% by mass or more and 5% by mass or less.

[0049] However, one aspect of the present invention is not limited to the above embodiments and [1] to [9] above. One aspect of the present invention can be further modified without departing from its spirit.

[0050] In the above embodiment, the first and second steps are performed in order, but are not limited to this. For example, a part of the second step may be performed before the first step. Also, in the second step, the base layer is formed after the printed layer and the coated layer are formed in order, but are not limited to this. For example, in the second step, the printed layer and the coated layer may be formed after the base layer is formed. In the second step, the printed layer, coated layer and base layer are formed by the same printing apparatus, but are not limited to this.

[0051] In the above embodiment, an aluminum layer is attached to the substrate layer from the viewpoint of gas barrier properties, but this is not limited to this. For example, a metal layer such as a chromium layer may be attached instead of the aluminum layer. [Examples]

[0052] The present disclosure will be further illustrated by the following embodiments, but the present disclosure is not limited to these examples.

[0053] (Example 1) As the paper-based base layer, art paper (manufactured by Nippon Paper Industries Ltd., "G Montblanc Fragment Art," basis weight: 79.1 g / m²) is used. 2 We prepared the following: We also prepared a 6μm thick aluminum foil as the aluminum layer.

[0054] First, a roll-to-roll method was used to bond the back surface of the base material layer to the aluminum layer using a commercially available polyethylene-based adhesive.

[0055] Next, a roll-to-roll method was used to sequentially form a printed layer and a coating layer on the surface of a substrate layer to which an aluminum layer had been attached. Then, a medium (Hydric PEP (FK2)) manufactured by Dainichi Seika Kogyo Co., Ltd. was selectively applied to the aluminum layer attached to the substrate layer. As a result, characters, patterns, figures, symbols, etc., protected by the coating layer were formed on the surface of the substrate layer. The printed layer was formed using colored ink (Gratone GWA) manufactured by Sakata Inx Co., Ltd. The coating layer was formed by diluting a mixture of medium (UPPS-ME-S medium, manufactured by Toyo Ink Co., Ltd.) and a matting agent (Matting Agent 500, manufactured by Toyo Ink Co., Ltd.) with an organic solvent consisting mainly of ethyl acetate and alcohol, and then applying and drying the coating solution to the substrate layer. The matting agent content in the above mixture was 1% by mass. In addition, a base layer was formed on the aluminum layer.

[0056] Next, a roll-to-roll method was used to inkjet print a variable information printing layer, including a predetermined two-dimensional code, onto the underlayer on the aluminum layer attached to the substrate layer. In Example 1, a printing machine (CTC Japan Co., Ltd., "SJ 750W-18H") and inkjet ink (Toyo Color Co., Ltd., "KY 060 BLACK") were used to inkjet print the variable information printing layer at a resolution of 600 dpi and a line speed of 150 m / min. The substrate layer on which the variable information printing layer was formed was then wound onto a roller.

[0057] Based on the above, a laminate comprising a coating layer, a printed layer, a paper substrate layer, an aluminum layer, a base layer, and a variable information printing layer was manufactured, and the laminate was wound onto a roll (1000m roll). Subsequently, a sealant layer was applied to the base layer of the laminate so as to cover the variable information printing layer. The sealant layer is a co-extruded film of EMMA resin film (thickness: 25μm) and olefin resin film (thickness: 15μm).

[0058] Multiple lid materials with handles were manufactured by sending out the laminated material and performing processes such as punching.

[0059] (Example 2) As the paper-based base layer, art paper (manufactured by Nippon Paper Industries Ltd., "G Montblanc Fragment Art," basis weight: 79.1 g / m²) is used. 2 A laminated material wound onto a roll (1000m roll) was manufactured in the same manner as in Example 1, except that the material used was the same. In addition, multiple lid materials were manufactured in the same manner as in Example 1.

[0060] (Example 3) A laminated material wound onto a roll (1000m roll) was manufactured in the same manner as in Example 1, except that the content of the matting agent in the mixture for forming the coating layer was set to 0.5% by mass. In addition, multiple lid materials were manufactured in the same manner as in Example 1.

[0061] (Comparative Example 1) A laminated material (1000m roll) wound onto a roll was manufactured in the same manner as in Example 1, except that the coating layer was formed using only medium (UPPS-ME-S medium, manufactured by Toyo Ink Co., Ltd.). In addition, multiple lid materials were manufactured in the same manner as in Example 1.

[0062] (Comparative Example 2) A laminated material (1000m roll) wound onto a roll was manufactured in the same manner as in Example 2, except that the coating layer was formed using only medium (UPPS-ME-S medium, manufactured by Toyo Ink Co., Ltd.). In addition, multiple lid materials were manufactured in the same manner as in Example 1.

[0063] (Comparative Example 3) A laminate (1000m roll) wound onto a roll was manufactured in the same manner as in Example 1, except that the coating layer was formed using a mixture of medium (UPPS-ME-S medium, manufactured by Toyo Ink Co., Ltd.) and a slip agent (ML slip agent, manufactured by Toyo Ink Co., Ltd.). In Comparative Example 3, the slip agent content in the mixture was 1% by mass. Multiple lid materials were also manufactured in the same manner as in Example 1.

[0064] (Comparative Example 4) A laminate (1000m roll) wound onto a roll was manufactured in the same manner as in Example 2, except that the coating layer was formed using a mixture of medium (UPPS-ME-S medium, manufactured by Toyo Ink Co., Ltd.) and a slip agent (ML slip agent, manufactured by Toyo Ink Co., Ltd.). In Comparative Example 4, the slip agent content in the mixture was 1% by mass. In addition, multiple lid materials were manufactured in the same manner as in Example 1.

[0065] (Comparative Example 5) A laminated material wound onto a roll (1000m roll) was manufactured in the same manner as in Example 1, except that the coating layer was formed using a release varnish (Sakata Inx Co., Ltd., "XGS-1815"). In addition, multiple lid materials were manufactured in the same manner as in Example 1.

[0066] (Comparative Example 6) A laminate (1000m roll) wound onto a roll was manufactured in the same manner as in Example 1, except that the coating layer was formed using a mixture of medium (Toyo Ink Co., Ltd., "Full Shade U-311") and an additive (Toyo Ink Co., Ltd., "UR300B"). In Comparative Example 5, the additive content in the mixture was 12% by mass. Furthermore, when attempting to manufacture multiple lids in the same manner as in Example 1, defects occurred during the die-cutting process, making mass production of the lids impossible.

[0067] <Quality check of the variable information printing layer> The laminates (1000m rolls) produced in each of Examples 1-3 and Comparative Examples 1-5 were left to stand at 40°C for 7 days. After that, the laminates were removed from the rolls and the quality of the variable information printing layer was visually inspected. In each of Examples 1-3, no adhesion of the substrate layer to the variable information printing layer, nor peeling of the variable information printing layer to the coating layer was observed. On the other hand, in each of Comparative Examples 1-5, adhesion of the substrate layer to the variable information printing layer was observed. As a result, in each of Comparative Examples 1-5, the two-dimensional code printed on the variable information printing layer could not be read accurately. [Explanation of symbols]

[0068] 1...Contents, 2...Container, 2a...Opening, 2b...Opening end, 10...Lid material, 10a...Outer surface, 10b...Inner surface, 11...Main body, 12...Tap, 21...Base material layer, 21a...Front surface, 21b...Back surface, 22...Printed layer, 23...Coating layer, 23a...Outer surface, 24...Aluminum layer, 25...Underlay layer, 26...Variable information printing layer, 27...Sealant layer, 100...Container with lid, 101...Roll, 102...Roll, 110...Inkjet printer, 111...Ink.

Claims

1. A lid material for sealing the opening of a container, A paper-based substrate layer, A coating layer located on the surface of the substrate layer, An aluminum layer located on the back surface of the aforementioned base material layer, A base layer located on the aforementioned aluminum layer and containing a first medium, A variable information printing layer that is inkjet printed on the aforementioned base layer, Equipped with, The coating layer comprises a second medium different from the first medium and a matting agent dispersed in the second medium. Lid material.

2. A printed layer is provided on the surface of the substrate layer, which is covered by the coating layer. The lid material according to claim 1, wherein the content of the matting agent contained in the coating layer is 0.5% by mass or more and 5% by mass or less.

3. The lid material according to claim 2, wherein the content of the matting agent in the coating layer is 0.5% by mass or more and 2% by mass or less.

4. The lid material according to any one of claims 1 to 3, wherein the matting agent is inorganic particles.

5. The first medium contains an acrylic resin, The lid material according to any one of claims 1 to 3, wherein the second medium comprises nitrocellulose.

6. The lid material according to any one of claims 1 to 3, further comprising a sealant layer located in the aforementioned base layer and welded to the container.

7. A lid material for a food container, as described in any one of claims 1 to 3.

8. A method for manufacturing a lid material that seals the opening of a container, The first step involves attaching an aluminum layer to the back of a paper-based substrate layer, A second step involves sequentially forming a printed layer and a coating layer on the surface of the substrate layer, and forming a base layer containing a first medium on the aluminum layer. After the second step, a third step is performed in which a variable information printing layer is inkjet printed onto the base layer, Equipped with, In the second step, a mixture containing a second medium different from the first medium and a matting agent dispersed in the second medium is applied to the surface of the substrate layer so as to cover the printing layer, thereby forming the coating layer. In the third step, the substrate layer on which the variable information printing layer is formed is wound up. A method for manufacturing lid material.

9. The method for producing a lid material according to claim 8, wherein the content of the matting agent in the mixture is 0.5% by mass or more and 5% by mass or less.

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