Aluminum foil information display, packaging container, and manufacturing methods therefor

Abstract

This aluminum foil information display (10) comprises: an aluminum foil (1) having an uneven surface (1C) in which dimple-shaped irregularities are formed; and patterns (2) formed on the uneven surface so as to expose a portion of the uneven surface. The portion of the uneven surface and the patterns constitute an information display unit (3). The area ratio of second phase particles present in a predetermined region on the uneven surface is at most 0.10%. The arithmetic mean curvature Spc (1 / mm) of dimple-shaped protrusions is 3,700-10,000. The vertex density (1 / mm2) of dimple-shaped recesses is 1,600,000-4,500,000.

Description

Aluminum foil information display body, packaging container, and manufacturing method thereof

[0001] The present invention relates to an aluminum foil information display body, a packaging container, and a method for manufacturing the same.

[0002] Aluminum foil is used as a lid material for packages that require barrier properties against the contents, such as a press-through pack (PTP) for storing medicines and the like, and a container for storing food or beverages.

[0003] Generally, a base layer called a white solid printing layer containing titanium oxide pigment or the like is formed on the surface of the aluminum foil used in such packaging materials, and a printed layer containing information about the contents (for example, the product name of the drug, the name of the manufacturer, and the capacity, etc.) is formed on the surface of the base layer (see, for example, JP 2018-002922 A (Patent Document 1)). The reason for using the base layer is to solve the problem that when the printed layer is formed directly on the surface of the aluminum foil, the printed layer cannot be accurately read due to the metallic luster of the surface of the aluminum foil.

[0004] Japanese Patent Application Laid-Open No. 2018-002922

[0005] The main object of the present invention is to provide an aluminum foil information display body, a packaging container, and a manufacturing method thereof, in which an information display section for displaying information such as a printed layer is readable without relying on a base layer such as a solid white printed layer.

[0006] The aluminum foil information display according to the present invention comprises an aluminum foil having an uneven surface on which dimple-shaped irregularities are formed, and a pattern formed on the uneven surface so as to expose a portion of the uneven surface. The portion of the uneven surface and the pattern constitute an information display section. The area ratio of second phase particles present in a predetermined region of the uneven surface is 0.10% or less. The arithmetic mean curvature Spc (1 / mm) of the dimple-shaped protrusions is 3700 or more and 10000 or less. The vertex density (1 / mm) of the dimple-shaped recesses is 0.10% or less. 2 ) is equal to or greater than 1,600,000 and equal to or less than 4,500,000.

[0007] In the aluminum foil information display, the total reflectance of the uneven surface of the aluminum foil for electromagnetic waves in the wavelength range of 250 nm to 2000 nm is preferably 70% to 90%. It is preferable that the total reflectance of the information display portion for electromagnetic waves in at least a part of the wavelength range of 250 nm to 2000 nm is 20% or more lower than the total reflectance of the uneven surface.

[0008] In the above aluminum foil information display body, the minimum reflectance of the information display portion measured in accordance with ISO standard 15416 (2016) is 3% or more and 33% or less, and the symbol contrast of the information display portion measured in accordance with ISO standard 15416 (2016) is 58% or more and 83% or less.

[0009] In the above-mentioned aluminum foil information display, the surface of the pattern is colored, and the material constituting the surface of the pattern preferably includes at least one selected from the group consisting of black pigment, brown pigment, green pigment, and blue pigment.

[0010] In the above aluminum foil information display body, the information display portion may be a one-dimensional barcode, a two-dimensional barcode, a matrix code, or a composite code.

[0011] In the above-mentioned aluminum foil information display, the aluminum foil may have a back surface located on the opposite side to the textured surface, and may further include a heat seal layer formed on the back surface.

[0012] In the aluminum foil information display, the aluminum foil preferably contains aluminum, 0.04% by mass or more and 0.11% by mass or less of iron, and 0.50% by mass or more and 1.20% by mass or less of manganese.

[0013] In the aluminum foil information display, the thickness of the aluminum foil is preferably 4 μm or more and 300 μm or less.

[0014] In the aluminum foil information display, the arithmetic mean roughness (Ra) of the uneven surface is preferably greater than 20 nm.

[0015] The method for manufacturing an aluminum foil information display according to the present invention includes the steps of: preparing an aluminum foil containing aluminum, 0.04% by mass or more and 0.11% by mass or less of iron, and 0.50% by mass or more and 1.20% by mass or less of manganese; exposing at least a portion of the surface of the aluminum foil to an alkaline aqueous solution to form at least a portion of the surface into a textured surface having dimple-shaped textures; and forming a pattern on the textured surface that exposes a portion of the textured surface, thereby forming an information display section composed of the portion of the textured surface and the pattern.

[0016] According to the present invention, it is possible to provide an aluminum foil information display body, a packaging container, and a manufacturing method thereof, in which the information display portion is readable without relying on a base layer such as a white solid print layer.

[0017] 6 is a schematic cross-sectional view showing an aluminum foil information display body according to the present embodiment. FIG. 7 is a diagram showing an example of an information display part of the aluminum foil information display body according to the present embodiment. FIG. 8 is a partially enlarged cross-sectional view illustrating dimple-shaped irregularities formed on at least a part of the surface of the aluminum foil of the aluminum foil information display body according to the present embodiment. FIG. 9 is a partially enlarged plan view illustrating dimple-shaped irregularities formed on at least a part of the surface of the aluminum foil of the aluminum foil information display body according to the present embodiment. FIG. 10 is a flowchart showing an example of a method for manufacturing the aluminum foil information display body shown in FIG. 1. FIG. 11 is a schematic cross-sectional view showing a modified example of the aluminum foil information display body according to the present embodiment. FIG. 12 is a flowchart showing an example of a method for manufacturing the aluminum foil information display body shown in FIG. 6. FIG. 13 is a diagram showing an example of a packaging container according to the present embodiment. FIG. 14 is a cross-sectional view taken along arrows IX-IX in FIG. 8. FIG. 15 is a schematic plan view illustrating a pattern formed on a heat seal layer in the packaging container shown in FIGS. 8 and 9. FIG. 16 is a diagram showing another example of a packaging container according to the present embodiment. FIG. 17 is a flowchart showing an example of a method for manufacturing the packaging container shown in FIGS. 8 and 9.

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0019] In this specification, the term "aluminum foil" is used to mean not only pure aluminum foil but also aluminum alloy foil.

[0020] <Configuration of Aluminum Foil Information Display> As shown in FIG. 1 , an aluminum foil information display 10 according to this embodiment includes an aluminum foil 1 and a pattern 2 .

[0021] The aluminum foil 1 has a first surface 1A and a second surface 1B as outward facing surfaces. The second surface 1B faces in the opposite direction to the first surface 1A. At least a portion of the first surface 1A is an uneven surface 1C on which dimple-shaped irregularities are formed. For example, the entire first surface 1A may be an uneven surface 1C. The second surface 1B may or may not have an uneven surface 1C. Details of the uneven surface 1C will be described later. In addition, in this specification, a plan view means a viewpoint seen from a direction perpendicular to the first surface 1A of the aluminum foil 1.

[0022] As shown in Figures 1 and 2, the pattern 2 is formed on the uneven surface 1C so as to expose a portion of the uneven surface 1C. The pattern 2 is formed on the uneven surface 1C without a white solid print layer. The pattern 2 has a lower surface in contact with another portion of the uneven surface 1C, an upper surface located opposite the lower surface, and a side surface extending between the lower surface and the upper surface. The portion of the uneven surface 1C and the pattern 2 constitute the information display unit 3. In other words, the aluminum foil information display body 10 has an information display unit 3 constituted by the portion of the uneven surface 1C and the pattern 2.

[0023] In this specification, the term "information display unit" refers to a portion that displays any information in an optically readable manner. The information display unit 3 is, for example, a portion that can generate a reflected wave that reflects the pattern 2 of the information display unit 3 in a manner that can be read by a reading device or the like when irradiated with electromagnetic waves having at least a part of the wavelength range of 250 nm to 2000 nm. The information display unit 3 is, for example, a portion that can generate a reflected light that reflects the pattern 2 of the information display unit 3 in a manner that can be recognized by an observer or read by a reading device or the like when irradiated with visible light.

[0024] The information display unit 3 includes, for example, an information code in which arbitrary information is encoded and is optically readable. The information display unit 3 includes, for example, at least one selected from the group consisting of a one-dimensional barcode, a two-dimensional barcode, a matrix code, and a composite code. For example, the information display unit 3 may include at least one selected from the group consisting of JAN / EAN / UPC, Interleaved 2 of 5 (ITF), Code 39, NW-7 (Codabar), Code 128, QR Code (registered trademark), PDF417, Data Matrix, Maxi Code, Aztec Code, and EAN / UCC Composite. The information display unit 3 may be composed only of an information code, or may further include at least any characters and / or graphics in addition to the information code. The information display unit 3 may not include an information code and may be composed only of at least any characters and / or graphics. The information display unit 3 may include a design consisting of at least one of characters and graphics, or may consist solely of such a design. Note that Figure 2 shows an example of the information display unit 3 configured as a GS1 data bar.

[0025] The aluminum foil information display is any component having an information display portion. The aluminum foil information display may be, for example, a packaging material that constitutes at least a part of a packaging container for medicines, food, beverages, office supplies, machine parts, daily necessities, kitchenware, etc. More specifically, the aluminum foil information display may be a PTP lid material, a medicine sachet, a lid material for a packaging container for dairy products such as pudding or yogurt, etc. When the aluminum foil information display is a packaging material, the information display portion includes, for example, information about the contents contained in the packaging material. The aluminum foil information display may be, for example, an information display member that constitutes at least a part of a label, a seal, a tray, a price tag, a tag, a card, etc.

[0026] (1) Structure of the Concave-Convex Surface As shown in FIGS. 3 and 4, the concave-convex surface 1C formed on the first surface 1A of the aluminum foil 1 is composed of a plurality of dimples formed so as to fill at least a portion of the first surface 1A without gaps. In this specification, the bottom surface portion including the bottom point (deepest part) of each of the plurality of dimples is referred to as a dimple-shaped concave portion. In this specification, the boundary portion between two adjacent dimples among the plurality of dimples is referred to as a dimple-shaped convex portion. The solid line within the frame in FIG. 3 illustrates the ridge line of the dimple-shaped convex portion (the boundary portion between two adjacent dimples among the plurality of dimples). The dimple-shaped concave portion is a portion located on the bottom point side of a reference plane that can be set when observing the above-mentioned concave-convex portions on the surface of the aluminum foil 1 using a laser microscope by the method described below. The dimple-shaped convex portion is a portion that protrudes on the opposite side of the bottom point from the reference plane.

[0027] As shown in FIGS. 3 and 4, the shape and size of each of the plurality of dimples and the connection relationship between adjacent dimples are not uniform but rather vary widely.

[0028] (A) Arithmetic mean curvature Spc of the dimple-shaped convex portion On the uneven surface 1C of the aluminum foil 1, the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portion is 3700 or more and 10000 or less. Preferably, the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portion is 3750 or more and 9900 or less.

[0029] The arithmetic mean curvature Spc of the dimple-shaped convex portion is the arithmetic mean curvature Spc of the peak of the convex portion measured from a three-dimensional shape observed using a confocal laser microscope by a measurement method in accordance with the International Organization for Standardization standard ISO 25178. The arithmetic mean curvature Spc of the dimple-shaped convex portion can be measured, for example, by obtaining three-dimensional shape data of the first surface 1A of the aluminum foil 1 in a rectangular field of view of 95.257 μm × 71.419 μm using a laser microscope VK-X3000 manufactured by Keyence Corporation, and using the data to perform multi-file analysis.

[0030] The inventors have confirmed that when the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions of the uneven surface 1C of the aluminum foil 1 is 3700 or more and 10,000 or less, the total reflectance measured using an integrating sphere in the wavelength range of 250 nm to 2000 nm is 70% or more, while the regular reflectance is suppressed to less than 4%, that is, the uneven surface 1C has a reduced metallic luster and exhibits a white appearance. The inventors have discovered that the aluminum foil 1 according to this embodiment does not require a white underlayer or anodized film, and that the uneven surface 1C alone converts most of the reflected light into a diffuse reflection component, and the intensity of the diffuse reflection component can be uniformed regardless of the reflection angle. The inventors have discovered that the uneven surface 1C of the aluminum foil 1 appears white when visible light is incident on it. Furthermore, the inventors have discovered that the degree of whiteness of the uneven surface 1C of the aluminum foil 1 is high enough to avoid the problems that arise with aluminum foil that is not whitened (no uneven surface 1C is formed, or no base layer or anodized film is formed), such as difficulty in accurately expressing colors or accurately reading information codes.

[0031] The inventors have confirmed that the L* value of the uneven surface 1C is 140 or more at 15° reflection, 70 or more at 45° reflection, and 30 or more at 110° reflection, and that even when packaging material patterns, information codes, etc. are printed directly on the uneven surface 1C of the aluminum foil 1, the occurrence of the above-mentioned problems regarding accurate color expression and accurate reading of information codes can be suppressed.

[0032] The L* value of the textured surface 1C of the aluminum foil 1 is measured using a color difference meter according to ASTM D2244, E308, E1164, and E2194. Specifically, the lightness L* values ​​of reflected light shifted 15°, 45°, and 110° toward the incident light are measured using a color difference meter with respect to specularly reflected light of visible light incident on the first surface 1A including the textured surface 1C at an incident angle of 45°.

[0033] The present inventors have discovered that when the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions on the uneven surface 1C of the aluminum foil 1 is 3700 or more and 10000 or less, the L * value, which is an index of the degree of whiteness in visible light, has a 15 ° reflection value of 140 or more, a 45 ° reflection value of 70 or more, and a 110 ° reflection value of 30 or more.

[0034] Furthermore, it was confirmed that when the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions on the uneven surface 1C of the aluminum foil 1 is smaller than 3700 or larger than 10000, the L* value of each angle is low.

[0035] If the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions is less than 3700, the angular range over which visible light incident on the convex-convex surface 1C is diffusely reflected is narrowed, and therefore the intensity of the specular reflection component is not sufficiently reduced, and the intensity of the diffuse reflection component is not sufficiently increased. The contrast difference between such a convex-convex surface 1C and the pattern formed thereon is smaller than the contrast difference between a convex-convex surface 1C having an arithmetic mean curvature Spc (unit: 1 / mm) of the convex portions of 3700 or more and 10,000 or less and the pattern 2 formed thereon. As a result, it is difficult to accurately read the information display unit 3 formed by the convex-convex surface 1C having an arithmetic mean curvature Spc (unit: 1 / mm) of the convex portions of less than 3700 and the pattern 2 formed thereon.

[0036] In particular, in a typical information code reading device such as a barcode reader, a light source that irradiates light toward an information code and a light receiving unit that receives reflected light from the information code are arranged adjacent to each other and configured as an integrated unit. It is difficult for the light receiving unit of a typical information code reading device to capture the specular reflection component. To accurately read an information code using a typical information code reading device, it is important to generate reflected light in which the intensity of the specular reflection component is reduced and the intensity of the diffuse reflection component is high. When the arithmetic mean curvature Spc (unit: 1 / mm) of the convex portion is less than 3700, as described above, the intensity of the specular reflection component is not sufficiently reduced and the intensity of the diffuse reflection component is not sufficiently increased, making it difficult to accurately read the information code using a typical information code reading device.

[0037] When the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions of the uneven surface 1C of the aluminum foil 1 is greater than 10,000, the angular range of diffuse reflection of visible light incident on the uneven surface 1C is too wide, and some of the visible light diffusely reflected on the wall surfaces of the timple-shaped convex portions or concave portions is diffusely reflected again on the opposing wall surfaces, increasing the amount of visible light reflected multiple times within the uneven surface 1C and reducing the amount of visible light emitted to the outside, which is thought to be the reason for the decrease in L* value. When the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions is greater than 10,000, the contrast difference between the uneven surface 1C and the pattern formed on the uneven surface 1C is smaller than the contrast difference between the uneven surface 1C and the pattern formed on the uneven surface 1C when the arithmetic mean curvature Spc (unit: 1 / mm) of the convex portions is 3,700 or more and 10,000 or less. As a result, it is difficult to accurately read the information display section 3, which is composed of an uneven surface 1C having an arithmetic mean curvature Spc (unit: 1 / mm) of the convex portion greater than 10,000 and a pattern 2 formed on the uneven surface 1C.

[0038] (B) Density of vertices of the dimple-shaped recesses In the aluminum foil 1, the density of vertices of the dimple-shaped recesses (unit: 1 / mm 2 The apex density of the dimple-shaped recesses (unit: 1 / mm 2) is greater than 1,510,000 and less than 4,650,000. Preferably, the apex density (unit: 1 / mm 2 ) is 1,610,000 or more and 4,000,000 or less. More preferably, the apex density (unit: 1 / mm 2 ) is greater than or equal to 1,620,000 and less than or equal to 3,500,000.

[0039] The apex density of the dimple-shaped recesses is the density of the valley bottom points of each of the plurality of dimples measured from a three-dimensional shape observed using a confocal laser microscope using a measurement method in accordance with the International Organization for Standardization standard ISO 25178. The apex density of the dimple-shaped recesses is, for example, obtained by using a laser microscope VK-X3000 manufactured by Keyence Corporation in a rectangular field of view of 95.257 μm × 71.419 μm to obtain three-dimensional shape data of the first surface 1A of the aluminum foil 1, inverting the data in the height direction with respect to the reference plane, and determining the peak density Spd (unit: 1 / mm ) specified in the International Organization for Standardization standard ISO 25178 from the inverted data using a multi-file analysis application attached to the microscope. 2 ) The reference surface of the three-dimensional shape data is set as a surface that represents the average of the concave and convex portions of the three-dimensional shape data. As described above, the concave portions of the dimple shape are the portions located closer to the valley bottom than the reference surface. In the above measurement method, the valley bottom of each dimple can be measured as the peak by inverting the three-dimensional shape data in the height direction relative to the reference surface.

[0040] The inventors have determined that the apex density (unit: 1 / mm) of the dimple-shaped recesses in the aluminum foil 1 is 2 It has been confirmed that when the L* value, which is an index of the degree of whiteness in visible light, is 1,600,000 or more and 4,500,000 or less, the 15° reflection value is 140 or more, the 45° reflection value is 70 or more, and the 110° reflection value is 30 or more.

[0041] The inventors have determined that the apex density (unit: 1 / mm) of the dimple-shaped recesses in the aluminum foil 1 is 2It was confirmed that when the apex density (unit: 1 / mm) of the dimple-shaped recesses is less than 1,510,000, the 15° reflection value of the L* value is less than 140, the 45° reflection value is less than 70, and the 110° reflection value is less than 30. 2 It is believed that if the apex density (unit: 1 / mm) of the dimple-shaped recesses is smaller than 1,510,000, the number of dimples is small, resulting in a small diffuse reflection component, or the planar dimensions of each dimple are large, resulting in a narrow angular range over which visible light is diffusely reflected. 2 ) is smaller than 1,510,000, the apex density (unit: 1 / mm 2 ) is 1,600,000 or more and 4,500,000 or less, the contrast difference between the uneven surface 1C and the pattern 2 formed on the uneven surface 1C becomes smaller, and it becomes difficult to accurately read the information display section 3 formed by the uneven surface 1C and the pattern 2 formed on the uneven surface 1C.

[0042] The inventors have determined that the apex density (unit: 1 / mm) of the dimple-shaped recesses in the aluminum foil 1 is 2 It was confirmed that when the L* value at angles of 15° and 45° is larger than 4,650,000, the L* value at angles of 15° and 45° is low. The inventors have found that the reason for this is that the apex density (unit: 1 / mm) of the dimple-shaped recesses is 2 It is believed that if the apex density (unit: 1 / mm) of the dimple-shaped recesses is greater than 4,650,000, the planar dimensions of each dimple will be too small, and some of the visible light diffusely reflected by the wall surfaces of the dimple-shaped protrusions or recesses will be diffusely reflected again by the opposing wall surfaces, increasing the amount of visible light that is reflected multiple times within the first surface 1A and reducing the amount of visible light that is emitted to the outside. 2 ) is greater than 4,650,000, the apex density (unit: 1 / mm 2 ) is 1,600,000 or more and 4,500,000 or less, the contrast difference between the uneven surface 1C and the pattern 2 formed on the uneven surface 1C becomes smaller, and it becomes difficult to accurately read the information display section 3 formed by the uneven surface 1C and the pattern 2 formed on the uneven surface 1C.

[0043] (C) Area Ratio of Second-Phase Particles Present on the Rough Surface In the aluminum foil 1, the area ratio of second-phase particles present within a predetermined region of the rough surface 1C is 0.10% or less. The second-phase particles refer to various intermetallic compounds, such as Al-Fe, Al-Fe-Mn, Al-Mg-Si, Al-Mn, Al-Fe-Si, and Al-Mn-Fe-Si, or alloying elements precipitated in the aluminum matrix. The second-phase particles present on the rough surface 1C originate from second-phase particles present in the aluminum foil before the rough surface 1C is formed, and are those that remain without being removed when the aluminum foil is subjected to the method for forming the rough surface 1C described below. In this specification, the predetermined region of the rough surface 1C of the aluminum foil 1 refers to a field in which second-phase particles can be observed visually or by microscope. The predetermined region of the rough surface 1C is, for example, 1188.49 μm 2 The field of view is a rectangular field of view (39.59 μm×30.02 μm). A plurality of dimples are formed without gaps in a predetermined region of the textured surface 1C of the aluminum foil 1.

[0044] The area ratio of the second phase particles was 1188.49 μm as imaged by a scanning electron microscope. 2 The area ratio of second phase particles can be measured by binarizing a backscattered electron image of a rectangular field of view (39.59 μm × 30.02 μm) of 1188.49 μm², and dividing the total area of ​​extracted second phase particles by the area of ​​the field. The area ratio of second phase particles can be measured, for example, by binarizing a backscattered electron image of a rectangular field of view (39.59 μm × 30.02 μm) of 1188.49 μm² taken with a JSM-7200F manufactured by JEOL Ltd. using image processing software WinRoof 2021 manufactured by Mitani Corporation, and dividing the total area of ​​extracted second phase particles by the area of ​​the field.

[0045] The reflectance of visible light incident on the surface of the second-phase particles present on the uneven surface 1C of the aluminum foil 1 is lower than the reflectance of electromagnetic waves incident on the uneven surface 1C itself of the aluminum foil 1. The inventors have confirmed that when the area fraction of the second-phase particles present in a predetermined region of the uneven surface 1C of the aluminum foil 1 is 0.10% or less, the L* value, which is an index of the degree of whiteness in visible light, has a 15° reflection value of 140 or more, a 45° reflection value of 70 or more, and a 110° reflection value of 30 or more. Furthermore, the inventors have confirmed that even when the area fraction of the second-phase particles present in a predetermined region of the uneven surface 1C of the aluminum foil 1 is 0.02% or more, the L* value, which is an index of the degree of whiteness in visible light, has a 15° reflection value of 140 or more, a 45° reflection value of 70 or more, and a 110° reflection value of 30 or more.

[0046] On the other hand, the present inventors have confirmed that when the area ratio of the second phase particles present in a predetermined region of the uneven surface 1C of the aluminum foil 1 is 1.97% or more, the L* value, which is an index of the degree of whiteness in visible light, decreases to a 45° reflection value of less than 70 and a 110° reflection value of less than 30.

[0047] The uneven surface 1C of the aluminum foil 1 as described above has high whiteness by itself. Since the information display unit 3 composed of the uneven surface 1C and the pattern 2 formed thereon can be read, the aluminum foil 1 is suitable as a substrate for the aluminum foil information display body 10.

[0048] (D) Total reflectance of the uneven surface In the aluminum foil information display 10, the total reflectance of the uneven surface 1C for electromagnetic waves in the wavelength range of 250 nm to 2000 nm is preferably 70% to 90%. The total reflectance of the uneven surface 1C can be measured, for example, using a UV-visible spectrophotometer V570 manufactured by JASCO Corporation, and using a Labsphere integrating sphere standard white plate as a reference, in the wavelength range of 250 nm to 2000 nm.

[0049] (E) Arithmetic mean roughness Ra of the uneven surface The arithmetic mean roughness Ra of the uneven surface 1C of the aluminum foil 1 is preferably greater than 20 nm. The arithmetic mean roughness Ra of the uneven surface 1C is measured by a measurement method in accordance with ISO 4287 (1997 edition). The arithmetic mean roughness Ra of the uneven surface 1C may be greater than 100 nm. The arithmetic mean roughness Ra of the uneven surface 1C may be less than 660 nm.

[0050] (2) Method for forming the uneven surface 1C The uneven surface 1C of the aluminum foil 1 can be formed by subjecting the surface of an aluminum foil prepared by any method to the following treatment. For example, the uneven surface 1C can be formed by exposing (immersing or contacting) the surface of the aluminum foil to an alkaline aqueous solution. The alkaline aqueous solution is not particularly limited, but is preferably a sodium hydroxide aqueous solution. In this case, the time for immersing the aluminum foil in the sodium hydroxide aqueous solution to form the uneven surface 1C is longer than the time for immersing the aluminum foil in the sodium hydroxide aqueous solution to clean the surface of the aluminum foil. The time for immersing the aluminum foil in the sodium hydroxide aqueous solution to form the uneven surface 1C is, for example, 5 minutes or more. The uneven surface 1C may be formed by subjecting the surface of the aluminum foil to treatments such as electropolishing, cutting, surface transfer (e.g., rolling, roll pressing, or embossing), etc. Alternatively, the uneven surface 1C may be formed by combining two or more of the above-mentioned treatment methods.

[0051] (3) Composition of Aluminum Foil The aluminum foil 1 contains aluminum (Al) and inevitable impurities. Preferably, the aluminum foil 1 further contains 0.04% by mass or more and 0.11% by mass or less of iron (Fe) and 0.50% by mass or more and 1.20% by mass or less of manganese (Mn). In such an aluminum foil 1, the uneven surface 1C can be easily formed using an alkaline aqueous solution.

[0052] When the aluminum foil 1 contains 0.04% by mass or more and 0.11% by mass or less of iron (Fe) and 0.50% by mass or more and 1.20% by mass or less of manganese (Mn), the above-mentioned uneven surface 1C can be efficiently formed by exposing the surface of the aluminum foil 1 to an alkaline aqueous solution. When the aluminum foil 1 contains Fe and Mn, second-phase particles such as Al-Fe-Mn and Al-Mn-based particles crystallize or precipitate. The Mn-containing second-phase particles are easily removed from the surface of the aluminum foil 1 during the process of exposing the surface of the aluminum foil 1 to an alkaline aqueous solution and dissolving the aluminum matrix. Furthermore, since the potential difference between the Fe-containing second-phase particles and the aluminum matrix is ​​greater than the potential difference between the Fe-free second-phase particles and the aluminum matrix, the Fe-containing second-phase particles dissolve more efficiently in an alkaline aqueous solution than the Fe-free second-phase particles. Therefore, by exposing the surface of aluminum foil 1 containing 0.04% by mass to 0.11% by mass of Fe and 0.50% by mass to 1.20% by mass of Mn to an alkaline aqueous solution, the above-mentioned uneven surface 1C having an area ratio of second phase particles of 0.10% or less can be easily formed. Furthermore, if aluminum foil 1 contains Fe and Mn simultaneously as described above, the growth of crystal grains is suppressed, for example, during annealing, compared to when aluminum foil 1 does not contain Fe and Mn simultaneously, and therefore the crystal grains in aluminum foil 1 can be made finer.

[0053] When the Fe content is less than 0.04% by mass, even when the surface of the aluminum foil 1 is exposed to an alkaline aqueous solution, the dissolution proceeds slowly, and the unevenness of the uneven surface 1C caused by the dissolution increases, which is thought to reduce the diffuse reflection component. In other words, when the surface of the aluminum foil 1 having an Fe content of less than 0.04% by mass is exposed to an alkaline aqueous solution to form the uneven surface 1C, the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions becomes smaller than 3700, and there is a concern that the regular reflectance will increase.

[0054] With regard to the composition of the aluminum foil 1, if the Fe content is greater than 0.11% by mass, the area ratio of second-phase particles present (remaining) on ​​the uneven surface 1C after the surface of the aluminum foil 1 is exposed to an alkaline aqueous solution to form the uneven surface 1C will be significantly higher than 0.10%, and there is a concern that the L* value, which is an index of the degree of whiteness in visible light, will decrease to a 45° reflection value of less than 70 and a 110° reflection value of less than 30.

[0055] If the Mn content is less than 0.50% by mass, after the surface of aluminum foil 1 is exposed to an alkaline aqueous solution to form the uneven surface 1C, second-phase particles having a small amount of Mn or no Mn will remain on the uneven surface 1C, and the area ratio of the second-phase particles will be higher than 0.10%, which raises a concern that the L* value, which is an index of the degree of whiteness in visible light, will decrease to less than 70 for the 45° reflection value and less than 30 for the 110° reflection value.

[0056] When the Mn content is more than 1.20 mass %, the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions becomes larger than 10,000 as described above, and the apex density (unit: 1 / mm) of the dimple-shaped concave portions becomes smaller. 2 ) becomes larger than 4,500,000, and there is a concern that the L* value, which is an index of the degree of whiteness in visible light, will decrease to a 45° reflection value of less than 70 and a 110° reflection value of less than 30.

[0057] In addition, it was confirmed that the L* value, which is an index of the degree of whiteness in visible light, had a 15° reflection value of 140 or more, a 45° reflection value of 70 or more, and a 110° reflection value of 30 or more. Such aluminum foil 1 can be used as an aluminum foil having a white surface without having a white printed base or an anodized coating.

[0058] Preferably, the content of silicon (Si) in the aluminum foil 1 is 0.001% or more and 0.3% by mass or less. Since Si has a high solid solubility in Al and is difficult to form crystallized deposits, a content that does not cause crystallized deposits to form in the aluminum foil is preferable from the viewpoint of rolling suitability. In other words, the inclusion of Si can improve the mechanical strength of the aluminum foil by solid solution strengthening, making it easier to roll thin foils. If the Si content is less than 0.001% by mass, the above-mentioned effects cannot be fully obtained. If the Si content exceeds 0.3% by mass, coarse crystallized deposits are likely to occur, not only reducing reflectivity but also impairing the above-mentioned crystal grain refinement effect, which tends to reduce strength and workability.

[0059] Preferably, the magnesium (Mg) content in the aluminum foil 1 is 3% by mass or less. Mg has a high solid solubility in Al of up to 18% by mass, and the generation of crystallized deposits is extremely low, so the mechanical strength of the aluminum foil 1 can be improved without significantly affecting the reflective properties of the surface (first surface 1A) of the aluminum foil 1. However, if the Mg content exceeds 3% by mass, the mechanical strength of the aluminum foil 1 becomes too high, and the rollability of the aluminum foil 1 tends to decrease. In order to combine the preferable reflective properties and mechanical strength of the aluminum foil 1, it is more preferable to set the Mg content to 2% by mass or less.

[0060] The aluminum foil 1 may contain elements such as copper (Cu), zinc (Zn), titanium (Ti), vanadium (V), nickel (Ni), chromium (Cr), zirconium (Zr), boron (B), gallium (Ga), and bismuth (Bi), in an amount that does not affect the above-mentioned properties and effects.

[0061] In the aluminum foil 1, the remainder other than the portion consisting of each of the above-mentioned additional elements consists of Al and inevitable impurities. The Al content in the aluminum foil 1 is, for example, 96% by mass or more, preferably 97% by mass or more, and more preferably 99.46% by mass or more.

[0062] The composition of the aluminum foil 1 can be measured by inductively coupled plasma optical emission spectroscopy. Examples of measuring devices include iCAP6500DUO manufactured by Thermo Fisher Scientific Co., Ltd. and ICPS-8100 manufactured by Shimadzu Corporation.

[0063] The thickness of the aluminum foil 1 is preferably 4 μm or more and 300 μm or less. If the thickness of the aluminum foil 1 is less than 4 μm, the mechanical strength of the aluminum foil cannot be maintained, and wrinkles occur on the surface of the aluminum foil due to handling during production. If the thickness of the aluminum foil 1 exceeds 300 μm, not only does the weight of the aluminum foil increase, but processing such as molding is also restricted, which is not preferable. More preferably, the thickness of the aluminum foil 1 is 6 μm or more and 250 μm or less. In order to make the thickness of the aluminum foil 1 within the above range, casting and rolling may be performed according to a general aluminum foil manufacturing method.

[0064] (4) Configuration of Information Display Unit and Pattern The surface of the pattern 2 is colored. The pattern 2 is a printing layer formed on the uneven surface 1C of the aluminum foil 1 by, for example, a printing method. The pattern 2 can be formed by a known printing method using a known colored printing ink. Specific examples of the printing method include a method of printing a pigment using an inkjet printer, a method of printing a pigment by screen printing, gravure printing, offset printing, flexographic printing, UV printing, etc. Gravure printing is particularly preferred as a method of forming the pattern 2 because it is capable of fine line printing.

[0065] Preferably, the total reflectance of the information display unit 3 is at least 20% lower than the total reflectance of the uneven surface 1C for electromagnetic waves of at least a portion of the wavelength range between 250 nm and 2000 nm. Such information display unit 3 can be realized by including at least one pigment selected from the group consisting of black pigment, brown pigment, green pigment, and blue pigment in the material constituting the surface of pattern 2. While the total reflectance of information display unit 3 is lower than that of uneven surface 1C, the contrast is clearer than in information display units in which the difference is less than 20%, allowing accurate reading with, for example, a general barcode reader using infrared light. More preferably, the material constituting the surface of pattern 2 includes at least one of the black pigment and blue pigment from the above group, which provides the greatest contrast difference with the white color of uneven surface 1C.

[0066] Preferably, the minimum reflectance of the information display unit 3 measured in accordance with ISO Standard 15416 (2016) is 3% or greater and 33% or less. Preferably, the symbol contrast of the information display unit 3 measured in accordance with ISO Standard 15416 (2016) is 58% or greater and 83% or less. Such an information display unit 3 can be realized by including in the material constituting the surface of the pattern 2 at least one selected from the group consisting of a black pigment, a brown pigment, a green pigment, and a blue pigment.

[0067] The material constituting pattern 2 may contain, as a colorant (pigment), at least one selected from the group consisting of carbon black, phthalocyanine blue, phthalocyanine green, quinacridone pigments, quinophthalene pigments, perylene pigments, dioxazine pigments, isoindolinone pigments, and iron oxide. The pigment content in pattern 2 is, for example, 10% to 40% by weight based on the solid content. Preferably, the pigment content in pattern 2 is, for example, 15% to 40% by weight based on the solid content. Pattern 2 may contain, as a binder resin, at least one selected from the group consisting of vinyl acetate resin, vinyl chloride resin, vinyl acetate-vinyl chloride copolymer resin, polyurethane resin, and nitrocellulose. Pattern 2 may be formed by a printing method other than black printing using carbon black, as long as it is readable as information display unit 3. The thickness of pattern 2 is, for example, 0.5 μm to 2.0 μm.

[0068] The pattern 2 may be configured as a laminate of the printing layer and a primer coating layer formed between the printing layer and the uneven surface 1C. The material constituting the primer coating layer may include at least one of vinyl chloride vinyl acetate copolymer and shellac. In the pattern 2 including the primer coating layer, the adhesion between the aluminum foil 1 and the pattern 2 is improved compared to the pattern 2 not including the primer coating layer, but the thermal conductivity between the aluminum foil 1 and the pattern 2 is reduced. Therefore, when the pattern 2 is formed so as to overlap the heat seal layer formed on the second surface 1B in a plan view, it is preferable that the pattern 2 does not include a primer coating layer.

[0069] <Method for manufacturing aluminum foil information display> As shown in FIG. 5, the method for manufacturing the aluminum foil information display 10 includes a first step (S10) of preparing an aluminum foil 1, a second step (S20) of forming a textured surface 1C on at least a portion of a first surface 1A of the prepared aluminum foil 1, and a third step (S30) of forming a pattern 2 on the textured surface 1C that exposes a portion of the textured surface 1C.

[0070] In the first step, an aluminum foil containing Al and inevitable impurities is prepared. Preferably, the aluminum foil contains Al, 0.04% by mass or more and 0.11% by mass or less of Fe, and 0.50% by mass or more and 1.20% by mass or less of Mn.

[0071] In the first step, first, an ingot whose composition is adjusted so as to obtain an aluminum foil having the above composition is obtained. The method for producing the ingot is not particularly limited, but may be, for example, semi-continuous casting, continuous casting, or mold casting. The ingot may be subjected to a homogenization heat treatment. The homogenization heat treatment is performed, for example, by holding the ingot at a temperature range of 400 ° C or higher and 630 ° C or lower for 1 hour to 20 hours.

[0072] In the first step, secondly, the ingot is rolled to obtain an aluminum foil of a predetermined thickness. In the rolling, for example, the ingot may be hot rolled and then the obtained hot-rolled material may be cold rolled. When a thin plate-shaped ingot is prepared by continuous casting, the ingot may be cold rolled without hot rolling. The number of hot rollings and the number of cold rollings are not particularly limited. When multiple cold rollings are performed, the multiple cold rollings may be performed with intermediate annealing in between. The conditions of the intermediate annealing may be within the range of general operating conditions. In addition, final annealing may be performed after rolling (after the final cold rolling if multiple rollings are performed). The conditions of the final annealing are, for example, an annealing temperature of 250°C to 450°C and an annealing time of 1 hour to 30 hours.

[0073] In the second step, at least a portion of the surface of the prepared aluminum foil is subjected to at least one of the above-described treatment methods for forming a concave-convex surface. The treatment conditions at this time are that the area ratio of second-phase particles present in a predetermined region of the concave-convex surface is 0.10% or less, the arithmetic mean curvature Spc (1 / mm) of the dimple-shaped convex portions is 3700 or more and 10000 or less, and the apex density (1 / mm) of the dimple-shaped concave portions is 0.10% or less. 2 ) is set to be equal to or greater than 1,600,000 and equal to or less than 4,500,000.

[0074] As an example of a treatment method for forming a textured surface, a method for forming the textured surface using an alkaline aqueous solution will be described below.

[0075] In the second step, at least a portion of the surface of the aluminum foil prepared in the first step is exposed to an alkaline aqueous solution to form dimple-shaped irregularities in that portion. For example, an aluminum foil having only the exposed area where the irregular surface is to be formed is immersed in an alkaline aqueous solution. In this step, any alkaline aqueous solution can be used, but a sodium hydroxide aqueous solution is preferred.

[0076] Conditions such as the concentration and temperature of the alkaline aqueous solution, and treatment time can be appropriately selected. The concentration of the alkaline aqueous solution is, for example, 0.1% by mass or more and 30% by mass or less. When the alkaline aqueous solution is a sodium hydroxide aqueous solution, the concentration of the sodium hydroxide aqueous solution is, for example, 0.1% by mass or more and 30% by mass or less. The temperature of the alkaline aqueous solution is, for example, room temperature. The treatment time is, for example, 1 minute or more and 60 minutes or less.

[0077] In the second step, preferably, at least a portion of the surface of the aluminum foil is exposed to an alkaline aqueous solution, and then a smut removal treatment is performed. Examples of the smut removal treatment include a treatment of removing smut using an acid or alkali different from acid washing or alkali washing. Smut may also be removed by physical treatment such as barrel polishing or electrolytic polishing.

[0078] In the third step, a pattern 2 exposing a portion of the uneven surface 1C is formed on the uneven surface 1C. The shape of the pattern 2 can be set arbitrarily depending on the information to be displayed on the information display unit 3. The pattern 2 is formed as a printed layer by, for example, a printing method. The pattern 2 can be formed as a laminate of multiple printed layers. For example, at least one of the printing methods described above is used as a method for forming the pattern 2. For example, at least one material selected from the group described above is used as a material for forming the pattern 2.

[0079] The present inventors have confirmed that the aluminum foil information display 10 can be manufactured by the above-described manufacturing method.

[0080] <Effects, etc.> The aluminum foil information display 10 comprises an aluminum foil 1 having an uneven surface 1C on which dimple-shaped unevenness is formed, and a pattern 2 formed on the uneven surface 1C so as to expose a portion of the uneven surface 1C. In the aluminum foil information display 10, the portion of the uneven surface 1C and the pattern 2 constitute an information display section 3. The area ratio of second phase particles present in a predetermined region of the uneven surface 1C is 0.10% or less, the arithmetic mean curvature Spc (1 / mm) of the dimple-shaped convex portions is 3700 or more and 10000 or less, and the vertex density (1 / mm) of the dimple-shaped concave portions is 0.10% or less. 2 The inventors have confirmed that the uneven surface 1C exhibits high whiteness, and as a result, the information display section 3 formed by the uneven surface 1C and the pattern 2 can be optically read accurately without relying on an underlayer such as a solid white print layer.

[0081] Furthermore, the inventors have confirmed that the above-mentioned uneven surface 1C can be easily formed by exposing the aluminum foil 1 to an alkaline aqueous solution, and that the pattern 2 can be easily formed on the uneven surface 1C by a printing method or the like.

[0082] According to the aluminum foil information display 10, the information display section 3 can be optically read accurately without relying on a solid white base layer, so manufacturing costs and environmental loads can be reduced compared to conventional aluminum foil information displays that have a solid white base layer.

[0083] In the aluminum foil information display 10, the total reflectance of the uneven surface 1C for electromagnetic waves in the wavelength range of 250 nm to 2000 nm is preferably 70% to 90%. It is preferable that the total reflectance of the information display unit 3 for electromagnetic waves of at least a portion of the wavelengths in the wavelength range of 250 nm to 2000 nm is 20% or more lower than the total reflectance of the uneven surface 1C. The inventors have confirmed that when the surface of the pattern 2 is colored and the material constituting the surface of the pattern 2 includes at least one selected from the group consisting of a black pigment, a brown pigment, a green pigment, and a blue pigment, the total reflectance of the information display unit 3 for electromagnetic waves of at least a portion of the wavelengths in the wavelength range of 250 nm to 2000 nm is 20% or more lower than the total reflectance of the uneven surface 1C. Furthermore, the inventors have confirmed that when the total reflectance of the information display unit 3 is 20% or more lower than the total reflectance of the uneven surface 1C for electromagnetic waves of at least some wavelengths in the wavelength range of 250 nm to 2000 nm, the minimum reflectance of the information display unit measured in accordance with ISO standard 15416 (2016) is 3% to 33%, and the symbol contrast of the information display unit measured in accordance with ISO standard 15416 (2016) is 58% to 83%. In the aluminum foil information display body 10 having the above configuration, the contrast of the information display unit 3 is clearer than that of an aluminum foil information display body 10 not having the above configuration, and the readability of the information display unit 3 is improved.

[0084] The information display portion 3 may be a one-dimensional barcode, a two-dimensional barcode, a matrix code, or a composite code. In a plan view, the pattern 2 included in the information display portion 3 may have any shape.

[0085] Preferably, the thickness of the aluminum foil 1 is 4 μm or more and 300 μm or less. Such an aluminum foil 1 also has high processability as described above.

[0086] The present inventors have confirmed that the arithmetic mean roughness (Ra) of the uneven surface 1C of the aluminum foil 1 is greater than 20 nm.

[0087] <Modification of Aluminum Foil Information Display Body> The aluminum foil information display body 10 may further include an overprint coating layer (not shown) formed on the uneven surface 1C so as to cover the information display portion 3. In this way, it is possible to prevent the pattern 2 from peeling off due to rubbing, scratching, etc. The overprint coating layer is, for example, an OP (overprint) varnish. Such an aluminum foil information display body 10 can be manufactured by carrying out a step of forming an overprint coating layer after the third step (S30) of the above-mentioned manufacturing method. In the step of forming the overprint coating layer, for example, a known method of forming an OP varnish can be used.

[0088] The aluminum foil information display 11 shown in FIG. 6 is a modified example of the aluminum foil information display 10 shown in FIG. 1. The aluminum foil information display 11 differs from the aluminum foil information display 10 in that it further includes a heat seal layer 4 formed on the second surface 1B (back surface, poppy surface) of the aluminum foil 1. The heat seal layer 4 is formed on at least a portion of the second surface 1B. In a plan view, at least a portion of the heat seal layer 4 may be arranged so as to overlap the information display section 3. The heat seal layer 4 may be formed on the entire second surface 1B. The heat seal layer 4 has a third surface 4A in contact with the second surface 1B and a fourth surface 4B located on the opposite side of the third surface 4A.

[0089] Since the aluminum foil information display 11 includes the heat seal layer 4, it can be bonded to the substrate to be bonded by heating and pressurizing at least a portion of the heat seal layer 4 superimposed on the substrate to be bonded. As a result, the aluminum foil information display 11 is suitable as a packaging material that constitutes at least a portion of packaging containers for medicines, food, beverages, office supplies, machine parts, daily necessities, kitchenware, etc. Configuration examples of packaging containers that include the aluminum foil information display 11 as a packaging material will be described later.

[0090] The material constituting the heat-seal layer 4 can be arbitrarily selected from, for example, known heat-sealing agents. The material constituting the heat-sealing layer 4 includes, for example, at least one selected from the group consisting of acrylic heat-sealing agents, modified polyolefin heat-sealing agents, polyester heat-sealing agents, vinyl chloride-vinyl acetate copolymer heat-sealing agents, ethylene-vinyl acetate copolymer heat-sealing agents, and vinyl acetate heat-sealing agents. Preferably, the material constituting the heat-sealing layer 4 includes a heat-sealing agent that has high adhesion to both the aluminum foil 1 and the substrates to be joined. For example, the material constituting the heat-sealing layer 4 preferably includes a polystyrene resin substrate for an acrylic heat-sealing agent, a polypropylene or polyethylene substrate for a modified polyolefin heat-sealing agent, a polyester substrate for a polyester-sealing agent, and a polyvinyl chloride substrate for a vinyl chloride-vinyl acetate copolymer heat-sealing agent or an ethylene-vinyl acetate copolymer heat-sealing agent.

[0091] The method for forming the heat seal layer 4 can be arbitrarily selected from known methods for forming heat seal layers. The heat seal layer 4 can be formed, for example, by applying the above-mentioned material before drying onto the second surface 1B using a bar coater or the like, and then drying the applied material.

[0092] The heat seal layer 4 may be formed by a T-die method. In this case, the material constituting the heat seal layer 4 may contain at least one selected from the group consisting of polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate EMA, ethylene-methacrylic acid copolymer EMAA, and ethylene-methyl methacrylate EMMA.

[0093] 1 does not include a heat seal layer 4. Such an aluminum foil information display 10 can be applied to, for example, an information display portion 3 constituting at least a part of a label, a seal, a tray, a price tag, a tag, a card, etc.

[0094] As shown in Figure 7, the manufacturing method of the aluminum foil information display 11 differs from the manufacturing method of the aluminum foil information display 10 in that it further includes a fourth step (S40) of forming a heat seal layer 4 on the second surface 1B (back surface, poppy surface) located opposite the uneven surface 1C of the aluminum foil 1.

[0095] The fourth step (S40) is performed, for example, after the third step (S30). Note that the fourth step (S40) may be performed between the first step (S10) and the second step (S20), or between the second step (S20) and the third step (S30).

[0096] In the fourth step (S40), the method for forming the heat seal layer 4 can be arbitrarily selected from known methods for forming a heat seal layer. The heat seal layer 4 can be formed by, for example, roll coating, various gravure coatings, a bar coater, doctor blade coating, a comma coater, spray coating, brush coating, or the like.

[0097] The present inventors have confirmed that the above-described manufacturing method can produce an aluminum foil information display 11. Furthermore, the present inventors have confirmed that, in an aluminum foil information display 11 that does not have a solid white base layer, the strength of the joint when the aluminum foil information display 11 is joined to an object to be joined via the heat seal layer 4 (hereinafter also referred to as seal strength) is improved compared to a conventional aluminum foil information display that has a solid white base layer.

[0098] <Configuration of Packaging Container> As described above, the aluminum foil information display 11 is suitable for use as a packaging material. Hereinafter, a configuration example of a packaging container including the aluminum foil information display 11 as a packaging material will be described.

[0099] 8 and 9 show a packaging container 31 configured as a PTP for packaging medicines and the like as an example of a packaging container according to this embodiment. In the packaging container 31, the substrate to which the heat seal layer 4 of the aluminum foil information display 11 is bonded is a separate member from the aluminum foil information display 11. As shown in FIGS. 8 and 9, the packaging container 31 may include the aluminum foil information display 11 and a container body 21. The container body 21 is bonded to the aluminum foil information display 11 via the heat seal layer 4. The container body 21 is a separate member from the aluminum foil information display 11. The container body 21 has, for example, a flange portion 21A bonded to the second surface 1B of the aluminum foil information display 11 via the heat seal layer 4, and a pocket portion 21B recessed relative to the flange portion 21A for accommodating contents. The pocket portion 21B is, for example, the same member as the flange portion 21A. The material constituting the container body 21 may be any material that can be heat-sealed via the heat seal layer 4. The material constituting the container body 21 includes, for example, a resin material. The material constituting the container body 21 may also include a polyvinyl chloride-based base material.

[0100] The heat seal layer 4 may be formed over the entire second surface 1B of the aluminum foil information display body 11. The heat seal layer 4 may be formed only on an area of ​​the second surface 1B of the aluminum foil information display body 11 that is intended to be overlapped with the flange portion 21A of the container body 21.

[0101] Only a portion of the heat-seal layer 4 may be joined to the container body 21. As shown in Figure 10, the heat-seal layer 4 may have a sealed portion 4C extending along the second surface 1B in two mutually perpendicular directions and heat-sealed to the container body 21, and an unsealed portion 4D surrounded by the sealed portion 4C and not heat-sealed to the container body 21. The width of the sealed portion 4C of the heat-seal layer 4 in a direction perpendicular to the extension direction is narrower than, for example, the distance between two adjacent sealed portions 4C in the perpendicular direction. Note that the pattern shape of the sealed portion 4C of the heat-seal layer 4 in a plan view is not limited to a lattice shape and may be any shape.

[0102] The information display section 3 may be formed on any desired area of ​​the uneven surface 1 C. At least a portion of the information display section 3 may be formed so as to overlap at least a portion of the heat seal layer 4 .

[0103] 11 shows a packaging container 32 as another example of a packaging container according to the present embodiment. In the packaging container 32, the substrate to which the heat seal layer 4 of the aluminum foil information display body 11 is bonded is another part of the aluminum foil information display body 11. In the packaging container 32, the aluminum foil information display body 11 has a folded-back portion and a pair of end portions spaced apart from the folded-back portion and positioned to sandwich the heat seal layer 4. The pair of end portions of the aluminum foil information display body 11 are bonded via the heat seal layer 4.

[0104] In the packaging containers 31 and 32, even when the information display section 3 is arranged so as to overlap the heat seal layer 4 in a planar view, the seal strength via the heat seal layer 4 is higher than that of a packaging container equipped with a conventional aluminum foil information display in which the information display section and a solid white base layer are arranged so as to overlap the heat seal layer. As a result, the packaging container according to the present embodiment is more reliable and less susceptible to deterioration of the contents than the conventional packaging container. For example, in the conventional packaging container, the solid white base layer and the information display section formed thereon may peel off from the aluminum foil. In contrast, the packaging container according to the present embodiment uses an aluminum foil information display 11 that does not have a solid white base layer, and the information display section 3 is less likely to peel off from the aluminum foil 1.

[0105] <Method for manufacturing packaging container> A method for manufacturing a packaging container includes a step of preparing an aluminum foil information display 11 having a heat seal layer 4 by a method for manufacturing an aluminum foil information display 11, and a step of bonding the aluminum foil information display 11 to a substrate to be bonded by heating and pressurizing at least a portion of the heat seal layer 4 in a state where the heat seal layer 4 is superimposed on the substrate to be bonded. In the bonding step, the contents to be contained in the packaging container are wrapped between the aluminum foil information display 11 and the substrate to be bonded.

[0106] 12, the manufacturing method of the packaging container 31 includes a fifth step (S50) of preparing an aluminum foil information display body 11, a sixth step (S60) of preparing a container body 21, and a seventh step (S70) of heat-sealing the aluminum foil information display body 11 and the container body 21 in a state where the second surface 1B and the flange portion 21A of the aluminum foil information display body 11 are laminated with the heat-seal layer 4 sandwiched between them. In the seventh step (S70), at least a portion of the heat-seal layer 4 is heated and pressurized relative to the container body 21 in which the contents are contained. The heating and pressurization treatment of the heat-seal layer 4 in the seventh step (S70) can be performed using, for example, a container packaging sealing machine.

[0107] The evaluation results for the aluminum foil information display of this embodiment are shown below. <Evaluation Sample 1> Using aluminum ingots with different compositions, aluminum foils A1 to A6 and B1 to B14 having the compositions shown in Tables 1 and 2 were produced by the manufacturing process shown below, and the aluminum foil information displays of Examples 1 to 6 and Comparative Examples 1 to 14 were further produced from each aluminum foil.

[0108]

[0109] First, an ingot was obtained by casting from molten aluminum adjusted to a predetermined composition, and then the ingot was subjected to homogenization heat treatment at a predetermined temperature and time. The ingot was then hot-rolled to obtain a hot-rolled material having a thickness of approximately 6.5 mm. The hot-rolled material was subjected to multiple cold rolling operations. Intermediate annealing was performed during multiple cold rolling operations. In this way, aluminum foils having the thicknesses (original thicknesses) shown in Table 2 were produced. Sample B14 was the aluminum foil described in WO 2017 / 158989.

[0110] Second, the aluminum foils of samples A1 to A6, B1 to B9, and B11 to B14 were subjected to an alkali treatment or an acid treatment to form a textured surface. The aluminum foils of samples A1 to A6, B1 to B9, and B12 were immersed in a 1% by mass aqueous sodium hydroxide solution for the time shown in Table 2. The aluminum foils of samples B11 and B13 were immersed in an aqueous solution containing 8% by mass hydrochloric acid and 4% by mass aluminum chloride for the time shown in Table 2. Sample B14 was immersed in a 1% by mass aqueous sodium hydroxide solution for the time shown in Table 2. The aluminum foil of sample B10 was not subjected to either the alkali treatment or the acid treatment. In other words, the aluminum foil of sample B10 did not have a textured surface. Furthermore, to remove smut, the aluminum foils of samples A1 to A6 and B1 to B14 were immersed in a 5% by mass aqueous nitric acid solution for 10 seconds, then washed with water, and dried. In this way, aluminum foils of samples A1 to A6 and samples B1 to B14 were prepared having the thicknesses (thickness after treatment) shown in Table 2. The liquid temperature of each of the above aqueous solutions was 35°C. The thicknesses of the aluminum foils of samples A1 to A6 and samples B1 to B14 after treatment were measured using a digital micrometer MDC-MX IP65 manufactured by Mitutoyo Corporation.

[0111]

[0112] Third, the aluminum foils of Samples A1 to A6 and Samples B1 to B14 prepared as described above were used to create the aluminum foil information displays of the following Examples 1 to 6 and Comparative Examples 1 to 14. For Samples A1 to A6, Samples B1 to B9, and Samples B11 to B14, the barcodes were formed on the textured surfaces.

[0113] (1) Example 1 Black ink (TF-842 805 Sumi, nitrocellulose-based, solids content 29% by mass, manufactured by DIC Graphics Corporation) was diluted with methyl ethyl ketone and adjusted to a viscosity of 30 seconds using a Zahn cup #3 to prepare a printing ink. The ink was printed on the textured surface of Sample A1 and then dried to prepare Sample A1 equipped with a barcode. Printing was performed by gravure printing using a gravure plate. The barcode was a GS1 data bar, with a barcode size (nominal 0.254 mm / module (line thickness minimum 0.2 to maximum 1.25 mm, spacing minimum 0.3 to maximum 0.8 mm)) and formed to a thickness of approximately 1.5 μm after drying. Drying was performed using an oven. The drying temperature was 130°C and the drying time was 30 seconds.

[0114] Next, a heat-seal coating agent primarily composed of vinyl chloride-vinyl acetate copolymer resin (Leader: LD#S837G clear, solids content 21% by mass) was applied to the back (poppy side) of Sample A1, followed by drying to produce the aluminum foil information display of Example 1, which had a barcode, aluminum foil, and heat-seal layer laminated together. In plan view, the heat-seal layer was formed to overlap the barcode. A bar coater #10 was used to apply the heat-seal coating agent. The heat-seal layer was formed so that its weight after drying was 3.5 g / m2. Drying was performed using an oven. The drying temperature was 130°C, and the drying time was 30 seconds.

[0115] (2) Example 2 An aluminum foil information display of Example 2 was produced in the same manner as in Example 1, except that Sample A2 was used as the substrate.

[0116] (3) Example 3 An aluminum foil information display of Example 3 was produced in the same manner as in Example 1, except that Sample A3 was used as the substrate.

[0117] (4) Example 4 An aluminum foil information display of Example 4 was produced in the same manner as in Example 1, except that Sample A4 was used as the substrate.

[0118] (5) Example 5 An aluminum foil information display of Example 5 was produced in the same manner as in Example 1, except that Sample A5 was used as the substrate.

[0119] (6) Example 6 An aluminum foil information display of Example 6 was produced in the same manner as in Example 1, except that Sample A6 was used as the substrate.

[0120] (7) Comparative Example 1 An aluminum foil information display of Comparative Example 1 was produced in the same manner as in Example 1, except that Sample B1 was used as the substrate.

[0121] (8) Comparative Example 2 An aluminum foil information display member of Comparative Example 2 was produced in the same manner as in Example 1, except that Sample B2 was used as the substrate.

[0122] (9) Comparative Example 3 An aluminum foil information display member of Comparative Example 3 was produced in the same manner as in Example 1, except that Sample B3 was used as the substrate.

[0123] (10) Comparative Example 4 An aluminum foil information display of Comparative Example 4 was produced in the same manner as in Example 1, except that Sample B4 was used as the substrate.

[0124] (11) Comparative Example 5 An aluminum foil information display member of Comparative Example 5 was produced in the same manner as in Example 1, except that Sample B5 was used as the substrate.

[0125] (12) Comparative Example 6 An aluminum foil information display member of Comparative Example 6 was produced in the same manner as in Example 1, except that Sample B6 was used as the substrate.

[0126] (13) Comparative Example 7 An aluminum foil information display of Comparative Example 7 was produced in the same manner as in Example 1, except that Sample B7 was used as the substrate.

[0127] (14) Comparative Example 8 An aluminum foil information display of Comparative Example 8 was produced in the same manner as in Example 1, except that Sample B8 was used as the substrate.

[0128] (15) Comparative Example 9 An aluminum foil information display of Comparative Example 9 was produced in the same manner as in Example 1, except that Sample B9 was used as the substrate.

[0129] (16) Comparative Example 10 An aluminum foil information display of Comparative Example 10 was produced in the same manner as in Example 1, except that Sample B10 was used as the substrate.

[0130] (17) Comparative Example 11 An aluminum foil information display of Comparative Example 11 was produced in the same manner as in Example 1, except that Sample B11 was used as the substrate.

[0131] (18) Comparative Example 12 An aluminum foil information display of Comparative Example 12 was produced in the same manner as in Example 1, except that Sample B12 was used as the substrate.

[0132] (19) Comparative Example 13 An aluminum foil information display member of Comparative Example 13 was produced in the same manner as in Example 1, except that Sample B13 was used as the substrate.

[0133] (20) Comparative Example 14 An aluminum foil information display of Comparative Example 14 was produced in the same manner as in Example 1, except that Sample B14 was used as the substrate.

[0134] (21) Comparative Example 15 A white pigmented ink (T&K TOKA Corporation, modified polyolefin-based, solid content 34% by mass) was applied to the glossy surface of a commercially available hard aluminum foil (50 μm, 1N30 material) and then dried to form a so-called solid white underlayer. A bar coater #6 was used for application. The solid white underlayer had a dry weight of 1.5 g / m 2 Drying was performed using an oven at a drying temperature of 130° C. for 30 seconds.

[0135] Next, a barcode was formed on the solid white underlayer in the same manner as in Example 1, and then a heat seal layer was formed on the poppy side of the hard aluminum foil in the same manner as in Example 1.

[0136] <Measurement of the arithmetic mean curvature Spc of the convex portions of the dimple shape and the apex density of the concave portions> For each of Examples 1 to 6 and Comparative Examples 1 to 14, the arithmetic mean curvature Spc of the convex portions of the dimple shape on the target surface and the apex density of the concave portions were measured. Specifically, the uneven surfaces of Samples A1 to A6, Samples B1 to B9, and Samples B11 to B14, as well as the surface of Sample B10, were observed using a laser microscope VK-X3000 manufactured by Keyence Corporation, and shape measurements were performed using a laser confocal microscope with a rectangular field of view of 95.257 μm × 71.419 μm. The obtained three-dimensional shape data was subjected to surface shape correction with a cutoff value of 0.1 mm to remove waviness, followed by height cut level correction with a cut level of 50 to remove laser light reflection noise components. A reference surface was set as a surface representing the average unevenness of the three-dimensional shape data after the correction.

[0137] From the three-dimensional shape data after the above correction, the arithmetic mean curvature Spc (unit: 1 / mm) of the peaks defined in the International Organization for Standardization standard ISO25178 was measured using a multi-file analysis application attached to the microscope.

[0138] Furthermore, the corrected three-dimensional shape data is inverted in the height direction relative to the reference plane, and the peak density Spd (unit: 1 / mm) defined in the International Organization for Standardization standard ISO25178 is calculated from the inverted data by the multi-file analysis application. 2 That is, the apex density of the dimple-shaped recesses was measured as the peak apex density of the inverted data.

[0139] <Measurement of Area Ratio of Second-Phase Particles> The area ratio of second-phase particles on the target surface was measured for each of Examples 1 to 6 and Comparative Examples 1 to 14. Specifically, the textured surface of each aluminum foil was observed at five randomly selected rectangular fields using a JSM-7200F manufactured by JEOL Ltd. The rectangular fields were 1188.49 μm 2The rectangular field of view was 39.59 μm×30.02 μm.

[0140] Second-phase particles were extracted by binarizing the backscattered electron images of each rectangular field of view using WinRoof 2021 image processing software from Mitani Corporation. The observation conditions for the backscattered electron images were set so that elements other than second-phase particles, such as rolling streaks, oil pits, and dimple shapes after surface formation, present in the rectangular field of view images, fell within the range of 0 to 70-130 in brightness extraction by lookup table conversion before binarization. Specifically, extraction by binarization was performed as follows. First, brightness extraction by lookup table conversion was performed to remove elements other than second-phase particles, such as rolling streaks, oil pits, and dimple shapes present in the obtained rectangular field of view images. Brightness extraction was performed by fixing the upper limit at 255 and adjusting the lower limit between 70 and 130. Next, multiple pixels extracted from the rectangular field of view images were binarized using a single threshold. The threshold for binarization was set to 1.0. The pixels finally extracted in this manner were taken as the pixels of the second-phase particles, and the sum of their areas was measured and divided by the area of ​​the entire field of view to measure the area ratio of the second-phase particles.

[0141] <Measurement of Total Reflectance> For each of Examples 1 to 6 and Comparative Examples 1 to 14, the total reflectance of the textured surface and the total reflectance of the barcode were measured. Total reflectance was measured using a UV-visible spectrophotometer V570 manufactured by JASCO Corporation, and the total reflectance in the integrating sphere was measured in the wavelength range of 250 nm to 2000 nm using a standard white plate for integrating spheres manufactured by Labsphere as a reference. From the total reflectance measurements obtained, the average value of ultraviolet light in the wavelength range of 250 nm to 400 nm was calculated. Total reflectance was measured in two directions, the rolling direction (MD) and the direction perpendicular to the rolling direction (TD), and the total reflectance was evaluated as the average of these values.

[0142] Table 3 shows the measured values ​​of the above parameters for each of the aluminum foils of Examples 1 to 6 and Comparative Examples 1 to 14.

[0143]

[0144] <Measurement of L* Value> For each of Examples 1 to 6 and Comparative Examples 1 to 15, the L* value was measured according to ASTM D2244, E308, E1164, and E2194. Specifically, the specular reflection of visible light incident on the uneven surface of each aluminum foil or the surface of the solid white base layer at an incident angle of 45° was measured using a BYK MACi color difference meter to measure the light intensity L* of the reflected light at angles of 15°, 45°, and 110° toward the incident light. <Evaluation of Barcode Readability> For each of Examples 1 to 6 and Comparative Examples 1 to 15, the readability of the barcode was evaluated according to the ISO / IEC 15416 standard. For this evaluation, a TRUCHECK (model number: TC-206) manufactured by Webscan, Inc. was used. The readability was evaluated as follows in accordance with the TC201-R WebScan Trucheck instruction manual 20150422. After calibration, the readability was evaluated five times. The average value of the overall ANSI Grade obtained from the five evaluations was used as the evaluation result.

[0145] The reading conditions for the device were "automatic laser multiple scan grading method, wavelength: 670 nm, aperture diameter: 6 mil, 10 scans." The reading procedure involved placing the barcode-printed side of each of Examples 1 to 6 and Comparative Examples 1 to 15 facing up, with the laser line crossing near the top of the barcode. The angle of the laser line relative to the barcode pattern was 90 degrees. The scanning direction of the laser line was the extension direction of the pattern. In scanning the laser line, the start and end positions of the laser line reading were inside both ends of the extension direction of the pattern. <Evaluation of Heat Sealability> Each of Examples 1 to 6 and Comparative Examples 1 to 15 was used as a PTP lid material, and the heat sealability (seal strength) was evaluated when heat-sealed to a container body. The container body was a PVC resin sheet (VSS-F120, 206 mm wide x 0.25 mm thick) manufactured by Sumitomo Bakelite Co., Ltd., molded to have the sheet shape shown in Figure 8 and the pocket shape shown in Figure 9. A container packaging sealing machine (CKD600UC manufactured by CKD Corporation) was used for heat sealing. The heat sealing conditions were 300 shots, 200°C, 0.35 MPa, and lattice sealing (conditions in which the shape of the sealed portion 4C was a lattice, as shown in Figure 11).

[0146] The evaluation conditions for the heat sealability of each packaging container using each of Examples 1 to 6 and Comparative Examples 1 to 15 as a PTP lid material were as follows: "Peeling method: 180-degree peeling, Peeling direction: Direction D in Figure 8, Peeling speed: 200 mm / min, Measurement location: 15 mm width within region G between pockets 21B in Figure 8." The heat sealability (seal strength) evaluation was performed using a threshold of 5.9 N / 15 mm, the seal strength at which leaks are generally believed to occur stochastically in PTP sheets. Those with a seal strength of 5.9 N / 15 mm or greater were judged to have good heat sealability. Those with a seal strength of less than 5.9 N / 15 mm were judged to have poor heat sealability.

[0147] Table 4 shows the measured L* values, the evaluation results of barcode readability, and the evaluation results of heat sealability for each of Examples 1 to 6 and Comparative Examples 1 to 14. The evaluation results of barcode readability are expressed in grades defined in the ISO / IEC 15416 standard.

[0148]

[0149] As shown in Table 3, Examples 1 to 6 had an uneven surface on which dimple-shaped irregularities were formed. In Examples 1 to 6, the arithmetic mean curvature Spc (unit: 1 / mm) of the convex portions of the uneven surface was 3700 to 10,000, the vertex density (unit: 1 / mm2) of the concave portions was 1,600,000 to 4,500,000, and the area ratio of second-phase particles present on the uneven surface was 0.1% or less. In Examples 1 to 6 having the above uneven surface, as shown in Table 4, the L* value of the uneven surface was 15° reflection value of 140 or more, 45° reflection value of 70 or more, and 110° reflection value of 30 or more, and the barcode readability grade was higher than D. Furthermore, the heat sealability of Examples 1 to 6 was good. From the above evaluation results, it was confirmed that the aluminum foil information display members of Examples 1 to 6 are suitable for packaging materials constituting at least a portion of packaging containers for medicines, food, beverages, office supplies, machine parts, daily necessities, kitchenware, etc.

[0150] On the other hand, the aluminum foils of Comparative Examples 1 to 9 and 12 had an uneven surface on which dimple-shaped irregularities were formed, but at least one of the arithmetic mean curvature Spc of the convex portions of the uneven surface, the vertex density of the concave portions, and the area ratio of the second-phase particles present on the uneven surface did not satisfy the above numerical ranges. The aluminum foils of Comparative Examples 10, 11, 13, and 14 did not have dimple-shaped irregularities. In the aluminum foils of Comparative Examples 1 to 14, as shown in Table 4, the L* value of the uneven surface was 15 ° reflection value less than 140, 45 ° reflection value less than 70, or 110 ° reflection value less than 30, so the barcode readability grade was F, lower than D.

[0151] From the above results, it can be seen that the arithmetic mean curvature Spc (unit: 1 / mm) of the convex portions of the uneven surface is 3700 or more and 10000 or less, and the apex density (unit: 1 / mm) of the concave portions is 2 ) is 1,600,000 or more and 4,500,000 or less, and the area ratio of second phase particles present on the uneven surface is 0.1% or less, it has been confirmed that the barcode readability is higher than that of an aluminum foil information display in which at least one of the above parameters does not satisfy the above numerical range or in which the uneven surface itself is not formed.

[0152] Furthermore, although not shown in Tables 3 and 4, the L* value of the surface of the solid white base layer of Comparative Example 15 was higher than the L* value of the uneven surfaces of Examples 1 to 6, and the barcode readability of Comparative Example 15 was graded A, which was higher than that of Examples 1 to 6, but the heat sealability of Comparative Example 15 was poor.

[0153] From the above results, in an aluminum foil information display body in which a portion of the uneven surface and the pattern constitute the information display section and the heat seal layer is formed on the back surface opposite the uneven surface, the information display section is accurately readable, but it has been confirmed that it has higher heat sealability than an aluminum foil information display body in which the solid white base layer and the pattern formed on its surface constitute the information display section and the heat seal layer is formed on the back surface of the aluminum foil opposite the solid white base layer.

[0154] The aluminum foils of Examples 1 to 6 contained 0.04% by mass or more and 0.11% by mass or less of Fe and 0.50% by mass or more and 1.20% by mass or less of Mn. In the aluminum foils of Examples 1 to 6, the uneven surface was formed by immersion in an alkaline aqueous solution of sodium hydroxide.

[0155] The Fe content was less than 0.04% by mass in the aluminum foil of Comparative Example 1. It is believed that when the aluminum foil having an Fe content of less than 0.04% by mass is exposed to an alkaline aqueous solution, the dissolution proceeds slowly, the unevenness of the uneven surface caused by the dissolution increases, and the arithmetic mean curvature Spc of the convex portions is lower than 3700.

[0156] In the aluminum foil of Comparative Example 5, the Fe content was less than 0.04% by mass and the Mn content was less than 0.50% by mass. In the aluminum foil of Comparative Example 8, the Fe content was more than 0.11% by mass and the Mn content was less than 0.50% by mass. In the aluminum foil having a Mn content of less than 0.50% by mass, Mn-free second-phase particles tend to remain on the surface of the aluminum foil when exposed to an alkaline aqueous solution, and it is thought that the area ratio of the second-phase particles present (remaining) on ​​the uneven surface was higher than 0.10%.

[0157] The Fe content was greater than 0.11% by mass in the aluminum foils of Comparative Examples 2 to 4 and 6 to 9. It is believed that in aluminum foils with an Fe content greater than 0.11% by mass, the area ratio of second-phase particles present (remaining) on ​​the uneven surface even when exposed to an alkaline aqueous solution was significantly higher than 0.10%.

[0158] The aluminum foils of Comparative Examples 11 and 13 had an Fe content of more than 0.11% by mass and an Mn content of less than 0.50% by mass. It is believed that the area ratio of second-phase particles present (remaining) on ​​the uneven surface after exposure to the acidic aqueous solution was significantly higher than 0.10% in the aluminum foils having an Fe content of more than 0.11% by mass and an Mn content of less than 0.50% by mass.

[0159] The aluminum foil of Comparative Example 12 had a Mn content of more than 1.20% by mass. When exposed to an alkaline aqueous solution, aluminum foil having a Mn content of more than 1.20% by mass has a large amount of fine Al—Fe—Mn-based crystallized products removed from the surface, resulting in the formation of densely packed fine dimples. This results in the arithmetic mean curvature Spc (unit: 1 / mm) of the dimple-shaped convex portions being greater than 10,000, and the apex density (unit: 1 / mm) of the dimple-shaped concave portions being greater than 10,000. 2 ) is thought to have become larger than 4,500,000.

[0160] <Evaluation Sample 2> Samples C1 to C11 were prepared using aluminum foil information displays equivalent to those in Example 1, with only the pattern color being different from one another. Sample C1 was prepared in the same manner as in Example 1. The indigo printing ink constituting the pattern of Sample C2 was prepared by diluting DIC Graphics' TF-842 Kanebo Con Eye (nitrocellulose-based, solids content 27% by mass) with methyl ethyl ketone and adjusting the viscosity to 30 seconds in Zahn Cup #3 to form a printing ink, except for the same procedure as in Example 1. The light blue printing ink constituting the pattern of Sample C3 was prepared by mixing DIC Graphics' TF-842 507 Genshoku Eye (nitrocellulose-based, solids content 27% by mass) and DIC Graphics' TF-842 Medium (nitrocellulose-based, solids content 21% by mass) in a 1:1 mass ratio, diluting with methyl ethyl ketone, and adjusting the viscosity to 30 seconds in Zahn Cup #3 to form a printing ink, except for the same procedure as in Example 1. The grass printing ink for the pattern of sample C4 was prepared by diluting TF-842 250P Green (nitrocellulose-based, solids content 28% by mass) manufactured by DIC Graphics with methyl ethyl ketone and adjusting the viscosity to 30 seconds on Zahn cup #3 to form a printing ink similar to that of Example 1. The thin grass printing ink for the pattern of sample C5 was prepared by mixing TF-842 250P Green (nitrocellulose-based, solids content 28% by mass) manufactured by DIC Graphics with TF-842 Medium (nitrocellulose-based, solids content 21% by mass) manufactured by DIC Graphics in a 1:1 mass ratio, diluting with methyl ethyl ketone, and adjusting the viscosity to 30 seconds on Zahn cup #3 to form a printing ink similar to that of Example 1. The brown printing ink constituting the pattern of Sample C6 was prepared in the same manner as in Example 1, except that TF-842 707 Cha (nitrocellulose-based, solids content 45% by mass) manufactured by DIC Graphics was diluted with methyl ethyl ketone and the viscosity was adjusted to 30 seconds using Zahn cup #3.The light brown printing ink for the pattern of Sample C7 was prepared by mixing TF-842 707 Cha (nitrocellulose-based, 45% solids by mass) manufactured by DIC Graphics with TF-842 Medium (nitrocellulose-based, 21% solids by mass) manufactured by DIC Graphics in a 1:1 mass ratio, diluting with methyl ethyl ketone and adjusting the viscosity to 30 seconds on a Zahn cup #3 scale to form a printing ink similar to Example 1. The reddish-brown printing ink for the pattern of Sample C8 was prepared by mixing TF-842 707 Cha (nitrocellulose-based, 45% solids by mass) manufactured by DIC Graphics with TF-842 105 Veneer (nitrocellulose-based, 27% solids by mass) manufactured by DIC Graphics in a 5:2 mass ratio, diluting with methyl ethyl ketone and adjusting the viscosity to 30 seconds on a Zahn cup #3 scale to form a printing ink similar to Example 1. The purple printing ink constituting the pattern of Sample C9 was prepared in the same manner as in Example 1, except that TF-842 607 Purple (nitrocellulose-based, solids content 21% by mass) manufactured by DIC Graphics was diluted with methyl ethyl ketone and the viscosity was adjusted to 30 seconds on a Zahn cup #3 scale to form a printing ink. The blue-purple printing ink constituting the pattern of Sample C10 was prepared in the same manner as in Example 1, except that TF-842 607 Purple (nitrocellulose-based, solids content 21% by mass) manufactured by DIC Graphics and TF-842 507 Genshokuai (nitrocellulose-based, solids content 27% by mass) manufactured by DIC Graphics were mixed in a mass ratio of 1:2, and the mixture was diluted with methyl ethyl ketone and the viscosity was adjusted to 30 seconds on a Zahn cup #3 scale to form a printing ink. The gray printing ink constituting the pattern of Sample C11 was prepared in the same manner as in Example 1, except that the printing ink was prepared by mixing TF-842 805 Sumi (nitrocellulose-based, solids content 29% by mass) manufactured by DIC Graphics Corporation and TF-842 Medium (nitrocellulose-based, solids content 21% by mass) manufactured by DIC Graphics Corporation in a 1:1 mass ratio, diluting the mixture with methyl ethyl ketone, and adjusting the viscosity to 30 seconds using Zahn cup #3.

[0161] For each of Samples C1 to C11, the minimum reflectance and maximum reflectance, symbol contrast, and readability of the barcode were evaluated in accordance with the ISO / IEC 15416 standard. The readability evaluation was performed using the method described above.

[0162]

[0163] As shown in Table 5, samples C1 to C11, which had a minimum barcode reflectance of 3% or more and 33% or less as measured in accordance with ISO Standard 15416 (2016) and a barcode symbol contrast of 58% or more and 83% or less as measured in accordance with ISO Standard 15416 (2016), had a barcode readability grade of C or higher.

[0164] From the above results, it was confirmed that an aluminum foil information display having a minimum reflectance of 3% or more and 33% or less of a barcode measured in accordance with ISO standard 15416 (2016) and a barcode symbol contrast of 58% or more and 83% or less has higher readability than an aluminum foil information display having a minimum reflectance of 33% or more and a symbol contrast of less than 58%.

[0165] Although the embodiments of the present disclosure have been described above, the above-described embodiments can be modified in various ways. Furthermore, the scope of the present disclosure is not limited to the above-described embodiments. The scope of the present disclosure is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0166] 1 Aluminum foil, 1A First surface, 1B Second surface, 2 Pattern, 3 Information display portion, 4 Heat seal layer, 4A Third surface, 4B Fourth surface, 4C Sealed portion, 4D Non-sealed portion, 10, 11 Aluminum foil information display body.

Claims

1. An aluminum foil having an uneven surface on which dimple-shaped irregularities are formed, and a pattern formed on the uneven surface so as to expose a portion of the uneven surface, wherein the portion of the uneven surface and the pattern constitute an information display section, the area ratio of second phase particles present in a predetermined region of the uneven surface is 0.10% or less, the arithmetic mean curvature Spc (1 / mm) of the dimple-shaped protrusions is 3700 or more and 10000 or less, and the vertex density (1 / mm) of the dimple-shaped recesses is 0.10% or less. 2 ) is 1,600,000 or more and 4,500,000 or less.

2. The aluminum foil information display according to claim 1, wherein the total reflectance of the uneven surface of the aluminum foil for electromagnetic waves in the wavelength range of 250 nm to 2000 nm is 70% to 90%, and the total reflectance of the information display portion for electromagnetic waves of at least some wavelengths in the wavelength range of 250 nm to 2000 nm is 20% or more lower than the total reflectance of the uneven surface.

3. The aluminum foil information display body according to claim 1 or 2, wherein the minimum reflectance of the information display unit measured in accordance with ISO Standard 15416 (2016) is 3% or more and 33% or less, and the symbol contrast of the information display unit measured in accordance with ISO Standard 15416 (2016) is 58% or more and 83% or less.

4. An aluminum foil information display according to claim 1 or 2, wherein the surface of the pattern is colored, and the material constituting the surface of the pattern includes at least one selected from the group consisting of black pigment, brown pigment, green pigment, and blue pigment.

5. The aluminum foil information display according to claim 1 or 2, wherein the information display portion includes at least one selected from the group consisting of a one-dimensional barcode, a two-dimensional barcode, a matrix code, and a composite code.

6. An aluminum foil information display according to claim 1 or 2, wherein the aluminum foil contains aluminum, 0.04 mass% or more and 0.11 mass% or less of iron, and 0.50 mass% or more and 1.20 mass% or less of manganese.

7. An aluminum foil information display according to claim 1 or 2, wherein the thickness of the aluminum foil is 4 μm or more and 300 μm or less.

8. The aluminum foil information display according to claim 1 or 2, wherein the arithmetic mean roughness (Ra) of the uneven surface is greater than 20 nm.

9. The aluminum foil information display according to claim 1 or 2, wherein the aluminum foil has a back surface located opposite the textured surface, and further comprises a heat seal layer formed on the back surface.

10. A packaging container comprising the aluminum foil information display body according to claim 9 and a container body joined to the aluminum foil information display body via the heat seal layer.

11. A packaging container having a bag portion formed from the aluminum foil information display body according to claim 9.

12. A method for manufacturing an aluminum foil information display, comprising the steps of: preparing an aluminum foil containing aluminum, 0.04% by mass or more and 0.11% by mass or less of iron, and 0.50% by mass or more and 1.20% by mass or less of manganese; exposing at least a portion of the surface of the aluminum foil to an alkaline aqueous solution to form at least a portion of the surface into a textured surface having dimple-shaped irregularities; and forming a pattern on the textured surface that exposes a portion of the textured surface, thereby forming an information display section composed of the portion of the textured surface and the pattern.

13. The method for producing an aluminum foil information display according to claim 12, further comprising the step of forming a heat seal layer on the back surface of the aluminum foil opposite the textured surface.

14. A method for manufacturing a packaging container, comprising the steps of: preparing an aluminum foil information display body having the heat seal layer by the method for manufacturing an aluminum foil information display body described in claim 13; preparing a container body having a flange portion and a pocket portion recessed relative to the flange portion; and heat sealing the aluminum foil information display body and the flange portion in a state in which the back surface of the aluminum foil information display body and the flange portion are stacked with the heat seal layer sandwiched between them.

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