Laminated sheet and packaging container

Abstract

To provide a laminated sheet comprising an aluminum foil layer or an aluminum vapor deposition layer and nonetheless excellent in a hue of a printed layer, and a packaging container.SOLUTION: A laminated sheet 10 comprises: a sealant layer 11; a barrier layer 13; a white film layer 15; a white printed layer 17; and a surface base material layer 18.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminated sheet and a packaging container.

Background Art

[0002] Conventionally, as a packaging material for packaging foods, cosmetics, pharmaceuticals, etc., a laminated sheet having an aluminum foil layer or an aluminum vapor deposition layer between a surface base material layer made of a resin film and a sealant layer is known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, the surface base material layer of a packaging material is printed with characters, patterns, etc. for the purpose of design and information display. However, the printed layer of a packaging material having an aluminum foil layer or an aluminum vapor deposition layer has a problem that the color tone becomes darker than when printed on a transparent resin film or paper, and white and light colors appear blackened.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a laminated sheet and a packaging container that have an aluminum foil layer or an aluminum vapor deposition layer and have an excellent color tone of the printed layer.

Means for Solving the Problems

[0006] The present invention has the following aspects. [1] A laminated sheet having a sealant layer, a barrier layer, a white film layer, a white printed layer, and a surface base material layer. [2] The barrier layer-containing laminated sheet according to [1], which includes a base material layer and an aluminum vapor deposition layer formed on one surface of the base material layer. [3] The barrier layer-containing laminated sheet according to [1] or [2], which includes an aluminum foil. [4] A packaging container, at least one surface of which is formed from the laminated sheet according to any one of [1] to [3]. [5] The packaging container according to [4], wherein the packaging container is a refill pouch container or a retort pouch container.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a laminated sheet and a packaging container that have an aluminum foil layer or an aluminum vapor deposition layer and have excellent color tone of the printing layer.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] Embodiments of the laminated sheet and the packaging container of the present invention will be described. Note that this embodiment is specifically described to better understand the gist of the invention, and does not limit the present invention unless otherwise specified.

[0010] [Laminated Sheet] FIG. 1 is a cross-sectional view schematically showing an embodiment of the laminated sheet of the present embodiment. As shown in FIG. 1, the laminated sheet 10 has, in this order, a sealant layer 11, a barrier layer 13, a white film layer 15, a white printing layer 17, and a surface base material layer 18. Specifically, the laminated sheet 10 has, in this order, a sealant layer 11, a first adhesive layer 12, a barrier layer 13, a second adhesive layer 14, a white film layer 15, a third adhesive layer 16, a white printing layer 17, and a surface base material layer 18. Note that the laminated sheet 10 may have, in this order, a sealant layer 11, a first adhesive layer 12, a barrier layer 13, a second adhesive layer 14, a white printing layer 17, a third adhesive layer 16, a white film layer 15, and a surface base material layer 18.

[0011] The sealant layer 11 is a layer used for heat-sealing the laminated sheet 10. For example, by folding the laminated sheet 10 or facing two or more sheets to each other with the sealant layer 11 facing inward and fusing the sealant layers 11 together, the laminated sheet 10 is heat-sealed (joined). In the package formed of the laminated sheet 10, the sealant layer 11 may be the innermost layer.

[0012] The sealant layer 11 is not particularly limited, and examples thereof include resin films such as polyolefin resin films such as an unstretched polypropylene (CPP) resin film, an unstretched polyethylene (PE) resin film, and a cyclic olefin resin film. The sealant layer 11 is not limited to a single layer, and may have a structure in which two or more resin films are laminated. In addition, a resin derived from biomass can be used for the resin film of the sealant layer 11. The thickness of the sealant layer 11 is not particularly limited, but is preferably, for example, 30 μm or more and 150 μm or less.

[0013] As the first adhesive layer 12, a configuration in which a sealant layer 11 and a barrier layer 13 are adhered can be mentioned. The adhesive used for the first adhesive layer 12 is not particularly limited, and examples thereof include curable adhesives such as urethane-based adhesives and epoxy-based adhesives, and adhesive resins such as carboxylic acid-modified polyolefin resins. The adhesive used for the first adhesive layer 12 can be appropriately selected and used according to the material of the adherend (sealant layer 11, barrier layer 13), etc. The thickness of the first adhesive layer 12 is not particularly limited, but for example, it is preferably 0.5 μm or more and 5 μm or less.

[0014] The barrier layer 13 includes a base material layer 20 and an aluminum vapor deposition layer 21 formed on one surface 20a of the base material layer 20. The thickness of the barrier layer 13 is not particularly limited, but for example, it is preferably 12 μm or more and 38 μm or less. The barrier layer 13 may be provided such that the aluminum vapor deposition layer 21 is located on the sealant layer 11 side, or may be provided such that the aluminum vapor deposition layer 21 is located on the white film layer 15 side.

[0015] Examples of the base material layer 20 include resin films such as polyethylene terephthalate (PET) films, nylon films, stretched polypropylene films, and unstretched polypropylene films. The base material layer 20 is not limited to a single layer, and a configuration in which two or more resin films are laminated may also be used. The thickness of the base material layer 20 is not particularly limited, but for example, it is preferably 12 μm or more and 50 μm or less.

[0016] The aluminum vapor deposition layer 21 is a layer formed on one surface 20a of the base material layer 20 by a vapor deposition method. The thickness of the aluminum vapor deposition layer 21 is not particularly limited, but for example, it is preferably 0.01 μm or more and 0.3 μm or less.

[0017] As the second adhesive layer 14, a configuration in which the barrier layer 13 and the white film layer 15 are adhered can be mentioned. The adhesive used for the second adhesive layer 14 is not particularly limited, but for example, the same adhesives as those used for the first adhesive layer 12 can be mentioned. The adhesive used for the second adhesive layer 14 can be appropriately selected and used according to the material of the adherend (barrier layer 13, white film layer 15), etc. The thickness of the second adhesive layer 14 is not particularly limited, but for example, it is preferably 0.5 μm or more and 5 μm or less.

[0018] The white film layer 15 is a layer containing a base resin and a white pigment dispersed in the base resin. In order to obtain the laminated sheet 10 having the desired whiteness, that is, in order to make the light transmittance (554 nm) when visible light is irradiated from the visual side to the laminate including the white film layer 15, the white printing layer 17, and the surface base material layer 18, for example, 30% or less, the content of the white pigment in the white film layer 15, the average particle diameter of the white pigment, the type of the white pigment, and the thickness of the white film layer 15 are adjusted.

[0019] The thickness of the white film layer 15 is not particularly limited, but for example, it is preferably 12 μm or more and 50 μm or less.

[0020] The base resin is not particularly limited, but for example, polyethylene terephthalate (PET), polyethylene, polypropylene, etc. can be mentioned.

[0021] The white pigment is not particularly limited, but for example, titanium oxide, zinc white, calcium carbonate, kaolin, etc. can be mentioned. Among these, titanium oxide is particularly preferable. As titanium oxide, there are rutile type, anatase type, brookite type, etc., and among these, rutile type is particularly preferable.

[0022] The average particle diameter of the white pigment is 0.1 μm or more and 0.5 μm or less, preferably 0.2 μm or more and 0.4 μm or less. If the average particle diameter of the white pigment is at least the above lower limit value, the efficiency of visible light scattering is good and the whiteness is improved. On the other hand, if the average particle diameter of the white pigment is at most the above upper limit value, white color can be obtained without making the coating film or the like brittle.

[0023] The average particle diameter of the white pigment can be measured, for example, by a particle size distribution measuring device based on the laser diffraction scattering method. As the average particle diameter, for example, the 50% cumulative particle diameter (mass basis or volume basis), the most frequent particle diameter, etc. can be adopted. As the particle size distribution measuring device, for example, SALD-7000 manufactured by Shimadzu Corporation can be used. The average particle diameter may be the average value of the measured values for a sufficient number (for example, 100 or more) of particles based on the image of the observed particles. The image of the particles is, for example, an observation image obtained using an optical microscope, an electron microscope or other devices. As the particle diameter of non-spherical particles, for example, the average value of the longest diameter and the shortest diameter in the observation image may be adopted.

[0024] Examples of the third adhesive layer 16 include a configuration in which the white film layer 15 and the white printing layer 17 are adhered. The adhesive used for the third adhesive layer 16 is not particularly limited, and examples thereof include the same adhesives as those used for the first adhesive layer 12. The adhesive used for the third adhesive layer 16 can be appropriately selected and used according to the material of the adherend (white film layer 15, white printing layer 17), etc. The thickness of the third adhesive layer 16 is not particularly limited, but is preferably 0.5 μm or more and 5 μm or less, for example.

[0025] The white printing layer 17 may be formed over the entire surface of one side of the surface base material layer 18 (the side on the side of the third adhesive layer 16), or may be formed on a part of one side of the surface base material layer 18. The layer provided for the purpose of light-shielding property is preferably formed over the entire surface of one side of the surface base material layer 18. The layer provided for the purpose of design property, information display, etc. may be patterned so as to constitute characters, figures, images, patterns, etc. on the surface. In order to obtain the laminated sheet 10 having the desired whiteness, that is, in order to make the light transmittance (554 nm) when visible light is irradiated from the visible side to the laminate including the white film layer 15, the white printing layer 17, and the surface base material layer 18, for example, 30% or less, in addition to adjusting the content of the white pigment, the average particle diameter of the white pigment, the type of the white pigment, and the thickness of the white film layer 15 in the above-described white film layer 15, the type of the ink used for forming the white printing layer 17 and the thickness of the white printing layer 17 are adjusted. Note that the thickness of the white printing layer 17 is adjusted according to the thickness of the white film layer 15. That is, the total of the thickness of the white printing layer 17 and the thickness of the white film layer 15 is within a predetermined range.

[0026] The thickness of the white printing layer 17 is not particularly limited, but is preferably, for example, 0.1 μm or more and 10 μm or less. The lower limit value of the thickness of the white printing layer 17 is more preferably 0.5 μm or more, further preferably 2.0 μm or more, and most preferably 3.0 μm or more. The upper limit value of the thickness of the white printing layer 17 is more preferably 8 μm or less, and further preferably 5 μm or less.

[0027] The white printing layer 17 can be composed of, for example, white ink containing a white pigment and a binder. The white pigment is not particularly limited, and examples thereof include titanium oxide, zinc white, calcium carbonate, kaolin, and the like. Among these, titanium oxide is particularly preferable. As titanium oxide, there are rutile type, anatase type, brookite type, etc., and among these, rutile type is particularly preferable.

[0028] The average particle size of the white pigment may be 0.3 μm or less, or may exceed 0.3 μm. Specific examples include 1 μm or less, or 0.1 μm or more and 0.3 μm or less. The average particle size of the white pigment can be measured by a particle size distribution measuring device based on the above-mentioned laser diffraction scattering method.

[0029] The binder is not particularly limited, and examples include polyurethane resins, acrylic resins, etc. Among these, polyurethane resins are particularly preferred. Examples of the polyol used in the polyurethane resin include polyether polyols, low molecular weight polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, glycols, acrylic polyols, etc. Examples of the diisocyanate compound used in the polyurethane resin include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc.

[0030] The ink used when forming the white printing layer 17 is preferably a solvent-based paint in which the white pigment and the binder are dispersed or dissolved. The solvent is not particularly limited, and examples include toluene, ethyl acetate, methyl acetate, propyl acetate, methyl ethyl ketone, methyl isobutyl ketone, propyl alcohol, isopropyl alcohol, normal propyl alcohol, 1-methoxy-2-propanol, etc. The printing layer composed of the solvent-based paint can form a thin film cured layer by applying and drying the solvent-based paint. The printing method is not particularly limited, and examples include offset printing, gravure printing, screen printing, etc.

[0031] The visible light transmittance of the white printing layer 17 is preferably, for example, 60% or less, more preferably 50% or less, in the entire wavelength range of visible light (wavelength 380 nm to 750 nm). The concealability of the aluminum vapor deposition layer 21 on the back side of the white printing layer 17 and the color (silver) of the aluminum foil 31 described later is improved, and the whiteness is enhanced.

[0032] The white printing layer 17 may have a multi-layer structure of two or more layers. By making the white printing layer 17 into a multi-layer structure of two or more layers, the visible light transmittance is made lower than that of a single-layer structure, so that the concealability of the aluminum vapor deposition layer 21 on the back side of the white printing layer 17 and the color (silver) of the aluminum foil 31 described later is improved, and the whiteness is enhanced. By enhancing the whiteness, for example, when displaying characters, figures, images, patterns, etc. by coloring, the contrast with the background becomes larger, and the display can be easily visually recognized.

[0033] The surface base material layer 18 is not particularly limited, and examples thereof include thermoplastic resin films such as polyethylene terephthalate (PET) resin film, polyamide (PA) resin film, polyethylene naphthalate (PEN) resin film, polyacrylonitrile (PAN) resin film, polycarbonate (PC) resin film, polyimide (PI) resin film, polyolefin resin film, and polyester resin film (not limited to PET and PEN). The resin film may be colored or colorless and transparent. When the resin film is colored, the resin film may have a pattern printing layer. The pattern printing layer may be formed on the surface of the laminated sheet 10 of the resin film that becomes the outermost surface, may be formed on the surface of the resin film on the side of the white printing layer 17, or may be embedded inside the resin film.

[0034] The light transmittance of the resin film is not particularly limited. The resin film may be transparent or opaque, and may have light-shielding properties or light-transmitting properties.

[0035] The surface base material layer 18 is not limited to a single layer, and a structure in which two or more resin films are laminated may be used. The thickness of the resin film constituting the surface base material layer 18 is not particularly limited, but for example, it is preferably 5 μm or more and 50 μm or less.

[0036] The resin film constituting the surface base material layer 18 may include a resin film having the function of a reinforcing layer. The reinforcing layer is not particularly limited, and examples thereof include aliphatic polyamide resins such as nylon (6-nylon, 6,6-nylon, etc.), polyester resins such as polyethylene terephthalate (PET), and polyolefin resins such as polypropylene (PP) and polyethylene (PE). Among these, stretched resin films such as biaxially stretched nylon (O-Ny), biaxially stretched polyethylene terephthalate (O-PET), and biaxially stretched polypropylene (OPP) are preferred. In addition, as the resin film of the surface base material layer 18, a resin derived from biomass can be used.

[0037] When the surface base material layer 18 is composed of a plurality of resin films, an adhesive layer may be provided between the respective resin films. The adhesive used for the adhesive layer between the resin films constituting the surface base material layer 18 is not particularly limited, and examples thereof include curable adhesives such as urethane-based adhesives and epoxy-based adhesives, and adhesive resins such as carboxylic acid-modified polyolefin resins. It can be appropriately selected and used according to the material of the adherend and the like. The thickness of the adhesive layer between the resin films constituting the surface base material layer 18 is preferably, for example, 0.5 μm or more and 5 μm or less.

[0038] The manufacturing method of the laminated sheet 10 is not particularly limited. For example, it includes a step of obtaining a surface material by printing a pattern printing layer or a white printing layer 17 on the surface base material layer 18, a step of extruding a base resin containing a white pigment to obtain a white film layer 15, a step of providing an aluminum vapor deposition layer 21 on one surface 20a of the base material layer 20 to obtain a barrier layer 13, and a step of laminating and integrating the surface material, the white film layer 15, the barrier layer 13, and the sealant layer 11 in a predetermined order through the first adhesive layer 12, the second adhesive layer 14, and the third adhesive layer 16. From the perspective of productivity, dry lamination is preferred as the laminating method.

[0039] According to the laminated sheet 10 of the present embodiment, since it has the sealant layer 11, the barrier layer 13, the white film layer 15, the white printing layer 17, and the surface base material layer 18 in this order, it has an excellent color tone of the white printing layer 17 while having the aluminum vapor deposition layer 21.

[0040] In the laminated sheet 10 of the present embodiment, the light transmittance when visible light is irradiated on the laminate including the white film layer 15, the white printing layer 17, and the surface base material layer 18 from the visible side is preferably, for example, 30% or less at 554 nm, which is the wavelength at which humans feel the brightest. As shown in the examples described later, by providing the white printing layer 17 and the white film layer 15, the light transmittance of the laminate at 554 nm is reduced, the lightness (L* value) on the surface of the visible side is improved, and the brightness of the color tone increases. This indicates that the light rays contributing to the brightness of the color tone are blocked by the white film layer 15 and the white printing layer 17, the light transmittance of the light rays incident on the laminated sheet 10 from the surface base material layer 18 side in the laminate decreases, and the amount of light rays reaching the aluminum vapor deposition layer 21 decreases. Therefore, it is possible to suppress the appearance of the pattern printing layer provided on the surface base material layer 18 from looking black due to the influence of the aluminum vapor deposition layer 21, and to realize a laminated sheet 10 with an excellent color tone of the pattern printing layer. In addition, since the laminated sheet 10 has a barrier layer (aluminum vapor deposition layer 21), it is possible to construct a packaging container with excellent storage properties for the contents.

[0041] [Other Embodiments] Note that the present invention is not limited to the above-described embodiments.

[0042] For example, a laminated sheet 30 according to a modified example as shown in FIG. 2 may be employed. In the laminated sheet 30 according to the modified example, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted, and only the different points will be described.

[0043] In the laminated sheet 30 according to the modified example shown in FIG. 2, the barrier layer 13 includes an aluminum foil 31.

[0044] The thickness of the aluminum foil 31 is not particularly limited, but for example, it is preferably 5 μm or more and 15 μm or less.

[0045] The manufacturing method of the laminated sheet 30 is not particularly limited. For example, a step of obtaining a surface material by printing a pattern printing layer or a white printing layer 17 on the surface base material layer 18, a step of obtaining a white film layer 15 by extrusion molding a base resin containing a white pigment, and the surface material, the white film layer 15, the barrier layer 13 (aluminum foil 31), and the sealant layer 11 are laminated and integrated in a predetermined order via the first adhesive layer 12, the second adhesive layer 14, and the third adhesive layer 16. The lamination method is preferably dry lamination from the viewpoint of productivity.

[0046] In the laminated sheet 30 of the present embodiment, the light transmittance when visible light is irradiated on the laminate including the white film layer 15, the white printing layer 17, and the surface base material layer 18 from the visible side is preferably, for example, 30% or less at 554 nm, which is the wavelength at which humans feel the brightest. According to the laminated sheet 30 of the present embodiment, the same effects as those of the laminated sheet 10 of the above-described embodiment can be obtained.

[0047] [Packaging Container] FIG. 3 is a cross-sectional view showing an embodiment of a packaging container. The packaging container 100 of the present embodiment is a standing pouch having a body portion formed by joining both side edges of a pair of body sheets 101 to each other, and a bottom portion formed by joining a bottom sheet 102 to the lower edge of the body sheet 101 and folding it between the body sheets 101. The joint portion between the sheets can be constituted by heat-sealing the sealant layers provided on the innermost layer of each sheet.

[0048] The bottom sheet 102 is folded with the fold line 102a facing upward. The lower edge 102b of the bottom sheet 102 and the lower edge 101b of the body sheet 101 are joined to form a lower edge joint portion. The length of the body sheet 101 from the upper edge 101a to the lower edge 101b is made larger than the length from the fold line 102a of the bottom sheet 102 to the lower edge 101b. An accommodation portion 103 for the content is formed between the body sheets 101 on the bottom sheet 102. Also, an opening 104 for taking the content in and out can be formed above the accommodation portion 103.

[0049] FIG. 4 and FIG. 5 are front views showing different specific examples of the packaging container 100 of FIG. 3. The packaging container 100A shown in FIG. 4 has a tapered spout 106 at the upper part. The packaging container 100B shown in FIG. 5 has the upper edge 101a of the body sheet 101 substantially parallel to the lower edge 101b and is generally substantially rectangular. Both side edges of the body sheet 101 are joined by a side edge joint portion 101s. The opening 104 can be sealed by an upper edge joint portion 105 that joins between the upper edges 101a of the body sheets 101.

[0050] Near the side edge joint portion 101s, the upper edge joint portion 105, the spout 106, etc., notches may be provided to facilitate the opening of the packaging containers 100, 100A, 100B. The shape of the notch is not particularly limited, and examples include V-shaped, U-shaped, I-shaped, etc. When making the packaging container resealable, for example, a closure such as a spout may be provided between the body sheets 101. The spout has a cylindrical portion through which the content can pass, and the tip of the cylindrical portion can be closed by a cap, a stopper, etc.

[0051] The above-mentioned laminated sheet 10 can be used for forming at least one surface constituting the packaging container. In the above-mentioned packaging containers 100, 100A, and 100B, the laminated sheet 10 can be used for the bottom sheet 102. Since the light-shielding property of the printing layer of the above-mentioned laminated sheet 10 is high, sufficient light-shielding property can be obtained without increasing the thickness. In addition, since the bonding strength between the printing layer and the adhesive layer of the above-mentioned laminated sheet 10 is improved, ink cracking, reduction of film strength, etc. are less likely to occur. Therefore, when the above-mentioned laminated sheet 10 is used for the bottom sheet 102, deterioration of the printing layer at the folding line 102a can be suppressed.

[0052] When packaging the contents in the packaging containers 100, 100A, and 100B, for example, a method of filling the contents into the accommodating portion 103 from the opening portion 104 and then sealing the opening portion 104 can be adopted. The packaging containers 100, 100A, and 100B filled with the contents can be subjected to high-temperature sterilization treatments such as retort sterilization and boiling sterilization. Retort sterilization refers to a sterilization method in which heating is performed under a pressure exceeding atmospheric pressure using steam or hot water at a temperature exceeding 100°C, for example, 110°C to 140°C. The heating time is not particularly limited, and for example, 1 minute to 90 minutes can be mentioned. Depending on the nature of the contents, it is also possible to fill without performing the high-temperature sterilization treatment. In addition, by sterilizing the packaging containers 100, 100A, and 100B before filling and then filling the contents in a clean environment, a sterile package can be obtained without performing the high-temperature sterilization treatment.

[0053] The use of the packaging container is not particularly limited, and examples include a pouch container for refilling, a retort pouch container, etc. A pouch container for refilling is a pouch container filled with (or for filling) the contents to be refilled into another container (for example, a bottle container). A retort pouch container is a pouch container that has been (or for which) subjected to retort sterilization treatment after filling. The contents of the packaging container are not particularly limited, and may be, for example, liquids, powders, granules, small pieces, lumps, molded articles, etc., such as foods, beverages, seasonings, cosmetics, detergents, bleaching agents, waxes, hair care products (shampoos, rinses, conditioners, etc.), electronic components, medical components, medical device components, precision mechanical components, and the like.

[0054] As described above, the present invention has been described based on preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. Since the laminated sheet of the present embodiment is excellent in gas barrier properties and light shielding properties, it can be used not only for packaging materials other than pouch containers, such as lid sheet materials for cup containers and bottle containers, but also for light shielding sheets, design sheets, cosmetic sheets, and the like.

Examples

[0055] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples.

[0056] [Examples] A laminated sheet having the configuration shown in FIG. 1 was manufactured. A pattern was printed on one surface of a nylon film having a thickness of 12 μm with a light intermediate color printing ink to form a pattern printing layer. White ink was printed on the pattern printing layer to form a single-layer white printing layer on the entire surface of the nylon film as a surface material. As the white ink for forming the white printing layer, Rialpha (registered trademark) manufactured by Toyo Ink Co., Ltd. was used. Separately, a white film having a thickness of 13 μm, Teflex (registered trademark) FW2 manufactured by Toyobo Film Solutions Co., Ltd., was used as the white film. In addition, a barrier material having an aluminum vapor deposition layer was prepared on the entire surface of one surface of a PET film having a thickness of 12 μm. An unstretched PE resin film having a thickness of 110 μm was prepared as the sealant layer. By dry lamination, a sealant layer and a PET film as a barrier material were adhered via an adhesive, an aluminum vapor deposition layer of the barrier material and a white film were adhered via an adhesive, and the white film and a white printing layer of a surface material were adhered via an adhesive to obtain a laminated sheet.

[0057] [Comparative Example 1] A laminated sheet was produced in the same manner as in the example, except that the white film was not used in the example. The structure of the laminated sheet is an unstretched PE resin film / adhesive layer / PET film / aluminum vapor deposition layer / adhesive layer / white printing layer / pattern printing layer / nylon film.

[0058] [Comparative Example 2] A laminated sheet was produced in the same manner as in the example, except that the white printing layer was not used in the example. The structure of the laminated sheet is an unstretched PE resin film / adhesive layer / PET film / aluminum vapor deposition layer / adhesive layer / white film / adhesive layer / pattern printing layer / nylon film.

[0059] [Measurement of Light Transmittance and Lightness (L* value)] Regarding the laminated sheet of the example, a laminate (excluding the pattern printing layer) including the white film, the white printing layer, and the surface base material layer was used as a sample, and the light transmittance and lightness (L* value) were measured by the following method. Regarding the laminated sheet of Comparative Example 1, a laminate (excluding the pattern printing layer) including the white printing layer and the surface base material layer was used as a sample, and the light transmittance and lightness (L* value) were measured by the following method. Regarding the laminated sheet of Comparative Example 2, a laminate (excluding the pattern printing layer) including the white film and the surface base material layer was used as a sample, and the light transmittance and lightness (L* value) were measured by the following method.

[0060] The measurement of light transmittance was carried out using an ultraviolet-visible spectrophotometer (product name: V-670, manufactured by JASCO Corporation, using an integrating sphere device). Visible light (wavelength 200 - 800 nm, bandwidth 1.0 nm) was irradiated from the side of the outermost PET film, and the light transmittance was measured. Table 1 shows the measurement results of the light transmittance at a wavelength of 554 nm, which is the wavelength at which humans feel the brightest. The measurement of lightness (L* value) was performed using a color difference meter under the conditions of C light source and 2° with the outermost nylon film as the measurement surface. The measurement results are shown in Table 1.

[0061]

Table 1

[0062] As shown in the results of Table 1, the samples of the examples with the white film and the white printing layer had a lower light transmittance at 554 nm and an improved surface lightness (L* value). On the other hand, the samples of Comparative Example 1 and Comparative Example 2, which had only one of the white printing layer or the white film, had a higher light transmittance at 554 nm and a lower surface lightness (L* value) than the examples. When the laminated sheets produced in the examples, Comparative Example 1, and Comparative Example 2 were observed from the surface material side, the laminated sheets of Comparative Example 1 and Comparative Example 2 were dark. Therefore, the color tone of the laminated sheet of the example appeared brighter than that of Comparative Example 1 and Comparative Example 2.

Explanation of Reference Signs

[0063] 10, 30 Laminated Sheet 11 Sealant Layer 12 First Adhesive Layer 13 Barrier Layer 14 Second Adhesive Layer 15 White Film Layer 16 Third Adhesive Layer 17 White Printing Layer 18 Surface Substrate Layer 20 Substrate Layer 21 Aluminum Evaporation Layer 31 Aluminum Foil 100, 100A, 100 Packaging containers 101 Body sheet 101a Upper edge of the body sheet 101b Lower edge of the body sheet 101s Side edge joint of the body sheet 102 Bottom sheet 102a Fold line of the bottom sheet 102b Lower edge of the bottom sheet 103 Accommodation part 104 Opening 105 Upper edge joint 106 Pouring outlet

Claims

1. It has a sealant layer, a barrier layer, a white film layer, a white printing layer, and a surface base material layer, The surface base material layer includes a resin film having the function of a reinforcing layer, and the reinforcing layer is a stretched resin film of an aliphatic polyamide resin or a polyester resin, The white film layer includes a base resin and a white pigment dispersed in the base resin, and the average particle diameter of the white pigment is 0.1 μm or more and 0.5 μm or less, The white pigment is titanium oxide, The thickness of the white film layer is 12 μm or more and 50 μm or less, The visible light transmittance of the white printing layer is 60% or less, A laminated sheet in which the light transmittance at 554 nm of a laminate including the white film layer, the white printing layer, and the surface base material layer is 21% or less.

2. The white printing layer is composed of white ink containing a white pigment and a binder, The laminated sheet according to claim 1, wherein the thickness of the white printing layer is 0.1 μm or more and 10 μm or less.

3. The laminated sheet according to claim 1 or 2, wherein the barrier layer includes a base material layer and an aluminum vapor deposition layer formed on one surface of the base material layer.

4. The laminated sheet according to any one of claims 1 to 3, wherein the barrier layer includes an aluminum foil.

5. A packaging container, at least one surface of which is formed from the laminated sheet according to any one of claims 1 to 4.

6. The packaging container according to claim 5, wherein the packaging container is a refill pouch container or a retort pouch container.

Images