Packaging materials, packaging containers and lids

Abstract

To provide a packaging material capable of imparting a calm metallic luster.SOLUTION: The packaging material includes at least a plastic film, a printing layer, an adhesive layer, and a sealant layer, stacked in this order from the outer layer side. The printing layer and the adhesive layer are adjacent to each other. The packaging material has a brilliant printing layer containing a brilliant pigment and a binder resin as the printing layer. The packaging material satisfies the following conditions 1 and 2. <Condition 1> Diffuse light reflection SCE is measured from the outer layer side of the packaging material, and when an L* value of the L*a*b* color system calculated from a spectral spectrum of the diffused light reflection SCE is denoted as an L*SCE, the L*SCE is 40 or more. <Condition 2> The 60-degree mirror glossiness is measured from the outer layer side of the packaging material in accordance with JIS Z8741: 1997, and a coefficient of variation of the 60-degree mirror glossiness calculated from the measured value is 0.100 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a packaging material, a packaging container, and a lid. [Background technology]

[0002] Packaging materials are sometimes decorated with a high-brightness metallic luster to enhance the luxury and splendor of the packaged items and to create a beautiful appearance. As such a decorative means, for example, a metal layer such as a metal vapor deposition film or a metal foil is generally formed.

[0003] However, packaging materials using metal layers have the problem of increased costs, and among metal layers, metal vapor deposition films have the problem of poor manufacturing efficiency because they cannot be produced in-line with other layers that make up the packaging material, and among metal layers, metal foils have the problem of being difficult to handle. Furthermore, when packaging material using a metal layer is heated in a microwave oven, the microwaves inside the microwave oven are reflected on the surface of the metal layer, causing sparks, which may lead to microwave oven failure or an accident, and there is also the problem that the contents inside the packaging container may not be heated sufficiently.

[0004] For this reason, for example, Patent Document 1 proposes a packaging material in which a glossy layer is formed from an ink agent containing a high-brightness aluminum paste of a predetermined concentration, instead of a metal layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-81589 Summary of the Invention [Problem to be solved by the invention]

[0006] However, packaging materials in which a glossy layer is formed using aluminum paste, as in Patent Document 1, have a certain metallic luster, but there have been many cases where they do not suit the tastes of people who prefer subdued designs.

[0007] The present invention has been made to solve the above-mentioned technical problems, and aims to provide a packaging material that can impart a subdued metallic luster, as well as a packaging container and a lid body that use the packaging material. [Means for solving the problem]

[0008] That is, the present invention provides the following [1] to [3]. [1] A packaging material having a structure in which at least a plastic film, a printing layer, an adhesive layer, and a sealant layer are laminated in this order from the outer layer side, the printing layer and the adhesive layer are adjacent to each other, the printing layer has a photoluminescent printing layer containing a photoluminescent pigment and a binder resin, and satisfies the following conditions 1 and 2. <Condition 1> Diffuse light reflection SCE was measured from the outer layer side of the packaging material, and L calculated from the spectrum of diffuse light reflection SCE * a * b * Color space L * Value L * When SCE is used, L * SCE is 40 or higher. <Condition 2> The 60-degree specular gloss is measured from the outer layer side of the packaging material in accordance with JIS Z8741:1997, and the coefficient of variation of the 60-degree specular gloss calculated from the measured values ​​is 0.100 or more. [2] A packaging container at least a portion of which is formed from the packaging material described in [1] above. [3] A lid formed from the packaging material described in [1] above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a packaging material, a packaging container, and a lid that can be imparted with a subdued metallic luster. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing an example of a layered structure of a packaging material of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing an example of a layered structure of a packaging material of the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of a layered structure of a packaging material of the present invention. [Figure 4] FIG. 2 is an image diagram of a cross section of a glittering printed layer 3a of the packaging material of the embodiment. [Figure 5] FIG. 10 is an image diagram of a cross section of a glittering printed layer 3a of a packaging material of a comparative example. [Figure 6] FIG. 1 is a cross-sectional view showing an example of a pouch for use in a microwave oven among the packaging containers of the present invention. [Figure 7] 1 is a top view showing an example of a lidded container among the packaging containers of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along line IV-IV of FIG. 7. [Figure 9] FIG. 2 is a schematic cross-sectional view showing another example of the layered structure of the packaging material of the present invention. [Figure 10] FIG. 10 is a schematic plan view showing another example of a microwave pouch among the packaging containers of the present invention. [Figure 11] 11 is a cross-sectional view taken along the line XI-XI in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The packaging material of the present invention, and the packaging container and lid using the packaging material will be described in detail below. In this specification, the expression "AA to BB" as a numerical range means "not less than AA and not more than BB."

[0012] [Packaging material] The packaging material of the present invention has a configuration in which at least a plastic film, a printing layer, an adhesive layer, and a sealant layer are laminated in this order from the outer layer side, the printing layer and the adhesive layer are adjacent to each other, the printing layer has a photoluminescent printing layer containing a photoluminescent pigment and a binder resin, and satisfies the following conditions 1 and 2. <Condition 1> Diffuse light reflection SCE was measured from the outer layer side of the packaging material, and L calculated from the spectrum of diffuse light reflection SCE * a * b * Color space L * Value L * When SCE is used, L * SCE is 40 or higher. <Condition 2> The 60-degree specular gloss is measured from the outer layer side of the packaging material in accordance with JIS Z8741:1997, and the coefficient of variation of the 60-degree specular gloss calculated from the measured values ​​is 0.100 or more.

[0013] <Layer structure> Figures 1 to 3 show an outline of the layer structure in the thickness direction of the packaging material 1 of the present invention. In Figures 1 to 3, the upper side is the outer layer side and the lower side is the inner layer side. The packaging material 1 in Figures 1 to 3 has a plastic film 2, a printed layer (a printed layer having a glittering printed layer 3a), an adhesive layer 6a, and a sealant layer 4 layered in this order from the outer layer side. 1 to 3 have an intermediate substrate layer 5 and another adhesive layer 6b between the printed layer and the sealant layer 4. The packaging material 1 in Fig. 2 has a picture printed layer 3b on the outer layer side of the glossy printed layer 3a as a printed layer, and the packaging material 1 in Fig. 3 has a picture printed layer 3b in parallel with the glossy printed layer 3a as a printed layer. The packaging material 1 in Fig. 3 also has a solid printed layer 3d on the inner layer side of the glossy printed layer 3a as a printed layer.

[0014] In addition, the packaging material 1 may have a gas barrier layer (not shown) formed between the plastic film 2 and the printed layer (printed layer having a photoluminescent printed layer 3a) or between the printed layer (printed layer having a photoluminescent printed layer 3a) and the sealant layer 4. Specific examples of the packaging material of the present invention include the following layered structures (1) to (4): In the following structures (1) to (4), the left-hand layer is the outer layer, and " / " indicates the boundary between layers. (1) Plastic film / Printed layer with photoluminescent printed layer / Adhesive layer / Intermediate substrate layer / Adhesive layer / Sealant layer (2) Plastic film / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / sealant layer (3) Plastic film / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / intermediate substrate layer / adhesive layer / sealant layer (4) Plastic film / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / intermediate substrate layer / adhesive layer / sealant layer In order to make the glossy printing layer visible from the outside, the layers formed on the outer side of the glossy printing layer 3a are made to be optically transparent in at least a portion of their planes. The gas barrier layers of (2) and (3) are preferably a single layer of inorganic oxide vapor deposition film, or a composite layer in which a gas barrier coating film is formed on an inorganic oxide vapor deposition film (in the composite layer, the inorganic oxide vapor deposition film is disposed on the plastic film side). The gas barrier layer of (4) is preferably a single layer of vapor deposition film, or a composite layer in which a gas barrier coating film is formed on a vapor deposition film (in the composite layer, the vapor deposition film is disposed on the intermediate substrate layer side).

[0015] The packaging material of the present invention must satisfy the following condition 1. <Condition 1> Diffuse light reflection SCE was measured from the outer layer side of the packaging material, and L calculated from the spectrum of diffuse light reflection SCE * a * b * Color space L * Value L * When SCE is used, L * SCE is 40 or higher.

[0016] Diffuse reflectance SCE is measured by using an integrating sphere to expose the sample surface to light from all directions and opening the light trap corresponding to the direction of specular reflection. This is the reflected light other than the light that escapes the light trap. When people view an object, they often look at it at an angle where there is no specular reflection. Therefore, the diffuse reflection SCE, which excludes specular reflection, is useful as a parameter for evaluating the appearance of an object. * a * b* Color space L * The value is an index of brightness. Therefore, the L calculated from the diffuse light reflectance SCE * Value (L * SCE) can be said to be useful as a parameter for evaluating the metallic luster of an object. In addition, L * a * b * The color system was standardized by the International Commission on Illumination (CIE) in 1976 and is adopted in JIS Z8781-4:2013.

[0017] L * If the SCE is less than 40 and condition 1 is not met, the metallic luster will not be felt sufficiently. * The SCE is preferably 45 or more, more preferably 50 or more, and even more preferably 55 or more. L * If the SCE is too large, the content of the glitter pigment becomes excessive, and the coating strength of the glitter printing layer tends to decrease. * The SCE is preferably 80 or less, and more preferably 75 or less.

[0018] A typical SCE measurement device is configured to comply with geometric condition c of JIS Z8722:2009. More specifically, a typical SCE measurement device uses D65 as the light source of an integrating sphere spectrophotometer, the position of the light receiver is +8 degrees relative to the normal to the sample, the aperture angle of the light receiver is 10 degrees, the position of the light trap is -8 degrees relative to the normal to the sample, and the viewing angle is 2 degrees or 10 degrees. In this specification, the viewing angle is set to 10 degrees. An example of a measuring device that satisfies the above conditions is a handheld spectrophotometer manufactured by Konica Minolta (product name "CM-700d").

[0019] As used herein, L * The SCE is the average value of the measurements at 20 locations. If the packaging material is light-transmitting, *The SCE and specular gloss are preferably measured from the plastic film side of a sample prepared by laminating a black plate to the sealant layer side surface of the packaging material via a transparent adhesive layer. The refractive index of the transparent adhesive layer of the sample can be such that the difference in refractive index between the sealant layer side layer of the packaging material and the black plate is within 0.05, preferably 0.00. In this specification, the refractive index refers to the refractive index at a wavelength of 589 nm. Also, L * The 20 locations where the SCE and specular gloss are measured are preferably measured at locations where the packaging material has the same layer structure, etc. For example, in the case of the packaging material of FIG. 1, the layer structure is the same at all locations, but in the packaging material of FIG. 2, there are locations that do not have the pattern printed layer 3b and locations that do. In such a case, it is preferable to first measure 20 locations only at locations that do not have the pattern printed layer 3b. Furthermore, in the packaging material of FIG. 2, measurements may be performed at 20 locations only at locations that have the pattern printed layer 3b. In such a case, it is preferable to measure at locations where the pattern printed layer 3b is approximately the same color and density. Furthermore, if part of the packaging material has a textured finish such as embossing, it is preferable to measure at 20 locations that have the textured finish or 20 locations that do not have the textured finish. It is preferable to measure the 20 measurement locations so that the measurement spots do not overlap. However, if the area of ​​the region with the same layer structure, etc. is small, measurements may be performed so that the measurement spots partially overlap. Also, L * It is preferable that the laminate structure etc. at the measurement point of SCE and the laminate structure etc. at the measurement point of specular glossiness are the same. If the results of the measurements as described above show that the laminated structure of the packaging material satisfies conditions 1 and 2 at least at some of the locations, the packaging material falls within the scope of the present invention. For example, in the packaging material of Fig. 2, if either the "measurement results at 20 locations that do not have the picture printed layer 3b" or the "measurement results at 20 locations where the picture printed layer 3b is of approximately the same color and density" satisfies conditions 1 and 2, the packaging material falls within the scope of the present invention.

[0020] The packaging material of the present invention must further satisfy the following condition 2. <Condition 2> The 60-degree specular gloss is measured from the outer layer side of the packaging material in accordance with JIS Z8741:1997, and the coefficient of variation of the 60-degree specular gloss calculated from the measured values ​​is 0.100 or more.

[0021] The coefficient of variation of the 60-degree specular gloss is obtained by dividing the variation (σ) of the 60-degree specular gloss by the average value of the 60-degree specular gloss. A coefficient of variation of 60-degree specular gloss of less than 0.100 means that the metallic gloss is highly uniform across the surface of the packaging material. General metals have excellent flatness and high uniformity of metallic gloss across the surface. Therefore, if the coefficient of variation of the 60-degree specular gloss of a packaging material is less than 0.100, people will get the impression that the packaging material has a high metallic texture and a clumsy design. On the other hand, if the coefficient of variation of the 60-degree specular gloss of the packaging material is 0.100 or more, the metallic texture of the packaging material is suppressed, and people get the impression that the packaging material has a subdued design. In other words, by satisfying conditions 1 and 2, a packaging material with a subdued metallic luster can be obtained.

[0022] The coefficient of variation of the 60-degree specular gloss is preferably 0.110 or more, more preferably 0.130 or more, and even more preferably 0.150 or more. If the coefficient of variation of the 60-degree specular gloss is too large and the uniformity of the metallic gloss within the surface is too low, the metallic gloss may appear uneven. Therefore, the coefficient of variation of the 60-degree specular gloss is preferably 0.300 or less, more preferably 0.250 or less, and even more preferably 0.200 or less.

[0023] Figure 4 is an image of a cross section of the glossy printed layer 3a of a packaging material that satisfies condition 2 (cross section of the glossy printed layer 3a of an embodiment), and Figure 5 is an image of a cross section of the glossy printed layer 3a of a packaging material that does not satisfy condition 2 (cross section of the glossy printed layer 3a of a comparative example). The slope of the glittering pigment y is random in the cross section of the glittering printing layer 3a in Figure 4, whereas the slope of the glittering pigment y is approximately uniform in the cross section of the glittering printing layer 3a in Figure 5. Therefore, the glittering printing layer 3a in Figure 4 has a large difference in specular gloss values ​​and a large coefficient of variation of specular gloss, whereas the glittering printing layer 3a in Figure 5 has approximately uniform specular gloss values ​​and a small coefficient of variation of specular gloss.

[0024] <Plastic film> The plastic film 2 serves as a base material on the outer layer side of the packaging material 1, and is made of a light-transmitting material so that the glittering print layer 3a can be seen from the outside. Specific examples include polyolefin resins such as polyethylene (PE) and polypropylene (PP), cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, poly(meth)acrylic resins, polycarbonate resins, polyvinyl alcohol resins, ethylene-vinyl alcohol copolymer (EVOH), saponified ethylene-vinyl ester copolymers, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyamide resins such as various nylons (Ny), polyurethane resins, acetal resins, cellulose resins, and polyvinylidene chloride resins (PVDC). The plastic film may be uniaxially or biaxially stretched. It may also be a composite film in which two or more of the above resin films are laminated. These plastic films may be formed by an inflation method or a melt extrusion coating method.

[0025] The plastic film is preferably one having excellent heat resistance from the viewpoint of heating in a microwave oven or retort treatment. Examples of resins constituting the plastic film having excellent heat resistance include polyester resins and polyamide resins. Specific examples of plastic films with excellent heat resistance include polyester films alone, polyamide films such as nylon films alone, and composite films containing one or more polyester and polyamide films. Examples of the composite films include co-extruded stretched films having a structure of PET / Ny / PET or PET / Ny from the outer layer side. Furthermore, the composite film preferably combines one or more polyester films and polyamide films with one or more ethylene-vinyl alcohol copolymer films and polyvinylidene chloride films.

[0026] The thickness of the plastic film is not particularly limited and can be set appropriately depending on the use of the packaging material, but it is usually preferably about 5 to 50 μm, more preferably 10 to 40 μm, and even more preferably 12 to 25 μm.

[0027] The plastic film preferably has a total light transmittance of 85% or more, more preferably 90% or more, according to JIS K7361-1:1997, and preferably has a haze of 1.0% or less, more preferably 0.5% or less, and even more preferably 0.3% or less, according to JIS K7136:2000.

[0028] The arithmetic mean roughness Ra of both surfaces of the plastic film is preferably 0.1 μm or less, more preferably 0.05 μm or less, at a cutoff value of 0.8 mm as measured in accordance with JIS B0601: 1994. By setting Ra of both surfaces of the plastic film within the above-mentioned range, the design can be improved.

[0029] <Print layer> The packaging material of the present invention has a printed layer on the inner layer side of the plastic film. The packaging material of the present invention also has a glitter printed layer as the printed layer, which contains a glitter pigment and a binder resin. The printed layer may be formed on the entire surface of the packaging material, or on only a part of the packaging material. Examples of printed layers other than the glitter printed layer include a picture printed layer and a solid printed layer.

[0030] <<Glitter printing layer>> The glittering printed layer 3a may be present on the entire surface of the packaging material as shown in Figures 1 and 2, or may be present on only a portion of the packaging material as shown in Figure 3. Furthermore, a picture printed layer 3b may be present on a portion of the outer layer side of the glittering printed layer 3a as shown in Figure 2. Furthermore, as shown in Figure 3, the glittering printed layer 3a and the picture printed layer 3b may be present side by side at the same position in the thickness direction of the packaging material. Furthermore, the glittering print layer 3a may be used to form pictures such as letters, figures, symbols, designs, and patterns.

[0031] The thickness of the glittering print layer is preferably 0.1 to 8.0 μm, more preferably 0.3 to 5.0 μm, from the viewpoint of being able to leave a sufficient impression of metallic gloss.

[0032] The luster pigment preferably contains at least one selected from metal flakes and pearl pigments.

[0033] Examples of pearl pigments include white pearl pigments, interference pearl pigments, colored pearl pigments, etc. Pearl pigments are preferred because they can easily improve the microwave resistance of packaging materials.

[0034] White pearlescent pigments are made by covering a scaly base material such as mica, aluminum, or glass with a coating layer made of a colorless, high-refractive index material such as titanium dioxide, and the coating layer is relatively thin, about 0.1 to 0.15 μm, and reflects almost all wavelengths of light, so they appear white or silvery. Interference pearlescent pigments have a coating layer made of a colorless, high-refractive-index material such as titanium dioxide, and the thickness of the coating layer is greater than that of white pearlescent pigments, exceeding 0.15 μm. This thickness changes the reflected and transmitted light, producing various interference colors. They are sometimes called rainbow-colored pearlescent pigments. Colored pearl pigments are chromatic, and include those in which the coating layer is made of a colored high refractive index material such as ferric oxide, those in which a white pearl pigment is further coated with a colored high refractive index material such as ferric oxide or other colored pigments, and those in which a pigment or other colorant is added to the coating layer.

[0035] The average length of the pearl pigment is preferably 5 to 70 μm, and more preferably 10 to 40 μm. The average length of the pearl pigment and the average length of the metal flakes are determined as the average length of any 20 particles (pearl pigment or metal flakes) observed from the planar direction of the packaging material using an optical microscope or an electron microscope. The length of one pearl pigment or one metal flake means the maximum length of one pearl pigment or one metal flake in the planar direction.

[0036] The average thickness of the pearl pigment is preferably 0.01 to 1 μm, more preferably 0.02 to 0.7 μm, and even more preferably 0.05 to 0.5 μm. The average thickness of the pearl pigment and metal flakes is determined as the average thickness of any 20 particles (pearl pigment or metal flakes) observed by observing the cross section of the packaging material with an optical microscope or electron microscope. The thickness of one pearl pigment or metal flake is determined by dividing the cross section of one pearl pigment or metal flake into five equal regions in the longitudinal direction, measuring the thickness of the center of each region (t1, t2, t3, t4, t5), and averaging t1 to t5.

[0037] In order to satisfy condition 1 while increasing the coating film strength, the content of the pearl pigment in the glossy printing layer is preferably 40 to 90 mass% of the total solids of the glossy printing layer, more preferably 50 to 85 mass%, and even more preferably 60 to 80 mass%.

[0038] Examples of materials for the metal flakes include metals and alloys such as aluminum, gold, silver, brass, titanium, chromium, nickel, nickel chromium, and stainless steel. The metal flakes can be obtained, for example, by peeling off a thin metal film formed by vacuum-depositing the metal or alloy onto a plastic film, and then crushing and stirring the peeled thin metal film; by mixing a powder of the metal or alloy with a solvent and spreading and / or crushing the powder using a media stirring mill, ball mill, attritor, or the like; or by coating the surfaces of these with a resin.

[0039] The metal flakes are preferably non-leafing metal flakes. Non-leafing metal flakes are uniformly dispersed within the glossy printed layer during the formation process of the layer, and therefore, even if the metal flakes are tilted in the glossy printed layer, the spacing between the metal flakes is prevented from narrowing, thereby preventing sparks from occurring and heat generation from the packaging material when heated in a microwave oven. Non-leafing type metal flakes are metal flakes that have not been surface-treated with stearic acid, and examples thereof include metal flakes that have been surface-treated with a surface treatment agent other than stearic acid, such as oleic acid, and metal flakes that have not been surface-treated.

[0040] The metal flakes are preferably those whose surfaces are coated with a resin, which prevents the spacing between the metal flakes from narrowing even if the metal flakes are tilted in the glittering printing layer, thereby preventing sparks from occurring and heat generation from the packaging material when heated in a microwave oven. Resin-coated metal flakes can be produced by the methods described in, for example, JP-A-62-253668, JP-A-64-40566, JP-A-2003-213157, and JP-A-2012-241039.

[0041] From the viewpoint of uniform dispersion in the glittering printing layer, the metal flakes preferably have an average length of 1 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 30 μm, and from the viewpoint of ease of handling and obtaining high metallic gloss, the average thickness is preferably 0.01 to 5 μm, more preferably 0.02 to 3 μm, and even more preferably 0.05 to 1 μm.

[0042] In order to satisfy condition 1 while achieving good microwave resistance, the content of metal flakes in the glossy printing layer is preferably 3% by mass or more and 50% by mass or less of the total solid content of the glossy printing layer, more preferably 3% by mass or more and less than 40% by mass, and even more preferably 10% by mass or more and 30% by mass or less.

[0043] The aspect ratio (average length / average thickness) of the luster pigment such as pearl pigment and metal flake is preferably 300 or less, more preferably 200 or less, and even more preferably 100 or less. By setting the aspect ratio of the luster pigment to 300 or less, the luster pigment becomes more likely to tilt within the luster printing layer, making it easier to satisfy condition 2. If the aspect ratio of the luster pigment is too small, the luster pigment may be tilted excessively in the luster printing layer, making it difficult to obtain a sufficient metallic luster. For this reason, the aspect ratio of the luster pigment is preferably 25 or more, and more preferably 40 or more.

[0044] Examples of binder resins in the glossy printing layer include polyolefin resins such as polyethylene resins and chlorinated polypropylene resins, poly(meth)acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymers, polystyrene resins, styrene-butadiene copolymers, vinylidene fluoride resins, polyvinyl alcohol resins, polyvinyl acetal resins, polyvinyl butyral resins, polybutadiene resins, polyester resins, polyamide resins, alkyd resins, epoxy resins, unsaturated polyester resins, thermosetting poly(meth)acrylic resins, melamine resins, urea resins, polyurethane resins, phenolic resins, xylene resins, maleic acid resins, cellulose resins such as nitrocellulose, ethyl cellulose, acetylbutyl cellulose, and ethyloxyethyl cellulose, rubber resins such as chlorinated rubber and cyclized rubber, petroleum resins, and natural resins such as rosin and casein. These may be used alone or in combination of two or more.

[0045] The glittering print layer may contain a colorant to enhance the design. As the colorant, general-purpose dyes and pigments (for example, inorganic pigments such as yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue, and organic pigments such as quinacridone red, isoindolinone yellow, and phthalocyanine blue) can be used. From the viewpoint of microwave resistance, it is preferable to use only a very small amount of colorants with low insulating properties, such as carbon black, if any. When the colorant is a pigment, the average particle size is preferably 250 nm or less in order to suppress diffusion of the colorant and maintain metallic luster. The average particle size of the pigment is determined as the mass average value d50 in particle size distribution measurement by laser diffraction method.

[0046] The content of the colorant is preferably 10 to 70 parts by mass, more preferably 20 to 60 parts by mass, and even more preferably 30 to 50 parts by mass, relative to 100 parts by mass of the bright pigment.

[0047] The glittering print layer preferably contains inorganic particles with an average particle size of 1 to 100 nm (hereinafter, sometimes referred to as "inorganic fine particles"). By including inorganic fine particles in the glittering print layer, the glittering pigment is prevented from sinking below the glittering print layer, improving the reflectivity, making it easier to satisfy condition 1. The average particle size of the inorganic fine particles is more preferably 2 to 50 nm, and further preferably 5 to 30 nm. The average particle size of the inorganic fine particles is determined as the mass average value d50 in particle size distribution measurement by laser light diffraction method.

[0048] The content of inorganic fine particles in the glittering print layer is preferably 10 to 70 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 20 to 35 parts by mass, per 100 parts by mass of the glittering pigment.

[0049] Examples of inorganic fine particles include silica, alumina, zirconia, and titania. Among these, silica is preferred because of its excellent transparency. Silica and alumina are also preferred because they have excellent insulating properties and can improve microwave resistance.

[0050] If necessary, any additives may be added to the glossy printing layer, such as fillers, stabilizers, plasticizers, antioxidants, light stabilizers such as ultraviolet absorbers, dispersants, thickeners, drying agents, lubricants, antistatic agents, crosslinking agents, etc.

[0051] <<Picture printing layer>> The packaging material of the present invention may have a picture printed layer 3b as a printed layer. The picture printed layer 3b can be formed, for example, on the outer layer side of the glitter printed layer 3a (FIG. 2), or can be formed so as to be parallel to the glitter printed layer 3a at the same position in the thickness direction of the packaging material (FIG. 3). Note that, in order to prevent the solvent contained in the coating liquid for forming the picture printed layer from excessively disrupting the arrangement of the glitter pigment, it is preferable that the picture printed layer be formed parallel to the glitter printed layer or on the outer layer side of the glitter printed layer.

[0052] The picture print layer 3b is preferably a print layer formed with a color that can be distinguished from the glitter print layer 3a, and is a broad concept that includes letters, figures, symbols, designs, patterns, solid prints, etc. The colorant for the picture print layer 3b can be a general-purpose dye or pigment (for example, inorganic pigments such as yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, cobalt blue, etc., or organic pigments such as quinacridone red, isoindolinone yellow, phthalocyanine blue, etc.). The thickness of the picture print layer is not particularly limited, and is usually about 0.1 to 5 μm, preferably about 1.0 to 5 μm, and more preferably 1.0 to 3 μm. Furthermore, as shown in Figure 2, forming the pattern printing layer 3b on the outer layer side of the glossy printing layer 3a and configuring the pattern printing layer 3b to be light-transmitting is preferable in that it increases the color of the areas that have a metallic luster and improves the design. While adding a colorant to the glossy printed layer is one way to enhance the color of areas with a metallic luster, forming a light-transmitting pattern printed layer on the outer side of the glossy printed layer is preferred. Forming a light-transmitting pattern printed layer on the outer side of the glossy printed layer ensures that most of the colorant is exposed to external light, and light reflected by the glossy printed layer passes through the pattern printed layer again, thereby reducing the amount of colorant used to achieve the same color. Furthermore, since the color of a pattern printed layer is typically expressed using multiple colorants, a configuration in which light reflected by the glossy printed layer passes through the pattern printed layer again allows light to be evenly applied to each colorant, which is preferable in that it reduces color unevenness. Furthermore, forming a light-transmitting pattern printed layer on the outer side of the glossy printed layer is also advantageous in that it makes it easier to increase the content of the glossy pigment in the glossy printed layer.

[0053] Examples of colorants for the light-transmitting picture-printed layer include general-purpose dyes and pigments (for example, inorganic pigments such as yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue, and organic pigments such as quinacridone red, isoindolinone yellow, and phthalocyanine blue). Dyes absorb light at specific wavelengths, which can reduce the intensity of light reflected by the glittering or anti-glittering printed layer. Also, pigments with large average particle sizes tend to scatter light more easily, which can reduce the metallic luster. For this reason, the colorant for the light-transmitting picture-printed layer is preferably a pigment having an average particle diameter of 100 nm or more and less than 380 nm. The average particle diameter of the pigment can be measured by a laser light scattering method.

[0054] The content of the colorant in the light-transmitting picture printed layer is preferably 3 to 50 parts by mass, more preferably 5 to 20 parts by mass, and even more preferably 7 to 15 parts by mass, relative to 100 parts by mass of the binder resin. The thickness of the light-transmitting picture printed layer is preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.6 μm, and even more preferably 0.2 to 0.4 μm.

[0055] <<Solid print layer>> The packaging material of the present invention may have a solid print layer 3d as a print layer. The solid print layer is preferably formed on the inner layer side of the glitter print layer 3a, as shown in FIG. By forming a solid print layer, the appearance of the packaged item can be improved depending on the type of packaged item. The color of the solid print layer is not particularly limited, but it is preferably white, which does not impair the color of the glossy print layer and has excellent hiding power. In other words, the solid print layer is preferably a white solid print layer. In addition, the white solid print layer may contain a small amount of dyes and pigments other than white pigments as colorants to adjust the color.

[0056] The solid print layer may be formed on only a portion of the surface of the packaging material, but from the viewpoint of easily achieving the above-mentioned effects, it is preferable to form it on the entire surface of the packaging material, as shown in Figure 3. The colorant for the solid print layer can be a general-purpose colorant. In the case of a white solid print layer, it is preferable to use one or more colorants selected from titanium oxides such as titanium dioxide, barium sulfate, magnesium oxide, calcium carbonate, zinc oxide, white lead, and other white pigments. The thickness of the solid print layer is not particularly limited, but is preferably about 1.0 to 5 μm, and more preferably 1.0 to 3 μm.

[0057] <Adhesive layer> The adhesive layer is disposed adjacent to the inner layer side of the print layer. The adhesive layer is preferably formed by applying a coating liquid for the adhesive layer, in which the components constituting the adhesive layer are diluted with a solvent, onto the printed layer and drying it. For example, in the case of Figures 1 and 2, the adhesive layer 6a is preferably formed by applying a coating liquid for the adhesive layer 6a onto the glossy printed layer 3a and drying it. Also, in the case of Figure 3, the adhesive layer 6a is preferably formed by applying a coating liquid for the adhesive layer 6a onto the white solid printed layer 3d and drying it. As described above, by applying the adhesive layer coating liquid onto the print layer and drying it to form the adhesive layer, the solvent of the adhesive layer-forming coating liquid penetrates into the shiny print layer of the print layer, and the penetrated solvent disrupts the arrangement of the shiny pigment as shown in Figure 4, which is thought to make it easier to satisfy condition 2. Note that in Figure 4, the arrangement of the shiny pigment is uniformly disrupted in the thickness direction, but if solvent penetration is the cause, it is thought that the arrangement of the shiny pigment closer to the adhesive layer is more likely to be disrupted.

[0058] The solvent content in the adhesive layer coating liquid is preferably 40 to 80% by mass, and more preferably 50 to 70% by mass. By making the solvent content 40% by mass or more, the solvent that has permeated into the glittering printing layer disrupts the arrangement of the glittering pigment, making it easier to satisfy condition 2. Furthermore, by making the solvent content 80% by mass or less, it is possible to prevent the time required for the solvent to dry from becoming excessive.

[0059] Examples of the solvent include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), and mixtures thereof may also be used.

[0060] If the relative evaporation rate of the solvent is slow, the drying time of the solvent will be too long, resulting in poor productivity, and the solvent will be more likely to remain in the packaging material. Furthermore, if the relative evaporation rate of the solvent is slow, the arrangement of the luster pigment may be excessively disordered, resulting in a decrease in metallic luster. Therefore, the relative evaporation rate of the solvent (relative evaporation rate when the evaporation rate of n-butyl acetate is set to 100) is preferably 300 or more, and more preferably 400 or more. On the other hand, if the solvent dries too quickly, it becomes difficult for the solvent to penetrate into the glittering print layer, making it difficult to satisfy condition 2. For this reason, the relative evaporation rate of the solvent is preferably 500 or less, and more preferably 450 or less. For mixed solvents, the relative evaporation rate of each solvent can be calculated by multiplying the relative evaporation rate of each solvent by the mass ratio of each solvent and adding up the results. For example, the relative evaporation rate of a 1:1 mixture of one solvent with a relative evaporation rate of 390 and another with a relative evaporation rate of 430 is 410. Examples of relative evaporation rates are 420 for ethyl acetate, 370 for methyl ethyl ketone (MEK), 200 for toluene, 160 for methyl isobutyl ketone (MIBK), 150 for isopropyl alcohol (IPA), and 32 for cyclohexanone.

[0061] Examples of adhesives include polyvinyl acetate adhesives, polyacrylic ester adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives such as urea resin and melamine resin, phenol resin adhesives, epoxy adhesives, polyurethane adhesives (for example, cured products of polyol and isocyanate compounds), reactive (meth)acrylic acid adhesives, rubber adhesives such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber, silicone adhesives, and inorganic adhesives such as alkali metal silicates and low-melting-point glass.

[0062] The adhesive layer may be disposed at a position adjacent to the inner layer side of the print layer, as well as at other positions. For example, as shown in FIGS. 1 to 3, an adhesive layer may be disposed between intermediate substrate 5 and sealant layer 4.

[0063] The thickness of the adhesive layer is preferably 0.5 to 10 μm, and more preferably 1 to 7 μm.

[0064] <Sealant layer> The inner surface of the sealant layer 4 comes into direct contact with the packaged item, and serves to protect the packaged item. In particular, when the packaging material 1 is used to form a packaging container for a liquid item, the sealant layer 4 is preferably made of a material that is impermeable to the liquid item. In addition, the innermost layer of the sealant layer 4 preferably has heat-sealing properties in order to form a pouch.

[0065] Examples of materials constituting the sealant layer 4 include polyolefin resins such as low-density PE (LDPE), linear low-density PE (LLDPE), medium-density PE (MDPE), high-density PE (HDPE), ethylene-vinyl acetate copolymer, propylene homopolymer, ethylene-propylene block copolymer, and ethylene-propylene random copolymer, and one or more of these resins can be used. The sealant layer 4 may be composed of a single layer or two or more layers. The sealant layer is preferably a non-stretched film made of the above-mentioned resin in order to suppress shrinkage during heat sealing.

[0066] From the viewpoint of heating in a microwave oven or retort processing, in order to enhance heat resistance, it is preferable that the sealant layer be made of a resin with excellent heat resistance. Specifically, propylene-based resins such as propylene homopolymer, ethylene-propylene block copolymer, and ethylene-propylene random copolymer, and HDPE are preferred. It is preferable to use the above propylene-based resins according to the purpose. Specifically, when cold resistance is important (for example, as a packaging material for frozen foods), an ethylene-propylene block copolymer is preferred, when transparency is important, an ethylene-propylene random copolymer is preferred, and when heat resistance is important, a propylene homopolymer is preferred. In addition, in the case of containers equipped with an automatic steaming mechanism, an ethylene-propylene block copolymer is preferred because the seal strength decreases at high temperatures, making it easier to release steam.

[0067] Furthermore, when the packaging material 1 is used to form a lid for a lidded container, the sealant layer 4 preferably has easy-peel properties. Easy peelability refers to the property that, for example, when the sealant layer 4 of the packaging material 1 of the lid of a lidded container is joined to the container body, the lid can be easily peeled from the container body when the lidded container is opened. A sealant layer having easy-peel properties can be formed by mixing two or more resins, one of which is a resin having good adhesion to the container body and another of which is a resin that is not compatible with the first resin. The type of resin varies depending on the material of the container, so no generalization can be made. However, if the container is made of PP, easy-peel properties can be imparted to the PP container by forming a sealant layer from a resin that is a mixture of PP, which is a resin having good adhesion to the container body, and one or more of PE, polybutene, and polystyrene, which are other resins that are not compatible with the first resin and that are not compatible with the first resin. The sealant layer may have a multi-layer structure, and easy peel properties may be imparted only to the side of the sealant layer that is joined to the container body (the innermost layer in the packaging material).

[0068] The thickness of the sealant layer 4 is not particularly limited and is set appropriately depending on the use of the packaging material 1 and the type and properties of the packaged item, but is usually preferably about 10 to 200 μm. In the case of a pouch (particularly a retort pouch), the thickness of the sealant layer 4 is more preferably 20 to 150 μm, and even more preferably 30 to 100 μm. In the case of a container with a lid, the thickness of the sealant layer 4 is more preferably 15 to 80 μm, and even more preferably 20 to 60 μm.

[0069] <Gas barrier layer> The gas barrier layer can be provided anywhere between the plastic film 2 and the sealant layer 4, as needed. The gas barrier layer serves to block the transmission of oxygen, water vapor, and the like between the packaged item in the packaging material 1 and the environment outside the packaging material 1. The gas barrier layer may also impart light-blocking properties, blocking the transmission of visible light, ultraviolet light, and the like. The gas barrier layer may be composed of only one layer, or may be composed of two or more layers. When the gas barrier layer is formed on the outer layer side of the glittering print layer 3a, it is made of a light-transmitting material, similar to the plastic film 2, so that the glittering print layer 3a can be seen from the outside.

[0070] The gas barrier layer can be formed as a vapor-deposited film or a coated film by a known method. The surface on which the gas barrier layer is to be formed may be subjected to a surface treatment in advance in order to improve the adhesion of the gas barrier layer. Examples of surface treatments include corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidizing agent treatment, and application of an anchor coating agent.

[0071] [Vapor-deposited film] Vapor-deposited films, which are an example of gas barrier layers, can be formed from inorganic substances such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc., or oxides thereof. Among these, when the packaging material is for use in a microwave oven, inorganic oxides such as silicon oxide, aluminum oxide, and magnesium oxide are preferred from the viewpoint of ensuring that the packaged food or the like can be sufficiently heated by the microwaves of the microwave oven. Examples of methods for forming a vapor-deposited film include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The vapor-deposited film disposed on the outer side of the printed layer having the glittering printed layer is preferably a vapor-deposited film of an inorganic oxide from the viewpoint of visibility of the printed layer.

[0072] The thickness of the vapor-deposited film varies depending on the forming material, the required gas barrier performance, etc., but is usually preferably about 5 to 200 nm, more preferably 5 to 150 nm, and even more preferably 10 to 100 nm. In the case of inorganic oxides such as silicon oxide and aluminum oxide, the thickness is preferably about 5 to 100 nm, more preferably 5 to 50 nm, and even more preferably 10 to 30 nm.

[0073] [Gas barrier coating film] As an example of the gas barrier layer, a gas barrier coating film may be used, for example, a compound represented by the general formula R 1 n M(OR 2 ) m (In the formula, R 1 , R 2 is an organic group having 1 to 8 carbon atoms, and M is a metal atom. n is an integer of 0 or more, m is an integer of 1 or more, and n+m is the valence of M. The film can be formed by applying a coating liquid obtained by polycondensing at least one alkoxide represented by the formula (I) above with a polyvinyl alcohol resin and / or an ethylene-vinyl alcohol copolymer by a sol-gel method in the presence of a sol-gel catalyst, an acid, water, and an organic solvent, and then heat-treating the liquid at 50 to 300°C for 0.05 to 60 minutes. The coating method can be, for example, by a coating means such as roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, applicator, etc. After one or more coatings, the dry thickness of the coating film is preferably about 0.01 to 30 μm, more preferably 0.05 to 20 μm, and even more preferably 0.1 to 10 μm. From the viewpoint of improving gas barrier properties, the gas barrier coating film is preferably formed on the surface of the vapor-deposited film.

[0074] Examples of packaging materials having a gas barrier layer include the following laminated structures (1') to (6'). In the following structures (1') to (6'), the layer on the left is the outer layer, and " / " indicates the boundary between layers. (1') Plastic film / vapor-deposited inorganic oxide film / printed layer with a photoluminescent printed layer / adhesive layer / sealant layer (2') Plastic film / vapor-deposited inorganic oxide film / gas barrier coating film / printed layer with a photoluminescent printed layer / adhesive layer / sealant layer (3') Plastic film / Printed layer with photoluminescent printed layer / Adhesive layer / Vapor deposition film / Intermediate substrate layer / Adhesive layer / Sealant layer (4') Plastic film / Printed layer with photoluminescent printed layer / Adhesive layer / Gas barrier coating film / Vapor deposition film / Intermediate substrate layer / Adhesive layer / Sealant layer (5') Plastic film / vapor-deposited inorganic oxide film / printed layer with a glossy printed layer / adhesive layer / intermediate substrate layer / adhesive layer / sealant layer (6') Plastic film / vapor-deposited inorganic oxide film / gas barrier coating film / printed layer with a glossy printed layer / adhesive layer / intermediate substrate layer / adhesive layer / sealant layer The vapor-deposited films (3') and (4') are preferably vapor-deposited films of inorganic oxides.

[0075] <Intermediate base material layer> The intermediate substrate layer is a layer that is provided as needed to improve the strength and processability of the packaging material 1, to change the texture of the packaging material, or to serve as a substrate for forming other layers. Examples of materials that can be used for the intermediate substrate layer include plastic film and paper. In the case of a plastic film, the same plastic film as that formed on the outer layer side of the glittering print layer 3a can be used. In the case of paper, properties such as shapeability, flex resistance, and rigidity can be imparted to the packaging material 1. For example, highly sizable bleached or unbleached kraft paper, pure white roll paper, paperboard, various processed papers, etc. can be used. The basis weight of the paper is usually 50 to 600 g / m 2 Preferably, it is about 60 to 500 g / m 2 , and more preferably 70 to 450 g / m 2 When the packaging material 1 is used for flexible packaging, the 2For paper container applications such as paper cups and liquid paper containers, the density is preferably less than 200 g / m 2 It is preferable that this is equal to or greater than this.

[0076] In order to enhance the heat resistance of the packaging material in consideration of heating in a microwave oven or retort treatment, the intermediate substrate layer is preferably one having excellent heat resistance. Specific examples of intermediate substrate layers having excellent heat resistance include paper and various plastic films exemplified as the plastic films having excellent heat resistance.

[0077] <Thermosoftening resin layer> As shown in FIG. 9, the packaging material 1 may have a heat-softening resin layer 7 in a partial region between the plastic film and the sealant layer. As shown in Fig. 9, the heat-softening resin layer 7 is formed in a portion near the edge of the packaging material 1, and is made of a resin that has a predetermined strength at temperatures below room temperature but loses that predetermined strength at high temperatures. When the packaging container is heated in a microwave oven and the pressure inside the container increases, part of the sealant layer breaks down, and part of the heat-softening resin layer undergoes interfacial peeling or cohesive failure, allowing steam to escape. This will be described in more detail in the second embodiment of the automatic steaming mechanism.

[0078] Heat-softening resins, i.e., resins that have a certain strength at temperatures below room temperature but lose that strength at high temperatures, include resins with a melting point of 60 to 110°C, preferably 60 to 90°C.Specific examples include ethylene-vinyl acetate copolymer resins, polyamide, soluble cellulose, and polyethylene wax, with mixed resins of polyamide, soluble cellulose, and polyethylene wax being preferred.An example of a resin containing polyamide, soluble cellulose, and polyethylene wax is MWOP varnish (softening point: 105°C) manufactured by DIC Graphics Corporation.

[0079] The thickness of the thermosoftening resin layer is preferably 1 to 5 μm. By making the thickness of the thermosoftening resin layer 1 μm or more, the thermosoftening resin layer and the sealant layer can be easily destroyed when heated in a microwave oven. Furthermore, by making the thickness of the thermosoftening resin layer 5 μm or less, when the film-like packaging material is wound into a roll, it is possible to prevent a bulge from occurring in a part of the packaging material, and to prevent the packaging material from stretching in that part.

[0080] The packaging material 1 may have a heat-generating printed layer in a portion of the area between the plastic film and the sealant layer. With this configuration, the area with the heat-generating printed layer (heat-generating area) rises in temperature faster than the area without the heat-generating printed layer (non-heat-generating area), and the sealed state of the heat-sealed portion at the location corresponding to the heat-generating area is broken, allowing automatic steaming (second embodiment B of the automatic steaming mechanism).

[0081] The heat-generating printed layer is a printed layer containing a conductive agent. The conductive agent may be one or more selected from conductive polymers and conductive particles. Conductive polymers include polyaniline, polythiophene, and polyacetylene.Conductive particles include carbon black and metal particles. When conductive particles are used as the conductive agent, the heat-generating print layer preferably contains a binder resin. Also, when a conductive polymer is used as the conductive agent, other resins may be contained to adjust the conductivity. The resins other than the conductive polymer in the heat-generating printed layer can be the same as those exemplified as the binder resin in the glittering printed layer.

[0082] The thickness of the heat-generating printed layer is preferably 0.1 μm or more, more preferably 0.5 to 10 μm. 2 It is preferable that it is 5 mm or more. 2 The upper limit of the area of ​​the heat generating region is not particularly limited, and may be adjusted appropriately according to the shape of the packaging material. The heat-generating printed layer preferably has a resistance value of 0.1 kΩ to 50 kΩ when measured with the terminals of a tester spaced 5 mm apart.

[0083] <Transparent matte layer> The packaging material of the present invention may have a transparent matte layer on a part of the surface of the plastic film opposite the glossy print layer. By having the transparent matte layer, it is possible to improve the design by providing a gloss matte effect and to prevent the package container from slipping when opened.

[0084] In order to prevent the hand from slipping when opening the packaging container, the transparent matte layer is preferably formed on the surface of the plastic film opposite the glossy printed layer, at least in a portion near the edge of said surface, where the near edge refers to a region within 3 mm from the edge of the packaging material. From the viewpoint of further suppressing slippage, it is preferable to further emboss the area where the transparent matte layer is formed.

[0085] The transparent matte layer preferably contains a matting agent and a binder resin. As the matting agent, particles made of inorganic substances such as silica, alumina, calcium carbonate, aluminosilicate, barium sulfate, etc. Among these, silica is preferred because of its excellent transparency. The shape of the matting agent may be spherical, polyhedral, scaly, irregular, etc. Among these, the irregular shape is preferred from the viewpoint of suppressing slippage.

[0086] The average particle size of the matting agent is preferably 0.1 to 15.0 μm, more preferably 1.0 to 10.0 μm, even more preferably 2.0 to 7.5 μm, and even more preferably 2.7 to 5.0 μm. The average particle size of the matting agent particles is measured as the mass average value d50 in particle size distribution measurement by laser light diffraction method.

[0087] The matting agent preferably has an oil absorption of 250 [g / 100 g] or more. By using a matting agent with an oil absorption of 250 [g / 100 g] or more, the matting agent absorbs water, making it difficult for a thin film of water to form on the surface of the transparent matte layer, which makes it easier to prevent wet hands from slipping. The oil absorption of the matting agent is preferably 270 [g / 100g] or more, and more preferably 280 [g / 100g] or more. There is no particular upper limit to the oil absorption of the matting agent. However, if the oil absorption is too high, the matting agent will have too strong aggregating properties, making it difficult to control the matte feel. Therefore, the upper limit is preferably 600 [g / 100g] or less, more preferably 500 [g / 100g] or less, and even more preferably 400 [g / 100g] or less. The oil absorption was measured according to JIS K5101-13-2 "Testing methods for pigments - Part 13: Oil absorption - Section 2: Boiled linseed oil method."

[0088] The content of the matting agent in the transparent matte layer is preferably 2.0 to 50.0% by mass, more preferably 5.0 to 40.0% by mass, and even more preferably 15.0 to 30.0% by mass, based on the total solid content.

[0089] The binder resin for the transparent matte layer may be a general-purpose thermoplastic resin or curable resin, preferably a two-component curable resin containing polyol and isocyanate.

[0090] The thickness of the transparent matte layer is preferably 1.0 to 15.0 μm, more preferably 1.5 to 10.0 μm, and even more preferably 1.8 to 6.0 μm.

[0091] The packaging material of the present invention described above can be used for various types of packaging, but since it can impress upon the purchaser the luxury of the contents, it is preferably used as packaging material for food, cosmetics, etc.

[0092] [Packaging container] The packaging container of the present invention is at least partially formed from the packaging material of the present invention described above. By forming at least a part of a packaging container from the packaging material of the present invention, a packaging container with a luxurious feel due to its metallic luster can be obtained even if metal itself is not used. The packaging material of the present invention may be applied to any desired portion of a packaging container to which it is desired to impart a luxurious feel due to its metallic luster, and the entire packaging container may be formed from the packaging material, or alternatively, the packaging material may be used for only a portion of the container.

[0093] The type and use of the packaging container of the present invention are not particularly limited, but when selling the contents contained in the packaging container, the packaging container can impress upon the purchaser the luxury of the contents, and can be suitably used, for example, as a food container or a cosmetic container. Examples of packaging containers include pouches, containers with lids, cups, and trays. These packaging containers partially contain the packaging material described above. That is, these packaging containers may be formed from a packaging material containing paper as an intermediate substrate layer. A specific example of the shape of the pouch is the shape of a pouch for use in a microwave oven, which will be described later, in Fig. 6. The pouch may be a retort container (a container that has been sterilized at high temperature and high pressure), or may be a packaging container for use in a microwave oven or a container other than a retort container. A specific shape of a lidded container is one that has a configuration comprising a container body having a storage section and a lid body joined to the container body so as to seal the storage section, and the lid body is formed from the packaging material. As described above, the packaging container can be suitably used for a microwave oven. The packaging container can also be used as a retort pouch container. Of course, the packaging container can also be used as a retort pouch container for a microwave oven.

[0094] When the packaging container is a container for use in a microwave oven or a retort pouch, the packaging material constituting the container preferably has a laminated structure of any one of the above-mentioned (1) to (4). In this case, it is preferable to use, as the plastic film, a polyester film alone, a polyamide film such as nylon, or a composite film containing at least one of a polyester film and a polyamide film. In this case, it is preferable to use, as the intermediate substrate, a polyester film alone, a polyamide film such as nylon, a composite film containing at least one of a polyester film and a polyamide film, and paper. In this case, the sealant layer is preferably made of a propylene-based resin such as a propylene homopolymer, an ethylene-propylene block copolymer, or an ethylene-propylene random copolymer, or HDPE. More specifically, in the case of retort pouch containers or microwave oven containers, the packaging material that constitutes the container preferably has a laminated structure of any one of the following (A1) to (A14). Note that " / " indicates the boundary between layers. In addition, in (A1) to (A14), PET is preferably a stretched film. Furthermore, ONy means stretched nylon.

[0095] (A1) PET / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / ethylene-propylene block copolymer (A2) PET / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / ethylene-propylene block copolymer (A3) PET / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / ONy / adhesive layer / ethylene-propylene block copolymer (A4) PET / printed layer with photoluminescent printed layer / adhesive layer / PET / adhesive layer / ethylene-propylene block copolymer (A5) PET / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / PET / adhesive layer / ethylene-propylene block copolymer (A6) PET / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / PET / adhesive layer / ethylene-propylene block copolymer (A7) Co-extruded stretched film (PET / Ny / PET) / printed layer with photoluminescent printed layer / adhesive layer / PET / adhesive layer / ethylene-propylene block copolymer (A8) Co-extruded stretched film (PET / Ny / PET) / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / PET / adhesive layer / ethylene-propylene block copolymer (A9) Co-extruded stretched film (PET / Ny / PET) / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / PET / adhesive layer / ethylene-propylene block copolymer (A10) Co-extruded stretched film (PET / Ny) / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / PET / adhesive layer / ethylene-propylene block copolymer (A11) Co-extruded stretched film (PET / Ny) / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / PET / adhesive layer / ethylene-propylene block copolymer (A12) PBT / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / ethylene-propylene block copolymer (A13) PBT / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / ethylene-propylene block copolymer (A14) PBT / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / ONy / adhesive layer / ethylene-propylene block copolymer The gas barrier layers of A2, 5, 8, 10, and 13 are preferably a single layer of a vapor-deposited inorganic oxide film, or a composite layer in which a gas barrier coating film is formed on a vapor-deposited inorganic oxide film (in such a composite layer, the vapor-deposited inorganic oxide film is disposed on the PET or co-extruded stretched film side).The gas barrier layers of A3, 6, 9, 11, and 14 are preferably a single layer of a vapor-deposited film, or a composite layer in which a gas barrier coating film is formed on a vapor-deposited film (in such a composite layer, the vapor-deposited film is disposed on the ONy or PET side).

[0096] In the case of containers for use in microwave ovens, the ethylene-propylene block copolymers constituting the sealant layers (A1) to (A14) above may be polyethylene resins such as LDPE, LLDPE, MDPE, and HDPE. In addition, when the automatic steaming mechanism configuration of the second embodiment A or B described below is adopted in a microwave oven container, the above-mentioned heat-softening resin layer or heat-generating printed layer can be formed in a portion between the plastic film and the sealant layer.

[0097] <Pouch> Figure 6 shows an example of a pouch, which is one embodiment of the packaging container of the present invention. The pouch 10 in Figure 6 is for use in a microwave oven and is a standing pouch formed by heat-sealing a body portion 11 and a bottom portion 12. As shown in Figure 6, the body portion 11 includes a pair of main surface sheets 13 consisting of a front main surface sheet 13a and a back main surface sheet 13b arranged opposite each other, and the sides 14 of the pair of overlapping main surface sheets 13 are heat-sealed to each other. A bottom surface sheet 16 forming the bottom portion 12 is arranged between lower edges 15 of the pair of main surface sheets 13. A storage space 17 for storing contents is formed within the area surrounded by the pair of main sheets 13 and bottom sheet 16. The bottom sheet 16 is bent convexly toward the storage space 17, and the vicinity of its peripheral edge is heat-sealed to the lower part of the overlapping main sheet 13. The bottom sheet 16 maintains the shape of the lower ends of the pair of main sheets 13, thereby imparting self-supporting properties to the pouch 10 and enabling it to be a standing pouch. 6 has an opening 19 formed between the upper edges 18 of the front main sheet 13a and the back main sheet 13b, and contents can be placed through the opening 19. After the contents are placed inside, the packaging container can be sealed by heat sealing the vicinity of the upper edge 18 where the opening 19 is formed. When removing the contents from the pouch 10, the pouch is opened by tearing the vicinity of the upper edge 18 from the notch 23.

[0098] The front main surface sheet 13a, back main surface sheet 13b, and bottom surface sheet 16 of this pouch 10 can be formed from packaging material 1. All of these sheets may be formed from packaging material 1 having a glittering printed layer 3a containing metallic flakes, or only any one of the sheets that requires metallic luster may be formed from packaging material 1. Figure 6 shows that the front main surface sheet 13a is formed from packaging material 1 having a laminated structure as shown in Figure 2, having a glittering printed layer 3a and a picture printed layer 3b. In addition, sheets other than the sheet used for packaging material 1 can be, for example, packaging material 1 that does not have a shiny printed layer 3a containing metal flakes formed thereon, or that does not include a printed layer.

[0099] <Automatic steaming mechanism> When the container is for use in a microwave oven, it is preferable that the container has an automatic steaming mechanism that automatically releases steam from the storage space to the outside when the pressure inside the pouch increases due to steam generated by cooking the contents, such as food, thereby preventing the pouch from bursting. The automatic steaming mechanism is preferably formed near the periphery of the container.

[0100] A first embodiment of the automatic steaming mechanism will be described with reference to Figure 6. The microwave pouch shown in Figure 6 has a first unsealed area 21 that is not heat-sealed near side edge 14 toward the upper side of the container (pouch). First unsealed area 21 reaches side edge 14 and has an opening 22. First unsealed area 21 also extends toward storage space 17. A heat-sealed portion 25 also extends toward storage space 17 to form a protruding portion 25a, surrounding first unsealed area 21 that protrudes toward storage space 17. More specifically, first unsealed area 21 and storage space 17 are separated, and protruding portion 25a is formed so as to be continuous with heat-sealed portion 25 for sealing the pouch. 6, automatic steaming mechanism 20 is formed by opening 22, first unsealed region 21, and a heat-sealed portion (extending portion 25a) that extends toward storage space 17. Specifically, when the pressure inside the container increases due to heating, a strong load is applied to the portion of heat-sealed portion 25 at extending portion 25a, causing extension region 25 to peel off first, thereby connecting storage space 17 and first unsealed region 21 and allowing steam to escape to the outside. Further details of the automatic steaming mechanism of the type shown in FIG. 6 are described in Japanese Patent Application Laid-Open Nos. 2015-120550, 2016-74457, and 2016-74458.

[0101] 6, a second unsealed area 23 is formed on the side edge 14 opposite to the first unsealed area 21. The second unsealed area 23 is formed from the viewpoint of improving the yield of forming the openings 22 in the first unsealed area 21 when multiple retort pouch containers 10 are continuously formed and then cut into individual pieces, and is not necessarily formed.

[0102] A second embodiment A of the automatic steaming mechanism will be described with reference to FIGS. The packaging container (pouch) 10 shown in Fig. 10 is made into a pouch by heat-sealing the periphery of the edge of the packaging material shown in Fig. 9 (packaging material having a thermosoftening resin layer in a portion near the edge between the plastic film and the sealant layer). Fig. 11 is a cross-sectional view taken along line XI-XI of the heat-sealed portion 25 around the edge of the packaging container 10 in Fig. 10. Note that, although not shown in Figs. 9 and 11, an adhesive layer is formed between the thermosoftening resin layer 7 and the glossy printing layer 3a in the area where the thermosoftening resin layer 7 is present, and an adhesive layer is formed between the sealant layer 4 and the glossy printing layer 3a in the area where the thermosoftening resin layer 7 is not present. 10, the heat-softening resin layer 7 needs to be formed from the inner edge to the outer edge of the heat-sealed portion 25 for sealing the pouch in at least a part of the heat-sealed portion 25 of the packaging container 10. The strength of the heat-softening resin layer 7 provided in such a position decreases when heated to a high temperature in a microwave oven. 11, when the internal pressure of the heat-softening resin layer 7 increases due to the expansion of the air inside the packaging container 10 or the water vapor contained in the contents when the packaging container 10 is heated in a microwave oven, a part of the sealant layer 4 breaks, starting from an arbitrary point "A" in the sealant layer 4 near the inner edge of the heat-sealed portion 25, and a part of the heat-softening resin layer 7 undergoes interfacial peeling or cohesive failure (the dashed line marked B indicates the imaginary line along which the sealant layer 4 breaks and the imaginary line along which the heat-softening resin layer 7 breaks). As a result, air and water vapor escape from the broken point, and the internal pressure of the packaging container 10 can be reduced. The automatic steaming mechanism of the second embodiment A can also be applied to a container with a lid, which will be described later.

[0103] For the packaging material constituting the container equipped with the second embodiment A of the automatic steaming mechanism, it is preferable to select a resin that is easily disintegrated as the resin constituting the sealant layer. Specifically, a polyethylene film such as LDPE or LLDPE (a copolymer of butene-1 and ethylene) is preferable. Furthermore, the packaging material constituting the container equipped with the second embodiment A of the automatic steaming mechanism preferably has a laminated structure of any one of the following (B1) to (B4). Note that " / " indicates the boundary between layers. Furthermore, in (B1) to (B4), PET is preferably a stretched film. Furthermore, ONy means stretched nylon.

[0104] (B1) PET / printed layer with photoluminescent printed layer / thermosoftening resin layer / adhesive layer / sealant layer (polyethylene film) (B2) PET / gas barrier layer / printed layer with photoluminescent printed layer / thermosoftening resin layer / adhesive layer / sealant layer (polyethylene film) (B3) ONy / printed layer with photoluminescent printed layer / thermosoftening resin layer / adhesive layer / sealant layer (polyethylene film) (B4) ONy / gas barrier layer / printed layer with photoluminescent printed layer / thermosoftening resin layer / adhesive layer / sealant layer (polyethylene film) The gas barrier layers of B2 and B4 are preferably a single layer of an inorganic oxide vapor deposition film, or a composite layer in which a gas barrier coating film is formed on an inorganic oxide vapor deposition film (in the composite layer, the inorganic oxide vapor deposition film is positioned on the PET or ONy side).

[0105] In addition, a second embodiment B of the automatic steaming mechanism may be a means of using a packaging material having a heat-generating printed layer in a partial area between the plastic film and the sealant layer. In the second embodiment B of the automatic steaming mechanism, the temperature rises faster in the area having the heat-generating printed layer (heat-generating area) than in the area not having the heat-generating printed layer (non-heat-generating area), so the sealed state in the heat-sealed portion corresponding to the heat-generating area is dissolved, allowing automatic steaming. The automatic steaming mechanism of the second embodiment B can be applied to a pouch and a lidded container described later.

[0106] For the packaging material constituting the container equipped with the second embodiment B of the automatic steaming mechanism, the resin constituting the sealant layer is preferably one whose main component is propylene. Specifically, a film made of a mixed resin of propylene and polyethylene is preferred. Furthermore, the packaging material constituting the container equipped with the second embodiment B of the automatic steaming mechanism preferably has any one of the laminated structures (B1') to (B4') below. Note that " / " indicates the boundary between layers. Furthermore, in (B1') to (B4'), PET is preferably a stretched film. Furthermore, ONy means stretched nylon.

[0107] (B1') PET / photoluminescent printing layer / heat-generating printing layer / sealant layer (film made of a mixed resin of propylene and polyethylene) (B2') PET / gas barrier layer / photoluminescent print layer / heat-generating print layer / sealant layer (film made of a mixed resin of propylene and polyethylene) (B3') ONy / photoluminescent printing layer / heat-generating printing layer / sealant layer (film made of a mixed resin of propylene and polyethylene) (B4') ONy / gas barrier layer / photoluminescent printing layer / heat-generating printing layer / sealant layer (film made of a mixed resin of propylene and polyethylene) The gas barrier layers of B2' and B4' are preferably a single layer of an inorganic oxide vapor deposition film, or a composite layer in which a gas barrier coating film is formed on an inorganic oxide vapor deposition film (in the composite layer, the inorganic oxide vapor deposition film is positioned on the PET or ONy side).

[0108] <Container with lid> Figures 7 and 8 show an example of an embodiment of a lidded container of the present invention. Figure 7 is a top view, and Figure 8 is a cross-sectional view taken along line IV-IV in Figure 7. The lidded container 30 shown in Figures 7 and 8 comprises a container body 32 in which a storage section 31 is formed, and a lid 33 joined to the container body 32 so as to seal the storage section 31 of the container body 32. In Figure 7, the shape of the container body 32 is generally rectangular, but this is not particularly limited. Furthermore, the method for forming the container body 32 is not particularly limited, and it may be, for example, a tray formed by injection molding or a container formed by deep drawing. Furthermore, since the material of the container body 32 is to be joined to the lid body 33, it is usually a thermoplastic resin such as PP or PET, and in particular, when it is a lidded container for use in a microwave oven, PP is preferably used from the standpoint of heat resistance, etc. A suitable container body is one in which the storage section and flange are mostly made of paper, with a thermoplastic resin layer formed on the surface of the flange. The thermoplastic resin layer formed on the surface of the flange is preferably made of PP and / or PE alone or in combination.

[0109] The lid body 33 of this lidded container 30 is preferably formed from the packaging material 1 of the present invention. Note that Fig. 7 shows that the lid body 33 is formed so as to have a glittering printed layer 3a and a picture printed layer 3b in the packaging material 1 having a laminated structure as shown in Fig. 2.

[0110] In order to make it easier to peel the lid body 33 from the container body 32 and open the lidded container 30, it is preferable that the lid body 33 has easy-peel properties, as described above in the explanation of the sealant layer 4 of the packaging material 1. The lid 33 and the container body 32 are joined together at a joining line 35 on the flange 34 of the container body 32. The joining line 35 may be formed by heat sealing the lid 33 and the flange 34 together, or may be formed by a separate component such as an adhesive layer.

[0111] When the lidded container 30 is used in a microwave oven, it is preferable that the lidded container 30 is equipped with an automatic steaming mechanism (third embodiment of the automatic steaming mechanism) that automatically releases steam from the lidded container 30 to the outside when the pressure inside the lidded container 30 increases due to steam generated by heating and cooking the contents, such as food, contained in the container body 32, thereby preventing the lidded container 30 from bursting. For example, flange portion 34 has protruding portion 34a that protrudes toward the center of container body 32, and joining line 35 also has protruding line 35a that is formed along this protruding portion 34a and protrudes toward the center of the container. By forming joining line 35 in this manner, as the pressure inside lidded container 30 increases due to heating, the joining line 35 is more likely to peel off from the location of protruding line 35a, allowing communication between storage portion 31 of container body 32 and the outside and allowing steam inside lidded container 30 to escape to the outside. In the lidded container 30 shown in Figures 7 and 8, protrusions 34a are formed on each of the opposing long sides of the flange portion 34, but it is not necessary to form two protrusions 34a. In the case of the third embodiment of the automatic steaming mechanism, the sealant layer of the lid body is preferably a film made of a mixed resin of polypropylene and polyethylene.

[0112] Furthermore, by using the packaging material shown in Figure 9 (a packaging material between the plastic film and the sealant layer and having a heat-softening resin layer in a portion near the edge) as the lid body 33 that constitutes the lidded container 30, steam can be released when heated in a microwave oven for the same reasons as explained in the second embodiment A of the automatic steaming mechanism described above. Furthermore, by using a packaging material having a heat-generating printed layer in a portion near the edge between the plastic film and the sealant layer as the lid that constitutes the lidded container, steam can be released when heated in a microwave oven for the same reasons as explained in the second embodiment B of the automatic steaming mechanism described above.

[0113] Examples of materials for the container body that constitutes the lidded container are shown in X1 to X5. For frozen foods, X2 or X4 is preferred. X1: PP + PE (PE is present in a small amount (PE is 5 to 40% by mass, the remainder is PP)) X2:PE X3: Paper (PP on the flange surface) X4: Paper (PE on the flange surface) X5:PP

[0114] Examples of materials for the innermost layer of the lid that constitutes the lidded container are shown in Y1 to Y3. Note that Y2 preferably has a PP layer on the outer layer side of PP+PE. Also, Y3 preferably has a PE layer on the outer layer side of PP+PE. Y1: PE (LDPE or LLDPE (copolymer of butene-1 and ethylene)) Y2: PP + PE (PP is the main component (PE is 5 to 40% by mass, PP is the remainder)) Y3: PP + PE (PE is the main component (PP is 5 to 40% by mass, PE is the remainder))

[0115] A lidded container combining the above X1 to X4 with the above Y1 or Y2 is preferable from the viewpoint of easy peelability. When combining X2 and X4 with Y1, the types of PE used should be different from each other. Examples of PE types include low-density PE (LDPE), linear low-density PE (LLDPE), medium-density PE (MDPE), and high-density PE (HDPE).

[0116] <Lid> The lid of the present invention is formed from the packaging material of the present invention described above.

[0117] The packaging material constituting the lid preferably has a laminated structure of any one of the above (1) to (4). Furthermore, when the lid is used as a microwave oven or retort container, it is preferable to use, as the plastic film, a polyester film alone, a polyamide film such as nylon alone, or a composite film containing one or more polyester films and polyamide films. Furthermore, when the lid is used for a microwave oven or as a retort container, it is preferable to use, as the intermediate substrate layer, a polyester film alone, a polyamide film such as nylon alone, a composite film containing one or more polyester films and polyamide films, or paper. Furthermore, when the lid is used as a microwave oven or retort container, it is preferable to use a film made of a resin that combines heat resistance and easy peelability as the sealant layer. While the type of film varies depending on the type of container, when the container is made of a general-purpose propylene-based resin, it is preferable to use a film made of a resin that is a mixture of PP and one or more selected from PE, polybutene, and polystyrene. The sealant layer may have a multi-layer structure, and easy peelability may be imparted only to the side of the sealant layer that is joined to the container body (the innermost layer of the packaging material).

[0118] More specifically, the packaging material constituting the microwave oven lid preferably has any one of the laminated structures (C1) to (C10) below. Note that " / " indicates the boundary between layers. In addition, in (C1) to (C10), PET is preferably a stretched film. Furthermore, ONy means stretched nylon. (C1) PET / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / sealant layer with easy peel properties (C2) PET / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / sealant layer with easy-peel properties (C3) PET / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / ONy / adhesive layer / sealant layer with easy peel properties (C4) PET / printed layer with glittering printed layer / adhesive layer / PET / adhesive layer / sealant layer with easy peel properties (C5) PET / gas barrier layer / printed layer with glossy printed layer / adhesive layer / PET / adhesive layer / sealant layer with easy-peel properties (C6) PET / printed layer with glittering printed layer / adhesive layer / gas barrier layer / PET / adhesive layer / sealant layer with easy peel properties (C7) ONy / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / sealant layer with easy peel properties (C8) ONy / gas barrier layer / printed layer with photoluminescent printed layer / adhesive layer / ONy / adhesive layer / sealant layer with easy-peel properties (C9) ONy / printed layer with photoluminescent printed layer / adhesive layer / gas barrier layer / ONy / adhesive layer / sealant layer with easy-peel properties (C10) ONy / printed layer with photoluminescent printed layer / adhesive layer / EVOH / adhesive layer / sealant layer with easy peel properties The gas barrier layers of C2, 5, and 8 are preferably a single layer of a vapor-deposited inorganic oxide film, or a composite layer in which a gas barrier coating film is formed on a vapor-deposited inorganic oxide film (in the composite layer, the vapor-deposited inorganic oxide film is disposed on the PET or ONy side).The gas barrier layers of C3, 6, and 9 are preferably a single layer of a vapor-deposited film, or a composite layer in which a gas barrier coating film is formed on a vapor-deposited film (in the composite layer, the vapor-deposited film is disposed on the ONy or PET side).

[0119] In addition, when the configuration of the second embodiment A or B of the automatic steaming mechanism described above is adopted for the lid body, the above-mentioned heat-softening resin layer or heat-generating printed layer can be formed in a portion between the plastic film and the sealant layer. [Example]

[0120] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

[0121] 1. Preparation of packaging materials [Example 1] A 12-μm-thick plastic film (PET film, Ra on both surfaces 0.05 μm or less) was subjected to corona discharge treatment on one surface, followed by the deposition of a 10-nm-thick silicon oxide film. This was followed by plasma treatment using a mixture of oxygen and argon gas, followed by the application of a coating solution primarily composed of ethyl silicate and polyvinyl alcohol using a gravure roll coater to form a gas barrier coating with a dry thickness of 300 nm. Next, the following ink 1 for glittering printing layer was gravure printed on the entire surface of the gas barrier layer and dried to form a glittering printing layer with a dry thickness of 1.5 μm. Next, a white pigment ink was gravure printed on the entire surface of the glitter print layer and dried to form a white solid print layer having a dry thickness of 1.5 μm. Next, a coating liquid for forming an adhesive layer containing a polyol and an isocyanate compound was applied onto the white solid print layer and dried to form a polyurethane adhesive layer with a thickness of 3 μm, and then an intermediate substrate layer (stretched Ny, thickness 15 μm) was laminated onto the adhesive. The solvent ratio of the coating liquid for forming the adhesive layer was 60 mass %, and the solvent in the coating liquid was ethyl acetate. Next, an adhesive layer-forming coating liquid containing a polyol and an isocyanate compound was applied onto the sealant layer (CPP, a single-layer film of an ethylene-propylene block copolymer, 70 μm thick) and dried to form a polyurethane-based adhesive layer with a thickness of 3 μm. Next, the sealant layer with the adhesive layer formed thereon was dry-laminated onto the surface of the intermediate substrate to obtain the packaging material of Example 1. The packaging material of Example 1 has, from the outer layer side, a plastic film, a vapor deposition film, a gas barrier coating film, a printed layer (a glossy printed layer, a white solid printed layer), an adhesive layer, an intermediate substrate layer, an adhesive layer, and a sealant layer.

[0122] <Ink for glitter printing layer 1> Composition containing metal flakes and mineral spirits: 9 parts by weight (Metal flake content: 85% by mass) (Metal flakes: non-leafing aluminum flakes, aspect ratio 41, average thickness 0.08 μm) Organic yellow pigment: 3 parts by weight (Average particle size: 150nm) ·Inorganic fine particles: 2 parts by mass (Silica, average particle size: 20 nm) Binder resin: 20 parts by weight (Polyurethane resin, melting point 140°C) Solvent 1: 70 parts by weight (Propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, isopropanol mixed solvent) Solvent 2: 6 parts by weight (mineral spirits)

[0123] [Example 2] A packaging material of Example 2 was obtained in the same manner as in Example 1, except that Ink 1 for glittering printing layer was changed to Ink 2 for glittering printing layer described below.

[0124] <Ink for glitter printing layer 2> White pearl pigment (average length 15 μm, average thickness 0.2 μm): 10 parts by weight Colored pearl pigment (a colored pearl pigment with a mica coating layer of ferric oxide, average length 15 μm, average thickness 0.2 μm): 20 parts by weight Carbon black: 0.001 parts by weight Anti-settling agent (fine silica particles): 0.1 parts by weight Binder resin (polyurethane resin): 10 parts by weight Solvent (mixture of propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, and isopropanol): 60 parts by weight

[0125] [Example 3] The packaging material of Example 3 was obtained in the same manner as Example 1, except that the amount of the composition containing metal flakes and mineral spirits in the ink 1 for glossy printing layers was changed from 9 parts by mass to 16 parts by mass.

[0126] [Example 4] A 12-μm-thick plastic film (PET film, Ra on both surfaces 0.05 μm or less) was subjected to corona discharge treatment on one surface, followed by the deposition of a 10-nm-thick silicon oxide film. This was followed by plasma treatment using a mixture of oxygen and argon gas, followed by the application of a coating solution primarily composed of ethyl silicate and polyvinyl alcohol using a gravure roll coater to form a gas barrier coating with a dry thickness of 300 nm. Next, the following ink 1 for the design layer was applied to the entire surface of the gas barrier layer and dried to form a light-transmitting design printed layer with a dry film thickness of 0.3 μm. Next, glossy printing ink 2 (an ink with the same formulation as the glossy printing layer ink 1 above, except that the organic yellow pigment was omitted) was gravure printed on the entire surface of the light-transmitting picture printing layer and dried to form a glossy printing layer with a dry film thickness of 1.5 μm. Next, a white pigment ink was gravure printed on the entire surface of the glitter print layer and dried to form a white solid print layer having a dry thickness of 1.5 μm. Next, a coating liquid for forming an adhesive layer containing a polyol and an isocyanate compound was applied onto the white solid print layer and dried to form a polyurethane adhesive layer with a thickness of 3 μm, and then an intermediate substrate layer (stretched Ny, thickness 15 μm) was laminated onto the adhesive. The solvent ratio of the coating liquid for forming the adhesive layer was 60 mass %, and the solvent in the coating liquid was ethyl acetate. Next, an adhesive layer-forming coating liquid containing a polyol and an isocyanate compound was applied onto the sealant layer (CPP, a single-layer film of an ethylene-propylene block copolymer, 70 μm thick) and dried to form a polyurethane-based adhesive layer with a thickness of 3 μm. Next, the sealant layer with the adhesive layer formed thereon was dry-laminated onto the surface of an intermediate substrate to obtain the packaging material of Example 4. The packaging material of Example 4 has, from the outer layer side, a plastic film, a vapor deposition film, a gas barrier coating film, a printed layer (a light-transmitting picture printed layer, a glossy printed layer, and a white solid printed layer), an adhesive layer, an intermediate substrate layer, an adhesive layer, and a sealant layer.

[0127] <Ink for design layer 1> Organic yellow pigment: 2 parts by weight (Average particle size: 150nm) Binder resin: 20 parts by weight (Polyurethane resin, melting point 140°C) Solvent 1 (a mixed solvent of propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, and isopropanol): 70 parts by mass

[0128] [Comparative Example 1] A packaging material of Comparative Example 1 was obtained in the same manner as in Example 1, except that the process of forming the adhesive layer and intermediate base material layer on the white solid print layer was changed to the following process. <Steps of Comparative Example 1> An adhesive layer-forming coating solution containing a polyol and an isocyanate compound was applied to an intermediate substrate layer (stretched Ny, thickness 15 μm) and dried to form a polyurethane-based adhesive layer with a thickness of 3 μm. Next, the intermediate substrate with the adhesive layer formed thereon was dry-laminated onto the surface of the white solid print layer.

[0129] Comparative Example 2 A packaging material of Comparative Example 2 was obtained in the same manner as in Example 2, except that the process of forming the adhesive layer and intermediate base material layer on the white solid print layer was changed to the following process. <Steps of Comparative Example 2> An adhesive layer-forming coating solution containing a polyol and an isocyanate compound was applied to an intermediate substrate layer (stretched Ny, thickness 15 μm) and dried to form a polyurethane-based adhesive layer with a thickness of 3 μm. Next, the intermediate substrate with the adhesive layer formed thereon was dry-laminated onto the surface of the white solid print layer.

[0130] 2. Measurement and Evaluation The packaging materials of the examples and comparative examples were subjected to the following measurements and evaluations. The results are shown in Table 1.

[0131] 2-1.L * SCE A black plate was attached to the CPP side of the packaging materials of Examples 1 to 4 and Comparative Examples 1 to 2 via a transparent adhesive layer to prepare samples in which the packaging materials of Examples 1 to 4 and Comparative Examples 1 to 2, the transparent adhesive layer, and the black plate were laminated in this order. The samples used had a refractive index difference between the CPP, transparent adhesive, and black plate of 0.05 or less. The refractive index difference between the CPP and the transparent adhesive layer, and the refractive index difference between the transparent adhesive layer and the black plate were all 0.05 or less. Next, a spectrophotometer (manufactured by Konica Minolta, product name "CM-700d") was used to measure the L from the plastic film side of the sample. *The SCE was measured. Measurements were made at 20 points for each sample, and the average value was calculated as the L of the packaging materials of Examples 1 to 4 and Comparative Examples 1 and 2. * The light source was D65 and the viewing angle was 10 degrees.

[0132] 2-2.60 degree specular gloss coefficient of variation The 60-degree specular gloss was measured from the plastic film side of the samples prepared in 2-1 in accordance with JIS Z8741: 1997. Using a gloss meter (Tetsutani Corporation, product name: Micro-Gloss 60°xs), measurements were taken at 20 locations for each sample, and the variation (σ) of the 60-degree specular gloss and the average value of the 60-degree specular gloss were calculated. The value obtained by dividing the variation (σ) by the average value was used as the coefficient of variation of the 60-degree specular gloss for the packaging materials of Examples 1 to 4 and Comparative Examples 1 and 2.

[0133] 2-3.Metallic luster (subtle metallic luster) In a room equipped with multiple fluorescent lights on the ceiling, curtains were closed to block external light, and the packaging materials of the examples and comparative examples were observed under the illumination of the multiple fluorescent lights to evaluate the aesthetic appearance due to the metallic luster. Twenty subjects evaluated the products, and the average scores were calculated. Items that had a metallic luster but also had a subdued, calming impression were given a score of 3, items that were neither good nor bad were given a score of 2, and items that had a metallic luster but were strongly metallic and gave an unsettling impression were given a score of 1. <Evaluation criteria> A: Average score of 2.5 or above A - :Average score is 2.3 or more but less than 2.5 B: Average score is over 2.0 and under 2.3 C: Average score below 2.0

[0134] [Table 1]

[0135] The results in Table 1 confirm that the packaging materials of Examples 1 to 4 are capable of imparting a subdued metallic luster. Furthermore, the packaging material of Example 4 does not contain a colorant in the glossy printed layer, but contains a colorant in the light-transmitting picture printed layer located on the outer layer side of the glossy printed layer, and therefore the coloring appeared more uniform within the surface than the packaging materials of Examples 1 to 3. Furthermore, although not evaluated in the table, when the packaging materials of Examples 1 to 4 were heated in a microwave oven (at 600 W for 2 minutes), no sparks were generated, and no holes were formed due to localized overheating. [Explanation of symbols]

[0136] 1 Packaging material 2. Plastic film 3a Glitter printing layer 3b Pattern printing layer 3D white solid print layer 4 Sealant Layer 5. Intermediate substrate layer 6a Adhesive layer 6b Adhesive layer 7 Thermoplastic resin layer 10 Packaging containers 11 Torso 12 Bottom 13 Main sheet 14 Side edges 15 Lower edge 16 Bottom sheet 17 Containment Space 18 Upper edge 19 Aperture 20 Automatic steaming mechanism 21 First unsealed area 22 Aperture 23 Second unsealed area 24 notches 25 Heat seal section 25a Overhang 30 Container with lid 31 Storage unit 32 Container body 33 Lid 34 Flange 35 Joint line

Claims

1. A packaging material (excluding those "having a shielding layer on the outer layer side of the glittering printing layer") that has a configuration in which at least a plastic film, a printing layer, an adhesive layer, and a sealant layer are laminated in this order from the outer layer side, the printing layer and the adhesive layer are adjacent to each other, the printing layer has a glittering printing layer that contains a glittering pigment and a binder resin, and satisfies the following conditions 1 and 2. <Condition 1> The diffuse light reflection SCE was measured from the outer layer side of the packaging material, and the L calculated from the diffuse light reflection SCE spectrum ＊ a ＊ b ＊ Color system L ＊ Value L ＊ When SCE is used, L ＊ SCE is 40 or above. <Condition 2> The 60-degree specular gloss is measured from the outer layer side of the packaging material in accordance with JIS Z8741:1997, and the coefficient of variation of the 60-degree specular gloss calculated from the measured values ​​is 0.118 or more and 0.300 or less.

2. The packaging material according to claim 1 , wherein the luster pigment comprises at least one selected from the group consisting of metal flakes and pearlescent pigments.

3. A packaging container, at least a portion of which is formed from the packaging material according to claim 1 or 2.

4. The packaging container according to claim 3, wherein the packaging container is a pouch.

5. 4. The packaging container according to claim 3, which is a lidded container comprising a container body having a storage portion and a lid body joined to the container body so as to seal the storage portion, and the lid body is formed from the packaging material.

6. The packaging container according to any one of claims 3 to 5, which is a retort container.

7. A lid formed from the packaging material according to claim 1 or 2.

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