Printing substrate, laminate for packaging material, packaging container and packaged article

Abstract

This printing substrate is obtained by forming a printing layer on a substrate. The substrate is a polyolefin resin film containing a recycled resin, and the recycled resin is a chemically recycled resin. A laminate for a packaging material comprises a printing substrate and a seal layer.

Description

[Technical Field]

[0001] The present disclosure relates to a printing substrate, a laminate for packaging, a packaging container, and a packaging article. [Background technology]

[0002] Packaging materials used in packaging containers such as packaging bags are required to have various properties depending on their applications. Therefore, in order to simultaneously satisfy such various performance requirements, packaging materials are generally composed of a laminate including a substrate and a sealant layer. A known example of such a packaging laminate is a laminate comprising a first layer including an inner liner and a second layer including an outer sheath, where the outer sheath is made of a post-consumer resin (hereinafter also referred to as "PCR") that may contain contaminants such as paper, ink, and food residue, and where each layer structure includes a printed film (see, for example, Patent Document 1 below). Another known packaging laminate is a laminate film comprising at least a recycled polyethylene layer and a linear low-density polyethylene layer, where the recycled polyethylene layer contains 20% by mass or more of recycled polyethylene relative to the total amount constituting the recycled polyethylene layer, and where a printed layer is formed on the recycled polyethylene layer (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-552096 [Patent Document 2] Japanese Patent Publication No. 2023-040660 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the laminate described in Patent Document 1 had the following problem when the PCR content was increased when the PCR was a recycled resin containing contaminants, a so-called material recycled resin: In the laminate described in Patent Document 1, foreign matter such as impurities, gels, and aggregates could appear on the surface of the outer sheath, and so when the laminate had a printed film on the surface of the outer sheath, there was room for improvement in terms of printed display. Furthermore, the laminate film described in Patent Document 2 has a printed layer on a recycled polyethylene layer. Therefore, foreign matter may be present on the surface of the recycled polyethylene layer containing recycled polyethylene. These foreign matter form protrusions, resulting in an uneven surface on the recycled polyethylene layer. When a printed layer is provided on the uneven surface of the recycled polyethylene layer, ink cannot adhere to the protrusions caused by the foreign matter, resulting in defects such as missing characters in the printed layer. Character missing is particularly likely to occur in printed layers with low halftone dot density. For this reason, the laminate film described in Patent Document 2 leaves room for improvement in terms of the surface condition of the printed layer provided on the recycled polyethylene layer, i.e., in terms of the printed display.

[0005] An object of the present disclosure is to provide a printing substrate, a laminate for packaging, a packaging container, and a packaging article that enable good printed displays even when a substrate containing recycled resin is used. [Means for solving the problem]

[0006] One aspect of the present disclosure provides a printing substrate comprising a printing layer formed on a substrate, wherein the substrate is a polyolefin resin film containing a recycled resin, and the recycled resin is a chemically recycled resin. According to the above-described printing substrate, the recycled resin used for the printing substrate is a chemically recycled resin. Chemically recycled resin is produced by first depolymerizing discarded resin through a process that involves gasification, liquefaction, and purification of naphtha to produce monomers, or by depolymerization to produce monomers, depending on the material's characteristics. Chemically recycled resin is therefore less likely to be contaminated with foreign matter such as impurities, gels, and aggregates than material recycled resin, which is made by cleaning and crushing recycled resin products such as used packaging, then melting them under heat to recycle them into raw materials. Furthermore, unlike material recycled resin, chemically recycled resin is not affected by heat treatments such as melting after the recycling process, making it less susceptible to thermal degradation and less likely to have foreign matter such as gels and aggregates on its surface. Therefore, protrusions due to foreign matter are less likely to form on the surface of the substrate, resulting in less unevenness. When a printing layer is formed on such a substrate, defects such as missing characters in the printing layer, known as character chipping, are less likely to occur. Character chipping is particularly less likely to occur in printing layers with low dot density. Furthermore, unevenness in the thickness of the printed layer due to the presence of foreign matter is less likely to occur. Therefore, the printing substrate described above makes it possible to produce a good printed display even when using a substrate containing recycled resin. Another aspect of the present disclosure provides a laminate for a packaging material, comprising the above-mentioned printing substrate and a seal layer. According to the above-mentioned laminate for packaging material, even when a printing substrate is used in which a printing layer is formed on a substrate containing recycled resin, a good printed display can be achieved.

[0007] The content of the recycled resin in the laminate for packaging material may be 10% by volume or more or 10% by mass or more. The higher the recycled resin content (usage ratio) in a packaging laminate, the more the environmental impact can be reduced. The recycled resin content in a packaging laminate is generally 10% by volume or more, preferably 20% by volume or more, more preferably 25% by volume or more, even more preferably 30% by volume or more, and particularly preferably 40% by volume or more. Here, if it is not easy to calculate the mass ratio (mass%) after the packaging laminate is made into a packaging material, the recycled resin content may be expressed in "volume %" so that it can be calculated using the film thickness ratio. In other words, the ratio of the film thickness of the layer using the recycled resin to the film thickness of the entire laminate can be used as the recycled resin content (volume %). The density of polyethylene and polypropylene, which constitute the majority of packaging materials, is 0.86 to 0.97 g / cm. 3 The range of the recycled resin content specified in volume percent generally also satisfies the value specified in mass percent.

[0008] The packaging laminate may further include an intermediate substrate between the substrate and the sealing layer. In this case, the intermediate base material reinforces the base material, thereby further improving the strength of the laminate.

[0009] In the laminate for packaging materials, the recycled resin may be a post-consumer recycled resin (PCR). PCR can be used in large quantities on the market, reducing the cost of laminates. The recycled resin may be a combination of PCR and post-industrial recycled resin (PIR).

[0010] In the above laminate for packaging materials, the sealing layer may be a sealant film or a heat seal varnish layer.

[0011] In the above-mentioned laminate for packaging material, the substrate and intermediate substrate may be bonded together with a solventless adhesive.

[0012] In the above-mentioned laminate for packaging material, the substrate or the intermediate substrate may further include a gas barrier layer. In this case, the gas barrier property of the laminate is further improved, and therefore, when the laminate is used to produce a packaging container and contents are placed in the packaging container, deterioration of the contents due to gases such as oxygen can be effectively suppressed.

[0013] Another aspect of the present disclosure provides a packaging container obtained using the above-mentioned laminate for packaging materials. As already mentioned, with the packaging container, the chemically recycled resin, which is the recycled resin in the substrate of the laminate, is less likely to be contaminated with foreign matter such as impurities, gels, and aggregates than materially recycled resin. Furthermore, unlike materially recycled resin, chemically recycled resin is not subject to heat treatments such as heat melting after the recycling process, making it less susceptible to thermal degradation and reducing the presence of foreign matter such as gels and aggregates on the surface of the substrate. Therefore, even when a printed layer is formed on such a substrate, unevenness in the thickness of the printed layer due to the presence of foreign matter is less likely to occur. Therefore, with the packaging container, good printed displays are possible even when using a laminate with a substrate containing recycled resin.

[0014] Yet another aspect of the present disclosure provides a packaging article including the packaging container described above and contents accommodated in the packaging container. As already mentioned, according to the packaging article, the chemically recycled resin used as the recycled resin contained in the substrate of the laminate is less likely to be contaminated with foreign matter such as impurities, gels, and aggregates than materially recycled resin. Furthermore, unlike materially recycled resin, chemically recycled resin is not subject to heat treatments such as heat melting after the recycling process, making it less susceptible to thermal degradation and reducing the presence of foreign matter such as gels and aggregates on the surface of the substrate. Therefore, even when a printed layer is formed on such a substrate, unevenness in the thickness of the printed layer due to the presence of foreign matter is less likely to occur. Therefore, according to the packaging article, good printed displays are possible even when a laminate having a substrate containing recycled resin is used. [Effects of the Invention]

[0015] According to the present disclosure, there are provided a printing substrate, a laminate for packaging, a packaging container, and a packaging article that enable good printed displays even when a substrate containing recycled resin is used. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing one embodiment of a packaging laminate according to the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing another embodiment of the packaging laminate according to the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view showing another embodiment of the packaging laminate according to the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view illustrating one embodiment of a packaging article according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of the present disclosure will be described in detail below. In the drawings, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be omitted.

[0018] <<Packaging laminate>> First, embodiments of the packaging laminate according to the present disclosure will be described with reference to Figures 1 to 3. Figures 1 to 3 are cross-sectional views showing various embodiments of the packaging laminate according to the present disclosure.

[0019] As shown in FIG. 1, a laminate for packaging material (hereinafter also referred to as “laminate”) 100 includes a printing substrate 10 and a seal layer 30. As shown in Fig. 2, the printing substrate 10 is formed by forming a printing layer 50 on a substrate 11. Here, the substrate 11 is a polyolefin resin film containing recycled resin, and the recycled resin is a chemically recycled resin. The laminate 100 may further include an intermediate substrate 20 between the printing substrate 10 and the sealing layer 30 . The laminate 100 may further include a gas barrier layer 60 as shown in FIG. When the laminate 100 is used for a tube container, as shown in FIG. 3, the laminate 100 may further include a second sealant layer 40 on the side of the printing substrate 10 opposite the sealing layer 30.

[0020] According to the laminate 100, even when a substrate containing recycled resin is used, a good printed display can be achieved. The content of recycled resin in the packaging laminate 100 is preferably 10% by volume or 10% by mass or more.

[0021] <Printing base material> The printing substrate 10 is a member formed by forming a printing layer 50 on a substrate 11.

[0022] (base material) The substrate 11 is made of a polyolefin resin film containing recycled resin, and the recycled resin is a chemically recycled resin.

[0023] The polyolefin resin film includes polyolefin resin films, such as polyethylene and polypropylene.

[0024] Polyethylene is a resin containing ethylene as a structural unit. Examples of polyethylene include ethylene homopolymers and copolymers of ethylene with other monomers. The proportion of ethylene in polyethylene is, for example, 80 mol % or more. Examples of other monomers include α-olefins, vinyl acetate, and acrylic esters. The α-olefin may be an olefin having a carbon number in the range of 3 to 20. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene. Examples of polyethylene include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, etc. These may be used alone or in combination of two or more.

[0025] Polypropylene is a resin containing propylene as a structural unit, but may not contain ethylene as a structural unit, and may be a copolymer of propylene alone or with ethylene or various α-olefins. Examples of polypropylene include homopolypropylene, block polypropylene, and random polypropylene.

[0026] The polyolefin resin may be a non-recycled polyolefin resin, a chemically recycled polyolefin resin, or a mixture thereof. The non-recycled polyolefin resin may be a petroleum-derived polyolefin resin obtained using petroleum-derived raw material monomers, a biomass-derived polyolefin resin obtained using biomass-derived raw material monomers, or a mixture thereof, but from the viewpoint of reducing the environmental load, a biomass-derived polyolefin resin is preferred. The chemically recycled polyolefin resin may be composed of a single chemically recycled polyolefin resin, or may be composed of a mixture of multiple types of chemically recycled polyolefin resins.

[0027] The substrate 11 may have a single layer or a multi-layer structure. In the case of a multi-layer structure, the substrate 11 is formed from a layer configuration of two or more layers, at least one of which contains a chemically recycled resin. Furthermore, the substrate 11 may be a layer formed by co-extrusion of a layer made of ethylene-vinyl alcohol copolymer or a layer made of polyamide, optionally with an adhesive resin, and then stretching the resulting film. Examples include a three-kind five-layer substrate made of chemically recycled resin / adhesive resin / ethylene-vinyl alcohol copolymer / adhesive resin / chemically recycled resin, a three-kind three-layer substrate made of chemically recycled resin / adhesive resin / ethylene-vinyl alcohol copolymer, a multilayer substrate made of petroleum-derived (natural) resin / chemically recycled resin / petroleum-derived (natural) resin, or a multilayer substrate made of petroleum-derived (natural) resin / other polyolefin / chemically recycled resin / other resin / petroleum-derived (natural) resin, etc. Note that in the multilayer substrate 10, the specific gravities of the same materials may differ depending on their functions.

[0028] The substrate 11 may further contain additives such as fillers, antistatic agents, plasticizers, lubricants, light-shielding pigments, and antioxidants, as needed. When the substrate 11 contains a light-shielding pigment, the substrate 11 can function as a light-shielding layer.

[0029] The substrate 11 may be an unstretched film or a stretched film. The stretched film may be a uniaxially stretched film or a biaxially stretched film. The substrate 11 may be composed of either a stretched film or an unstretched film. When the substrate 11 is uniaxially stretched, the tearability and heat resistance of the laminate 100 can be improved. When the substrate 11 is a biaxially stretched film, the mechanical strength and dimensional stability of the laminate 100 can be improved.

[0030] When an adhesive layer is provided on the surface of the substrate 11, various pretreatments such as corona treatment, plasma treatment, ozone treatment, and flame treatment may be performed on the surface on the adhesive layer side in order to enhance adhesion to the adhesive layer, or a coating layer such as an easy-adhesion layer may be provided.

[0031] The thickness of the substrate 11 is not particularly limited and is, for example, 10 μm or more and 100 μm or less. From the viewpoint of reducing materials to reduce environmental impact and from the viewpoint of obtaining excellent heat resistance, impact resistance, and gas barrier properties, the thickness of the substrate 11 may be 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, or 40 μm or more. The thickness of the substrate 11 may also be 60 μm or less, or 50 μm or less.

[0032] (Printing layer) The printed layer 50 may be provided between layers or on the outside of the laminate 100, as shown in FIG. 2 or FIG. 3. When the printed layer 50 is provided between layers, it is provided on the surface opposite the sealing layer 30 (the outer surface), as shown in FIG. 2 or FIG. 3, for example. The printed layer 50 may also be provided on the surface of the outer layer substrate 10 facing the sealing layer 30 (the inner surface). When the printed layer 50 is provided on the inner surface of the outer layer substrate 10, the outer layer substrate 10 protects the printed layer 50, preventing deterioration of the printed layer 50. When the printed layer 50 is provided on the outer surface of the outer layer substrate 10 and the printed layer 50 is the outermost layer of the laminate 100, the printed layer 50 can be easily removed when recycling the packaging containing the laminate 100 after disposal. Furthermore, when the laminate 100 includes an intermediate substrate 20 as shown in FIG. 2 or FIG. 3, the printed layer 50 may be provided on the intermediate substrate 20. Here, the printed layer 50 may be provided between the outer layer substrate 10 and the intermediate substrate 20 as shown in FIG. 2 or FIG. 3, or may be provided between the intermediate substrate 20 and the sealing layer 30.

[0033] Furthermore, when the laminate 100 includes a second sealant layer 40, the printed layer 50 may be provided on the second sealant layer 40. When the printed layer 50 is provided on the second sealant layer 40, providing the printed layer 50 on the surface (outer surface) of the second sealant layer 40 opposite the outer layer substrate 10 makes it possible to easily remove the printed layer 50 when recycling the package containing the laminate 100 after disposal.

[0034] The print layer 50 is a layer that displays characters, pictures, etc., and can be formed using ink. As the ink, for example, inks obtained by adding various pigments, plasticizers, drying agents, stabilizers, etc. to a binder resin such as a urethane-based, acrylic-based, nitrocellulose-based, or rubber-based ink can be used.

[0035] The ink may be either a water-based ink or an oil-based ink, but is preferably a water-based ink. A water-based ink uses water or alcohol as a solvent, which can further reduce the environmental impact. In particular, when the adhesive is a solventless adhesive, using a water-based ink as the ink can significantly reduce the environmental impact. Furthermore, the ink may or may not be a biomass ink, but from the perspective of reducing the environmental impact, a biomass ink is preferred. Here, biomass ink refers to an ink containing components obtained from biological resources (biomass), such as cotton, pulp, rice bran, vegetable oil, and angiosperm seeds. The ink may be recycled ink, which is made by collecting and recycling used ink, or may be non-recycled ink, but recycled ink is preferred from the viewpoint of environmental impact.

[0036] Furthermore, an easily recyclable ink can also be used as the ink. By using an easily recyclable ink, it becomes possible to easily recycle the packaging including the laminate 100 after it has been discarded. Specifically, an example of an easily recyclable ink is "SunSpectro Solvawash" manufactured by DIC Corporation.

[0037] <Sealing layer> The sealing layer 30 is used to bond the sealing layers 30 together by applying heat and pressure when manufacturing a packaging container such as a packaging bag using the laminate 100, and a sealant film or a heat seal varnish layer can be used.

[0038] The sealing layer 30 preferably has a melting point lower than that of the substrate 11 disposed on the outside. In this case, when the laminate 100 is heat-sealed, it is possible to heat-seal the sealing layer 30 while suppressing melting of the substrate 11. Furthermore, by heating the laminate 100, the substrate 11 and the sealing layer 30 can be easily separated, and material recycling of each of the substrate 11 and the sealing layer 30 can be easily performed.

[0039] The sealing layer 30 may further contain additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, an antistatic agent, and a light-shielding pigment, as required. When the sealing layer 30 contains a light-blocking pigment, the sealing layer 30 can function as a light-blocking layer.

[0040] The sealing layer 30 may be composed of a single layer or multiple layers. When the sealing layer 30 is composed of a single layer, the sealing layer 30 may be a recycled polyolefin resin film containing recycled resin, or may be a non-recycled polyolefin resin film. As the recycled polyolefin resin film, chemically recycled polyolefin resin is preferred because it is excellent in terms of hygiene and quality. When the sealing layer 30 has three layers, the layers may be composed of a first outer layer, a middle layer, and a second outer layer. Here, the first outer layer and the second outer layer may be made of a non-recycled polyolefin resin film, and the intermediate layer may be made of a recycled polyolefin resin film. The sealing layer 30 may be colored white or the like. For example, a white sealant containing a titanium oxide-based white pigment may be used. The sealing layer 30 is not limited to a white sealant, and may be formed of a sealing layer of a different color by containing a pigment other than the white pigment.

[0041] (sealant film) The sealant film may be a polyolefin resin film or a polyester resin film. The polyolefin resin film is suitable for use in terms of sealing suitability and contains a resin made of polyolefin resin. The polyolefin resin may be the same as the resin used in the substrate 11. The polyester resin film may be a copolymer polyester obtained by copolymerizing two or more copolymers, and such a polyester resin film is preferred in terms of low adsorption of ingredients in the contents and flavor barrier properties.

[0042] The thickness of the sealant film is not particularly limited and may be adjusted appropriately depending on the application of the laminate 100. The thickness of the sealant film may be, for example, 10 μm or more, 25 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. The thickness of the sealant film may also be 100 μm or less, 80 μm or less, 60 μm or less, or 50 μm or less.

[0043] (heat seal varnish layer) The heat seal varnish layer can be used primarily for light packaging applications containing lightweight snacks. The heat seal varnish layer is obtained by applying and drying an acrylic, elastomer, or olefin-based heat seal varnish. Examples of heat seal varnishes that can be used include those obtained by dispersing heat seal varnish components in an aqueous solvent (e.g., water). Examples of heat seal varnishes that can be used include acrylic resin emulsions obtained by dispersing acrylic resins as heat seal varnish components in an aqueous solvent, styrene-acrylic emulsions obtained by dispersing styrene-acrylic copolymer resins as heat seal varnish components in an aqueous solvent, ionomer-based emulsions obtained by dispersing ionomers as heat seal varnish components in an aqueous solvent, and polyolefin-based emulsions obtained by dispersing polyolefin resins as heat seal varnish components in an aqueous solvent. In particular, it is preferable to use an aqueous heat seal varnish prepared by dispersing an aqueous polyolefin resin having at least one selected from the group consisting of a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester in an aqueous solvent as a heat seal varnish component, among polyolefin emulsions. Specific examples of heat seal varnish that can be used include A450NS (acrylic type) manufactured by DIC Corporation and Chemipearl S (polyolefin type) manufactured by Mitsui Chemicals, Inc. The thickness of the heat seal varnish layer may be, for example, 0.05 μm or more, 0.5 μm or more, or 1 μm or more, and may be 20 μm or less, 10 μm or less, or 5 μm or less. The thickness of the heat seal varnish layer is preferably 1 to 5 μm. In this case, sufficient heat seal strength can be obtained while also providing resistance to bending.

[0044] <Second sealant layer> The second sealant layer 40 may be the same as the sealing layer 30 described above. The thickness of the second sealant layer 40 may be the same as or different from the thickness of the sealing layer 30. The material constituting the second sealant layer 40 may also be the same as or different from the material constituting the sealing layer 30.

[0045] <Intermediate substrate> The intermediate substrate 20 is a substrate that reinforces the printing substrate 10, and can further improve the strength of the laminate 100. The intermediate substrate 20 can be a film substrate made of a resin material. Examples of such resin materials include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene, polypropylene, and cyclic olefin copolymers COC and COP; and engineering plastics such as polystyrene, polyamides such as nylon 66, polycarbonate, polyacrylonitrile, and polyimide. Resin materials with mechanical strength and dimensional stability are preferred. The resin materials are processed into a film and used as the film substrate. The film substrate may be an unstretched film or a stretched film.

[0046] The intermediate substrate 20 may be a single layer or a laminate of multiple layers. When the intermediate substrate 20 is configured as a single layer, the intermediate substrate 20 may be a recycled resin film, or may be a non-recycled resin film such as a petroleum-derived resin or a biomass-derived resin. When the intermediate substrate 20 is composed of multiple layers, all of the layers may be recycled resin films, or non-recycled resin films, or some of the layers may be non-recycled resin films and the rest may be recycled resin films. When the plurality of layers is three layers, the plurality of layers may be composed of a first outer layer, a middle layer, and a second outer layer. Here, the first and second outer layers may be made of non-recycled resin films, and the intermediate layer may be made of recycled resin film. In this case, the possibility that foreign matter such as impurities, gels, and aggregates will migrate from the intermediate substrate 20 through the sealing layer 30 to the contents as a result of heating during retort or boiling treatment of the packaging bag can be further reduced. Therefore, the laminate 100 can be used safely to package contents such as food.

[0047] The thickness of the intermediate substrate 20 is not particularly limited and is adjusted appropriately depending on the application of the laminate 100. The thickness of the intermediate substrate 20 may be, for example, 10 μm or more, 25 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. The thickness of the intermediate substrate 20 may also be 100 μm or less, 80 μm or less, 60 μm or less, or 50 μm or less.

[0048] <Adhesive layer> Examples of the adhesive layer include an adhesive layer formed using an adhesive agent and an adhesive layer containing an adhesive resin (hereinafter also referred to as an "adhesive resin layer").

[0049] Examples of adhesives include known adhesives such as urethane adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, and isocyanate adhesives.

[0050] The adhesive may or may not contain a biomass-derived component, but preferably contains a biomass-derived component from the viewpoint of reducing the environmental impact. Specific examples of biomass-derived components include the "DIC Dry BM Series" manufactured by DIC Corporation and the "ECOAD Series" manufactured by Toyo Ink Co., Ltd.

[0051] The adhesive may be an adhesive containing an organic solvent or an adhesive containing no organic solvent, but from the viewpoint of reducing the environmental load, an adhesive containing no organic solvent (solvent-free adhesive) is preferred.

[0052] The adhesive resin layer may be an extruded or non-extruded resin layer. The adhesive resin is a heat-sealable adhesive thermoplastic resin that can be melted by heat and fused to each other. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, methylpentene polymer, acid-modified polyolefin resins obtained by modifying polyolefin resins such as polyethylene or polypropylene with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, and the like can be used.

[0053] The thickness of the adhesive layer is not particularly limited and may be, for example, 1 μm or more. By making the thickness of the adhesive layer 1 μm or more, sufficient adhesive strength can be obtained. The thickness of the adhesive layer may be 2 μm or more. The thickness of the adhesive layer may be 50 μm or less, 5 μm or less, or 3 μm or less.

[0054] <Gas barrier layer> The laminate 100 may include a gas barrier layer 60 together with the printed layer 50, as shown in Fig. 2 or 3. The gas barrier layer 60 may be provided on at least one surface of the substrate 11. Furthermore, when the laminate 100 includes an intermediate substrate 20, the gas barrier layer 60 may be provided on at least one surface of the intermediate substrate 20, as shown in Fig. 2 or 3. The gas barrier layer 60 is a layer that improves the gas barrier properties of the laminate 100 . The gas barrier layer 60 has a barrier property against gases such as water vapor or oxygen.

[0055] The gas barrier layer 60 may be, for example, a vapor deposition layer such as a metal vapor deposition layer or an inorganic compound vapor deposition layer. Metals include aluminum and silicon. Inorganic oxides include aluminum oxide and silicon oxide (silica). When the gas barrier layer 60 is a vapor-deposited layer of a metal such as aluminum, the gas barrier layer 60 can function as a light-shielding layer. The gas barrier layer 60 may further include an overcoat layer on the vapor deposition layer. The overcoat layer may be a coating layer obtained using a composition containing a water-soluble polymer and silicon alkoxide, or a coating layer made of a resin such as polyurethane.

[0056] <Other layers> The laminate 100 may further include a layer containing a non-polyolefin resin. Examples of non-polyolefin resins include polyamide resins such as nylon, and polyester resins such as polyethylene terephthalate (PET).

[0057] (Laminate) (A) Recycled resin content In the laminate 100, the content of recycled resin in the laminate 100 is preferably 10% by volume or more or 10% by mass or more. When the recycled resin content in the polyolefin resin film containing recycled resin is 100% by volume (100% by mass), the recycled resin content in the laminate 100 can be determined as the ratio of the total thickness of the film to the total thickness of the laminate 100. However, when the recycled resin content in the polyolefin resin film containing recycled resin is X% by mass (less than 100% by mass) and the thickness of the film is Y1 (μm), the recycled resin content of the film thickness Y2 (μm) is calculated as X / 100×Y1 (μm). The recycled resin content in the laminate 100 is preferably 20% by volume or more or 20% by mass or more, more preferably 25% by volume or more or 25% by mass or more, even more preferably 30% by volume or more or 30% by mass or more, and particularly preferably 40% by volume or more or 40% by mass or more.

[0058] In the present disclosure, the above-mentioned recycled resin is a chemical recycled resin and does not include material recycled resin. The chemically recycled resin may be post-consumer recycled resin (PCR), post-industrial recycled resin (PIR), or a mixture thereof, but is preferably PCR. PCR is available in large quantities on the market, so if the chemically recycled resin is PCR, the cost of the laminate 100 can be reduced.

[0059] (B) Odor components In a total ion chromatogram obtained by performing mass analysis of the laminate 100 using purge-and-trap gas chromatography-mass spectrometry, when the ratio of the peak area of ​​nonanal as an indicator of odor components to the sum of the peak area values ​​of all aliphatic hydrocarbon components is defined as R1 (%), and the ratio of the peak area of ​​decanal to the sum of the peak area values ​​of all aliphatic hydrocarbon components is defined as R2 (%), R1 is preferably less than 1.5%, more preferably 1.0% or less, and particularly preferably 0.5% or less. Furthermore, R2 is preferably less than 3.5%, more preferably 2.5% or less, and particularly preferably 1.5% or less. It is preferable that R1 is less than 1.5% and R2 is less than 3.5%, in which case thermal degradation is suppressed overall in the laminate 100, and the quality of the laminate 100 can be further improved. Specifically, the above mass analysis is carried out by cutting out a 1.0 gram sample from the laminate 100, placing this sample in a 20 mL vial together with an odor component collector, heating it at 60°C for 1 hour to adsorb the volatile components from the sample onto the collector, and then analyzing the volatile components in the collector using a purge-and-trap gas chromatograph mass spectrometer.

[0060] (C) Fisheye Fisheyes are foreign objects such as gelled or charred particles that look like fish eyes and are found on film. If a fisheye has a diameter of 1 mm or more, the product will be deemed defective. The number of fisheyes with a diameter of 0.5 mm or more but less than 1 mm must be 100 / m. 2 Less than or equal to 50 particles / m 2 Less than 10 pieces / m 2 It would be better if it was below.

[0061] (D) Variation in kinetic friction force On the surface of the printing substrate 10 of the laminate 100, the variation (in-plane variation) σ of the dynamic friction force refers to the standard deviation of the dynamic friction force. σ is preferably less than 0.45, more preferably less than 0.35, and particularly preferably less than 0.2. When σ is less than 0.45, the transportability of the laminate 100 can be improved when the layer having σ of less than 0.45 is placed on the transport roller side. Furthermore, on the surface of the layer, regions where the dynamic friction force received from the transport roller is large and regions where it is small appear, and the difference in stress between these regions is reduced, thereby reducing residual strain in the layer and suppressing a decrease in the strength of the laminate 100 due to the residual strain. From the viewpoint of the strength of the laminate, σ is preferably 0.1 or more, more preferably 0.2 or more, and particularly preferably 0.3 or more. The dynamic friction coefficient is measured for the laminate 100 using a multi-function static and dynamic friction tester TL201Tt (manufactured by Trinity Lab Co., Ltd.) and a tactile probe. The standard deviation σ of the dynamic friction force is a value obtained based on JIS K 7125-ISO8295, and specifically, is determined by placing the laminate 100 on a test table with the printing substrate 10 facing downwards and moving a tactile probe at a sliding speed of 10 mm / sec while contacting the laminate 100 with a load of 50 grams.

[0062] (F) Impurities The laminate 100 is analyzed using a Fourier transform infrared spectrophotometer (FT-IR: Fourier transform infrared spectroscopy) by attenuated total reflection (ATR) to obtain an ATR spectrum. In the ATR spectrum, -1 Absorption coefficients of methylene CH inverse symmetric stretching near 1720cm from polyesters and polyurethanes -1 The ratio R3 of the absorption coefficients for C=O stretching near the polyolefin is preferably less than 0.1, more preferably less than 0.05, and particularly preferably 0.01 or less, as an index showing that there are few resin components other than polyolefin. In the above analysis, a diamond prism is used as the prism to be brought into close contact with the laminate 100, and the angle of incidence with respect to the surface of the laminate 100 is set to 45°.

[0063] When the laminate 100 includes a substrate 10 and a sealing layer 30, both the substrate 10 and the sealing layer 30 may be recycled resin films.

[0064] <<Packaged goods>> Next, an embodiment of a packaging article according to another aspect of the present disclosure will be described with reference to Fig. 4. Fig. 4 is a cross-sectional view showing one embodiment of a packaging article according to another aspect of the present disclosure.

[0065] As shown in FIG. 4, a packaged item 500 includes a packaging bag 400 as a packaging container and contents C contained in the packaging bag 400. The packaging bag 400 is obtained using a pair of laminates 100. The packaging bag 400 is obtained, for example, by bringing the seal layers 30 of the pair of laminates 100 face to face and bonding their peripheral edges together. The packaging bag 400 is composed of a storage section that stores the contents C and an adhesive section that is provided around the storage section. The adhesive section is a section formed by bonding the seal layers 30 of opposing laminates 100 together, and the packaging section is a section where the seal layers 30 of opposing laminates 100 are not bonded together.

[0066] According to the packaging article 500, the chemically recycled resin contained in the substrate 11 of the laminate 100 is a recycled resin produced by first depolymerizing discarded resin through a process that involves gasifying, liquefying, and monomerizing it via refined naphtha, or by depolymerizing it to monomerize it, depending on the material's characteristics. Therefore, chemically recycled resin is less likely to be contaminated with foreign matter such as impurities, gels, and aggregates than material recycled resin, which is a resin made by cleaning, crushing, and then melting resin products such as recovered used packaging materials to recycle them into raw materials. Furthermore, unlike material recycled resin, chemically recycled resin is not subject to heat treatments such as melting after the recycling process, making it less susceptible to thermal degradation and reducing the presence of foreign matter such as gels and aggregates on the surface of the substrate 11. Therefore, protrusions due to foreign matter are less likely to form on the surface of the substrate 11, resulting in less unevenness. When a printed layer 50 is formed on such a substrate 11, defects such as missing characters in the printed layer 50 are less likely to occur. In particular, missing characters are less likely to occur in the printed layer 50 with a low dot density. Also, uneven thickness of the printed layer 50 due to the presence of foreign matter is less likely to occur. Therefore, the packaging article 500 enables good printed display even when using the laminate 100 including the substrate 11 containing recycled resin. Furthermore, because the laminate 100 can improve quality, the packaging article 500 including the packaging bag 400 obtained using the packaging laminate 100 can improve properties such as strength.

[0067] (Contents) The contents C are not particularly limited and may be selected appropriately depending on the intended use of the packaging bag 400. The contents C are not particularly limited, and examples of the contents C include food, shampoo, conditioner, body soap, detergent, etc.

[0068] (packaging bag) The pair of laminates 100 constituting the packaging bag 400 may have the same configuration as each other, or may have different configurations from each other.

[0069] The packaging bag 400 may have a half-cut line, and may further have an easy-open processed part at both ends or one end of the half-cut line. Examples of the easy-open processed part include a group of scars, and a V-shaped, U-shaped, or I-shaped notch.

[0070] In the adhesive portion of the packaging bag 400, the seal layers 30 of the pair of laminates 100 may be directly bonded to each other by heat sealing (see FIG. 4), or may be bonded to each other by an adhesive.

[0071] (Manufacturing method of packaging articles) Next, an example of a method for manufacturing a packaged article 500 using the laminate 100 will be described.

[0072] First, a pair of laminates 100 is prepared. Then, the seal layers 30 of the pair of laminates 100 are placed opposite each other and bonded together. At this time, parts of the peripheral edges of the laminates are bonded together in a U-shape to form bonded sections, and also to form unbonded sections (unbonded sections). In this way, a packaging bag having an opening formed by the unbonded sections is obtained.

[0073] Next, the contents C are filled into the packaging bag through the opening. After that, the seal layers 30 of the laminate 100 are bonded together at the unbonded portions, so that the unbonded portions also become bonded portions. In this way, a packaged article 500 including the packaging bag 400 and the contents C contained therein can be manufactured.

[0074] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, in the packaged article 500 shown in Fig. 4, the packaging bag 400 is formed using a pair of laminates 100. However, the packaging bag may be manufactured by folding one laminate 100 with the sealing layer 30 on the inside and bonding the overlapping peripheral edges together.

[0075] 4, the packaging bag 400 may be a standing pouch-shaped packaging bag, a two-sided bag, a three-sided bag, a four-sided bag, a palm-shaped bag, or a gusset bag. The packaging bag 400 may be provided with a stopper or a synthetic resin zipper that can be repeatedly sealed by fitting a strip-shaped protrusion and a strip-shaped groove.

[0076] In the above embodiment, the packaging container is configured as a packaging bag, but the packaging container may also be a tube container. When the packaging container is a tube container, the laminate 100 includes a second sealant layer 40 that is adhered to the outer layer base material 10.

[0077] The embodiments of the present disclosure have been described above, and the outline of the present disclosure is as follows. [1] A printing substrate having a printing layer formed on a substrate, A printing substrate, wherein the substrate is a polyolefin resin film containing a recycled resin, and the recycled resin is a chemically recycled resin. [2] A laminate for packaging materials comprising the printing substrate according to [1] and a seal layer. [3] The laminate for packaging material according to [2], wherein the content of the recycled resin in the laminate for packaging material is 10% by volume or 10% by mass or more. [4] The laminate for packaging materials according to [2] or [3], further comprising an intermediate substrate between the substrate and the sealing layer. [5] The laminate for packaging materials according to any one of [2] to [4], wherein the recycled resin is a post-consumer recycled resin. [6] The laminate for packaging materials according to any one of [2] to [5], wherein the sealing layer comprises a sealant film or a heat seal varnish layer. [7] The laminate according to [4], wherein the substrate and the intermediate substrate are bonded together with a solventless adhesive. [8] The laminate for packaging materials according to [4], wherein the substrate or the intermediate substrate further comprises a gas barrier layer. [9] A packaging container obtained by using the laminate for packaging material according to any one of [1] to [8].

[10] [9] A packaging container according to the present invention; and a content contained within the packaging container. [Example]

[0078] The present disclosure will be explained in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0079] Example 1 The base material was a chemically recycled low-density polyethylene (PCR ChemiR 100%-LDPE) film (35 μm thick) made from used packaging, and the sealant film, or sealing layer, was a petroleum-derived low-density polyethylene (petroleum-derived LDPE) film (60 μm thick). Note that "PCR ChemiR 100%-LDPE" means that the content of post-consumer chemical recycled resin (PCR ChemiR) in the base material is 100% by volume (100% by mass). Then, a printing layer was formed on one surface of the substrate using aqueous flexographic ink to obtain a printing substrate, and then a dry laminating adhesive (urethane adhesive) was applied to the surface of the printing layer to form an adhesive layer 3 μm thick (dry film thickness).A sealant layer was then attached to the adhesive layer to produce a laminate for packaging (printing substrate (substrate / printing layer) / adhesive layer / sealing layer).

[0080] Example 2 A laminate for packaging (printed layer / substrate / adhesive layer / sealing layer) was produced in the same manner as in Example 1, except that the substrate was changed from a PCR ChemiR 100%-LDPE film (35 μm thick) to a PCR ChemiR 100%-LDPE film (25 μm thick), the sealant film serving as the sealing layer was changed from a petroleum-derived LDPE film (60 μm thick) to a biomass-derived low-density polyethylene (biomass-derived LDPE) film (60 μm thick), the dry lamination adhesive (urethane-based adhesive) was changed to a 1.5 μm thick solvent-free adhesive (polyester-based), and the printing layer was provided on the outside (the side of the substrate opposite the sealing layer).

[0081] Example 3 A PCR ChemiR 100%-LDPE film (25 μm thick) was prepared as the substrate, a PCR ChemiR 100%-LDPE film (25 μm thick) was prepared as the intermediate substrate, and a petroleum-derived LDPE film (60 μm thick) was prepared as the sealant film, which is the sealing layer. Then, a printing layer was formed on one surface of the substrate using aqueous flexographic ink, and then a dry laminating adhesive (urethane-based adhesive) was applied to the surface of the printing layer to form a first adhesive layer with a thickness of 3 μm (dry film thickness), and an intermediate substrate was bonded to the first adhesive layer. Next, a dry lamination adhesive (urethane-based adhesive) was applied to the surface of the intermediate substrate to form a second adhesive layer 3 μm thick (dry film thickness), and a sealing layer was attached to the second adhesive layer to produce a packaging laminate (substrate / printing layer / first adhesive layer / intermediate substrate / second adhesive layer / sealing layer).

[0082] Example 4 The substrate was a chemically recycled low-density polyethylene (PCR ChemiR 100%-LDPE) film (35 μm thick) made from used packaging. Note that "PCR ChemiR 100%-LDPE" means that the content of post-consumer chemical recycled resin (PCR ChemiR) in the substrate is 100% by volume (100% by mass). A printed layer was then formed on one surface of the substrate using aqueous flexographic ink, and a polyolefin-based heat seal varnish was then applied to the surface of the printed layer and dried to form a seal layer (thickness 1 μm), producing a laminate for packaging (substrate / printed layer / seal layer). An aqueous polyolefin dispersion (Chemipearl S, manufactured by Mitsui Chemicals, Inc.) was used as the polyolefin-based heat seal varnish.

[0083] Example 5 A laminate for packaging (substrate / printing layer / first adhesive layer / intermediate substrate / second adhesive layer / sealing layer) was produced in the same manner as in Example 3, except that the substrate was changed from a PCR ChemiR 100%-LDPE film (25 μm thick) to a PCR ChemiR 100%-HDPE film (25 μm thick), the intermediate substrate was changed from a PCR ChemiR 100%-LDPE film (25 μm thick) to a petroleum-derived LDPE film (25 μm thick), and the sealant film, which is the sealing layer, was changed from a petroleum-derived LDPE film (60 μm thick) to a petroleum-derived LDPE film (50 μm thick).

[0084] Example 6 A laminate for packaging (substrate / printed layer / first adhesive layer / intermediate substrate / second adhesive layer / sealant layer) was produced in the same manner as in Example 5, except that the substrate was changed from a PCR ChemiR 100%-HDPE film (thickness 25 μm) to a laminated co-extruded film produced by co-extruding three layers: a PCR ChemiR 100%-stretched HDPE film (thickness 15 μm), a petroleum-derived stretched MDPE film (thickness 15 μm), and a PCR ChemiR 100%-stretched HDPE film (thickness 15 μm).

[0085] Example 7 A PCR Chemi R 100%-OPP film (25 μm thick) was prepared as the substrate, and a laminated film was prepared by sequentially forming an SiOx vapor deposition layer (10 nm thick) and an overcoat layer (0.3 μm thick) on the PCR Chemi R 100%-OPP film (25 μm thick) as the intermediate substrate, and a petroleum-derived CPP film (60 μm thick) was prepared as the sealing layer. The overcoat layer was formed by mixing 10.4 g of tetraethoxysilane (Si(OC2H5)4: hereafter referred to as "TEOS") with 89.6 g of hydrochloric acid (0.1N) and stirring for 30 minutes to produce a hydrolyzed solution (liquid A) with a solid content of 3 wt% (SiO2 equivalent) and a 3.0 wt% water / isopropyl alcohol solution of polyvinyl alcohol (water:isopropyl alcohol weight ratio of 90:10) (liquid B) in a mixing ratio (weight ratio) of liquid A / liquid B at a 60 / 40, applying the coating agent with a bar coater and drying in a dryer at 120°C for 1 minute. A printed layer was then formed on one surface of the substrate using aqueous flexographic ink, a dry laminating adhesive (urethane adhesive) was applied to the surface of the printed layer to form a first adhesive layer 3 μm thick (dry film thickness), and a laminated film was attached using the first adhesive layer with the overcoat layer facing the first adhesive layer. Next, a dry laminating adhesive (urethane adhesive) was applied to the surface of the laminated film to form a second adhesive layer 3 μm thick (dry film thickness), and a seal layer was attached to the second adhesive layer to produce a packaging laminate (substrate / printed layer / first adhesive layer / laminate film (intermediate substrate) / second adhesive layer / sealing layer).

[0086] Example 8 A laminate for packaging (substrate / printed layer / first adhesive layer / laminated film (intermediate substrate) / second adhesive layer / sealing layer) was prepared in the same manner as in Example 7, except that the sealing layer was changed from a petroleum-derived CPP film (thickness 60 μm) to a petroleum-derived LDPE film (thickness 60 μm).

[0087] (Comparative Example 1) The substrate was a low-density polyethylene (PCRMR100%-LDPE) film (25 μm thick) made from recycled polyethylene bags, and the sealing layer was a petroleum-derived LDPE film (60 μm thick) as a sealant film. Note that "PCRMR100%-LDPE" means that the content of post-consumer mechanically recycled resin (PCRMR) in the substrate is 100% by volume (100% by mass). A printing layer was then formed on one surface of the substrate using aqueous flexographic ink, a dry laminating adhesive (urethane adhesive) was applied to the surface of the printing layer to form an adhesive layer 3 μm thick (dry film thickness), and a sealing layer was attached to the adhesive layer to produce a packaging laminate (substrate / printing layer / adhesive layer / sealing layer).

[0088] (Comparative Example 2) A laminate for packaging was produced in the same manner as in Comparative Example 1, except that the substrate was changed from a PCRMR100%-LDPE film (thickness 20 μm) to a low-density polyethylene (PCRMR40%-LDPE) film (thickness 60 μm) obtained by mixing low-density polyethylene (PCRMR-LDPE) pellets obtained by cleaning and mechanically recycling used polyethylene bags with petroleum-derived LDPE pellets in a 40:60 (mass ratio) mixture, and the sealing layer was changed from a petroleum-derived LDPE film (thickness 60 μm) to a petroleum-derived LDPE film (thickness 50 μm). Note that "PCRMR40%-LDPE" means that the content of post-consumer mechanically recycled resin (PCRMR) in the substrate is 40% by mass. In this case, the volume of a layer made from recycled materials can be calculated by taking into account the density of the mixed resin, and this can be used to calculate the film thickness ratio. Note that the density of the mixed resins is the same, so mass% = volume%. In addition, the density of the PCRMR-LDPE 40% film used as the substrate is low (0.920 g / cm 3 ) was decided.

[0089] (Comparative Example 3) A PCRMR100%-LDPE film (thickness 25 μm) was prepared as the substrate, a PCRMR100%-LDPE film (thickness 25 μm) was prepared as the intermediate substrate, and a petroleum-derived LDPE film (thickness 60 μm) was prepared as the sealing layer. A printed layer was formed on one surface of the substrate using aqueous flexographic ink, a laminating adhesive (urethane adhesive) was applied to the surface of the printed layer to form a first adhesive layer 3 μm thick (dry film thickness), and an intermediate substrate was bonded to the first adhesive layer. Next, a dry laminating adhesive (urethane adhesive) was applied to the surface of the intermediate substrate to form a second adhesive layer 3 μm thick (dry film thickness), and a seal layer was bonded to the second adhesive layer to produce a packaging laminate (substrate / printed layer / first adhesive layer / intermediate substrate / second adhesive layer / seal layer).

[0090] Comparative Example 4 A laminate for packaging (substrate / printing layer / adhesive layer / sealing layer) was produced in the same manner as in Comparative Example 1, except that the substrate was changed from a PCRMR100%-LDPE film (thickness 25 μm) to a linear low-density polyethylene (PCRMR100%-LLDPE) film (thickness 35 μm) recycled from used polyethylene bags.

[0091] (Comparative Example 5) The substrate was a recycled low-density polyethylene (PCRMR-HDPE-LLDPE100%) film (25 μm thick) made from used packaging material (high-density polyethylene (HDPE) layer / printed layer / HDPE layer / LLDPE sealant layer), and the seal layer was a petroleum-derived LDPE film (60 μm thick). Note that "PCRMR-HDPE-LLDPE100%" means that the total content of mechanically recycled high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) in the substrate is 100% by volume (100% by mass). A printing layer was then formed on one side of the substrate using aqueous flexographic ink, and a laminating adhesive (urethane adhesive) was applied to the surface of the printed surface to form an adhesive layer 3 μm thick (dry film thickness). A sealing layer was then attached to the adhesive layer to produce a packaging laminate (substrate / printing layer / adhesive layer / sealing layer).

[0092] (Comparative Example 6) The substrate was a low-density polyethylene (PCRMR40%-LDPE) film (thickness 60 μm) obtained by washing used polyethylene bags and mixing low-density polyethylene (PCRMR-LDPE) pellets obtained by mechanical recycling with petroleum-derived LDPE pellets in a ratio of 40:60 (mass ratio).A petroleum-derived LDPE film (thickness 35 μm) was prepared as the intermediate substrate, and a petroleum-derived LDPE film (thickness 60 μm) was prepared as the sealing layer. A printed layer was then formed on one surface of the substrate using aqueous flexographic ink, a laminating adhesive (urethane adhesive) was applied to the surface of the printed layer to form a first adhesive layer 3 μm thick (dry film thickness), and an intermediate substrate was bonded to the first adhesive layer. Subsequently, a dry laminating adhesive (urethane adhesive) was applied to the surface of the intermediate substrate to form a second adhesive layer 3 μm thick (dry film thickness), and a seal layer was bonded to the second adhesive layer to produce a packaging laminate (substrate / printed layer / first adhesive layer / intermediate substrate / second adhesive layer / seal layer). Note that "PCRMR40%-LDPE" means that the content of post-consumer mechanically recycled resin (PCRMR) in the substrate is 40% by mass. In this case, the volume of a layer made from recycled material can be calculated by taking into account the density of the mixed resin, and this can be used to calculate the film thickness ratio. Note that the density of the mixed resins is the same, and the mass % is also the volume %. In addition, the density of the PCRMR-LDPE 40% film used as the substrate is low (0.920 g / cm 3 ) was decided.

[0093] (Reference example 1) A petroleum-derived LDPE film (thickness: 25 μm) was prepared as the substrate, and a petroleum-derived LDPE film (thickness: 60 μm) was prepared as the sealing layer. A printed layer was then formed on one side of the substrate using aqueous flexographic ink, and a laminating adhesive (urethane adhesive) was applied to the surface of the printed surface to form an adhesive layer 3 μm thick (dry film thickness). A sealing layer was then attached to the adhesive layer to produce a laminate for packaging.

[0094] <Recycled resin content> For the laminates for packaging materials of the Examples, Comparative Examples and Reference Examples prepared as described above, the content of recycled resin in the laminates for packaging materials was calculated according to the following formula. Recycled resin content = 100 x total thickness of layers containing recycled resin / total thickness of laminate for packaging material However, when the layer containing recycled resin is a layer containing recycled resin and petroleum-derived resin, the value obtained by multiplying the thickness of this layer by the content (mass%) of recycled resin in the layer was used as the thickness value of the layer containing recycled resin. Since the thicknesses of the printed layer, the vapor-deposited layer, and the overcoat layer are quite small, they were not taken into consideration when determining the recycled resin content in the laminate.

[0095] <Evaluation> The laminates for packaging materials of the Examples, Comparative Examples, and Reference Examples prepared as described above were evaluated as follows: Evaluation 1 (generation of odorous components), Evaluation 2 (fisheyes), Evaluation 3 (impurities), Evaluation 4 (variation in dynamic frictional force), and Evaluation 5 (printability). Here, Evaluation 1 is an evaluation regarding quality, and Evaluations 2 and 3 are evaluations regarding hygiene.

[0096] (1) Evaluation 1 (Odor component generation) First, the packaging laminate was analyzed using purge-and-trap gas chromatography-mass spectrometry. Specifically, a 1.0 gram sample was cut from the packaging laminate, placed in a 20 mL vial together with an odor component collector, and heated at 60°C for 1 hour to adsorb the volatile components from the sample onto the collector. The volatile components in the collector were then analyzed using a purge-and-trap gas chromatography-mass spectrometry system, and a total ion chromatogram was obtained. Next, in the total ion chromatogram obtained as described above, the ratio R1 of the peak area of ​​nonanal to the sum of the peak area values ​​of all aliphatic hydrocarbon components, and the ratio R2 of the peak area of ​​decanal to the sum of the peak area values ​​of all aliphatic hydrocarbon components, were calculated as indicators of odor components. The results were evaluated based on the following criteria: Tables 1 to 3 show the results. (Evaluation criteria) ◎ R1 is less than 1.5% and R2 is less than 0.35% ○···R1 is less than 1.5% and R2 is 0.35% or more, or R1 is 1.5% or more and R2 is less than 0.35% × R1 is 1.5% or more and R2 is 0.35% or more

[0097] (2) Rating 2 (Fisheye) A sample measuring 1 m x 1 m was cut from the packaging laminate and placed on a black table with the seal layer side facing down. Protrusions (protruding foreign matter) with a diameter of 0.5 mm or more but less than 1 mm were counted visually as fisheye 1 (N1), and protrusions (protruding foreign matter) with a diameter of 1 mm or more were counted visually as fisheye 2 (N2), and the evaluation was carried out based on the following evaluation criteria. The results are shown in Tables 1 to 3. (Evaluation criteria) ◎ N1 is 10 or less and N2 is 0 ○ N1 is 11 to 99 and N2 is 0 × N1 is 100 or more or N2 is 1 or more

[0098] (3) Rating 3 (impurities) The packaging laminate was analyzed using a Fourier transform infrared spectrophotometer (FT-IR) by attenuated total reflection (ATR) to obtain an ATR spectrum. A diamond prism was used as the prism to be attached to the packaging laminate, and the incident angle to the surface of the packaging laminate was set to 45°. In the ATR spectrum, the 2915 cm peak originating from polyethylene -1 Absorption coefficients of methylene CH inverse symmetric stretching near 1720cm from polyesters and polyurethanes -1 The ratio R3 of the absorption coefficients of C═O stretching near the nucleus was calculated, and the results were evaluated based on the following criteria. The results are shown in Tables 1 to 3. (Evaluation criteria) ◎ R3 is less than 0.05 ○ R3 is 0.05 or more and less than 0.1 × R3 is 0.1 or more

[0099] (4) Evaluation 4 (variation in dynamic friction force) The dynamic friction force of the laminate for packaging material was measured using a multi-function static and dynamic friction tester TL201Tt (manufactured by Trinity Lab Co., Ltd.) and a tactile measuring probe. Specifically, the packaging laminate was placed on a test table with the sealant layer facing down, and a tactile probe was moved at a sliding speed of 10 mm / sec while being in contact with the packaging laminate (substrate side) with a load of 50 grams, and the standard deviation of the dynamic friction force was determined. This standard deviation σ of the dynamic friction force was taken as the variation in the dynamic friction force. Evaluation was then performed based on the following evaluation criteria. The results are shown in Tables 1 to 3. (Evaluation criteria) A σ is less than 0.35 B σ is 0.35 or more and less than 0.45 C···σ is 0.45 or more (4) Rating 5 (Print) The printing properties of the packaging laminate were evaluated as follows. Specifically, five samples measuring 10 cm x 10 cm were cut out from the packaging laminate, and these samples were placed on a light table. Using a magnifying glass, bright spots were visually inspected as ink voids. The bright spots were irregular in shape, and bright spots with a narrowest length of 0.4 mm or more were considered ink voids. The number of such bright spots was counted, and the total number of bright spots on the five samples was evaluated based on the following evaluation criteria. The results are shown in Tables 1 to 3. (Evaluation criteria) A: 10 or fewer bright spots B: Number of bright spots (ink voids) is 11 to 99 C: The number of bright spots (ink voids) is 100 or more

[0100] [Table 1] [Table 2] [Table 3]

[0101] From the results shown in Tables 1 to 3, all of the packaging laminates of Examples 1 to 8, even though they used a substrate containing recycled resin, generated almost no odorous components, contained little foreign matter or impurities such as gels or aggregates, and had good printed displays, and had performance equivalent to that of the packaging laminate of Reference Example 1. In contrast, when the recycled resin content of the packaging laminates of Comparative Examples 1 to 5, which used material recycled resin, was increased to 10% by volume or more, at least one of the following occurred: an increased amount of odorous components, an increased number of fish eyes, and an increased amount of impurities; the printed display was not good; and the packaging laminates did not have the same performance as the packaging laminate of Reference Example 1.

[0102] From the above, it has been confirmed that the laminate for packaging materials of the present disclosure makes it possible to produce good printed displays even when using a printing substrate in which a printing layer is formed on a substrate containing recycled resin. [Explanation of symbols]

[0103] 10...printing substrate, 11...substrate, 20...intermediate substrate, 30...sealing layer, 50...printing layer, 60...gas barrier layer, 100...laminated body, 400...packaging bag (packaging container), 500...packaged article, C...contents.

Claims

1. A packaging laminate comprising a printed substrate obtained by directly forming a printing layer on a substrate (excluding the substrates (A) and (B) below), and a sealing layer (excluding packaging laminates comprising the substrate, adhesive layer, and sealing layer, in which at least one selected from the substrate, adhesive layer, and sealing layer contains biomass-derived polyethylene as at least a portion of the polyethylene), the substrate is a polyolefin resin film containing recycled resin, The recycled resin is a chemical recycled resin, the sealing layer is composed of a first outer layer, an intermediate layer, and a second outer layer; the first outer layer and the second outer layer are made of a non-recycled polyolefin resin film, The laminate for packaging materials, wherein the intermediate layer is made of a recycled polyolefin resin film. (A) A substrate having a crystallinity of 35% or more, which is the ratio of the crystalline peak area to the total peak area, measured by the parallel beam method of X-ray diffraction in the diffraction angle range of 10° to 30°. (B) A substrate having a coating layer containing a resin material having a polar group formed on its surface.

2. 2. The packaging laminate according to claim 1, wherein the content of the recycled resin in the packaging laminate is 10% by volume or 10% by mass or more.

3. The laminate for packaging materials according to claim 1 , further comprising an intermediate substrate between the substrate and the sealing layer.

4. 2. The laminate for packaging materials according to claim 1, wherein the recycled resin is a post-consumer recycled resin.

5. 2. The packaging laminate according to claim 1, wherein the sealing layer comprises a sealant film.

6. The packaging laminate according to claim 3 , wherein the substrate and the intermediate substrate are bonded together with a solventless adhesive.

7. The laminate for packaging materials according to claim 3 , wherein the substrate or the intermediate substrate further comprises a gas barrier layer.

8. A packaging container obtained by using the laminate for packaging material according to any one of claims 1 to 7.

9. The packaging container according to claim 8; and a content contained within the packaging container.

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