Substrate

Abstract

To suppress adhesion of powder to a mono-materialized packaging material.SOLUTION: The base material includes a stretched polyethylene layer and a surface layer provided on the stretched polyethylene layer, wherein the stretched polyethylene layer contains polyethylene as a main component and the surface layer contains an antistatic agent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate. [Background technology]

[0002] Film products are manufactured using films of different materials (for example, a polyester film as a base material and a polyethylene film as a sealant layer) in order to achieve various functions (see, for example, Patent Document 1). Packaging containers are made from such film products. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-095454 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, efforts to address environmental issues such as plastic marine pollution and global warming have become increasingly important. Therefore, packaging materials and other materials are required to be highly recyclable. However, film products made from films of different materials are generally difficult to separate, making them difficult to recycle. To solve this problem, a technology called mono-materialization has been investigated, which aims to increase recyclability by manufacturing film products from polyethylene films of the same material.

[0005] Mono-material polyethylene can be achieved by using polyethylene films with different properties, for example, by using a stretched polyethylene film as the base material and a polyethylene film as the sealant layer.

[0006] Furthermore, packaging containers may contain powders such as wheat flour and powdered medicine. When packaging such powders, static electricity can cause the powder to adhere to the heat-sealed portion of the sealant layer. Therefore, when sealing the opening of the packaging container, the presence of the powder can cause poor fusion of the heat-sealed portion.

[0007] The present inventors have investigated the use of an antistatic polyethylene film (hereinafter also referred to as "antistatic") as a sealant layer from the viewpoint of suppressing adhesion of powder to the heat-sealed portion and also taking into consideration the possibility of mono-materialization. However, the present inventors have found that even in such a case, adhesion of powder cannot be sufficiently suppressed.

[0008] One problem to be solved by the present disclosure is to suppress the adhesion of powder to mono-material packaging materials. [Means for solving the problem]

[0009] The present inventors have found that the above-mentioned powder adheres to the surface of the substrate, and the adhered powder can contaminate the heat-sealed portion of the sealant layer and the production line, resulting in poor powder filling. Therefore, the present inventors have found that imparting the above-mentioned antistatic properties to the substrate can effectively suppress the adhesion of the above-mentioned powder. The substrate of the present disclosure comprises a stretched polyethylene layer and a surface layer provided on the stretched polyethylene layer, the stretched polyethylene layer containing polyethylene as a main component, and the surface layer containing an antistatic agent. [Effects of the Invention]

[0010] According to the present disclosure, a polyethylene substrate having antistatic properties can be provided. By using this polyethylene substrate, adhesion of powder to a mono-material packaging material can be effectively suppressed. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a schematic cross-sectional view of one embodiment of a substrate of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view of one embodiment of the substrate of the present disclosure. [Figure 3] FIG. 3 is a schematic cross-sectional view of one embodiment of the laminate of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view of one embodiment of the laminate of the present disclosure. [Figure 5] FIG. 5 is a front view of one embodiment of a packaging bag. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each layer more schematically than in the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0013] [Base material] The substrate of the present disclosure includes a stretched polyethylene layer and a surface layer provided on the stretched polyethylene layer. The stretched polyethylene layer contains polyethylene as a main component, and the surface layer contains an antistatic agent.

[0014] Figures 1 and 2 show one embodiment of a substrate of the present disclosure. The substrate 10 in Figure 1 comprises an oriented polyethylene layer 12 and a surface layer 14 provided on one side of the oriented polyethylene layer 12. The substrate 10 in Figure 2 comprises a design layer 16 on a partial area of ​​the surface layer 14.

[0015] <Stretched polyethylene layer> The oriented polyethylene layer contains polyethylene as a main component. The oriented polyethylene layer is a polyethylene layer that has been subjected to an orientation treatment. When the resin material constituting the stretched polyethylene layer is polyethylene, which is the same type of resin material as the resin material constituting the sealant layer, for example, when producing a laminate as described below, a laminate having such a configuration can be suitably used as a laminate for producing mono-material packaging containers.

[0016] For example, polyethylene includes high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, which are classified as the same type of resin material, whereas polyethylene and polyester are not classified as the same type of resin material.

[0017] In the present disclosure, the terms "AAA contains polyethylene as a main component," "AAA containing polyethylene as a main component," and similar expressions mean that the polyethylene content in the AAA is more than 50% by mass, preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0018] In the present disclosure, polyethylene refers to a polymer in which the content of ethylene-derived structural units in all repeating structural units is 50 mol% or more. In this polymer, the content of ethylene-derived structural units is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The content can be measured by NMR.

[0019] In the present disclosure, the polyethylene may be a homopolymer of ethylene or a copolymer of ethylene and an ethylenically unsaturated monomer other than ethylene. Examples of the ethylenically unsaturated monomer other than ethylene include α-olefins having 3 to 20 carbon atoms, such as 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; vinyl monomers, such as vinyl acetate and vinyl propionate; and (meth)acrylic acid esters, such as methyl (meth)acrylate and ethyl (meth)acrylate.

[0020] In the present disclosure, polyethylene includes, for example, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, and very low density polyethylene.

[0021] In the present disclosure, the density of the polyethylene is as follows: The density of the high density polyethylene is preferably 0.945 g / cm 3 The upper limit of the density of high-density polyethylene is, for example, 0.965 g / cm 3 The density of the medium density polyethylene is preferably 0.925 g / cm 3 More than 0.945g / cm 3 The density of the low density polyethylene is preferably less than 0.900 g / cm 3 More than 0.925g / cm 3 The density of the linear low density polyethylene is preferably less than 0.900 g / cm 3 More than 0.925g / cm 3 The density of the very low density polyethylene is preferably less than 0.900 g / cm 3 The lower limit of the density of the ultra-low density polyethylene is, for example, 0.860 g / cm 3 The density of polyethylene is measured in accordance with JIS K7112, particularly Method D (density gradient tube method, 23°C).

[0022] Low-density polyethylene is typically obtained by polymerizing ethylene using a high-pressure polymerization process. Linear low-density polyethylene is typically obtained by polymerizing ethylene and a small amount of α-olefins using a low-pressure polymerization process (e.g., polymerization using a Ziegler-Natta catalyst or a metallocene catalyst).

[0023] Polyethylenes with different densities or branches can be obtained by appropriately selecting a polymerization method. For example, it is preferable to use a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst and carry out polymerization in one or more stages by any of gas phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization.

[0024] A single-site catalyst is a catalyst capable of forming a uniform active species, and is usually prepared by contacting a metallocene transition metal compound or a non-metallocene transition metal compound with an activating cocatalyst. Single-site catalysts are preferred because they have a more uniform structure of the active site than multi-site catalysts, making it possible to obtain polymers with high molecular weights and highly uniform structures.

[0025] The single-site catalyst is preferably a metallocene catalyst, which comprises a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organometallic compound as needed, and a support as needed.

[0026] Examples of the transition metal in the transition metal compound include zirconium, titanium, and hafnium, with zirconium and hafnium being preferred.

[0027] The cyclopentadienyl skeleton in the transition metal compound is a cyclopentadienyl group or a substituted cyclopentadienyl group. The substituted cyclopentadienyl group has at least one substituent selected from, for example, a hydrocarbon group having from 1 to 30 carbon atoms, a silyl group, a silyl-substituted alkyl group, a silyl-substituted aryl group, a cyano group, a cyanoalkyl group, a cyanoaryl group, a halogen group, a haloalkyl group, and a halosilyl group. The substituted cyclopentadienyl group has one or more substituents, and the substituents may be bonded to each other to form a ring, such as an indenyl ring, a fluorenyl ring, an azulenyl ring, or a hydrogenated product thereof. The ring formed by bonding the substituents to each other may further have a substituent.

[0028] The transition metal compound usually has two ligands having a cyclopentadienyl skeleton. The ligands having each cyclopentadienyl skeleton are preferably bonded to each other via a bridging group. Examples of the bridging group include alkylene groups having 1 to 4 carbon atoms, silylene groups, substituted silylene groups such as dialkylsilylene groups and diarylsilylene groups, and substituted germylene groups such as dialkylgermylene groups and diarylgermylene groups. Among these, substituted silylene groups are preferred.

[0029] The co-catalyst refers to a component that enables a transition metal compound of Group IV of the periodic table to function effectively as a polymerization catalyst or a component that balances the ionic charge in a catalytically activated state. Examples of the co-catalyst include benzene-soluble aluminoxanes or benzene-insoluble organoaluminum oxy-compounds, ion-exchangeable layered silicates, boron compounds, ionic compounds consisting of a cation with or without an active hydrogen group and a non-coordinating anion, lanthanoid salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing a fluoro group.

[0030] Examples of organometallic compounds that may be used as needed include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organoaluminum compounds are preferred.

[0031] The transition metal compound may be used by being supported on an inorganic or organic carrier, preferably a porous oxide of an inorganic or organic compound, such as montmorillonite or other ion-exchangeable layered silicates, SiO2, Al2O3, MgO, ZrO2, TiO2, BO3, CaO, ZnO, BaO, ThO2, or mixtures thereof.

[0032] In the present disclosure, polyethylene may be derived from biomass (hereinafter also referred to as "biomass polyethylene"). That is, as a raw material for obtaining polyethylene, ethylene derived from biomass may be used instead of ethylene obtained from fossil fuels. Biomass polyethylene is a carbon-neutral material, and therefore can reduce the environmental impact of laminates or packaging materials. Biomass polyethylene can be produced, for example, by the method described in JP 2013-177531 A. Commercially available biomass polyethylene may also be used.

[0033] Biomass-derived ethylene, which is the raw material for biomass polyethylene, can be obtained by a conventionally known method. An example of a method for producing biomass-derived ethylene will be described below.

[0034] Biomass-derived ethylene can be produced, for example, using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. As the plant raw material, conventionally known plants can be used, for example, corn, sugarcane, beet, and manioc.

[0035] Fermented ethanol derived from biomass refers to ethanol produced by contacting a culture solution containing a carbon source obtained from plant raw materials with an ethanol-producing microorganism or a product derived from the disrupted microorganism, followed by purification. Purification of ethanol from the culture solution can be achieved by conventional methods such as distillation, membrane separation, and extraction. Examples include methods of adding benzene, cyclohexane, etc., followed by azeotropy, or removing water by membrane separation. To obtain the ethylene, the ethanol may be further purified at this stage to reduce the total impurity content to 1 ppm or less.

[0036] A catalyst is usually used when obtaining ethylene by the dehydration reaction of ethanol. A conventionally known catalyst can be used as the catalyst. The reaction mode advantageous from the viewpoint of process is a fixed-bed flow reaction, which allows easy separation of the catalyst and the product. For example, γ-alumina is preferred.

[0037] Since this dehydration reaction is an endothermic reaction, it is usually carried out under heated conditions. The heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, but is preferably 100°C or higher, more preferably 250°C or higher, and even more preferably 300°C or higher. There is no particular upper limit, but from the viewpoint of energy balance and equipment, it is preferably 500°C or lower, more preferably 400°C or lower.

[0038] In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in the ethanol supplied as a raw material. Generally, when performing a dehydration reaction, it is preferable to avoid water in terms of the efficiency of water removal. However, in the case of ethanol dehydration using a solid catalyst, the absence of water tends to increase the amount of other olefins, particularly butene, produced. This is presumably because the presence of a small amount of water makes it difficult to suppress ethylene dimerization after dehydration. The water content is, for example, 0.1% by mass or more, preferably 0.5% by mass or more. From the viewpoints of material balance and heat balance, the water content is, for example, 50% by mass or less, preferably 30% by mass or less, and more preferably 20% by mass or less.

[0039] By carrying out the dehydration reaction of ethanol in this manner, a mixture of ethylene, water, and a small amount of unreacted ethanol is obtained. Since ethylene is in a gaseous state at room temperature and below about 5 MPa, water and ethanol can be removed from this mixture by gas-liquid separation to obtain ethylene. This can be done by a known method.

[0040] The ethylene obtained by the gas-liquid separation is further distilled. The distillation method, operation temperature, residence time, etc. are not particularly limited, except that the operation pressure at this time must be atmospheric pressure or higher.

[0041] When the raw material is biomass-derived ethanol, the resulting ethylene contains trace amounts of impurities introduced during the ethanol fermentation process, such as carbonyl compounds (e.g., ketones, aldehydes, and esters) and their decomposition products (carbon dioxide), as well as nitrogen-containing compounds (e.g., amines and amino acids) and their decomposition products (ammonia). Depending on the intended use of ethylene, these trace amounts of impurities may be problematic, so they may be removed by purification. Purification can be carried out by conventionally known methods. Suitable purification procedures include, for example, adsorption purification. Conventionally known adsorbents can be used as the adsorbent. For example, a material with a high surface area is preferred, and the type of adsorbent is selected depending on the type and amount of impurities in the ethylene obtained by the dehydration reaction of biomass-derived ethanol.

[0042] A caustic water treatment may be used in combination as a method for purifying impurities in ethylene. When caustic water treatment is used, it is preferable to perform it before adsorption purification. In this case, it is necessary to perform a water removal treatment after the caustic treatment and before adsorption purification.

[0043] Biomass polyethylene is polyethylene obtained by polymerizing a monomer containing biomass-derived ethylene. As the biomass-derived ethylene, it is preferable to use ethylene obtained by the above-mentioned production method. Since biomass-derived ethylene is used as the raw material monomer, the polymerized polyethylene is biomass-derived.

[0044] The raw material monomers for biomass polyethylene do not have to contain 100% by mass of biomass-derived ethylene. The raw material monomers for biomass polyethylene may further contain ethylene derived from fossil fuels in addition to biomass-derived ethylene.

[0045] Atmospheric carbon dioxide contains a certain proportion of C14 (105.5 pMC), and it is known that the C14 content in plants that grow by absorbing atmospheric carbon dioxide, such as corn, is also approximately 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, the proportion of biomass-derived carbon can be calculated by measuring the proportion of C14 in total carbon atoms. In this disclosure, "biomass ratio" refers to the weight ratio of biomass-derived components. Take polyethylene terephthalate as an example. Polyethylene terephthalate is a polymer formed by polymerizing ethylene glycol containing two carbon atoms and terephthalic acid containing eight carbon atoms in a 1:1 molar ratio. When only biomass-derived ethylene glycol is used, the weight ratio of biomass-derived components in the polyester is 31.25%. Therefore, the theoretical biomass ratio is 31.25%. Specifically, the mass of polyethylene terephthalate is 192, of which 60% is derived from biomass-derived ethylene glycol. Therefore, 60 ÷ 192 × 100 = 31.25. The weight ratio of biomass-derived components in the fossil fuel-derived polyester produced using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass content of the fossil fuel-derived polyester is 0%. Hereinafter, unless otherwise specified, "biomass content" refers to the weight ratio of biomass-derived components.

[0046] Theoretically, if all ethylene derived from biomass is used as a raw material for polyethylene, the concentration of biomass-derived ethylene will be 100%, and the biomass content of biomass polyethylene will be 100%. However, the concentration of biomass-derived ethylene in fossil fuel polyethylene produced only from fossil fuel-derived raw materials will be 0%, and the biomass content of fossil fuel polyethylene will be 0%.

[0047] Specific examples of biomass polyethylene include biomass high-density polyethylene, biomass medium-density polyethylene, biomass low-density polyethylene, biomass linear low-density polyethylene, and biomass very low-density polyethylene. In one embodiment, the biomass content of the biomass polyethylene is 80% or more, 85% or more, 90% or more, or 95% or more. As the biomass polyethylene, plant-derived polyethylene is preferred.

[0048] In the present disclosure, the biomass polyethylene or biomass-derived resin layer does not need to have a biomass content of 100%. This is because if biomass-derived raw materials are used even in a part of the laminate, it is in line with the purpose of reducing the amount of fossil fuel used compared to conventional methods.

[0049] The polyethylene may be recycled mechanically or chemically. This reduces the environmental impact of laminates or packaging materials. Mechanical recycling generally involves crushing recovered polyethylene film, washing it with an alkali to remove dirt and foreign matter from the film surface, and then drying it at high temperature and reduced pressure for a certain period of time to disperse any contaminants remaining inside the film, decontaminating it, and returning it to polyethylene. Chemical recycling generally involves breaking down recovered polyethylene film to the monomer level and repolymerizing the monomer to obtain polyethylene. The above description of polyethylene is applicable to the polyethylene in the following description.

[0050] As the polyethylene contained in the stretched polyethylene layer, high density polyethylene and medium density polyethylene are preferred from the viewpoint of the strength and heat resistance of the stretched polyethylene layer, and medium density polyethylene is preferred from the viewpoint of suitability for stretching.

[0051] From the viewpoint of film-forming properties and processability, the melt flow rate (MFR) of the polyethylene constituting the stretched polyethylene layer is preferably 0.1 g / 10 min or more and 50 g / 10 min or less, more preferably 0.2 g / 10 min or more and 30 g / 10 min or less, even more preferably 0.2 g / 10 min or more and 10 g / 10 min or less, and particularly preferably 0.2 g / 10 min or more and 5.0 g / 10 min or less. The MFR of polyethylene is measured by Method A in accordance with JIS K7210 under conditions of a temperature of 190°C and a load of 2.16 kg.

[0052] For example, when a stretched polyethylene layer is produced by the T-die method, the MFR of the polyethylene constituting the stretched polyethylene layer is preferably 3.0 g / 10 min or more and 20 g / 10 min or less from the viewpoint of film formability and processability.

[0053] For example, when the stretched polyethylene layer is produced by an inflation method, the MFR of the polyethylene constituting the stretched polyethylene layer is preferably 0.2 g / 10 min or more and 5.0 g / 10 min or less from the viewpoint of film formability and processability.

[0054] From the viewpoint of heat resistance, the melting point (Tm) of the polyethylene constituting the stretched polyethylene layer is preferably 100° C. or higher and 140° C. or lower, more preferably 110° C. or higher and 140° C. or lower, and even more preferably 120° C. or higher and 140° C. or lower. Tm is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0055] The oriented polyethylene layer can contain one or more types of polyethylene. The content of polyethylene in the stretched polyethylene layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. Such a configuration can improve the recyclability of the laminate, for example.

[0056] When the stretched polyethylene layer has a multilayer structure, the polyethylene content in each layer constituting the stretched polyethylene layer is independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. Such a configuration can, for example, improve the recyclability of the laminate.

[0057] The stretched polyethylene layer may contain one or more resin materials other than polyethylene. Examples of such resin materials include polyolefins such as polypropylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. When the stretched polyethylene layer has a multilayer structure, each layer constituting the stretched polyethylene layer may independently contain the above-mentioned resin materials.

[0058] The stretched polyethylene layer may contain one or more additives. Examples of additives include crosslinking agents, antiblocking agents, slip agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, dyes, and modifying resins. When the stretched polyethylene layer has a multilayer structure, each layer constituting the stretched polyethylene layer may independently contain the above-mentioned additives.

[0059] The stretched polyethylene layer may contain an antistatic agent, which will be described later, but preferably does not substantially contain an antistatic agent. For example, the content of the antistatic agent in the stretched polyethylene layer, as measured by pyrolysis GC, is preferably 100 ppm or less. This can reduce the cost of the substrate and improve the productivity of the substrate, for example.

[0060] The stretched polyethylene layer is a polyethylene layer that has been subjected to a stretching treatment. Stretching can improve, for example, the heat resistance and strength of the polyethylene layer. Such a stretched polyethylene layer can satisfy the physical properties required, for example, as an outer layer of a packaging material.

[0061] The stretching may be uniaxial or biaxial. In one embodiment, the stretching ratio in the machine direction (MD) of the stretched polyethylene layer is preferably 2 to 10 times, more preferably 3 to 7 times. In one embodiment, the stretching ratio in the transverse direction (TD) of the stretched polyethylene layer is preferably 2 to 10 times, more preferably 3 to 7 times.

[0062] A stretching ratio of 2 times or more can improve, for example, the rigidity, strength, and heat resistance of the substrate, improve the printability of the substrate, and improve the transparency of the substrate.A stretching ratio of 10 times or less can achieve good stretching without causing breakage of the film, for example.

[0063] In one embodiment, the oriented polyethylene layer is a uniaxially oriented film, more specifically, a uniaxially oriented film that has been stretched in the machine direction (MD).

[0064] The stretched polyethylene layer may have a single-layer structure or a multi-layer structure. Hereinafter, a stretched polyethylene layer having a multi-layer structure will also be referred to as a "stretched multi-layer PE layer." A stretched multi-layer PE layer is preferred from the viewpoint of improving its strength, heat resistance, and stretchability.

[0065] The stretched multi-layer PE layer has a multi-layer structure of two or more layers. In one embodiment, the number of layers in the stretched multi-layer PE layer is from 2 to 7, for example, from 3 to 7, or from 3 to 5. The number of layers in the stretched multi-layer PE layer is preferably an odd number, for example, 3, 5, or 7. The multi-layer structure of the stretched multi-layer PE layer can improve the balance between the rigidity, strength, heat resistance, printability, and stretchability of the stretched polyethylene layer. Each layer of the stretched multi-layer PE layer also preferably contains polyethylene as a main component.

[0066] Hereinafter, several examples of embodiments of the stretched multilayer PE layer will be described. Hereinafter, a layer containing 80% or more of high-density polyethylene will be referred to as a "high-density polyethylene layer," a layer containing 80% or more of medium-density polyethylene will be referred to as a "medium-density polyethylene layer," a layer containing 80% or more of low-density polyethylene will be referred to as a "low-density polyethylene layer," a layer containing 80% or more of linear low-density polyethylene will be referred to as a "linear low-density polyethylene layer," and a layer containing 80% or more of very-low-density polyethylene will be referred to as an "ultra-low-density polyethylene layer."

[0067] The stretched multilayer PE layer of the first embodiment comprises a high-density polyethylene layer and a medium-density polyethylene layer in this order in the thickness direction. The surface resin layer of the stretched polyethylene layer is a high-density polyethylene layer, which can improve, for example, the strength and heat resistance of the stretched polyethylene layer. The stretched polyethylene layer comprises a medium-density polyethylene layer, which can improve, for example, the stretchability of the laminate before stretching.

[0068] The stretched multilayer PE layer of the second embodiment includes a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer in this order in the thickness direction. This configuration can improve the strength and heat resistance of the stretched polyethylene layer, suppress curling in the stretched polyethylene layer, and improve the stretchability of the pre-stretched laminate, for example.

[0069] In the multilayer stretched polyethylene layers of the first and second embodiments, the thickness of the high-density polyethylene layer is preferably equal to or less than the thickness of the medium-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer (high-density polyethylene layer / medium-density polyethylene layer) is preferably 0.1 or more and 1 or less, more preferably 0.2 or more and 0.5 or less.

[0070] The stretched multilayer PE layer of the third embodiment comprises, in this order in the thickness direction, a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer or an ultra-low-density polyethylene layer (for simplicity, these three layers are collectively referred to as the "low-density polyethylene layer, etc."), a medium-density polyethylene layer, and a high-density polyethylene layer. This configuration can, for example, improve the stretchability of the laminate before stretching, improve the strength and heat resistance of the stretched polyethylene layer, and suppress curling in the stretched polyethylene layer.

[0071] In the stretched multilayer polyethylene layer of the third embodiment, the thickness of the high-density polyethylene layer is preferably equal to or less than the thickness of the medium-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer (high-density polyethylene layer / medium-density polyethylene layer) is preferably 0.1 or more and 1 or less, more preferably 0.2 or more and 0.5 or less.

[0072] In the stretched multilayer PE layer of the third embodiment, the thickness of the high-density polyethylene layer is preferably equal to or greater than the thickness of the low-density polyethylene layer, etc. The ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer, etc. (high-density polyethylene layer / low-density polyethylene layer, etc.) is preferably 1 or more and 4 or less, more preferably 1 or more and 2 or less.

[0073] Other embodiments of the stretched multilayer PE layer include a stretched polyethylene layer having, in the thickness direction, a high-density polyethylene layer, a high-density polyethylene layer, a blend layer of medium-density polyethylene and high-density polyethylene, a high-density polyethylene layer, and a high-density polyethylene layer, in that order; and a stretched polyethylene layer having, in the thickness direction, a medium-density polyethylene layer, a high-density polyethylene layer, a linear low-density polyethylene layer, a high-density polyethylene layer, and a medium-density polyethylene layer, in that order.

[0074] Another example is a stretched polyethylene layer having, in the thickness direction, a high-density polyethylene layer, a blend layer of high-density polyethylene and medium-density polyethylene, a low-density polyethylene layer or the like, a blend layer of high-density polyethylene and medium-density polyethylene, and a high-density polyethylene layer in this order.

[0075] The stretched multilayer PE layer of the fourth embodiment includes, in the thickness direction, a medium-density polyethylene layer, a high-density polyethylene layer, a blend layer of medium-density polyethylene and high-density polyethylene, a high-density polyethylene layer, and a medium-density polyethylene layer, in this order. This configuration can improve, for example, the printability, strength, and heat resistance of the stretched polyethylene layer, and the stretchability of the pre-stretched laminate.

[0076] In the blend layer of medium-density polyethylene and high-density polyethylene, the mass ratio of medium-density polyethylene to high-density polyethylene (medium-density polyethylene / high-density polyethylene) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less.

[0077] The stretched multilayer PE layer of the fifth embodiment includes, in the thickness direction, a medium-density polyethylene layer, a medium-density polyethylene layer, a blend layer of medium-density polyethylene and linear low-density polyethylene, a medium-density polyethylene layer, and another medium-density polyethylene layer, in this order. This configuration can improve, for example, the printability, strength, and heat resistance of the stretched polyethylene layer, and the stretchability of the pre-stretched laminate.

[0078] In the blend layer of medium-density polyethylene and linear low-density polyethylene, the mass ratio of medium-density polyethylene to linear low-density polyethylene (medium-density polyethylene / linear low-density polyethylene) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less.

[0079] The stretched multilayer PE layer of the sixth embodiment includes, in the thickness direction, a blend layer of medium-density polyethylene and high-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, a linear low-density polyethylene layer, a blend layer of medium-density polyethylene and linear low-density polyethylene, and a blend layer of medium-density polyethylene and high-density polyethylene, in this order. This configuration can improve, for example, the printability, strength, and heat resistance of the stretched polyethylene layer, and the stretchability of the pre-stretched laminate.

[0080] In the blend layers of medium-density polyethylene and high-density polyethylene, the mass ratio of medium-density polyethylene to high-density polyethylene (medium-density polyethylene / high-density polyethylene) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less.

[0081] In the blend layer of medium-density polyethylene and linear low-density polyethylene, the mass ratio of medium-density polyethylene to linear low-density polyethylene (medium-density polyethylene / linear low-density polyethylene) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less.

[0082] The stretched multilayer PE layer of the seventh embodiment includes, in the thickness direction, a blend layer of high-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, a blend layer of linear low-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, and a blend layer of high-density polyethylene and medium-density polyethylene. This configuration can improve, for example, the printability, strength, and heat resistance of the stretched polyethylene layer, and the stretchability of the pre-stretched laminate.

[0083] In the blend layers of high-density polyethylene and medium-density polyethylene, the mass ratio of medium-density polyethylene to high-density polyethylene (medium-density polyethylene / high-density polyethylene) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less.

[0084] In the blend layer of linear low-density polyethylene and medium-density polyethylene, the mass ratio of linear low-density polyethylene to medium-density polyethylene (linear low-density polyethylene / medium-density polyethylene) is preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2.4 or less.

[0085] The stretched multilayer PE layer of the eighth embodiment comprises, in the thickness direction, a first layer containing medium-density polyethylene and high-density polyethylene, a second layer containing high-density polyethylene, a third layer containing linear low-density polyethylene, a fourth layer containing high-density polyethylene, and a fifth layer containing medium-density polyethylene and high-density polyethylene, in this order.

[0086] The mass ratio of the medium-density polyethylene to the high-density polyethylene (medium-density polyethylene / high-density polyethylene) in the first layer and the fifth layer is preferably 1.1 or more and 5 or less, more preferably 1.5 or more and 3 or less, thereby further improving the balance between ink adhesion and heat resistance.

[0087] The total content of the medium-density polyethylene and the high-density polyethylene in the first layer and the fifth layer is independently preferably at least 80% by mass, more preferably at least 90% by mass, and even more preferably at least 95% by mass, thereby further improving the ink adhesion and heat resistance of the stretched polyethylene layer.

[0088] The second layer and the fourth layer may each independently further contain a low-density polyethylene, which can further improve the balance between heat resistance, rigidity, and processability of the oriented polyethylene layer.

[0089] The mass ratio of high-density polyethylene to low-density polyethylene (high-density polyethylene / low-density polyethylene) in the second layer and the fourth layer is preferably from 1 to 4, and more preferably from 1.5 to 3. This allows the oriented polyethylene layer to have a better balance of heat resistance, rigidity, and processability.

[0090] The content of high-density polyethylene in each of the second layer and the fourth layer is independently preferably more than 50% by mass, more preferably 55% by mass or more, and even more preferably 60% by mass or more, thereby further improving the heat resistance of the stretched polyethylene layer.

[0091] The total content of high-density polyethylene and low-density polyethylene in the second layer and the fourth layer is independently preferably at least 80% by mass, more preferably at least 90% by mass, and even more preferably at least 95% by mass, thereby further improving the balance between heat resistance, rigidity, and processability of the stretched polyethylene layer.

[0092] The thickness of each of the second layer and the fourth layer is independently preferably 0.5 μm or more and 15 μm or less, more preferably 1 μm or more and 10 μm or less, and even more preferably 1 μm or more and 8 μm or less, thereby further improving the heat resistance of the stretched polyethylene layer.

[0093] The third layer may further contain low density polyethylene.

[0094] The content of the linear low-density polyethylene in the third layer is preferably more than 50% by mass, more preferably at least 60% by mass, even more preferably at least 70% by mass, and even more preferably at least 80%, at least 90%, or at least 95% by mass, thereby further improving the balance between heat resistance, rigidity, and extensibility.

[0095] When the third layer contains low-density polyethylene, the content of low-density polyethylene is preferably less than 50% by mass, more preferably 5% to 40% by mass, and even more preferably 10% to 30% by mass.

[0096] The thickness of the third layer is preferably from 1 μm to 50 μm, more preferably from 2 μm to 40 μm, and even more preferably from 5 μm to 30 μm, which can further improve the balance between heat resistance, rigidity, and stretchability.

[0097] The ratio of the total thickness of the second layer and the fourth layer to the thickness of the third layer (total thickness of the second layer and the fourth layer / thickness of the third layer) is preferably 0.1 to 10, more preferably 0.2 to 5, and even more preferably 0.5 to 2. This allows the rigidity, strength, and heat resistance of the stretched polyethylene layer to be further improved.

[0098] In the stretched multilayer PE layers of the fourth to eighth embodiments, the thickness of each of the two surface resin layers is preferably from 0.5 μm to 10 μm, more preferably from 1 μm to 8 μm, and even more preferably from 1 μm to 5 μm, which can further improve, for example, the heat resistance and printability of the stretched polyethylene layer.

[0099] In the stretched multilayer polyethylene layers of the fourth to eighth embodiments, the thickness of each of the two surface resin layers is preferably smaller than the total thickness of the three inner layers (the multilayer intermediate layer). The ratio of the thickness of each of the two surface resin layers to the total thickness of the multilayer intermediate layer (surface resin layer / multilayer intermediate layer) is preferably 0.05 to 0.8, more preferably 0.1 to 0.7, and even more preferably 0.1 to 0.4. This can further improve, for example, the rigidity, strength, and heat resistance of the stretched polyethylene layer.

[0100] In the stretched multi-layer PE layer, the density of the polyethylene constituting each layer may be the same or different. For example, the stretched multi-layer PE layer may have a density gradient among the layers. By providing a density gradient in the stretched multi-layer PE layer, for example, its strength, heat resistance, and stretchability can be improved.

[0101] In the stretched multi-layer PE layer having a density gradient, it is preferable that the absolute value of the density difference between any two adjacent layers is small. The absolute value of the density difference is preferably 0.040 g / cm 3 or less, more preferably 0.030 g / cm 3 or less, more preferably 0.020 g / cm 3This configuration makes it possible to effectively prevent, for example, delamination at the interfaces between the layers.

[0102] In the present disclosure, the density of each layer may be measured in accordance with the above-mentioned JIS K7112, or may be calculated from the density of the components constituting the layer. For example, when one layer contains multiple components (n types; n is an integer of 2 or more) with different densities (e.g., polyethylene), the average density D calculated according to the following formula (f1) av may be the density of the layer.

[0103] D av = ΣW i ×D i …(f1) In formula (f1), Σ is W for i from 1 to n. i ×D i where n is an integer greater than or equal to 2, and W i denotes the mass fraction of the i-th component, and D i is the density of the i-th component (g / cm 3 ) is shown.

[0104] The haze value of the stretched polyethylene layer is preferably 25% or less, more preferably 15% or less, and even more preferably 12% or less. A smaller haze value is preferable, but in one embodiment, the lower limit may be 0.1% or 1%. The haze value of the stretched polyethylene layer is measured in accordance with JIS K7136.

[0105] The thickness of the stretched polyethylene layer is preferably 10 μm or more and 60 μm or less, more preferably 15 μm or more and 50 μm or less. When the thickness of the stretched polyethylene layer is 10 μm or more, rigidity and strength can be improved. When the thickness of the stretched polyethylene layer is 60 μm or less, processability can be improved.

[0106] The stretched polyethylene layer may be subjected to a surface treatment. This can improve the adhesion between the stretched polyethylene layer and a layer laminated thereon, for example. Examples of surface treatment methods include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using gases such as oxygen gas and nitrogen gas, and glow discharge treatment; and chemical treatments such as oxidation treatment using chemicals. An anchor coat layer may be formed on the surface of the stretched polyethylene layer using a conventional anchor coat agent.

[0107] The stretched polyethylene layer can be produced by, for example, forming a film of polyethylene or a polyethylene composition by the inflation method or the T-die method, and stretching the film. The stretched multilayer PE layer can be produced by, for example, forming a laminate from multiple polyethylenes or polyethylene compositions by the inflation method or the T-die method, and stretching the resulting laminate. The stretching treatment can improve the transparency, rigidity, strength, and heat resistance of the polyethylene layer, making the stretched polyethylene layer suitable for use as, for example, a base material for packaging materials. Stretching can also be performed in an inflation film-forming machine.

[0108] In one embodiment, the stretched polyethylene layer having a multilayer structure is a coextruded resin film, and each layer constituting the stretched polyethylene layer is a coextruded resin layer. The coextruded resin film can be produced by film formation using, for example, an inflation method or a T-die method.

[0109] In one embodiment, the stretched multilayer PE layer is obtained by stretching a laminate (precursor) having a multilayer structure. Specifically, the resin materials constituting each layer are co-extruded into a tubular shape to form a film, thereby producing a laminate. Alternatively, the resin materials constituting each layer are co-extruded into a tubular shape, and then the opposing layers are pressure-bonded together using a rubber roll or the like to produce a laminate. By producing a laminate using this method, the number of defective products can be significantly reduced, and production efficiency can be improved.

[0110] In one embodiment, the stretched polyethylene layer contains biomass polyethylene. The biomass content of the stretched polyethylene layer may be, for example, 10% or more, 10% to 65%, 20% to 55%, or 25% to 50%.

[0111] When the stretched polyethylene layer has a multilayer structure, that is, when the stretched polyethylene layer has two or more resin layers containing polyethylene as a main component, at least one of the resin layers may contain biomass polyethylene.

[0112] For example, consider a stretched polyethylene layer having, in the thickness direction, a first resin layer containing high-density polyethylene as a main component, a second resin layer containing medium-density polyethylene as a main component, and a third resin layer containing high-density polyethylene as a main component, in that order. In this case, at least one selected from the high-density polyethylene in the first resin layer, the medium-density polyethylene in the second resin layer, and the high-density polyethylene in the third resin layer may be biomass polyethylene.

[0113] <Surface layer> The substrate of the present disclosure comprises a surface layer formed on an oriented polyethylene layer. The surface layer contains an antistatic agent. This can impart good antistatic or antistatic properties to, for example, the substrate, and therefore to one surface of the laminate described below. For example, when producing a packaging container containing powder as its contents, adhesion of the powder to the substrate surface can be suppressed. In one embodiment, the surface layer containing an antistatic agent is formed on only one surface of the oriented polyethylene layer.

[0114] Examples of the antistatic agent include anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, and nonionic antistatic agents. Specific examples include anionic antistatic agents such as adipic acid, glutamic acid, sulfonates, sulfates, phosphates, and phosphonates; cationic antistatic agents such as amines, imidazolines, amine oxide ethylene adducts, quaternary ammonium salts, and pyridinium salts; amphoteric antistatic agents having both cationic and anionic groups, such as guanidine salts obtained by reacting alkylamines with maleic anhydride, and sulfonic acids derived from polyethyleneimine; and nonionic antistatic agents such as polyols, ester compounds of polyols and aliphatic carboxylic acids, ether compounds, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid amides, and their ethylene oxide adducts. The surface layer may contain one or more antistatic agents.

[0115] The amount of antistatic agent in the surface layer is preferably 0.1 g / m 2 More than 2.0g / m 2 Less than or equal to 0.3 g / m 2 More than 1.5g / m 2 More preferably, 0.3 g / m or less 2 More than 1.2g / m 2 This makes it possible to obtain a substrate having, for example, superior antistatic properties.

[0116] In one embodiment, the surface resistivity of the surface layer is 9.0×10 12 Ω / □ or less, preferably 9.0×10 11 Ω / □ or less, 9.0×10 10 Ω / □ or less or 9.0×10 9 The surface resistivity may be, for example, 1.0×10 8 In the present disclosure, the surface resistivity can be measured in accordance with JIS K6911:1995, and the surface resistivity is measured in an environment with a temperature of 20°C and a relative humidity of 65%.

[0117] In one embodiment, the surface layer may contain one or more resin materials, such as cellulose resin, (meth)acrylic resin, urethane resin, alkyd resin, polyester, polycarbonate, polyolefin, polystyrene, norbornene resin, polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate copolymer.

[0118] In one embodiment, the surface layer may contain one or more additives, such as lubricants, antioxidants, light stabilizers, UV absorbers, plasticizers, fillers, colorants, curing agents, and crosslinking agents.

[0119] The surface layer can be formed, for example, using an ink composition containing the above-mentioned components and, if necessary, a solvent. Examples of methods for forming the surface layer include gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. In one embodiment, from the viewpoint of reducing environmental impact, flexographic printing may be used.

[0120] The thickness of the surface layer is preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.2 μm or more and 5.0 μm or less, and even more preferably 0.3 μm or more and 3.0 μm or less.

[0121] <Design layer> The substrate of the present disclosure may further include a design layer on a partial region of the surface layer. That is, the substrate of the present disclosure may further include a design layer on a partial region of the surface of the surface layer opposite to the surface on the stretched polyethylene layer side.

[0122] The design layer has an image. Examples of the image include letters, figures, patterns, symbols, and combinations thereof. The image may include text information such as the product name, the name of the contents in the packaging container, the manufacturer, and the names of raw materials. The image may be a single, solid color (a so-called solid image).

[0123] In one embodiment, the design layer contains one or more colorants. Examples of colorants include pigments such as inorganic pigments and organic pigments, and dyes such as acid dyes, direct dyes, disperse dyes, oil-soluble dyes, metal-containing oil-soluble dyes, and sublimable dyes. Examples of colorants also include fluorescent materials such as ultraviolet light-emitting materials that emit fluorescence by absorbing ultraviolet light, and infrared light-emitting materials that emit fluorescence by absorbing infrared light.

[0124] The content of the colorant in the design layer is preferably 1% by mass to 90% by mass, more preferably 3% by mass to 70% by mass, and even more preferably 5% by mass to 50% by mass.

[0125] The design layer may contain a resin material and may also contain an additive. The details of the resin material and additives are as specifically explained in the section on the surface layer. In one embodiment, the content of the resin material in the design layer may be, for example, 10% by mass or more and 99% by mass or less, 30% by mass or more and 97% by mass or less, or 50% by mass or more and 95% by mass or less.

[0126] The design layer can be formed, for example, using an ink composition containing the above-mentioned components and, if necessary, a solvent. Methods for forming the design layer include, for example, gravure printing, offset printing, flexographic printing, screen printing, letterpress printing, and transfer printing. In one embodiment, flexographic printing may be used from the viewpoint of reducing environmental impact.

[0127] The area ratio of the design layer provided on a partial region of the surface layer may be, for example, 5% to 50% or 20% to 60% of the area of ​​the surface layer (100%) when viewed from above the base material.

[0128] The thickness of the design layer is preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.2 μm or more and 5.0 μm or less, and even more preferably 0.3 μm or more and 3.0 μm or less.

[0129] [Laminate] The laminate of the present disclosure comprises the above-described substrate of the present disclosure (hereinafter also referred to as "antistatic substrate") and a polyethylene layer as a sealant layer. The antistatic substrate is disposed so that the stretched polyethylene layer of the antistatic substrate faces the sealant layer. That is, the laminate comprises, in this order in the thickness direction, a sealant layer, a stretched polyethylene layer, and a surface layer containing an antistatic agent. In one embodiment, the laminate of the present disclosure comprises an adhesive layer between the antistatic substrate and the sealant layer.

[0130] In one embodiment of the laminate of the present disclosure, the antistatic substrate and the sealant layer each contain the same resin material, polyethylene, as a main component. By using a laminate having such a configuration, for example, a packaging container with excellent recyclability can be produced.

[0131] In one embodiment, the laminate of the present disclosure contains biomass polyethylene. The biomass content of the laminate of the present disclosure may be, for example, 5% to 70%, 8% to 50%, or 10% to 30%. This can reduce the environmental impact of the laminate or packaging material, for example.

[0132] The polyethylene content in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. Since such a laminate uses polyethylene, which is the same type of resin material, it can be classified as a so-called monomaterial material and can be suitably used, for example, for producing monomaterial packaging containers.

[0133] Figures 3 and 4 show one embodiment of a laminate of the present disclosure. The laminate 1 of Figure 3 includes an antistatic substrate 10, an adhesive layer 20, and a sealant layer 30, in this order in the thickness direction. The laminate 1 of Figure 4 includes the adhesive layer 20 as an extruded resin layer, and further includes an anchor coat layer 22 between the antistatic substrate 10 and the adhesive layer 20. The adhesive layer 20 is in contact with the anchor coat layer 22.

[0134] <Vapor deposition film> In one embodiment, the laminate of the present disclosure may include a vapor-deposited film formed on the surface of the antistatic substrate on the sealant layer side, which can improve, for example, the oxygen barrier property and water vapor barrier property of the laminate.

[0135] Examples of vapor-deposited films include those made of metals such as aluminum, chromium, tin, nickel, copper, silver, gold, and platinum; or inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among these, aluminum vapor-deposited films, aluminum oxide (alumina) vapor-deposited films, silicon oxide (silica) vapor-deposited films, and carbon-containing silicon oxide vapor-deposited films are preferred.

[0136] The carbon-containing silicon oxide vapor-deposited film contains silicon, oxygen, and carbon. In one embodiment of the carbon-containing silicon oxide vapor-deposited film, the carbon content C is preferably 3% to 50%, more preferably 5% to 40%, and even more preferably 10% to 35%, relative to the total of the three elements silicon, oxygen, and carbon (100%). By setting the carbon content C within the above range, for example, deterioration in gas barrier properties can be suppressed even when the laminate is bent. In this specification, the proportion of each element is on a molar basis.

[0137] In one embodiment of the carbon-containing silicon oxide vapor-deposited film, the silicon content Si is preferably 1% to 45%, more preferably 3% to 38%, and even more preferably 8% to 33%, relative to 100% of the total of the three elements silicon, oxygen, and carbon. The oxygen content O is preferably 10% to 70%, more preferably 20% to 65%, and even more preferably 25% to 60%, relative to 100% of the total of the three elements silicon, oxygen, and carbon. By setting the silicon content Si and the oxygen content O within the above ranges, for example, deterioration of the gas barrier property can be further suppressed even when the laminate is bent.

[0138] In one embodiment of the carbon-containing silicon oxide vapor-deposited film, the oxygen ratio O is preferably higher than the carbon ratio C, and the silicon ratio Si is preferably lower than the carbon ratio C. The oxygen ratio O is preferably higher than the silicon ratio Si, that is, the ratios preferably decrease in the order of ratio O, ratio C, and ratio Si. This makes it possible to further suppress a decrease in gas barrier properties, for example, even when the laminate is bent.

[0139] The proportions C, Si, and O in the carbon-containing silicon oxide vapor-deposited film can be measured by narrow scan analysis using X-ray photoelectron spectroscopy (XPS) under the following measurement conditions.

[0140] (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectral collection conditions Incident X-ray: MgKα (monochromatic X-ray, hν=1253.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): approx. 6 mm diameter Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching range: 10mmφ Ion sputtering time: 30 seconds, and the spectrum was collected.

[0141] The thickness of the vapor-deposited film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less. By making the thickness of the vapor-deposited film 1 nm or more, for example, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. By making the thickness of the vapor-deposited film 150 nm or less, for example, the occurrence of cracks in the vapor-deposited film can be suppressed and the recyclability of the laminate can be improved.

[0142] 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-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The vapor-deposited film may be a composite film containing two or more vapor-deposited films of different inorganic oxides, formed by combining both physical vapor deposition and chemical vapor deposition.

[0143] The vacuum level in the deposition chamber was 10 -2 ~10 -8 After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6 The pressure is preferably about 100 mbar. The amount of oxygen introduced varies depending on the size of the deposition machine. An inert gas such as argon, helium, or nitrogen may be used as a carrier gas for the oxygen introduced, provided that no problems occur. The transport speed of the target film on which the deposition film is formed is, for example, 10 m / min or more and 800 m / min or less.

[0144] The surface of the vapor-deposited film may be subjected to the above-mentioned surface treatment, which can improve the adhesion between the vapor-deposited film and a layer adjacent to the vapor-deposited film, for example.

[0145] <Barrier coat layer> For example, when the vapor-deposited film is composed of an inorganic oxide such as aluminum oxide or silicon oxide, a barrier coating layer may be provided on the surface of the vapor-deposited film. By adopting such a configuration, for example, the gas barrier properties of the laminate can be improved and the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0146] In one embodiment, the barrier coat layer contains a gas barrier resin as a main component, such as polyesters (e.g., ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate), polyamides (e.g., nylon 6, nylon 6,6, and polymetaxylylene adipamide), polyurethanes, and (meth)acrylic resins.

[0147] The content of the gas barrier resin in the barrier coat layer is preferably more than 50% by mass, more preferably 60% by mass or more, and even more preferably 70% by mass or more. Such a configuration can improve, for example, the gas barrier properties of the barrier coat layer.

[0148] The thickness of the barrier coat layer is preferably 0.01 μm or more and 10.0 μm or less, more preferably 0.1 μm or more and 5.0 μm or less. By making the thickness of the barrier coat layer 0.01 μm or more, for example, the gas barrier property can be further improved.

[0149] The barrier coat layer can be formed, for example, by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent, applying the resulting coating liquid, and drying it. The barrier coat layer can also be formed by applying and drying a commercially available barrier coating agent.

[0150] In another embodiment, the barrier coat layer is a gas barrier coating layer formed by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and then adding water, an organic solvent, and a sol-gel catalyst to obtain a gas barrier composition, which is then coated on a vapor-deposited film and dried. The gas barrier coating layer contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing a metal alkoxide or the like by a sol-gel method. By providing such a barrier coat layer on a vapor-deposited film, the occurrence of cracks in the vapor-deposited film can be effectively suppressed. Each of the above components can be used alone or in combination.

[0151] The metal alkoxide is represented by, for example, formula (1). R 1 n M(OR 2 ) m (1) In formula (1), R 1 and R 2 each independently represents an organic group having 1 to 8 carbon atoms; M represents a metal atom; n represents an integer of 0 or more; m represents an integer of 1 or more; and n+m represents the valence of M.

[0152] R 1 and R 2 Examples of the organic group include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-hexyl group, and an n-octyl group. The metal atom M is, for example, silicon, zirconium, titanium or aluminum.

[0153] Examples of metal alkoxides include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0154] Examples of water-soluble polymers include polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Depending on the desired physical properties, such as oxygen barrier property, water vapor barrier property, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination. Alternatively, a gas barrier coating layer obtained using polyvinyl alcohol and a gas barrier coating layer obtained using ethylene-vinyl alcohol copolymer may be laminated. The amount of water-soluble polymer used is preferably 5 to 500 parts by mass per 100 parts by mass of the metal alkoxide.

[0155] As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used, and an organoalkoxysilane having an epoxy group is preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the metal alkoxide.

[0156] The gas barrier composition may contain water in a proportion of preferably 0.1 to 100 moles, more preferably 0.5 to 60 moles, per mole of metal alkoxide. By setting the water content at or above the lower limit, for example, the oxygen barrier property and water vapor barrier property of the laminate can be improved. By setting the water content at or below the upper limit, for example, the hydrolysis reaction can be carried out quickly.

[0157] Examples of organic solvents that can be used in preparing the gas barrier composition include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, and n-butyl alcohol.

[0158] The sol-gel catalyst is preferably an acid or an amine compound. Examples of the acid include mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid; and organic acids such as acetic acid and tartaric acid. The amount of the acid used is preferably 0.001 mol or more and 0.05 mol or less per 1 mol of the total molar amount of the metal alkoxide and the alkoxide portion (e.g., silicate portion) of the silane coupling agent.

[0159] Examples of the amine compound include N,N-dimethylbenzylamine, tripropylamine, tributylamine, and tripentylamine. The amount of the amine compound used is preferably 0.01 to 1.0 parts by mass per 100 parts by mass of the total amount of the metal alkoxide and the silane coupling agent.

[0160] Examples of methods for applying the gas barrier composition include roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0161] Hereinafter, one embodiment of the method for forming the gas barrier coating layer will be described. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually progresses within the composition. The composition is then coated onto the vapor-deposited film by a conventional method and dried. This drying process further promotes polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one) to form a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above process. For example, the coated composition is heated at a temperature of preferably 20°C to 150°C, more preferably 50°C to 120°C, and even more preferably 50°C to 100°C, for 1 second to 10 minutes. This process forms a gas barrier coating layer.

[0162] The thickness of the gas barrier coating layer is preferably 0.01 μm to 10.0 μm, more preferably 0.1 μm to 5.0 μm, and even more preferably 0.1 μm to 2.0 μm, which can improve the gas barrier properties and prevent cracks from occurring in the vapor-deposited film, for example.

[0163] <Adhesive layer> In one embodiment, the laminate of the present disclosure includes an adhesive layer between the antistatic substrate and the sealant layer. Examples of the adhesive layer include an extruded resin layer containing polyethylene as a main component and an adhesive.

[0164] In one embodiment, the laminate of the present disclosure includes an extruded resin layer containing polyethylene as a main component between the antistatic substrate and the sealant layer. The extruded resin layer functions as an adhesive layer between the antistatic substrate and the sealant layer, or between a laminate including the antistatic substrate and the sealant layer. The laminate including the antistatic substrate includes, for example, the antistatic substrate and other layers such as an anchor coat layer.

[0165] The laminate of the present disclosure includes an extruded resin layer containing polyethylene as a main component as an antistatic substrate or an adhesive layer between the laminate and a sealant layer, which allows the polyethylene content in the laminate to be higher than when a conventional non-polyethylene adhesive (e.g., a two-component curing polyurethane adhesive) is used, thereby further improving the recyclability of the laminate.

[0166] The extruded resin layer contains polyethylene as a main component. The details of the polyethylene are as described above. The polyethylene in the extruded resin layer and the polyethylene in the antistatic substrate may be the same or different.

[0167] In the laminate of the present disclosure, the polyethylene constituting the extruded resin layer is preferably at least one selected from low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene from the viewpoint of adhesiveness, and more preferably low-density polyethylene or linear low-density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may also be used.

[0168] The melt flow rate (MFR) of the polyethylene constituting the extruded resin layer is preferably 0.1 g / 10 min or more and 50 g / 10 min or less, more preferably 0.2 g / 10 min or more and 30 g / 10 min or less, and even more preferably 3.0 g / 10 min or more and 20 g / 10 min or less, from the viewpoints of film-forming properties and processability of the laminate.

[0169] From the viewpoint of a balance between heat resistance and adhesiveness, the melting point (Tm) of the polyethylene constituting the extruded resin layer is preferably 100°C or higher and 140°C or lower, more preferably 100°C or higher and 130°C or lower, and even more preferably 100°C or higher and 120°C or lower.

[0170] The extruded resin layer may contain one or more polyethylenes. The content of polyethylene in the extruded resin layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. Such a configuration can improve the recyclability of the laminate, for example.

[0171] In one embodiment, the extruded resin layer contains biomass polyethylene. The biomass content of the extruded resin layer may be, for example, 30% or more, 50% or more, or 70% or more. The upper limit of the biomass content is not particularly limited, but may be, for example, 99% or 98%.

[0172] The extruded resin layer may contain an antistatic agent, but preferably does not substantially contain an antistatic agent. For example, the content of the antistatic agent in the extruded resin layer measured by pyrolysis GC is preferably 100 ppm or less. This can, for example, prevent a decrease in interlayer adhesion strength in a laminate including a sealant layer containing an antistatic agent.

[0173] In the laminate of the present disclosure, the thickness of the extruded resin layer serving as the adhesive layer is preferably 5 μm or more and 40 μm or less, more preferably 10 μm or more and 30 μm or less, which can improve, for example, adhesiveness and recyclability.

[0174] The extruded resin layer can be formed, for example, by melting polyethylene or a polyethylene composition and extruding it onto the antistatic substrate or a laminate comprising the antistatic substrate at a melting temperature of, for example, 280°C or higher and 340°C or lower, preferably 290°C or higher and 335°C or lower.

[0175] In one embodiment of the present disclosure, a melt extrusion lamination method, particularly a sand lamination method, using a molten resin containing polyethylene as a primary component is used to bond an antistatic substrate or a laminate including the antistatic substrate to a polyethylene film serving as a sealant layer. Alternatively, an extruded resin layer serving as an adhesive layer may be formed on the antistatic substrate or a laminate including the antistatic substrate, and then an extruded resin layer serving as a sealant layer may be formed on the adhesive layer. This method increases the polyethylene content of the laminate. Furthermore, compared to laminating the antistatic substrate or the laminate and the sealant layer by, for example, dry lamination, the time required for the drying and aging processes can be reduced, thereby improving the production efficiency of the laminate.

[0176] In one embodiment, the laminate of the present disclosure includes an adhesive layer formed of an adhesive between the antistatic substrate and the sealant layer, which can improve adhesion between the antistatic substrate and the sealant layer, for example.

[0177] The adhesive may be any of a one-component curing adhesive, a two-component curing adhesive, and a non-curing adhesive. The adhesive may be a solvent-based adhesive or a solventless adhesive. Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives. Examples of solventless adhesives include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing urethane-based adhesives are more preferred.

[0178] Examples of adhesive coating methods include direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fontaine coating, and transfer roll coating.

[0179] In the laminate of the present disclosure, the thickness of the adhesive layer formed from the adhesive is, for example, 0.1 μm or more and 10 μm or less, preferably 0.2 μm or more and 8 μm or less, and more preferably 0.5 μm or more and 6 μm or less.

[0180] In one embodiment, the laminate of the present disclosure can be produced by bonding an antistatic substrate and a resin film corresponding to the sealant layer together by a lamination method using the above-mentioned adhesive. For example, the laminate can be produced by bonding them together by a dry lamination method using a solvent-based adhesive, or by a non-solvent lamination method using a solvent-free adhesive.

[0181] <Anchor coat layer> In one embodiment, when the laminate of the present disclosure includes an extruded resin layer as an adhesive layer, the laminate may further include an anchor coat layer between the antistatic substrate and the extruded resin layer. This can improve interlayer adhesion in the laminate, for example. The anchor coat layer is formed from an anchor coating agent. In this embodiment, the extruded resin layer is in contact with the anchor coat layer.

[0182] Examples of anchor coating agents include polyurethane-based, polyolefin-based, polyethyleneimine-based, and epoxy resin-based anchor coating agents. In one embodiment, the anchor coating agent is a two-component curing resin, and is composed of, for example, a polyol as a base agent and a polyisocyanate as a curing agent.

[0183] Examples of polyols include polyether polyols, polyester polyols, and (meth)acrylic polyols. Examples of polyisocyanates include aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenylene polyisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate.

[0184] In one embodiment, the anchor coat layer is made of polyurethane obtained by reacting a polyol with a polyisocyanate. Specific examples of polyurethane include polyether polyurethane, polyester polyurethane, and poly(meth)acrylic polyurethane.

[0185] The anchor coat layer can be formed, for example, by applying an anchor coat agent to the antistatic substrate by a coating method such as roll coating, gravure roll coating, or kiss coating, or by printing.

[0186] The thickness of the anchor coat layer is, for example, 0.05 μm or more and 3.0 μm or less, preferably 0.1 μm or more and 2.0 μm or less, and more preferably 0.2 μm or more and 1.0 μm or less.

[0187] <Sealant layer> The laminate of the present disclosure comprises a polyethylene layer as a sealant layer. The polyethylene layer contains polyethylene as a main component. In one embodiment, the polyethylene layer serving as the sealant layer is an unstretched layer (unstretched polyethylene layer). The unstretched layer is a layer that has not been subjected to a stretching treatment, such as an extruded film that has not been subjected to a stretching treatment. Details of the stretching treatment are as described above in the description of the substrate.

[0188] The polyethylene in the sealant layer may be the same as or different from the polyethylene in the stretched polyethylene layer or the polyethylene in the extruded resin layer.

[0189] From the viewpoint of heat sealing property, the polyethylene constituting the sealant layer is preferably at least one selected from low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, and more preferably at least one selected from low-density polyethylene and linear low-density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may also be used.

[0190] The melt flow rate (MFR) of the polyethylene constituting the sealant layer is preferably 0.1 g / 10 min or more and 50 g / 10 min or less, more preferably 0.2 g / 10 min or more and 30 g / 10 min or less, and even more preferably 0.3 g / 10 min or more and 20 g / 10 min or less, from the viewpoints of film-forming properties and processability of the laminate.

[0191] From the viewpoint of a balance between heat resistance and heat sealability, the melting point (Tm) of the polyethylene constituting the sealant layer is preferably 90°C or higher and 140°C or lower, more preferably 90°C or higher and 130°C or lower, and even more preferably 90°C or higher and 120°C or lower.

[0192] The sealant layer may contain one or more polyethylenes. The content of polyethylene in the sealant layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. With such a configuration, for example, the recyclability of packaging materials made of the laminate of the present disclosure can be improved.

[0193] The sealant layer may contain one or more resin materials other than polyethylene. Examples of such resin materials include polyolefins such as polypropylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. When the sealant layer has a multilayer structure, each layer constituting the sealant layer may independently contain the above-mentioned resin materials.

[0194] The sealant layer may contain one or more additives. Examples of additives include antistatic agents, antiblocking agents, crosslinking agents, slip agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, pigments, dyes, and modifying resins. When the sealant layer has a multilayer structure, each layer constituting the sealant layer may independently contain the above-mentioned additives.

[0195] In one embodiment, the sealant layer contains an antistatic agent. This can impart good antistatic properties to the sealant layer, and therefore to one surface of the laminate. For example, when producing a packaging container containing powder as its contents, adhesion of the powder to the sealant layer surface, particularly to the heat-sealed portion, can be suppressed, thereby achieving good heat-seal strength.

[0196] Examples of the antistatic agent include anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, and nonionic antistatic agents. Specific examples include anionic antistatic agents such as adipic acid, glutamic acid, sulfonates, sulfates, phosphates, and phosphonates; cationic antistatic agents such as amines, imidazolines, amine oxide ethylene adducts, quaternary ammonium salts, and pyridinium salts; amphoteric antistatic agents having both cationic and anionic groups, such as guanidine salts obtained by reacting alkylamines with maleic anhydride, and sulfonic acids derived from polyethyleneimine; and nonionic antistatic agents such as polyols, ester compounds of polyols and aliphatic carboxylic acids, ether compounds, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid amides, and their ethylene oxide adducts.

[0197] In one embodiment, the sealant layer contains an anionic antistatic agent and an amphoteric antistatic agent. The sealant layer may contain an organic sulfonate such as an alkyl sulfonate as the anionic antistatic agent, and an ester compound, an ether compound, or an alkyl dialcohol amide of a polyol and a carboxylic acid as the amphoteric antistatic agent.

[0198] In one embodiment, the antistatic agent may be added to the sealant layer in the form of a masterbatch that includes polyethylene as a base material and the antistatic agent. The sealant layer may contain one or more antistatic agents.

[0199] The content of the antistatic agent in the sealant layer is preferably 0.03% by mass or more and 3% by mass or less, more preferably 0.05% by mass or more and 2.5% by mass or less, and even more preferably 0.07% by mass or more and 2% by mass or less. This results in a sealant layer that is excellent in both heat-sealing properties and antistatic properties, for example. The content of additives such as antistatic agents can be measured, for example, by GC / MS.

[0200] The sealant layer may have a single-layer structure or a multi-layer structure.

[0201] In one embodiment, the number of layers in the sealant layer having a multilayer structure is 2 to 7, for example, 3 to 7, or 3 to 5. The number of layers in the sealant layer is preferably an odd number, for example, 3, 5, or 7. With such a configuration, for example, the symmetry of the laminated structure of the sealant layer is increased, and curling in the sealant layer can be suppressed.

[0202] In one embodiment, the sealant layer is an extruded resin layer containing polyethylene as a main component. For example, the extruded resin layer as the sealant layer can be formed by melt-extrusion coating polyethylene or a polyethylene composition onto the antistatic substrate, anchor coat layer, or adhesive layer. Here, as described above, the adhesive layer may also be an extruded resin layer containing polyethylene as a main component.

[0203] In the laminate of the present disclosure, the polyethylene constituting the extruded resin layer (sealant layer) is preferably at least one selected from low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, from the viewpoint of low-temperature sealability, and more preferably at least one selected from low-density polyethylene and linear low-density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may also be used.

[0204] In the laminate of the present disclosure, the melting point (Tm) of the polyethylene constituting the extruded resin layer (sealant layer) is preferably 80°C or higher and 130°C or lower, more preferably 80°C or higher and 120°C or lower, and even more preferably 90°C or higher and 110°C or lower, from the viewpoint of low-temperature sealability.

[0205] In one embodiment, the sealant layer having a multilayer structure is a coextruded resin film, and each layer constituting the sealant layer is a coextruded resin layer. The coextruded resin film can be produced by film formation using, for example, an inflation method or a T-die method. For example, a laminate can be produced by laminating the antistatic substrate and the coextruded resin film corresponding to the sealant layer using the above-mentioned adhesive, or by melt extrusion lamination (particularly sand lamination) using a molten resin containing polyethylene as a main component.

[0206] In one embodiment, the sealant layer having a multilayer structure includes a resin layer (1) and a resin layer (2). The resin layer (1) constitutes a surface layer (e.g., a sealing layer) on the side opposite the antistatic substrate side of the sealant layer, and contains polyethylene as a main component. In one embodiment, when a packaging container is produced using a packaging material made of the laminate of the present disclosure, the resin layer (1) is the layer facing the contents to be contained in the packaging container. The resin layer (2) constitutes a surface layer (e.g., a laminate layer) on the antistatic substrate side of the sealant layer, and contains polyethylene as a main component. The sealant layer may further include an intermediate layer containing polyethylene as a main component between the resin layer (1) and the resin layer (2).

[0207] From the viewpoint of heat sealing property, the polyethylene constituting the resin layer (1) is preferably at least one selected from low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, and more preferably linear low-density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may also be used.

[0208] The content of polyethylene in the resin layer (1) is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more. Such a configuration can improve, for example, the recyclability of the laminate. It is preferable that the content of linear low-density polyethylene is within the above range.

[0209] The resin layer (1) may contain one or more of the above additives.

[0210] In one embodiment, the resin layer (1) contains one or more antistatic agents, which can impart good antistatic properties to the sealant layer, and therefore to one surface of the laminate, for example.

[0211] The content of the antistatic agent in the resin layer (1) is preferably 0.04% by mass to 5% by mass, more preferably 0.08% by mass to 4% by mass, and even more preferably 0.1% by mass to 3% by mass, thereby obtaining a sealant layer that is excellent in both heat-sealing property and antistatic property, for example.

[0212] The density of the resin layer (1) is preferably 0.930 g / cm 3 or less, more preferably 0.860 g / cm 3 More than 0.930g / cm 3 or less, more preferably 0.900 g / cm 3 More than 0.925g / cm 3 The following is the result.

[0213] The ratio of the thickness of the resin layer (1) to the total thickness of the sealant layer having a multi-layer structure is preferably 2% or more and 40% or less, more preferably 5% or more and 35% or less, and even more preferably 10% or more and 30% or less.

[0214] The polyethylene constituting the resin layer (2) is preferably at least one selected from low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, and more preferably low-density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may also be used.

[0215] The content of polyethylene in the resin layer (2) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. Such a configuration can improve, for example, the recyclability of the laminate. It is preferable that the content of low-density polyethylene is within the above range.

[0216] The resin layer (2) may contain one or more of the above additives. The content of the additives in the resin layer (2) is preferably 0.05% by mass or less, more preferably 0.01% by mass or less.

[0217] The resin layer (2) may contain an antistatic agent, but preferably does not substantially contain an antistatic agent. For example, the content of the antistatic agent in the resin layer (2) measured by pyrolysis GC is preferably 100 ppm or less. This can, for example, prevent a decrease in the adhesive strength between the sealant layer and other layers.

[0218] The density of the resin layer (2) is preferably 0.900 g / cm 3 Exceeds 0.930g / cm 3 or less, more preferably 0.905 g / cm 3 More than 0.928g / cm 3 or less, more preferably 0.910 g / cm 3 More than 0.925g / cm 3This configuration increases the symmetry of density in the layer direction in the sealant layer having a multi-layer structure, for example, and can suppress curling in the sealant layer.

[0219] In the sealant layer having a multi-layer structure, the difference (D2-D1) between the density D2 of the resin layer (2) and the density D1 of the resin layer (1) is preferably 0.020 g / cm 3 or less, more preferably 0.015 g / cm 3 or less, more preferably 0.010 g / cm 3 This configuration improves the symmetry of the laminated structure of the sealant layer, and for example, it is possible to suppress the occurrence of curling in the sealant layer.

[0220] The ratio of the thickness of the resin layer (2) to the total thickness of the sealant layer having a multilayer structure, when no intermediate layer is present, is preferably 60% or more and 98% or less, more preferably 65% ​​or more and 95% or less, and even more preferably 70% or more and 90% or less.

[0221] When an intermediate layer is present, the ratio of the thickness of the resin layer (2) to the total thickness of the sealant layer having a multilayer structure is preferably 2% or more and 40% or less, more preferably 5% or more and 35% or less, and even more preferably 10% or more and 30% or less.

[0222] The sealant layer having a multi-layer structure may further include an intermediate layer containing polyethylene as a main component between the resin layer (1) and the resin layer (2). The number of intermediate layers may be one, two or more, for example, three or more and five or less.

[0223] The polyethylene constituting the intermediate layer is preferably at least one selected from low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may also be used.

[0224] The content of polyethylene in the intermediate layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate can be improved.

[0225] The intermediate layer may contain one or more of the above additives. The content of the additives in the intermediate layer is preferably 0.05% by mass or less, and more preferably 0.01% by mass or less.

[0226] The intermediate layer may contain an antistatic agent, but preferably does not substantially contain an antistatic agent. For example, the content of the antistatic agent in the intermediate layer measured by pyrolysis GC is preferably 100 ppm or less. This can, for example, prevent a decrease in the adhesive strength between the sealant layer and other layers.

[0227] The ratio of the thickness of the intermediate layer to the total thickness of the sealant layer having a multi-layer structure is preferably 20% or more and 96% or less, more preferably 30% or more and 90% or less, and even more preferably 40% or more and 80% or less.

[0228] The total thickness of the sealant layer is preferably from 10 μm to 300 μm, more preferably from 10 μm to 250 μm, and in one embodiment from 10 μm to 60 μm, or from 40 μm to 200 μm. From the viewpoint of the strength and processability of the sealant layer, it is preferable that the total thickness of the sealant layer be changed appropriately depending on the mass of the contents to be contained in the packaging container described below.

[0229] For example, when the packaging container is a small pouch, the total thickness of the sealant layer is preferably 10 μm or more and 60 μm or less. In this case, for example, 1 g or more and 200 g or less of contents can be well accommodated in the small pouch. When the sealant layer is thin, bonding the antistatic substrate and the sealant film using a conventional non-polyethylene adhesive significantly reduces the polyethylene content in the entire laminate. In one embodiment of the present disclosure, the antistatic substrate and the sealant film are bonded together using an extruded resin layer containing polyethylene as a main component, thereby increasing the polyethylene content.

[0230] For example, when the packaging container is a stand-up pouch, the total thickness of the sealant layer is preferably 40 μm to 200 μm, more preferably 60 μm to 150 μm, so that the contents of, for example, 50 g to 2000 g can be easily accommodated in the stand-up pouch.

[0231] In one embodiment, the sealant layer contains biomass polyethylene. The biomass content of the sealant layer may be, for example, 10% or more, 10% to 80%, 20% to 75%, or 30% to 70%.

[0232] When the sealant layer has a multi-layer structure, that is, when the sealant layer has two or more resin layers containing polyethylene as a main component, at least one of the resin layers may contain biomass polyethylene.

[0233] For example, in the case of the sealant layer described above having a resin layer (1), and optionally an intermediate layer and a resin layer (2) in this order in the thickness direction, at least one layer selected from the resin layer (1), and optionally the intermediate layer and the resin layer (2) may contain biomass polyethylene.

[0234] The surface of the sealant layer facing the antistatic substrate may be subjected to the above-mentioned surface treatment, which can improve the adhesion between the sealant layer and a layer adjacent to the sealant layer, for example.

[0235] The laminate of the present disclosure may include a vapor-deposited film formed on the surface of the sealant layer facing the antistatic substrate. This can improve, for example, the oxygen barrier property and water vapor barrier property of the laminate. Details of the vapor-deposited film are as described above.

[0236] The surface of the vapor-deposited film may be subjected to the above-mentioned surface treatment, which can improve the adhesion between the vapor-deposited film and a layer adjacent to the vapor-deposited film, for example.

[0237] In one embodiment, the surface resistivity of the sealant layer side of the laminate of the present disclosure is 9.0×10 12 Ω / □ or less, preferably 9.0×10 11 The surface resistivity of the sealant layer side is, for example, 1.0 × 10 8 Ω / □ or more, 1.0×10 9 Ω / □ or more or 1.0×10 10 It can be Ω / □ or more.

[0238] In one embodiment, the surface resistivity of the substrate side of the laminate of the present disclosure (i.e., the surface resistivity of the surface layer) is 9.0×10 12 Ω / □ or less, preferably 9.0×10 11 Ω / □ or less, 9.0×10 10 Ω / □ or less or 9.0×10 9 The surface resistivity of the substrate side may be, for example, 1.0×10 8 It is Ω / □ or more.

[0239] [Application] The laminate of the present disclosure can be suitably used for packaging material applications. The packaging material is used to produce a packaging container. The packaging material comprises the laminate of the present disclosure. The packaging container can be produced by using at least the packaging material comprising the laminate of the present disclosure.

[0240] A packaging container includes the laminate of the present disclosure. Examples of packaging containers include packaging bags, tube containers, and lidded containers. The lidded container includes a container body having a storage section and a lid material joined (heat sealed) to the container body so as to seal the storage section.

[0241] Examples of heat sealing methods include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing.

[0242] Examples of packaging bags include various types of packaging bags such as a standing pouch type, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a palm seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type.

[0243] The packaging bag may have an easy-to-open portion. Examples of the easy-to-open portion include a notch portion that serves as a starting point for tearing the packaging bag, and a half-cut line formed by laser processing or a cutter as a path for tearing the packaging bag.

[0244] In one embodiment, a packaging bag can be produced by folding the laminate of the present disclosure in half and overlapping it so that the antistatic substrate is on the outside and the sealant layer is on the inside, and then heat-sealing the edges, etc. In another embodiment, a packaging bag can be produced by overlapping multiple laminates of the present disclosure so that the sealant layers face each other, and then heat-sealing the edges, etc. The entire packaging bag may be made of the above-mentioned laminate, or only a portion of the packaging bag may be made of the above-mentioned laminate.

[0245] In one embodiment, the laminate of the present disclosure is used as a lid material for a lidded container.

[0246] The contents contained in the packaging container can be, for example, liquids, solids, powders, and gels. The contents can be food or beverages, or non-food or beverages such as chemicals, cosmetics, and pharmaceuticals. The packaging container of the present disclosure has excellent antistatic properties, and is therefore suitable for powders such as powdered foods (e.g., furikake (rice seasoning), fried chicken powder), powdered medicines, and powdered beverages (e.g., coffee, tea). After the contents are contained in the packaging container, the packaging container can be hermetically sealed by heat-sealing the opening of the packaging container.

[0247] As specific examples of packaging bags, small pouches and standing pouches will be described below. A sachet is a small packaging bag used to store contents of, for example, 1 g to 200 g. Examples of contents that can be stored in a sachet include powders such as powdered foods (e.g., furikake (seasoning) or fried chicken powder), powdered medicines, and powdered drinks (e.g., coffee and tea); sauces, soy sauce, dressings, ketchup, syrup, cooking alcohol, and other liquid or viscous seasonings; liquid soups, powdered soups, fruit juices; spices; liquid drinks, jelly drinks, instant foods, and other foods and drinks. Specifically, a pharmaceutical sachet is preferred as a sachet.

[0248] Stand-up pouches are used to store contents of, for example, 50 g to 2000 g, including shampoo, rinse, conditioner, hand soap, body soap, air freshener, deodorant, insect repellent, detergent, dressing, cooking oil, mayonnaise, other liquid or viscous seasonings, liquid beverages, jelly-like beverages, instant foods, other foods and beverages, and creams.

[0249] Fig. 5 is a front view showing one embodiment of the packaging bag of the present disclosure. An example of the packaging bag will be described below with reference to Fig. 5. The packaging bag 40 of Fig. 5 includes a storage section 40a that stores contents.

[0250] The packaging bag 40 includes an upper portion 41, a lower portion 42, and a side portion 43, and has a generally rectangular outline in a front view. Note that the names "upper portion," "lower portion," and "side portion," as well as terms such as "above" and "below," merely represent the relative positions and directions of the packaging bag 40 and its components. The position, etc., of the packaging bag 40 during transportation or use is not limited by the names and terms used in this specification.

[0251] As shown in Fig. 5, the packaging bag 40 includes a top sheet 44 that forms the top surface and a back sheet 45 that forms the back surface. In the packaging bag 40 shown in Fig. 5, the top sheet 44 and the back sheet 45 are formed from a single laminate 1. At this time, the laminate 1 is folded back at a lower portion 42 so that the sealant layer 30 is positioned inside the packaging bag 40. Although not shown, in the packaging bag 40, the top sheet 44 and the back sheet 45 may each be formed from a single laminate 1. In this case, the packaging bag 40 has seal portions that extend along the edges in all four directions of the packaging bag 40.

[0252] The inner surfaces of the top sheet 44 and the back sheet 45 are joined together by a sealed portion. In the front view of the packaging bag 40 shown in Fig. 5, the sealed portion is hatched.

[0253] 5, packaging bag 40 has a seal portion extending along the edges in three directions of packaging bag 40. The seal portion includes an upper seal portion 41a extending along the upper portion 41 and a pair of side seal portions 43a extending along a pair of side portions 43. In packaging bag 40 in a state before it is filled with contents (a state in which no contents are filled), an opening (not shown) is formed in upper portion 41 of packaging bag 40. After the contents are placed in packaging bag 40, the inner surface of top sheet 44 and the inner surface of back sheet 45 are joined at upper portion 41 to form upper seal portion 41a and seal packaging bag 40.

[0254] The upper seal portion 41a and the side seal portion 43a are seal portions formed by joining the inner surface of the top sheet 44 and the inner surface of the back sheet 45 together.

[0255] There are no particular limitations on the method for forming the sealed portion, as long as it is possible to join the opposing sheets 44, 45 together and seal the packaging bag 40. For example, the sealed portion is formed by melting the inner surfaces of the sheets by heating or the like and fusing the inner surfaces together, i.e., by heat sealing.

[0256] The present disclosure relates to, for example, the following [1] to [6]. [1] A substrate comprising a stretched polyethylene layer and a surface layer provided on the stretched polyethylene layer, wherein the stretched polyethylene layer contains polyethylene as a main component and the surface layer contains an antistatic agent. [2] The substrate according to [1] above, wherein the stretched polyethylene layer is a polyethylene layer that has been subjected to a uniaxial stretching treatment or a biaxial stretching treatment. [3] The amount of antistatic agent in the surface layer is 0.1 g / m 2 More than 2.0g / m 2 The substrate according to the above [1] or [2], which is: [4] The surface resistivity of the surface layer is 9.0 × 10 12 The substrate according to any one of the above [1] to [3], which has a resistivity of Ω / □ or less. [5] The substrate according to any one of the above [1] to [4], further comprising a design layer on a partial region of the surface layer. [6] The substrate according to any one of the above [1] to [5], which is used for packaging material applications. [Example]

[0257] The antistatic substrate and laminate of the present disclosure will be described in more detail based on examples, but the antistatic substrate and laminate of the present disclosure are not limited to these examples.

[0258] In the following description, polyethylene film will also be referred to as "PE film," high-density polyethylene as "HDPE," medium-density polyethylene as "MDPE," low-density polyethylene as "LDPE," and linear low-density polyethylene as "LLDPE." Anchor coating agents are also referred to as "AC agents." The extruded polyethylene resin layer is also referred to as "EC-PE." The extruded resin layer of polyethylene containing an antistatic agent is also referred to as "antistatic EC-PE." The extruded resin layer of biomass polyethylene is also referred to as "EC-PEb." Polyurethane adhesives are also referred to as "PU adhesives." Masterbatch is also abbreviated as "MB."

[0259] [Production of stretched PE substrate (substrate film)] <Preparation of uniaxially stretched PE film (A)> MDPE (density: 0.941g / cm 3 A 125 μm-thick PE film was formed from a uniaxially stretched PE film (e.g., melting point: 129°C, MFR: 1.3 g / 10 min, Dow Chemical, trade name: Elite 5538G) by inflation molding. This PE film was stretched in the machine direction (MD) at a stretch ratio of 5 times to obtain a 25 μm-thick stretched PE film. Both sides of this stretched PE film were subjected to corona treatment, and the wetting index was adjusted to 52 dyn. The substrate thus obtained is also referred to as "uniaxially stretched PE film (A)." The haze value of the uniaxially stretched PE film (A) was measured in accordance with JIS K7136 and was found to be 6.5%.

[0260] <Preparation of uniaxially stretched PE film (B)> HDPE (density: 0.961g / cm 3 , melting point: 135°C, MFR: 0.7g / 10min, ExxonMobil, trade name: HTA108) and MDPE (density: 0.941g / cm 3A 125 μm-thick PE film was obtained by coextrusion using an inflation molding method. The HDPE layer, MDPE layer, and HDPE layer were each 25 μm thick, and the MDPE layer was 75 μm thick. This PE film was stretched in the machine direction (MD) at a stretch ratio of 5 times to obtain a 25 μm-thick stretched PE film. Both sides of this stretched PE film were subjected to a corona treatment to adjust the wetting index to 52 dyn. The substrate thus obtained is also referred to as "uniaxially stretched PE film (B)." The haze value of the uniaxially stretched PE film (B) was 8.9%.

[0261] <Preparation of uniaxially stretched PE film (C)> HDPE (density: 0.952g / cm 3 , MFR: 2.0 g / 10 min, biomass content: 96%, Braskem, product name: SGE7252) and MDPE (density: 0.941 g / cm 3 A 125 μm-thick PE film consisting of an HDPE layer, an MDPE layer, and an HDPE layer was obtained by coextrusion using an inflation molding method. The HDPE layers were each 25 μm thick, and the MDPE layer was 75 μm thick. This PE film was stretched in the machine direction (MD) at a stretch ratio of 5 times to obtain a 25 μm-thick stretched PE film. Both sides of this stretched PE film were subjected to a corona treatment to adjust the wetting index to 52 dyn. The substrate thus obtained is also referred to as "uniaxially stretched PE film (C)." The haze value of the uniaxially stretched PE film (C) was 10.9%, and the biomass content was 38%.

[0262] [Preparation of sealant film] <Preparation of anti-static PE film (A)> 80 parts by mass of LLDPE (density: 0.916 g / cm 3, melting point: 116°C, MFR: 2.3 g / 10 min, Prime Polymer Co., Ltd., product name: SP2020) and 15 parts by mass of antiblocking agent MB (density: 0.961 g / cm 3 , MFR: 4.0 g / 10 min, base material: LLDPE, antiblocking agent: synthetic zeolite, content of antiblocking agent: 10 mass%, Sumitomo Chemical Co., Ltd., product name: Sumikasen E EMB-21) and 5 mass parts of antistatic agent MB (density: 0.920 g / cm 3 , MFR: 2.1 g / 10 min, base material: LDPE, antistatic agent content: 18.0 mass %, Takemoto Yushi Co., Ltd., product name: Elecut Master LM-530) is referred to as "Mixture (1)".

[0263] LDPE (density: 0.924 g / cm) as a laminating layer 3 A 30 μm-thick sealant film was obtained by co-extrusion using an LDPE layer (laminate layer) having a thickness of 24 μm and a 6 μm-thick layer of the above-mentioned mixture (1) (sealing layer). One side of this sealant film was subjected to a corona treatment. The sealant film thus obtained is also referred to as "anti-static PE film (A)."

[0264] <Preparation of anti-static PE film (B)> The laminate layer was made of the above LDPE (F224N), and the intermediate layer was made of plant-derived LDPE (density: 0.923 g / cm 3 Braskem SEB853 (MFR: 2.7 g / 10 min, biomass content: 95%) and the above mixture (1) as a sealing layer were co-extruded by inflation molding to obtain a 30 μm thick sealant film consisting of a 6 μm thick LDPE layer, an 18 μm thick plant-derived LDPE layer, and a 6 μm thick layer of the above mixture (1). The biomass content was 57%. One side of this sealant film was subjected to a corona treatment. The sealant film obtained in this manner is also referred to as "anti-static PE film (B)."

[0265] [Example 1] A cationic antistatic ink (Dainichiseika Color & Chemicals Mfg. Co., Ltd., product name: SP-V Antistatic Agent (K)) was applied to one side of the uniaxially stretched PE film (A) to form a surface layer with a thickness of 1 μm. Next, a white ink (Toyo Ink Co., Ltd., product name: OPP Carbon 63 White) was applied to a partial area of ​​the surface layer to form a design layer with a thickness of 1 μm. In this way, an antistatic substrate was obtained. A polyethyleneimine-based anchor coating agent (Tosoh Corporation, product name: Toyobine 210K) was applied to the other side of the uniaxially stretched PE film (A) to form an anchor coating layer with a thickness of 0.3 μm. The anchor coating layer was coated with LDPE (density: 0.920 g / cm 3 A 20 μm-thick extruded resin layer (adhesive layer) was formed by melt-extrusion coating with LDPE (density: 0.919 g / cm , MFR: 7.0 g / 10 min, melting point: 106°C, Sumitomo Chemical Co., Ltd., trade name: Sumikathen CE4009). 3 A 20 μm-thick extruded resin layer (sealant layer) was formed by melt-extrusion coating with a resin having a MFR of 10 g / 10 min, a melting point of 106° C., manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumikathene CE4043. In this way, a laminate was obtained.

[0266] [Example 2] An antistatic substrate and a laminate were obtained in the same manner as in Example 1, except that the uniaxially oriented PE film (B) was used instead of the uniaxially oriented PE film (A).

[0267] [Example 3] An anti-static substrate and a laminate were obtained in the same manner as in Example 1, except that a 25 μm thick biaxially oriented polyethylene film (JINDAL, product name: 25HD-200) was used instead of the uniaxially oriented PE film (A).

[0268] [Example 4] The antistatic ink (SP-V antistatic agent (K)) was applied to one side of the uniaxially stretched PE film (B) to form a surface layer with a thickness of 1 μm. Next, the white ink (OPP carbon 63 white) was applied to a portion of the surface layer to form a design layer with a thickness of 1 μm. In this way, an antistatic substrate was obtained. The other side of the uniaxially stretched PE film (B) was bonded to the corona-treated surface of the antistatic PE film (A) via a 3 μm-thick adhesive layer made of a two-component curing polyurethane adhesive (Rock Paint Co., Ltd., RU-77T / H-7), to obtain a laminate.

[0269] [Example 5] The antistatic ink (SP-V antistatic agent (K)) was applied to one side of the uniaxially stretched PE film (B) to form a 1 μm thick surface layer. Next, the white ink (OPP carbon 63 white) was applied to a portion of the surface layer to form a 1 μm thick design layer. In this way, an antistatic substrate was obtained. The other side of the uniaxially stretched PE film (B) was bonded to the corona-treated side of the antistatic PE film (B) via a 3 μm thick adhesive layer made of a two-component curing polyurethane adhesive (Rock Paint Co., Ltd., RU-77T / H-7) to obtain a laminate. The biomass content of the laminate was 28.5%.

[0270] [Example 6] The uniaxially oriented PE film (B) was used instead of the uniaxially oriented PE film (A), and plant-derived LDPE (density: 0.918 g / cm) was used instead of the LDPE (Sumikasen CE4009) used to form the adhesive layer. 3 An antistatic substrate and a laminate were obtained in the same manner as in Example 1, except that a polyester fiber (Braskem, product name: SBC818, MFR: 8.3 g / 10 min, biomass content: 95%) was used. The biomass content of the laminate was 28.2%.

[0271] [Example 7] Except for using the uniaxially oriented PE film (C) instead of the uniaxially oriented PE film (A), an antistatic substrate and a laminate were obtained in the same manner as in Example 1. The biomass content of the laminate was 14.1%.

[0272] [Example 8] An antistatic substrate and a laminate were obtained in the same manner as in Example 5, except that the uniaxially oriented PE film (C) was used instead of the uniaxially oriented PE film (B). The biomass ratio of the laminate was 44.3%.

[0273] [Example 9] An anti-static substrate and a laminate were obtained in the same manner as in Example 1, except that the uniaxially oriented PE film (C) was used instead of the uniaxially oriented PE film (A) and the plant-derived LDPE (SBC818) was used instead of the LDPE (Sumikathene CE4009) for forming the adhesive layer. The biomass content of the laminate was 42.3%.

[0274] [Comparative Example 1] The above-mentioned white ink (OPP Carbon 63 White) was applied to a portion of one side of a 12 μm-thick antistatic PET film (Toyobo Co., Ltd., product name: T6142, antistatic PET film) to form a 1 μm-thick design layer. The above-mentioned polyethyleneimine-based anchor coating agent (Toyobain 210K) was applied to the other side of the antistatic PET film to form a 0.3 μm-thick anchor coat layer. The above-mentioned LDPE (Sumikathene CE4009) was melt-extrusion coated onto the anchor coat layer to form a 20 μm-thick extruded resin layer (adhesive layer), and then the above-mentioned antistatic agent-containing LDPE (Sumikathene CE4043) was melt-extrusion coated to form a 20 μm-thick extruded resin layer (sealant layer). In this way, a laminate was obtained.

[0275] Comparative Example 2 The above white ink (OPP Carbon 63 White) was applied to a partial area on one side of a 12 μm thick antistatic PET film (Toyobo Co., Ltd., product name: T6142, antistatic PET film) to form a 1 μm thick design layer. The other side of the antistatic PET film was bonded to the corona-treated side of the antistatic PE film (A) via a 3 μm thick adhesive layer made of a two-component curing polyurethane adhesive (Rock Paint Co., Ltd., RU-77T / H-7), to obtain a laminate.

[0276] Comparative Example 3 A laminate was produced in the same manner as in Example 1, except that the antistatic ink was not applied.

[0277] [Surface resistivity measurement method] The surface resistivity of the surface (surface layer) and back surface (sealant layer) of the laminate was measured in accordance with JIS K6911: 1995. The measuring instrument used was a high resistivity meter, Hirester UX MCP-HT800 (Mitsui Chemicals Analytech, Inc.).

[0278] The surface resistivity was measured using the laminate after it had been stored for 24 hours at a temperature of 40° C. The environment during the measurement of the surface resistivity was a temperature of 20° C. and a relative humidity of 65%.

[0279] [Seal strength measurement method] Two sheets of each laminate prepared in the examples and comparative examples were used, and the sealant layers of the laminates were bonded together at a temperature of 140°C and a pressure of 1 kgf / cm 2 The sample was heat-sealed for 1 second, forming a seal. The portion containing the seal was then cut out to prepare a test piece measuring 15 mm in width and 100 mm in length for measuring the seal strength. The length of the seal was 15 mm. The seal strength was measured in accordance with JIS K7127:1999 at a test speed of 300 mm / min. The measuring instrument used was an SA-1150 tensile tester manufactured by Orientec Co., Ltd.

[0280] [Ash Test] A 10 cm x 10 cm piece of film was cut out from the laminates produced in the Examples and Comparative Examples. An arbitrary amount of ash was placed on the front or back of the film, which was then tilted 90° and shaken vertically five times, after which the adhesion of ash was evaluated. Cases where ash was attached were rated as BB, and cases where no ash was attached at all were rated as AA.

[0281] [Table 1]

[0282] [Table 2]

[0283] [Table 3] [Explanation of symbols]

[0284] 1: Laminate 10: Base material 12: Stretched polyethylene layer 14: Surface layer 16: Design layer 20: Extruded resin layer 22: Anchor coat layer 30: Sealant layer

Claims

1. a stretched polyethylene layer; a surface layer provided on the stretched polyethylene layer; A substrate comprising: the stretched polyethylene layer contains polyethylene as a main component, The substrate, wherein the surface layer contains an antistatic agent.

2. 2. The substrate of claim 1, wherein the oriented polyethylene layer is a uniaxially or biaxially oriented polyethylene layer.

3. The amount of the antistatic agent in the surface layer is 0.1 g / m ２ 2.0g / m or more ２ 3. The substrate according to claim 1 or 2, wherein:

4. The surface resistivity of the surface layer is 9.0×10 １２ The substrate according to any one of claims 1 to 3, having a resistance of Ω / □ or less.

5. The substrate according to any one of claims 1 to 4, further comprising a design layer on a partial area of ​​the surface layer.

6. The substrate according to any one of claims 1 to 5, which is used for packaging material applications.

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