JP2023121080A - Laminate and packaging container - Google Patents

Abstract

To provide a laminate that exhibits antistatic properties while inhibiting outgas generation without significant loss of low-temperature sealing properties.SOLUTION: A laminate at least comprises a base material and a sealant layer. The sealant layer at least comprises a first polyethylene layer and a second polyethylene layer. The second polyethylene layer contains polyethylene as a main component, and a donor-acceptor antistatic agent. The second polyethylene layer constitutes one surface layer of the laminate.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to laminates and packaging containers.

A laminate for packaging containers formed by laminating a sealant film such as a polyethylene film on a substrate such as a biaxially oriented polyester film or a biaxially oriented nylon film having excellent strength is known (for example, Patent Document 1 reference). Conventionally, a sealant film having antistatic properties has been used in order to suppress the adhesion of dust or contents to the heat-sealed portion when filling the contents into a packaging container, and the deterioration of quality due to electrification. (See Patent Document 2, for example). For example, it is known that a sealant film produced by adding a masterbatch containing a surfactant to polyethylene exhibits antistatic properties due to bleeding out of the surfactant onto the film surface.

JP 2006-051995 A Japanese Patent Application Laid-Open No. 2006-219608

Films containing surfactants have problems such as requiring a certain amount of humidity, bleedout can contaminate the contents, and high surface specific resistivity. Films containing polymeric antistatic agents such as polyether-based or polyethylene glycol-based antistatic agents are also known for suppressing bleed out. However, in order to develop antistatic properties, it is necessary to add a large amount of high-molecular antistatic agents, and when heat-sealed at low temperatures, the seal strength (low-temperature sealability) decreases or outgassing occurs. It may become easier.

One problem to be solved by the present disclosure is to provide a laminate that exhibits antistatic properties without significantly impairing low-temperature sealability and while suppressing outgassing.

The laminate of the present disclosure includes at least a substrate and a sealant layer, the sealant layer includes at least a first polyethylene layer and a second polyethylene layer, and the second polyethylene layer contains polyethylene as a main component. and a donor-acceptor antistatic agent, and the second polyethylene layer constitutes one surface layer of the laminate.

According to the present disclosure, it is possible to provide a laminate that exhibits antistatic properties without significantly impairing low-temperature sealability and while suppressing outgassing.

FIG. 1 is a schematic cross-sectional view of one embodiment of a sealant layer. FIG. 2 is a schematic cross-sectional view of one embodiment of a sealant layer. FIG. 3 is a schematic cross-sectional view of one embodiment of the laminate of the present disclosure. FIG. 4 is a schematic cross-sectional view of one embodiment of the laminate of the present disclosure. FIG. 5 is a schematic cross-sectional view of one embodiment of the laminate of the present disclosure. FIG. 6 is a schematic cross-sectional view of one embodiment of the laminate of the present disclosure. FIG. 7 is a front view of one embodiment of the packaging bag. FIG. 8 is a plan view showing a test piece for evaluating impact strength. FIG. 9 is a schematic diagram showing a method of measuring impact strength.

Hereinafter, embodiments of the present disclosure will be described in detail. This disclosure may be embodied in many different forms and should not be construed as limited to the description of the illustrative embodiments below. In order to make the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each layer compared to the embodiment, but this is only an example and does not limit the interpretation of the present disclosure. . In this specification and each figure, elements similar to those already described with respect to previous figures may be denoted by the same reference numerals, and detailed description thereof may be omitted as appropriate.

A laminate of the present disclosure includes at least a substrate and a sealant layer.
Hereinafter, after explaining the sealant layer, the laminated body will be explained.

[Sealant layer]
The sealant layer comprises at least a first polyethylene layer and a second polyethylene layer. In one embodiment, the first polyethylene layer is one surface layer of the sealant layer and the second polyethylene layer is the other surface layer of the sealant layer. The sealant layer may further comprise an intermediate layer between the first polyethylene layer and the second polyethylene layer.

The laminate of the present disclosure can be suitably used as a packaging material. When a packaging container is produced using the packaging material, the first polyethylene layer is a layer facing the substrate side of the packaging material, and the second polyethylene layer faces the content contained in the packaging container. It is the layer (the innermost layer of the packaging container). In such a case, the first polyethylene layer is also called the "laminate layer" and the second polyethylene layer is also called the "seal layer".

1 and 2 show schematic cross-sectional views of one embodiment of the sealant layer.
The sealant layer (laminated film) 10 in FIG. 1 comprises a first polyethylene layer 12 and a second polyethylene layer 14 . The sealant layer 10 of FIG. 2 includes a first polyethylene layer 12, an intermediate layer 16, and a second polyethylene layer 14 in this order in the thickness direction.

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

In the present disclosure, polyethylene may be a homopolymer of ethylene or a copolymer of ethylene and an ethylenically unsaturated monomer other than ethylene. Examples of ethylenically unsaturated monomers other than ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. , 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene and 6-methyl-1-heptene, α-olefins having 3 to 20 carbon atoms; vinyls such as vinyl acetate and vinyl propionate monomers; and (meth)acrylic acid esters such as methyl (meth)acrylate and ethyl (meth)acrylate.

In the present disclosure, polyethylene includes, for example, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and ultra low density polyethylene.

In the present disclosure, the density of the polyethylene is as follows.
The density of high density polyethylene is preferably 0.945 g/cm ³ or higher. The upper density limit of high-density polyethylene is, for example, 0.965 g/cm ³ . The density of medium density polyethylene is preferably 0.925 g/cm ³ or more and less than 0.945 g/cm ³ . The density of the low-density polyethylene is preferably 0.900 g/cm ³ or more and less than 0.925 g/cm ³ . The linear low-density polyethylene preferably has a density of 0.900 g/cm ³ or more and less than 0.925 g/cm ³ . The density of ultra-low density polyethylene is preferably less than 0.900 g/ ^cm3 . The lower limit of the density of ultra-low density polyethylene is, for example, 0.860 g/cm ³ . The density of polyethylene is measured according to JIS K7112, particularly D method (density gradient tube method, 23°C).

Low-density polyethylene is usually polyethylene obtained by polymerizing ethylene by a high-pressure polymerization method (high-pressure low-density polyethylene). Linear low-density polyethylene is usually polyethylene obtained by polymerizing ethylene and a small amount of α-olefin by a low-pressure polymerization method (eg, a polymerization method using a Ziegler-Natta catalyst or a metallocene catalyst).

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

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

Biomass-derived ethylene, which is a 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.

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. Conventionally known plants such as corn, sugar cane, beet and manioc can be used as the plant raw material.

Biomass-derived fermented ethanol refers to ethanol produced by contacting a culture solution containing a carbon source obtained from a plant material with a microorganism that produces ethanol or a product derived from a crushed product thereof, and then refining the ethanol. Conventionally known methods such as distillation, membrane separation and extraction can be applied to purify ethanol from the culture medium. For example, a method of adding benzene, cyclohexane or the like to cause azeotropy, or removing water by membrane separation or the like can be mentioned. In order to obtain the above ethylene, at this stage, advanced purification such as reducing the total amount of impurities in ethanol to 1 ppm or less may be further performed.

A catalyst is usually used to obtain ethylene by the dehydration reaction of ethanol. A conventionally known catalyst can be used as the catalyst. A reaction form that is advantageous in terms of process is a fixed bed flow reaction that facilitates separation of the catalyst and the product. For example, γ-alumina is preferred.

Since this dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. Although the heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, a temperature of preferably 100° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher is suitable. Although the upper limit is not particularly limited, it is preferably 500° C. or less, more preferably 400° C. or less from the viewpoint of energy balance and equipment.

In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in ethanol supplied as a raw material. In general, when a dehydration reaction is performed, it is preferable that there is no water, considering the removal efficiency of water. However, in the case of ethanol dehydration using a solid catalyst, the absence of water tends to increase the amount of other olefins, especially butenes. It is presumed that ethylene dimerization after dehydration cannot be suppressed unless a small amount of water is present. The content of water is, for example, 0.1% by mass or more, preferably 0.5% by mass or more. The content of water is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, from the viewpoint of material balance and heat balance.

By carrying out the dehydration reaction of ethanol in this way, a mixture of ethylene, water and a small amount of unreacted ethanol is obtained. Since ethylene is a gas at room temperature of about 5 MPa or less, ethylene can be obtained by removing water and ethanol from the mixture by gas-liquid separation. This may be done by a known method.

Ethylene obtained by gas-liquid separation is further distilled, and the distillation method, operating temperature, residence time, etc. are not particularly limited except that the operating pressure at this time is normal pressure or higher.

When the raw material is biomass-derived ethanol, the resulting ethylene contains carbonyl compounds such as ketones, aldehydes, and esters that are impurities mixed in the ethanol fermentation process, carbon dioxide that is their decomposition products, and enzymatic decomposition products and contaminants. Nitrogen-containing compounds such as amines and amino acids, which are substances, and ammonia, etc., which are decomposition products thereof, are contained in extremely small amounts. Depending on the use of ethylene, these trace amounts of impurities may pose a problem, so they may be removed by refining. Purification can be performed by a conventionally known method. Suitable purification operations include, for example, adsorption purification methods. As the adsorbent to be used, a conventionally known adsorbent can be used. For example, a material with a high surface area is preferable, and the type of adsorbent is selected according to the type and amount of impurities in ethylene obtained by the dehydration reaction of biomass-derived ethanol.

As a method for purifying impurities in ethylene, caustic water treatment may be used in combination. When caustic water treatment is performed, it is desirable to perform it before adsorption purification. In that case, after the caustic treatment, it is necessary to apply moisture removal treatment before adsorption purification.

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 production method. Since biomass-derived ethylene is used as a raw material monomer, the polymerized polyethylene is biomass-derived.

Raw material monomers for biomass polyethylene may not contain 100% by mass of biomass-derived ethylene. Raw material monomers for biomass polyethylene may further contain ethylene derived from fossil fuels in addition to ethylene derived from biomass.

Since carbon dioxide in the atmosphere contains a certain proportion of C14 (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in all carbon atoms, the ratio of biomass-derived carbon can be calculated. In the present disclosure, “biomass degree” indicates the weight ratio of biomass-derived components. Take polyethylene terephthalate, for example. Polyethylene terephthalate is a polymer obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms in a molar ratio of 1:1. When only biomass-derived ethylene glycol is used, the weight ratio of the biomass-derived component in the polyester is 31.25%. Therefore, the theoretical value of biomass degree is 31.25%. Specifically, the mass of polyethylene terephthalate is 192, of which the mass derived from biomass-derived ethylene glycol is 60. Therefore, 60÷192×100=31.25. The weight ratio of the biomass-derived component in the fossil fuel-derived polyester produced using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass degree of the fossil fuel-derived polyester is 0%. is. Hereinafter, unless otherwise specified, the “biomass degree” indicates the weight ratio of biomass-derived components.

Theoretically, if all biomass-derived ethylene is used as the raw material for polyethylene, the biomass-derived ethylene concentration is 100%, and the biomass degree of biomass polyethylene is 100%. The concentration of biomass-derived ethylene in fossil fuel polyethylene produced only from fossil fuel-derived raw materials is 0%, and the biomass degree of fossil fuel polyethylene is 0%.

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 ultra-low density polyethylene. The biomass degree of biomass polyethylene is 80% or more, 85% or more, 90% or more, or 95% or more in one embodiment.
Biomass polyethylene is preferably plant-derived polyethylene.

In the present disclosure, biomass polyethylene and biomass-derived resin layers do not need to have a biomass degree of 100%. This is because if a biomass-derived raw material is used for even a part of the laminate, it is in line with the idea of reducing the amount of fossil fuel used compared to the past.

As polyethylene, polyethylene recycled by mechanical recycling or chemical recycling may be used. As a result, the environmental impact of the laminate or packaging material can be reduced. Mechanical recycling generally involves pulverizing collected polyethylene film, washing with alkali to remove dirt and foreign matter from the surface of the film, and then drying it for a certain period of time under high temperature and reduced pressure to remain inside the film. This is a method of decontaminating by diffusing contaminants, removing dirt from the film, and returning it to polyethylene again. Chemical recycling is generally a method of decomposing a recovered polyethylene film or the like down to the level of monomers and polymerizing the monomers again to obtain polyethylene.

The description of polyethylene above is applicable to polyethylene in the description below.

The total thickness of the sealant layer is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more; preferably 300 μm or less, more preferably 250 μm or less, even more preferably 200 μm or less. The total thickness of the sealant layer is, for example, 10 μm or more and 300 μm or less. From the viewpoint of the strength and workability of the sealant layer, it is preferable to change the total thickness of the sealant layer as appropriate according to the mass of the contents accommodated in the packaging container.

For example, when the packaging container is a sachet, 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 bag.

For example, when the packaging container is a standing pouch, the total thickness of the sealant layer is preferably 40 μm or more and 200 μm or less, more preferably 60 μm or more and 150 μm or less. In this case, for example, contents of 50 g or more and 2000 g or less can be well accommodated in the standing pouch.

From the viewpoint of heat sealability, the sealant layer is preferably an unstretched film. An unstretched film is a film that has not been stretched, for example, an extruded film that has not been stretched. The details of the stretching process will be described later in the description of the base material.

The sealant layer may contain biomass polyethylene. The biomass degree of the sealant layer may be, for example, 10% or more, 10% or more and 80% or less, 20% or more and 75% or less, or 30% or more and 70% or less.

In the sealant layer comprising a first polyethylene layer, optionally an intermediate layer and a second polyethylene layer in this order in the thickness direction, selected from the first polyethylene layer, optionally the intermediate layer and the second polyethylene layer At least one layer applied may contain biomass polyethylene. For example, the intermediate layer may contain biomass polyethylene.

The surface resistivity of the sealant layer on the side of the second polyethylene layer is preferably 9.0×10 ¹¹ Ω/□ or less, more preferably 9.0×10 ¹⁰ Ω/□ or less, and still more preferably 9.0. ×10 ⁹ Ω/□ or less, particularly preferably 5.0 × 10 ⁹ Ω/□ or less or 4.0 × 10 ⁹ Ω/□ or less. The surface resistivity of the second polyethylene layer side surface is, for example, 1.0×10 ⁸ Ω/□ or more, and may be 1.0×10 ⁹ Ω/□ or more. In the present disclosure, the specific surface resistivity is measured according to JIS K6911:1995, and the environment for measuring the specific surface resistivity is temperature 23° C. and relative humidity 50%.

The half-life of the initial electrification voltage on the surface of the sealant layer on the side of the second polyethylene layer is preferably 10 seconds or less, more preferably 5 seconds or less, and still more preferably 3 seconds or less. Although the lower limit of the half-life is not particularly limited, it may be 0.1 seconds, for example. In the present disclosure, the half-life is measured by a static voltage decay test conforming to JIS L1094:2014, and the environment for measuring the half-life is a temperature of 23° C. and a relative humidity of 50%.

The haze of the laminate film constituting the sealant layer is preferably 15% or less, more preferably 13% or less, and still more preferably 12% or less. Although the lower limit of haze is not particularly limited, it may be, for example, 1%. Thereby, the transparency of the laminated film can be improved. The haze of the laminated film is measured according to JIS K7136.

In one embodiment, the laminated film that constitutes the sealant layer generates a small amount of outgassing from the film. A packaging container equipped with such a laminated film as a heat seal layer reduces outgassing components adhering to the contents filled in the packaging container, or suppresses adhesion to semiconductors and silicon wafers, thereby reducing the defect rate. can be reduced. Here, the amount of outgassing generated from the laminated film can be obtained from the peak area of headspace gas chromatography (HS-GC).

The amount of outgassing can be measured as follows. Eight test pieces obtained by cutting the laminate film constituting the sealant layer into a size of 5 cm × 5 cm were sealed in a vial and treated at an HS temperature of 120°C, a loop temperature of 140°C, and a TR-LINE temperature of 140°C. , 1 ml of air in the head space is introduced, the temperature is raised to 320° C., and the components are detected by HS-GC when the temperature is maintained for 5 minutes.
Measurement device: carried out with Agilent 6890 Carrier gas: He

The sealant layer, in one embodiment, has a low leaching amount of organic components into water. Therefore, the packaging container provided with such a sealant layer can reduce the concentration of organic substances eluted into the liquid content filled in the packaging container, and can suppress changes in the taste, smell, properties, etc. of the liquid content. . Here, the concentration of organic matter in the liquid content can be indicated by the concentration of total organic carbon (TOC).

TOC indicates the concentration of the total amount of organic matter (organic carbon) that can be oxidized in water in terms of the concentration of carbon content, and is used as one of the typical water quality indicators. Organic carbon (TOC) automatic measuring instrument), etc. are standardized.

Using the laminate of the present disclosure, a pouch having an area of 44 × 15 cm ² was prepared, the pouch was filled with 1 L of water at 65 ° C., and left to stand at a temperature of 35 ° C. for 336 hours. The total organic carbon (TOC) elution amount in water is preferably 2.0 mg/L or less, more preferably 1.6 mg/L or less, and even more preferably 1.0 mg/L or less. Distilled water or ion-exchanged water should be used for filling. The TOC concentration in water can be measured with a general TOC meter such as TOC200S (manufactured by Toray Engineering Co., Ltd.).

<First polyethylene layer>
The first polyethylene layer preferably contains polyethylene as a main component.
In the present disclosure, "main component" refers to a component whose content in the layer is more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

The polyethylene is preferably at least one selected from linear low-density polyethylene, high-pressure low-density polyethylene, medium-density polyethylene, and high-density polyethylene. At least one selected from low-density polyethylene is more preferred, and linear low-density polyethylene is even more preferred. Biomass polyethylene, or mechanically or chemically recycled polyethylene may be used.

The melt flow rate (MFR) of the polyethylene contained in the first polyethylene layer is preferably 0.1 g/10 min or more, more preferably 0.2 g/10 min or more, from the viewpoint of film formability and processability. preferably 0.3 g/10 min or more, particularly preferably 0.5 g/10 min or more; preferably 50 g/10 min or less, more preferably 30 g/10 min or less, even more preferably 20 g/10 min or less, especially Preferably, it is 5.0 g/10 minutes or less. The MFR of polyethylene is, for example, 0.1 g/10 minutes or more and 50 g/10 minutes or less. The MFR of polyethylene is measured by A method in accordance with JIS K7210 under conditions of a temperature of 190° C. and a load of 2.16 kg.

The melting point (Tm) of the polyethylene contained in the first polyethylene layer is preferably 90° C. or higher, more preferably 95° C. or higher, and still more preferably 100° C. or higher, from the viewpoint of the balance between heat resistance and heat sealability; It is preferably 140° C. or lower, more preferably 130° C. or lower, and still more preferably 125° C. or lower. Tm of polyethylene is, for example, 90° C. or higher and 140° C. or lower. The Tm of polyethylene is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

The first polyethylene layer can contain one or more polyethylenes.
The content of polyethylene in the first polyethylene layer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate of the present disclosure can be improved.

The first polyethylene layer may contain one or more resin materials other than polyethylene. Examples of the resin material include polyolefins such as polypropylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

The first polyethylene layer may contain one or more additives. Additives include, for example, antistatic agents, antiblocking agents, cross-linking agents, slip agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, pigments, dyes and modifying resins. is mentioned.

The first polyethylene layer may contain an antistatic agent, but in one embodiment is preferably substantially free of antistatic agents. For example, in the first polyethylene layer, the content of the antistatic agent measured by pyrolysis GC method is preferably 100 ppm or less. Thereby, for example, it is possible to suppress a decrease in adhesion strength between the sealant layer and other layers laminated on the sealant layer.

In one embodiment, the first polyethylene layer may contain a donor-acceptor antistatic agent, which will be described later. For example, when the first polyethylene layer is one surface layer of the sealant layer and the second polyethylene layer is the other surface layer of the sealant layer, both the first polyethylene layer and the second polyethylene layer It may contain an inhibitor.

In one embodiment, the content of the donor-acceptor antistatic agent in the first polyethylene layer is, for example, 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, more preferably 0.3% by mass or more; preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. The content of the donor-acceptor antistatic agent in the first polyethylene layer is, for example, 0.01% by mass or more and 5.0% by mass or less.

A surface treatment may be applied to the surface of the first polyethylene layer opposite to the surface of the second polyethylene layer. Thereby, for example, the adhesion strength between the sealant layer and the layer laminated on the sealant layer can be improved. 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, glow discharge treatment; and oxidation treatment using chemicals. Chemical treatment can be mentioned.

<Second polyethylene layer>
The second polyethylene layer contains polyethylene as a main component and a donor-acceptor antistatic agent. With such a configuration, for example, good antistatic properties can be imparted to the surface of the sealant layer without significantly impairing film physical properties such as mechanical strength, low-temperature sealing properties, low elution properties, low outgassing properties, and transparency. . The second polyethylene layer has high antistatic properties against static electricity and other instantaneous charges and even in a low humidity environment.

For example, when the laminate of the present disclosure is used as a packaging material that constitutes a packaging container, it is possible to suppress the adhesion of contents and dust to the heat-sealed portion of the surface of the sealant layer, thus obtaining good heat-sealing strength. In addition, there is little possibility that the donor-acceptor type antistatic agent in the sealant layer will contaminate the contents. Further, when the laminate of the present disclosure is used as a protective film for protecting a semiconductor wafer, for example, the donor-acceptor antistatic agent in the sealant layer is less likely to contaminate the wafer.

Thus, in one embodiment, the laminate of the present disclosure has excellent mechanical strength, low-temperature sealing properties, low elution properties, low outgassing properties, and transparency, and has a small risk of contamination of the contents and adherends, and Since it is also excellent in antistatic properties, it is suitable as a protective film for protecting packaging materials, semiconductor wafers, industrial materials, and the like. Moreover, the laminate of the present disclosure is excellent in workability.

The polyethylene is preferably at least one selected from linear low-density polyethylene, high-pressure low-density polyethylene, medium-density polyethylene, and high-density polyethylene. At least one selected from low-density polyethylene is more preferred, and linear low-density polyethylene is even more preferred. Biomass polyethylene, or mechanically or chemically recycled polyethylene may be used.

Numerical ranges of the MFR and Tm of the polyethylene contained in the second polyethylene layer include the same numerical ranges as those of the MFR and Tm of the polyethylene contained in the first polyethylene layer, respectively.

The melt flow rate (MFR) of the polyethylene contained in the second polyethylene layer is preferably 5.0 g/10 min or less, more preferably 4.0 g/10 min or less, still more preferably 3.0 g/10 min or less, Particularly preferably, it is 2.0 g/10 minutes or less. When the MFR of the polyethylene mixed with the donor-acceptor antistatic agent is equal to or less than the above-mentioned upper limit, for example, the antistatic properties are exhibited more satisfactorily.

The second polyethylene layer can contain one or more polyethylenes.
The content of polyethylene in the second polyethylene layer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate of the present disclosure can be improved.

The second polyethylene layer may contain one or more resin materials other than polyethylene. Examples of the resin material include polyolefins such as polypropylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

Donor-acceptor type antistatic agent (hereinafter also referred to as "antistatic agent (X)") is, for example, at least one donor component and at least one acceptor component, uniformly mixed It is an inhibitor. The antistatic agent (X) can express good antistatic properties at a low addition amount in combination with polyethylene, therefore, film physical properties such as mechanical strength, low temperature sealing properties, low elution properties, low outgassing properties and transparency can suppress the decrease in

The antistatic agent (X) includes, for example, an antistatic agent containing a boron compound, and an antistatic agent containing a boron compound having a structure represented by formula (1) in the molecule is preferred.

The antistatic agent (X) is obtained by reacting a semipolar organic boron compound having a structure represented by formula (1) in the molecule as a donor component with a basic nitrogen compound as an acceptor component. antistatic agents are preferred.

In the antistatic agent (X), both the donor component and the acceptor component preferably have one or more linear hydrocarbon groups. In this case, it is believed that the antistatic properties are maintained well in the second polyethylene layer. The antistatic agent (X) is a semipolar organic boron compound having one structure represented by formula (1) in the molecule and at least one linear hydrocarbon group having 5 to 28 carbon atoms, and a molecule It is preferably composed of a basic organic compound having one basic nitrogen atom group and at least one linear hydrocarbon group having 5 to 28 carbon atoms therein.

The semipolar organic boron compound is, for example, reacting the remaining adjacent hydroxy groups in the ester of a polyhydric alcohol and a linear fatty acid with boric acid or a borate ester of a lower alcohol, or by reacting the adjacent hydroxy groups. Either react boric acid or a borate ester of a lower alcohol with a straight-chain hydrocarbon compound having a It is a compound obtained by reacting a linear fatty acid with the hydroxy group remaining after the reaction, and the compound obtained by this reaction is characterized in that it is a solid with a strong Van der Waals force. have.

Polyhydric alcohols or fatty acid partial esters of polyhydric alcohols used in the preparation of semipolar organic boron compounds (borate ester complexes) include, for example, glycerin, diglycerin, triglycerin, polyglycerin such as tetraglycerin, and 14 carbon atoms. Polypentaerythritol such as 1,2-alkanediol, sorbitol, sorbitan, sucrose, pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, trimethylolpropane, polyoxyethylene glycerin, polyoxyethylene Polyhydric alcohols such as sorbitan, polyglycerin higher fatty acid monoesters such as glycerin higher fatty acid monoester, diglycerin higher fatty acid monoester, triglycerin higher fatty acid monoester, tetraglycerin higher fatty acid monoester, sorbitol higher fatty acid monoester, sorbitan higher Polypentaerythritol higher fatty acid mono- or diesters such as fatty acid monoesters, sucrose higher fatty acid mono-esters, pentaerythritol higher fatty acid mono- or diesters, dipentaerythritol higher fatty acid mono- or diesters, tripentaerythritol higher fatty acid mono- or diesters, trimethylolethane Higher fatty acid partial esters of polyhydric alcohols such as higher fatty acid monoesters, trimethylolpropane higher fatty acid monoesters, polyoxyethylene glycerin higher fatty acid monoesters, polyoxyethylene sorbitan higher fatty acid monoesters (as higher fatty acids, for example, hexanoic acid , octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid, oleic acid, erucic acid). Among these, glycerin higher fatty acid monoesters and pentaerythritol higher fatty acid mono- or diesters are preferred.

The basic nitrogen compounds are, for example, N-alkyl-substituted primary, secondary and tertiary amines having at least one linear hydrocarbon group as such or primary and secondary amines having at least one linear hydrocarbon group. A compound obtained by adding ethylene oxide to and binding an N-hydroxyethyl substituent, a compound obtained by reacting a terminal hydroxy group with a linear fatty acid, or ammonia and a linear carbonization The straight-chain 2-hydroxyaliphatic amines formed by reacting with epoxidants of hydrogen, either as such, or by addition of ethylene oxide to primary and secondary linear 2-hydroxyaliphatic amines to form N -A compound to which a hydroxyethyl substituent is attached, or by reacting a polyalkylenepolyamine and a linear fatty acid in a molar ratio such that one amino group in the polyalkylenepolyamine remains, and another amino group are all fatty acid amidated compounds, and as a feature, they are solids with a strong van der Waals force, like semipolar organoboron compounds.

Basic nitrogen compounds (aliphatic amines) include, for example, octylamine, laurylamine, myristylamine, palmitylamine, stearylamine, oleylamine, cocoamine, tallowamine, soyamine, N,N-dicocoamine, N,N-ditallowamine, N,N-disoiamine, N-lauryl-N,N-dimethylamine, N-myristyl-N,N-dimethylamine, N-palmityl-N,N-dimethylamine, N-stearyl-N,N-dimethylamine, N-coco-N,N-dimethylamine, N-tallow-N,N-dimethylamine, N-soy-N,N-dimethylamine, N-methyl-N,N-ditalouamine, N-methyl-N,N -dicocoamine, N-oleyl-1,3-diaminopropane, N-tallow-1,3-diaminopropane, hexamethylenediamine, N-lauryl-N,N,N-trimethylammonium chloride, N-palmityl-N,N , N-trimethylammonium chloride, N-stearyl-N,N,N-trimethylammonium chloride, N-docosyl-N,N,N-trimethylammonium chloride, N-coco-N,N,N-trimethylammonium chloride, N -tallow-N,N,N-trimethylammonium chloride, N-soy-N,N,N-trimethylammonium chloride, N-lauryl-N,N-dimethyl-N-benzylammonium chloride, N-myristyl-N,N -dimethyl-N-benzylammonium chloride, N-stearyl-N,N-dimethyl-N-benzylammonium chloride, N-coco-N,N-dimethyl-N-benzylammonium chloride, N,N-dioleyl-N,N -dimethylammonium chloride, N,N-dicco-N,N-dimethylammonium chloride, N,N-ditallow-N,N-dimethylammonium chloride, N,N-disoy-N,N-dimethylammonium chloride, N,N -bis(2-hydroxyethyl)-N-lauryl-N-methylammonium chloride, N,N-bis(2-hydroxyethyl)-N-stearyl-N-methylammonium chloride, N,N-bis(2-hydroxy ethyl)-N-oleyl-N-methylammonium chloride, N,N-bis(2-hydroxyethyl)-N-coco-N-methylammonium chloride, N,N-bis(polyoxyethylene)-N-lauryl- N-methylammonium chloride, N,N-bis(polyoxyethylene)-N-stearyl-N-methylammonium chloride, N,N-bis(polyoxyethylene)-N-oleyl-N-methylammonium chloride, N, N-bis(polyoxyethylen)-N-coco-N-methylammonium chloride, N,N-bis(2-hydroxyethyl)laurylaminobetaine, N,N-bis(2-hydroxyethyl)tridecylaminobetaine , N,N-bis(2-hydroxyethyl)myristylaminobetaine, N,N-bis(2-hydroxyethyl)pentadecylaminobetaine, N,N-bis(2-hydroxyethyl)palmitylaminobetaine, N, N-bis(2-hydroxyethyl)stearylaminobetaine, N,N-bis(2-hydroxyethyl)oleylaminobetaine, N,N-bis(2-hydroxyethyl)docosylaminobetaine, N,N-bis( 2-hydroxyethyl)octacosylaminobetaine, N,N-bis(2-hydroxyethyl)cocoaminobetaine, N,N-bis(2-hydroxyethyl)tallowaminobetaine, hexamethylenetetramine, N-(2- hydroxyethyl)laurylamine, N-(2-hydroxyethyl)tridecylamine, N-(2-hydroxyethyl)myristylamine, N-(2-hydroxyethyl)pentadecylamine, N-(2-hydroxyethyl)pal mytylamine, N-(2-hydroxyethyl)stearylamine, N-(2-hydroxyethyl)oleylamine, N-(2-hydroxyethyl)docosylamine, N-(2-hydroxyethyl)octacosylamine, N-(2 -hydroxyethyl)cocoamine, N-(2-hydroxyethyl)tallowamine, N-methyl-N-(2-hydroxyethyl)laurylamine, N-methyl-N-(2-hydroxyethyl)tridecylamine, N-methyl -N-(2-hydroxyethyl)myristylamine, N-methyl-N-(2-hydroxyethyl)pentadecylamine, N-methyl-N-(2-hydroxyethyl)palmitylamine, N-methyl-N- (2-hydroxyethyl)stearylamine, N-methyl-N-(2-hydroxyethyl)oleylamine, N-methyl-N-(2-hydroxyethyl)docosylamine, N-methyl-N-(2-hydroxyethyl)octa Cosylamine, N-methyl-N-(2-hydroxyethyl)cocoamine, N-methyl-N-(2-hydroxyethyl)tallowamine, N,N-bis(2-hydroxyethyl)laurylamine, N,N-bis (2-hydroxyethyl)tridecylamine, N,N-bis(2-hydroxyethyl)myristylamine, N,N-bis(2-hydroxyethyl)pentadecylamine, N,N-bis(2-hydroxyethyl) palmitylamine, N,N-bis(2-hydroxyethyl)stearylamine, N,N-bis(2-hydroxyethyl)oleylamine, N,N-bis(2-hydroxyethyl)docosylamine, N,N-bis( N,N-bis(2-hydroxyethyl)aliphatic amines such as 2-hydroxyethyl)octacosylamine, N,N-bis(2-hydroxyethyl)cocoamine, N,N-bis(2-hydroxyethyl)tallowamine mono- or diesters of said N,N-bis(2-hydroxyethyl)aliphatic amines with fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid and erucic acid; polyoxyethylene lauryl; Amino ether, polyoxyethylene aliphatic amino ether such as polyoxyethylene stearyl amino ether, polyoxyethylene oleyl amino ether, polyoxyethylene coco amino ether, polyoxyethylene tallow amino ether, said polyoxyethylene aliphatic amino ether and said Mono- or diesters with fatty acids; N-(lauroyloxyethyl)-N-(stearoyloxyethoxyethyl)stearylamine, N,N,N',N'-tetra(2-hydroxyethyl)-1,6-diaminohexane , N-lauryl-N,N′,N′-tris(2-hydroxyethyl)-1,3-diaminopropane, N-stearyl-N,N′,N′-tris(2-hydroxyethyl)-1, 3-diaminopropane, N-coco-N,N',N'-tris(2-hydroxyethyl)-1,3-diaminopropane, N-tallow-N,N',N'-tris(2-hydroxyethyl )-1,3-diaminopropane, N,N-dicoco-N′,N′-bis(2-hydroxyethyl)-1,3-diaminopropane, N,N-ditallow-N′,N′-bis( 2-hydroxyethyl)-1,3-diaminopropane, N-coco-N,N',N'-tris(2-hydroxyethyl)-1,6-diaminohexane, N-tallow-N,N',N '-Tris(2-hydroxyethyl)-1,6-diaminohexane, N,N-dicoko-N',N'-bis(2-hydroxyethyl)-1,6-diaminohexane, N,N-ditallow- N',N'-bis(2-hydroxyethyl)-1,6-diaminohexane, N-(2-hydroxyethyl)-2-hydroxylaurylamine, N-(2-hydroxyethyl)-2-hydroxymyristylamine , N-(2-hydroxyethyl)-2-hydroxypalmitylamine, N-(2-hydroxyethyl)-2-hydroxystearylamine, N,N-bis(2-hydroxyethyl)-2-hydroxylaurylamine, N,N-bis(2-hydroxyethyl)-2-hydroxymyristylamine, N,N-bis(2-hydroxyethyl)-2-hydroxypalmitylamine, N,N-bis(2-hydroxyethyl)-2 - hydroxystearylamine, 2,2'-bis(lauric acid amide) diethylamine, 2,2'-bis(myristic acid amide) diethylamine, 2,2'-bis(palmitic acid amide) diethylamine, 2,2'-bis (stearamido) diethylamine, N-(2-(lauramido))ethyl-N-(2′-(stearamido))ethylamine, N-(2-(myristateamide))ethyl-N-( 2′-(stearamido))ethylamine, N-(3-(lauramido))propyl-N,N-dimethylamine, N-(3-(myristateamide))propyl-N,N-dimethylamine , N-(3-(palmitamide))propyl-N,N-dimethylamine, N-(3-(stearamido))propyl-N,N-dimethylamine, N-(3-(lauroyloxy) ) propyl-N,N-dimethylamine, N-(3-(myristoyloxy))propyl-N,N-dimethylamine, N-(3-(palmitoyloxy))propyl-N,N-dimethylamine, N- (3-(stearoyloxy))propyl-N,N-dimethylamine, N,N-bis(3-(lauramido)propyl)methylamine, N,N-bis(3-(myristateamido)propyl) methylamine, N,N-bis(3-(palmitamido)propyl)methylamine, N,N-bis(3-(stearamido)propyl)methylamine.

As the basic nitrogen compound, an aliphatic amine represented by formula (2') and an aliphatic amine represented by formula (3') are preferable.

In formulas (2′) and (3′), R ³ and R ⁴ are each independently CH ₃ —, C ₂ H ₅ —, HOCH ₂ —, HOC ₂ H ₄ — or HOCH ₂ CH(CH ₃ )-, R ⁵ is -C ₂ H ₄ - or -C ₃ H ₆ -, and R ⁶ is an alkyl group having 11 to 21 carbon atoms.

The antistatic agent (X) is preferably a donor-acceptor type antistatic agent obtained by reacting a semipolar organic boron compound as a donor component and a basic nitrogen compound as an acceptor component, and has formula (2). Or a donor-acceptor type antistatic agent represented by formula (3) is more preferable.

In formulas (2) and (3), R ¹ and R ² are each independently R ⁷ CO—OCH ₂ — or HOCH ₂ —, and at least one is R ⁷ CO—OCH ₂ —; R ³ and R ⁴ are each independently CH ₃ —, C ₂ H ₅ —, HOCH ₂ —, HOC ₂ H ₄ — or HOCH ₂ CH(CH ₃ )—, and R ⁵ is —C ₂ H ₄ — or —C ₃ H ₆ —, and R ⁶ and R ⁷ are each independently an alkyl group having 11 to 21 carbon atoms.

Specific examples of the antistatic agent (X) are shown in formulas (4) to (11).

Formulas (4) to (11) are donors obtained by reacting the upper semipolar organic boron compound portion as a donor component and the lower tertiary amine portion as an acceptor component at a molar ratio of about 1:1. • It is an acceptor-type antistatic agent. In the above donor component, “δ +” indicates that polarity exists in the covalent bond in the molecule, (+) indicates that the electron donating property of the oxygen atom is strong, and (−) indicates boron. It indicates that the electron-withdrawing property of the atom is strengthened, "→" indicates a path through which electrons are attracted, and "---" indicates a state in which the bonding force between atoms is weakened.

The donor-acceptor type antistatic agent is preferably prepared in advance by mixing and melting a donor component and an acceptor component and allowing them to react before mixing with polyethylene. When the donor component and the acceptor component are separately mixed with the polyethylene without being reacted in advance, there is very little opportunity for the two components to react in the mixture, so that the molecular compound having the above structure is hardly formed. It may be difficult to obtain the desired effect. The mixing molar ratio of the donor component and the acceptor component (donor component:acceptor component) is preferably 1:0.8 to 1:1.25, and the closer to 1:1 the better. With such a mixing molar ratio, the molecular compound is sufficiently formed.

The content of the antistatic agent (X) in the second polyethylene layer is, for example, 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.3%. % by mass or more; preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. The content of the antistatic agent (X) in the second polyethylene layer is, for example, 0.01% by mass or more and 5.0% by mass or less. When the content of the antistatic agent (X) is at least the lower limit, sufficient antistatic properties tend to be obtained. If the content of the antistatic agent (X) is less than the upper limit, the antistatic agent (X) bleeds out to the surface of the sealant layer, and the sealant layer due to the high content of the antistatic agent (X) problems such as deterioration of the mechanical strength of the resin tend not to occur, and the recyclability tends to be high. The content of additives such as antistatic agents can be measured, for example, by the GC/MS method.

Antistatic agent (X) can be added to the second polyethylene layer, for example in the form of a masterbatch comprising polyethylene as base material and antistatic agent (X). The content of the antistatic agent (X) in the masterbatch is preferably 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less, and still more preferably 5% by mass or more and 15% by mass or less. .

A commercially available product may be used as the antistatic agent (X). Specifically, manufactured by Boron Institute, trade name: Biomicel BN-105 (masterbatch of the compound represented by the above formula (2), mC ₄₂ H ₈₁ O ₈ B + nC ₂₃ H ₄₈ ON ₂ , see Product Safety Data Sheet) ) and Biomicel BN-77 (masterbatch of the compound represented by formula (3) above, mC ₄₂ H ₈₁ O ₈ B+nC ₂₃ H ₄₇ O ₂ N, see Product Safety Data Sheet).

The second polyethylene layer may contain one or more additives other than the antistatic agent. Additives include, for example, anti-blocking agents, cross-linking agents, slip agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, pigments, dyes and modifying resins.

<Middle layer>
The sealant layer may further comprise an intermediate layer between the first polyethylene layer and the second polyethylene layer. The intermediate layer preferably contains polyethylene as a main component.

The polyethylene is preferably at least one selected from linear low-density polyethylene, high-pressure low-density polyethylene, medium-density polyethylene, and high-density polyethylene. At least one selected from low-density polyethylene is more preferred, and linear low-density polyethylene is even more preferred. Biomass polyethylene, or mechanically or chemically recycled polyethylene may be used.

Numerical ranges of the MFR and Tm of the polyethylene contained in the intermediate layer include the same numerical ranges as those of the MFR and Tm of the polyethylene contained in the first polyethylene layer, respectively.

The intermediate layer can contain one or more polyethylenes.
The content of polyethylene in the intermediate layer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate of the present disclosure can be improved.

The intermediate layer may contain one or more of the above resin materials other than polyethylene.
The intermediate layer may contain one or more of the above additives.

The intermediate layer may contain an antistatic agent, but preferably contains substantially no antistatic agent. For example, in the intermediate layer, the content of the antistatic agent measured by pyrolysis GC method is preferably 100 ppm or less. Thereby, for example, it is possible to suppress a decrease in adhesion strength between the sealant layer and other layers laminated on the sealant layer.

The intermediate layer may have a single layer structure or a multilayer structure.
The number of layers of the intermediate layer having a multilayer structure is, for example, 2 to 5 layers.

<Deposited film>
The sealant layer may comprise a deposited film formed on the surface of the first polyethylene layer opposite to the surface facing the second polyethylene layer. Thereby, for example, the oxygen barrier property and water vapor barrier property of the sealant layer can be improved. Details of the vapor deposition film will be described later. The surface of the deposited film may be subjected to the surface treatment described above. Thereby, for example, the adhesion strength between the vapor deposition film and other layers stacked on the vapor deposition film can be improved.

<Structure and manufacturing method of sealant layer>
The ratio of the thickness of the first polyethylene layer to the total thickness of the sealant layer is preferably 60% or more and 98% or less, more preferably 65% or more and 95% or less, still more preferably 70% when the intermediate layer is not present. % or more and 90% or less.

The ratio of the thickness of the first polyethylene layer to the total thickness of the sealant layer, when the intermediate layer is present, is preferably 2% or more and 40% or less, more preferably 5% or more and 35% or less, further preferably 10%. % or more and 30% or less.

The ratio of the thickness of the second polyethylene layer to the total thickness of the sealant layer is preferably 2% or more and 40% or less, more preferably 5% or more and 35% or less, still more preferably 10% or more and 30% or less.

The ratio of the thickness of the intermediate layer to the total thickness of the sealant layer is preferably 20% or more and 96% or less, more preferably 30% or more and 90% or less, and still more preferably 40% or more and 80% or less.

The laminate film that constitutes the sealant layer can be produced by a conventionally known method. The laminated film is preferably a co-extruded resin film, and can be produced, for example, by a co-extrusion film-forming method, more preferably by a T-die method or an inflation method.

[Laminate]
The laminate of the present disclosure includes at least a substrate and a sealant layer, the details of which are described above. The sealant layers are arranged such that the first polyethylene layer faces the substrate and the second polyethylene layer constitutes one outermost layer of the laminate. That is, the laminate of the present disclosure includes a substrate, a first polyethylene layer, and a second polyethylene layer in this order in the thickness direction.
Laminates of the present disclosure may comprise an adhesive layer between the substrate and the sealant layer.

3 to 6 show schematic cross-sectional views according to one embodiment of the laminate of the present disclosure.
The laminate 100 of FIG. 3 includes a substrate 20, an adhesive layer 30, and a sealant layer 10 in this order in the thickness direction. The sealant layer 10 is arranged such that the second polyethylene layer 14 constitutes one surface layer of the laminate 100, and the same applies to FIGS. 4-6.
The laminate 100 of FIG. 4 includes a substrate 20, an anchor coat layer 32, an extruded resin layer 30, a metal foil 40, an anchor coat layer 32, an extruded resin layer 30, and a sealant layer 10 in the thickness direction. in this order.
The laminate 100 of FIG. 5 includes a base material 20 having a resin film 22 and a deposited film 24, an adhesive layer 30, a resin film 22, an adhesive layer 30, and a sealant layer 10 in this order in the thickness direction. Prepare. The vapor deposition film including the resin film 22 and the vapor deposition film 24 is arranged so that the resin film 22 constitutes the other surface layer of the laminate 100 , and the vapor deposition film constitutes the substrate 20 .
A laminate 100 of FIG. 6 includes a substrate 20, an anchor coat layer 32, an extruded resin layer 30, and a sealant layer 10 in this order in the thickness direction.
The sealant layer 10 in the laminate 100 of FIGS. 3-6 may further comprise an intermediate layer (not shown) between the first polyethylene layer 12 and the second polyethylene layer 14. FIG.

Laminates of the present disclosure may contain biomass polyethylene. The biomass degree of the laminate of the present disclosure may be, for example, 5% or more and 70% or less, 8% or more and 50% or less, or 10% or more and 40% or less. This makes it possible, for example, to reduce the environmental impact of the laminate or packaging material.

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

In one embodiment, the content of polyethylene in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more. . Since such a laminate uses polyethylene, which is a resin material of the same kind, it can be classified as a so-called mono-material material, and can be suitably used, for example, for producing a mono-material packaging container.

<Base material>
Examples of the substrate include polyolefin films such as polyethylene films and polypropylene films, polyester films such as polyethylene terephthalate films and polyethylene naphthalate films, nylon films, polyimide films, polyvinylidene chloride films, and ethylene-vinyl acetate copolymer films. resin films such as; and paper substrates. The substrate may be, for example, a laminate of resin films, a laminate of paper substrates, or a laminate of a resin film and a paper substrate. Among the resin films, at least one selected from polyester films, nylon films and polyolefin films is preferable because of its excellent mechanical strength, pinhole resistance and the like.

The resin film is preferably a stretched film, and may be a monoaxially stretched film or a biaxially stretched film. By using a stretched film as the resin film, the strength and heat resistance of the substrate can be improved, and the suitability for vapor deposition and printability on the resin film can be improved. Examples include oriented polyethylene terephthalate film, oriented nylon film, oriented polyethylene film and oriented polypropylene film.

The stretching process will be explained. The draw ratio of the stretched film is preferably 2 times or more, more preferably 3 times or more, in the machine direction (MD) of the stretched film. The stretch ratio of the stretched film is, for example, 10 times or less in the MD direction, and may be 7 times or less. The draw ratio of the stretched film is preferably 2 times or more, more preferably 3 times or more, in the direction (TD) perpendicular to the flow direction of the stretched film. The draw ratio of the stretched film is, for example, 10 times or less in the TD direction, and may be 7 times or less.

The haze value of the stretched film is preferably 30% or less, more preferably 20% or less, still more preferably 15% or less. Thereby, the transparency of a stretched film can be improved. The haze value of the stretched film is measured according to JIS K7136.

The resin film may be a multilayer coextruded stretched film. A multilayer coextruded stretched film can be made by stretching a film comprising a plurality of layers. The multi-layer coextruded stretched film includes, for example, a coextruded stretched film comprising a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer in this order.

The thickness of the resin film and the paper substrate is preferably 1 μm or more and 200 μm or less, more preferably 5 μm or more and 100 μm or less, and still more preferably 10 μm or more and 80 μm or less.

The surface of the resin film may be subjected to the surface treatment described above. Thereby, for example, the adhesion strength between the resin film and the layer adjacent to the resin film can be improved.

The base material may be a deposited film including the resin film described above and a deposited film provided on the resin film. Thereby, for example, the oxygen barrier property and water vapor barrier property of the laminate can be improved.

Deposited films include, for example, metals such as aluminum, chromium, tin, nickel, copper, silver, gold, and platinum; or aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, and hafnium oxide. , barium oxide and silicon carbide oxide (carbon-containing silicon oxide). Among these, an aluminum vapor deposition film, an aluminum oxide (alumina) vapor deposition film, a silicon oxide (silica) vapor deposition film, and a carbon-containing silicon oxide vapor deposition film are preferable.

The thickness of the 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 still more preferably 10 nm or more and 40 nm or less. By setting the thickness of the deposited film to 1 nm or more, for example, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. By setting the thickness of the deposited film to 150 nm or less, for example, it is possible to suppress the occurrence of cracks in the deposited film and improve the recyclability of the laminate.

Examples of methods for forming a deposited film include physical vapor deposition (PVD) such as vacuum deposition, sputtering and ion plating; plasma chemical vapor deposition, thermal chemical vapor deposition and photochemical vapor deposition. A chemical vapor deposition method (CVD method) such as a phase growth method can be used. The deposited film may be a composite film including two or more layers of deposited films of different kinds of inorganic oxides, which is formed using both physical vapor deposition and chemical vapor deposition.

The surface of the deposited film may be subjected to the surface treatment described above. Thereby, for example, the adhesion strength between the vapor deposition film and the layer adjacent to the vapor deposition film can be improved.

Examples of vapor-deposited films include vapor-deposited polyester films such as silica-deposited stretched polyethylene terephthalate films and alumina-deposited stretched polyethylene terephthalate films; vapor-deposited nylon films such as silica-deposited stretched nylon films and alumina-deposited stretched nylon films.

For example, when the deposited film is composed of inorganic oxides such as aluminum oxide and silicon oxide, a barrier coat layer may be provided on the surface of the deposited film. That is, the deposited film may include a resin film, a deposited film, and a barrier coat layer in this order in the thickness direction. With such a configuration, for example, the gas barrier properties of the laminate can be improved, and the occurrence of cracks in the deposited film can be effectively suppressed.

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

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. With such a configuration, for example, the gas barrier properties of the barrier coat layer can be improved.

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 setting the thickness of the barrier coat layer to 0.01 μm or more, for example, gas barrier properties can be further improved.

The barrier coat layer can be formed by, for example, dissolving or dispersing a material such as a gas barrier resin in water or a suitable organic solvent, applying the obtained coating liquid, and drying. The barrier coat layer can also be formed by applying and drying a commercially available barrier coat agent.

In another embodiment, the barrier coat layer is a gas barrier obtained by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and adding water, an organic solvent, and a sol-gel catalyst. It is a gas-barrier coating layer formed by coating a vapor-deposited film with a gas-barrier composition and drying it. The gas barrier coating layer contains a hydrolyzed 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 the vapor deposition film, it is possible to effectively suppress the occurrence of cracks in the vapor deposition film. Each of the above components can be used alone or in combination of two or more.

A metal alkoxide is represented by Formula (12), for example.
^R1nM ₍ ^OR2 ) _m (12)
In formula (12), R ¹ and R ² each independently represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, and m is an integer of 1 or more. and n+m represents the valence of M.

Examples of organic groups for R ¹ and R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-hexyl group and Examples thereof include alkyl groups having 1 to 8 carbon atoms such as n-octyl group.
Metal atoms M are, for example, silicon, zirconium, titanium or aluminum.

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

Examples of water-soluble polymers include polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Either one of polyvinyl alcohol and ethylene-vinyl alcohol copolymer may be used, or both may be used in combination, depending on desired physical properties such as oxygen barrier properties, water vapor barrier properties, water resistance, and weather resistance. Alternatively, a gas barrier coating layer obtained using polyvinyl alcohol and a gas barrier coating layer obtained using an ethylene-vinyl alcohol copolymer may be laminated. The amount of the water-soluble polymer used is preferably 5 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the metal alkoxide.

As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used, and organoalkoxysilanes having an epoxy group are preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy Propylmethyldiethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane are included. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the metal alkoxide.

The gas barrier composition may contain water in a proportion of preferably 0.1 mol or more and 100 mol or less, more preferably 0.5 mol or more and 60 mol or less, relative to 1 mol of the metal alkoxide. By making the water content equal to or higher than the lower limit, for example, the oxygen barrier properties and water vapor barrier properties of the laminate can be improved. By making the water content equal to or less than the upper limit, for example, the hydrolysis reaction can be carried out quickly.

Examples of organic solvents used for preparing gas barrier compositions include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol and n-butyl alcohol.

As the sol-gel process catalyst, an acid or amine compound is preferable.
Acids include, for example, 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 to be used is preferably 0.001 mol or more and 0.05 mol or less per 1 mol of the total molar amount of the alkoxide portion (for example, silicate portion) of the metal alkoxide and the silane coupling agent.

Amine compounds include, for example, N,N-dimethylbenzylamine, tripropylamine, tributylamine and tripentylamine. The amount of the amine compound used is preferably 0.01 parts by mass or more and 1.0 parts by mass or less with respect to 100 parts by mass of the total amount of the metal alkoxide and the silane coupling agent.

Examples of the method of applying the gas barrier composition include application means such as roll coating such as gravure roll coater, spray coating, spin coating, dipping, brush, bar coating and applicator.

An embodiment of the method for forming the gas barrier coating layer will be described below.
A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and optionally a silane coupling agent. A polycondensation reaction proceeds gradually in the composition. The above composition is applied onto the deposited film by a conventional method and dried. This drying further promotes polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains a silane coupling agent) to form a composite polymer layer. The above operation may be repeated to laminate a plurality of composite polymer layers. For example, the applied composition is heated at a temperature of preferably 20° C. to 150° C., more preferably 50° C. to 120° C., still more preferably 50° C. to 100° C. for 1 second to 10 minutes. Thereby, a gas barrier coating layer can be formed.

The thickness of the gas barrier coating 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, and still more preferably 0.1 μm or more and 2.0 μm or less. Thereby, for example, the gas barrier property can be improved, and the occurrence of cracks in the deposited film can be suppressed.

A laminate of the present disclosure may comprise two or more substrates. For example, it may be a laminate comprising a deposited film as a first base material, a resin film as a second base material, and a sealant layer in this order in the thickness direction. , a vapor-deposited film as a second base material, and a sealant layer in this order in the thickness direction.

<Metal foil>
A laminate of the present disclosure may comprise a metal foil. Thereby, for example, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. As the metal foil, conventionally known metal foils can be used, and examples thereof include metal foils composed of metals such as aluminum and magnesium. Aluminum foil is preferable from the viewpoint of gas barrier properties that prevent permeation of oxygen gas and water vapor, and light shielding properties that prevent permeation of visible light, ultraviolet rays, and the like.

The thickness of the metal foil is preferably 3 μm or more and 100 μm or less, more preferably 5 μm or more and 25 μm or less. By setting the thickness of the metal foil to 3 μm or more, for example, the oxygen barrier properties and water vapor barrier properties of the laminate can be further improved.
The metal foil can be laminated via an adhesive layer, for example.

<Design layer>
The laminate of the present disclosure may further include a design layer such as a printed layer on the substrate.
The design layer has an image. Images include, for example, characters, graphics, patterns, symbols, and combinations thereof. The image may include textual information such as the product name, the name of the contents in the package, the manufacturer, and the name of the ingredients. The image may be a solid monochrome image (so-called solid image).

In one embodiment, the design layer contains one or more colorants.
Examples of coloring agents include pigments such as inorganic pigments and organic pigments; dyes such as acid dyes, direct dyes, disperse dyes, oil-soluble dyes, metal-containing oil-soluble dyes, and sublimation dyes. Further, examples of the coloring agent include fluorescent light-emitting materials such as ultraviolet light-emitting materials that emit fluorescence by absorbing ultraviolet rays and infrared light-emitting materials that emit fluorescence by absorbing infrared rays.

The content of the colorant in the design layer is preferably 1% by mass or more and 90% by mass or less, more preferably 3% by mass or more and 70% by mass or less, and still more preferably 5% by mass or more and 50% by mass or less.

The design layer may contain a resin material and may contain an additive.
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.

The design layer can be formed, for example, using an ink composition containing the components described above and, if necessary, a solvent. Examples of methods for forming the design layer include gravure printing, offset printing, flexographic printing, screen printing, letterpress printing and transfer printing. In one embodiment, a flexographic printing method may be used from the viewpoint of reducing environmental load.

The thickness of the design layer is preferably 0.1 μm or more and 10 μm or less, more preferably 0.2 μm or more and 5.0 μm or less, and still more preferably 0.3 μm or more and 3.0 μm or less.

<Adhesive layer>
Laminates of the present disclosure may comprise an adhesive layer between the substrate and the sealant layer. Examples of the adhesive layer include an extruded resin layer containing polyethylene as a main component and an adhesive layer composed of an adhesive.

In one embodiment, the laminate of the present disclosure includes at least one of the following: between the substrate and the sealant layer, between the substrates, between the substrate and the metal foil, and between the metal foil and the sealant layer. First, it has an extruded resin layer containing polyethylene as a main component. The extruded resin layer functions as an adhesive layer between the two.

By providing an extruded resin layer containing polyethylene as a main component in the laminate of the present disclosure as the adhesive layer, compared with the case where a conventional non-polyethylene adhesive (for example, a two-liquid curing polyurethane adhesive) is used. As a result, the content of polyethylene in the laminate can be made higher. Thereby, the recyclability of the laminate can be further improved.

The extruded resin layer contains polyethylene as a main component. Details of the polyethylene are as described above. The polyethylene in the extruded resin layer and the polyethylene in the sealant layer may be the same or different.

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 ultra-low-density polyethylene from the viewpoint of adhesiveness. More preferred is polyethylene or linear low density polyethylene. Biomass polyethylene, or mechanically or chemically recycled polyethylene may be used.

The melt flow rate (MFR) of polyethylene constituting the extruded resin layer is preferably 0.1 g/10 minutes or more and 50 g/10 minutes or less, more preferably 0.2 g/10 minutes, from the viewpoint of film-forming properties, processability, etc. minutes or more and 30 g/10 minutes or less, more preferably 3.0 g/10 minutes or more and 20 g/10 minutes or less.

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, still more preferably 100° C. or higher, from the viewpoint of the balance between heat resistance and adhesiveness. 120° C. or less.

The extruded resin layer can 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 still more preferably 95% by mass or more. With such a configuration, for example, adhesion and recyclability can be improved.

The extruded resin layer may contain biomass polyethylene. The biomass degree of the extruded resin layer may be, for example, 30% or more, 50% or more, or 70% or more. Although the upper limit of the biomass degree is not particularly limited, it may be, for example, 99% or 98%.

The extruded resin layer may contain an antistatic agent, but preferably contains substantially no antistatic agent. For example, in the extruded resin layer, the content of the antistatic agent measured by the pyrolysis GC method is preferably 100 ppm or less. Thereby, for example, a decrease in interlayer adhesion strength in a laminate including a sealant layer containing an antistatic agent can be suppressed.

In the laminate of the present disclosure, the thickness of the extruded resin layer 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. This can improve adhesion and recyclability, for example.

The extruded resin layer can be formed, for example, by melting polyethylene or a polyethylene composition and extruding it onto a substrate or metal foil. The melting temperature at this time is, for example, 280° C. or higher and 340° C. or lower, preferably 290° C. or higher and 335° C. or lower.

In the present disclosure, as a method of bonding a base material and a laminated film as a sealant layer, a base material to each other, a base material and a metal foil, or a metal foil and a laminated film, for example, polyethylene is contained as a main component. A melt extrusion lamination method, particularly a sand lamination method, using a melted resin can be used. Thereby, the polyethylene content ratio of the laminate can be increased. In addition, the time required for the drying process and the aging process can be reduced compared to the case of laminating these by dry lamination, for example, so that the production efficiency of the laminate can be improved.

In one embodiment, the laminate of the present disclosure includes at least one of the following: between the substrate and the sealant layer, between the substrates, between the substrate and the metal foil, and between the metal foil and the sealant layer. One is an adhesive layer composed of an adhesive. Thereby, for example, the adhesion strength between the two can be improved.

The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may be a solvent-type adhesive or a non-solvent-type 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. Solvent-free adhesives include, for example, 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-liquid curing urethane-based adhesives are more preferred.

Examples of adhesive coating methods include a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a fonten method and a transfer roll coating method.

In the laminate of the present disclosure, the thickness of the adhesive layer composed of the adhesive is preferably 0.1 μm or more and 10 μm or less, more preferably 0.2 μm or more and 8 μm or less, and still more preferably 0.5 μm or more and 6 μm or less. is.

The laminate of the present disclosure is obtained by laminating a substrate and a laminated film as a sealant layer, between substrates, between a substrate and a metal foil, or between a metal foil and a laminated film by a lamination method using the above adhesive. It can be produced by laminating, for example, it may be produced by laminating by a dry lamination method using a solvent-based adhesive, or by laminating by a non-solvent lamination method using a solvent-free adhesive. good.

<Anchor coat layer>
When the laminate of the present disclosure includes an extruded resin layer as an adhesive layer, it may further include an anchor coat layer between the substrate or metal foil and the extruded resin layer. Thereby, for example, the adhesion between layers in the laminate can be improved. The anchor coat layer is formed of, for example, an anchor coat agent. In this embodiment, the extruded resin layer is in contact with the anchor coat layer.

Examples of anchor coating agents include polyurethane, polyolefin, polyethyleneimine, and epoxy resin anchor coating agents. In one embodiment, the anchor coating agent is a two-pack curing resin, and is composed of, for example, polyol as a main agent and polyisocyanate as a curing agent.

Polyols include, for example, polyether polyols, polyester polyols and (meth)acrylic polyols. Polyisocyanates include, for example, aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate.

The anchor coat layer consists in one embodiment of a polyurethane obtained by reacting a polyol with a polyisocyanate. Polyurethanes specifically include polyether polyurethanes, polyester polyurethanes and poly(meth)acrylic polyurethanes.

The anchor coat layer can be formed, for example, by applying an anchor coat agent to the substrate or metal foil. The anchor coating agent can be applied, for example, by a coating method such as a roll coating method, a gravure roll coating method and a kiss coating method, or a printing method.

The thickness of the anchor coat layer is preferably 0.05 μm or more and 3.0 μm or less, more preferably 0.1 μm or more and 2.0 μm or less, and still more preferably 0.2 μm or more and 1.0 μm or less.

<Sealant layer>
A laminate of the present disclosure comprises a sealant layer. Since the sealant layer has already been explained in detail, the description in this column is omitted.

<Layer structure>
As the layer structure of the laminate of the present disclosure, for example,
1. base material/adhesive layer/sealant layer,
2. base material/adhesive layer/metal foil/adhesive layer/sealant layer,
3. substrate/adhesive layer/substrate/adhesive layer/sealant layer,
4. base material/adhesive layer/base material/adhesive layer/metal foil/adhesive layer/sealant layer,
5. base material/adhesive layer/metal foil/adhesive layer/base material/adhesive layer/sealant layer,
are mentioned. "/" indicates an interlayer.

The substrate in the example of the above layer structure may be a resin film, a paper substrate, or a deposited film. The adhesive layer in the example of the above layer structure may be an extruded resin layer or an adhesive layer. A design layer may be provided on one surface of the substrate. When the adhesive layer is an extruded resin layer, an anchor coat layer may be provided between the extruded resin layer and the substrate or metal foil.

In one embodiment, the haze of the laminate of the present disclosure may be 15% or less, 13% or less, or 12% or less. Although the lower limit of haze is not particularly limited, it may be, for example, 1%. Thereby, the transparency of the laminate can be improved. The haze of the laminate is measured according to JIS K7136.

[Use]
The laminate of the present disclosure can be suitably used as a packaging material that constitutes a packaging container. The second polyethylene layer in the laminate constitutes the inner surface of the packaging container (the surface with which the contents in the packaging container come into contact). The second polyethylene layer has high antistatic properties against static electricity and other instantaneous charges and even in a low humidity environment.

A packaging container comprises the laminate of the present disclosure. Packaging containers include, for example, packaging bags, tube containers, and containers with lids. A lidded container includes a container body having an accommodating portion, and a lid member joined (heat-sealed) to the container body so as to seal the accommodating portion.

A packaging container usually has a heat-sealed portion (heat-sealed portion). Methods of heat sealing include, for example, bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing and ultrasonic sealing.

As packaging bags, for example, standing pouch type, side seal type, two side seal type, three side seal type, four side seal type, envelope pasted seal type, palm pasted seal type (pillow seal type), plaited seal type, flat bottom seal. There are various types of packaging bags such as type, square bottom seal type and gusset type.

The packaging bag may be provided with an easy-to-open portion. The easy-to-open portion includes, for example, a notch portion serving as a starting point for tearing the packaging bag, and a half-cut line formed by laser processing, a cutter, or the like as a path for tearing the packaging bag.

In one embodiment, the laminate of the present disclosure is folded in half so that the base material is located outside and the sealant layer is located inside, and the edges and the like are heat-sealed to produce a packaging bag. . In another embodiment, a packaging bag can be produced by stacking a plurality of laminates of the present disclosure such that the sealant layers face each other and heat-sealing the ends and the like. The entire packaging bag may be composed of the laminate, or part of the packaging bag may be composed of the laminate.

In one embodiment, the laminate of the present disclosure is used as a lid material in a lidded container.

Contents contained in packaging containers include, for example, liquids, solids, powders, and gels. The contents may be food or drink, or may be non-food or drink such as chemicals, cosmetics, and pharmaceuticals. Since the packaging container of the present disclosure has excellent antistatic properties, powders such as powdered foods (e.g., furikake, fried chicken powder), powdered drugs, and powdered beverages (e.g., coffee, tea) are suitable. . After containing the contents in the packaging container, the packaging container can be sealed by heat-sealing the opening of the packaging container.

The contents may be, for example, electronic parts such as integrated circuits (ICs), capacitors and semiconductor elements, and precision machine parts. That is, the packaging container may be an electronic component container or a precision machine component container. 2. Description of the Related Art In recent years, electronic components have become smaller and more sophisticated, and damage to electronic components due to slight static electricity during storage or transportation of electronic components has become a problem. Since the laminate of the present disclosure has excellent antistatic properties as described above, it is suitable as a packaging material that constitutes an electronic component container. The electronic component container can be manufactured by various molding methods such as vacuum pressure molding, vacuum molding, pressure molding, and plug assist molding.

As specific examples of packaging bags, small bags and standing pouches will be described below.
A sachet is a small packaging bag, and is used to contain, for example, 1 g or more and 200 g or less of contents. Examples of contents contained in small bags include powders such as powdered foods (e.g. furikake, fried chicken powder), powdered medicines, powdered beverages (e.g. coffee, tea); sauces, soy sauce, dressings, ketchup, syrup , cooking alcoholic beverages, other liquid or viscous seasonings; liquid soups, powdered soups, fruit juices; spices; liquid drinks, jelly-like drinks, instant foods, and other foods and drinks.

Standing pouches are used, for example, to contain contents of 50 g or more and 2000 g or less. Contents contained in the standing pouch include, for example, shampoo, rinse, conditioner, hand soap, body soap, fragrance, deodorant, deodorant, insect repellent, detergent; dressing, edible oil, mayonnaise, and others. Liquid or viscous seasonings; liquid beverages, jelly-like beverages, instant foods, other foods and drinks; and creams.

FIG. 7 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. The packaging bag 50 of FIG. 7 includes a storage portion 50a that stores contents. The packaging bag 50 includes an upper portion 51, a lower portion 52 and side portions 53, and has a substantially rectangular outline in front view. Names such as “upper”, “lower” and “side” and terms such as “upper” and “lower” refer to relative positions and directions of the packaging bag 50 and its components. It's nothing more than The orientation and the like of the packaging bag 50 during transport and use are not limited by the names and terms in this specification.

As shown in FIG. 7, the packaging bag 50 includes a top sheet 54 forming the front side and a back sheet 55 forming the back side. In the packaging bag 50 shown in FIG. 7, the top sheet 54 and the back sheet 55 are formed of one laminated body. At this time, the laminate is folded back at the lower portion 52 so that the sealant layer is positioned inside the packaging bag 50 . Although not shown, in the packaging bag 50, each of the topsheet 54 and the backsheet 55 may be formed by stacking one sheet each. In this case, the packaging bag 50 has seal portions extending along four edges of the packaging bag 50 .

The inner surfaces of the top sheet 54 and the back sheet 55 are joined together by a sealing portion. In the front view of the packaging bag 50 shown in FIG. 7, the sealing portion is hatched.

As shown in FIG. 7 , the packaging bag 50 has seal portions extending along edges in three directions of the packaging bag 50 . The seal portion includes an upper seal portion 51a extending along the upper portion 51 and a pair of side seal portions 53a extending along a pair of side portions 53. As shown in FIG. An opening (not shown) is formed in the upper portion 51 of the packaging bag 50 before it is filled with the contents (not filled with the contents). After the contents are accommodated in the packaging bag 50, the inner surface of the top sheet 54 and the inner surface of the back sheet 55 are joined together at the upper portion 51 to form the upper sealing portion 51a and the packaging bag 50 is sealed. .

The upper seal portion 51a and the side seal portion 53a are seal portions formed by joining the inner surface of the top sheet 54 and the inner surface of the back sheet 55 together.

As long as the facing sheets 54 and 55 can be joined together to seal the packaging bag 50, the method for forming the seal portion is not particularly limited. For example, the inner surface of the sheet is melted by heating, etc., and the inner surfaces are fused together, that is, by heat sealing, to form the sealed portion.

The present disclosure relates to, for example, the following [1] to [7].
[1] A laminate comprising at least a substrate and a sealant layer, wherein the sealant layer comprises at least a first polyethylene layer and a second polyethylene layer, the second polyethylene layer being a main component A laminate comprising polyethylene and a donor-acceptor antistatic agent, wherein the second polyethylene layer constitutes one surface layer of the laminate.
[2] The laminate according to [1] above, wherein the donor-acceptor antistatic agent contains a semipolar organic boron compound as a donor component and a basic nitrogen compound as an acceptor component.
[3] The laminate according to [1] or [2] above, wherein the content of the donor-acceptor antistatic agent in the second polyethylene layer is 0.01% by mass or more and 5.0% by mass or less.
[4] The first polyethylene layer contains at least one polyethylene selected from linear low-density polyethylene, high-pressure low-density polyethylene, medium-density polyethylene and high-density polyethylene, and the second polyethylene layer comprises The laminate according to any one of [1] to [3] above, wherein the polyethylene comprises at least one type of polyethylene selected from linear low-density polyethylene and high-pressure low-density polyethylene.
[5] The laminate according to any one of [1] to [4] above, which has a haze of 15% or less as measured according to JIS K7136.
[6] The second polyethylene layer side surface has a half-life of 10 seconds or less as measured by a static voltage decay test, and a surface specific resistivity of the second polyethylene layer side surface is 1.0×10 ⁸ Ω. / □ or more and 9.0×10 ¹¹ Ω/□ or less, the laminate according to any one of the above [1] to [5].
[7] A packaging container comprising the laminate according to any one of [1] to [6] above.

The laminate of the present disclosure will be described in more detail based on examples, but the laminate of the present disclosure is not limited by the examples.

[Evaluation of the physical properties]
Methods for evaluating physical properties of laminated films and laminates obtained in the following examples are described below.

<Surface resistivity>
The laminated film and laminated body were allowed to stand for 24 hours in an environment with a temperature of 23° C. and a relative humidity of 50% RH. After that, the surface specific resistivity was measured according to JIS K6911:1995. Specifically, using a resistivity meter (trade name: Hiresta-UX MCP-HT800, manufactured by Nitto Seiko Analytic Tech), under the condition of an applied voltage of 1,000 V, the surface specific of the seal layer surface of the laminated film and laminate Resistivity (Ω/□) was measured. The environment during the measurement of the surface specific resistivity was a temperature of 23° C. and a relative humidity of 50% RH.

<Half-life (charged voltage decay test)>
The laminated film and laminated body were allowed to stand for 24 hours in an environment with a temperature of 23° C. and a relative humidity of 50% RH. After that, charging voltage attenuation measurement was performed in accordance with JIS L1094:2014. Specifically, using a static charge decay meter (trade name: STATIC HONESTMETER H-0110-S4A, manufactured by Shishido Electrostatic), a voltage of 10 kV was applied for 30 seconds to the sealing layer surface of the laminated film and laminate, After the voltage was applied, the time (seconds) until the initial charged voltage became 1/2 was measured. The environment during the withstand voltage decay test was a temperature of 23° C. and a relative humidity of 50% RH.

<Haze>
A 21 mm square test piece was prepared by cutting each of the laminated film and the laminate. The haze of the test piece was measured using a haze meter (manufactured by Murakami Color Research Laboratory, trade name: haze meter HM-150N, D65 light source) in accordance with JIS K7136.

<Tensile breaking strength and tensile breaking elongation>
The tensile strength at break and tensile elongation at break of the laminated film were measured in the MD and TD directions of the laminated film in accordance with JIS Z1702:1994. As a measuring instrument, a Tensilon universal material testing machine (manufactured by Orientec, trade name: RTC-1530) was used. As the test piece, a dumbbell-shaped cut out of the laminated film was used. The measurement width of the test piece is 5 mm, the distance between the pair of chucks holding the test piece at the start of measurement is 80 mm, and the tensile speed is 300 mm/min. The environment during the measurement of tensile strength at break and tensile elongation at break was temperature of 23° C. and relative humidity of 50% RH.

<Puncture Strength>
The puncture strength of the laminated film was measured according to JIS Z1707:2019. As a measuring instrument, a tabletop tension/compression tester MCT1150 manufactured by A&D Co., Ltd. was used. The film was cut into 5 cm squares, pierced with a semicircular needle with a diameter of 1.0 mm and a tip shape radius of 0.5 mm at a test speed of 50 mm/min, and the maximum force (N) until the needle penetrated was measured. The environment during the measurement was a temperature of 23° C. and a relative humidity of 50% RH.

<Impact strength>
The impact strength of the laminated film was measured according to ASTM D3420. A film impact tester BU-302 manufactured by Tester Sangyo Co., Ltd. was used as a measuring instrument. Specifically, first, as shown in FIG. 8, a test piece 80 was sandwiched between ring-shaped jigs 81 and 82 and fixed. Next, as shown in FIG. 9, the fixed test piece 80 is placed, the arm portion 84 is swung down around the fulcrum portion 83, and the conical indenter 85 at the tip of the arm portion 84 breaks through the test piece 80, The strength when breaking through was measured. The diameter of the indenter 105 was about 1 inch (about 25.4 mm), the load was about 30 kg·cm, and the lifting angle of the arm was about 90°. The environment during impact strength measurement was a temperature of 23° C. and a relative humidity of 50% RH.

<Workability>
The workability of the laminated film was evaluated according to the following criteria.
- O: Workability was good.
* x: Processability was not enough.

<TOC elution amount>
Using the laminate, a pouch having an area of 44 × 15 cm ² was prepared, filled with 1 L of distilled water at 65°C, left to stand at a temperature of 35°C for 336 hours, and then all the water in the pouch was removed. It was measured with an organic carbon automatic analyzer (TOC200S, Toray Engineering).

<Outgas>
Eight test pieces obtained by cutting the laminated film into a size of 5 cm × 5 cm were sealed in a vial, treated at an HS temperature of 120 ° C., a loop temperature of 140 ° C., and a TR-LINE temperature of 140 ° C., and the air in the head space was removed. 1 ml of the solution was introduced, the temperature was raised to 320° C., and the components were measured by a headspace gas chromatography (HS-GC) when the temperature was maintained for 5 minutes.
Measurement device: carried out with Agilent 6890 Carrier gas: He

<Seal strength>
Two laminates were prepared. The sealant layers (laminated films) of two laminates are superimposed and heat-sealed under the conditions of a temperature of 120°C, 130°C, 140°C or 150°C, a crimping time of 1 second, and a pressure of 1 kgf/ ^cm2 . formed. Subsequently, a portion including the seal portion was cut out to prepare a test piece having a width of 15 mm and a length of 100 mm for measuring the seal strength. The length of the seal portion was 15 mm. Based on JIS Z1707:2019, the seal strength was measured under the conditions of a test speed of 300 mm/min and T-shaped peeling. As a measuring instrument, a Tensilon universal material testing machine (manufactured by Orientec, trade name: RTC-1530) was used. The environment during the measurement of the seal strength was a temperature of 23° C. and a relative humidity of 50% RH.

[Preparation of laminated film (sealant film)]
The ingredients used in the examples below are shown.
・LLDPE (1)
Linear low-density polyethylene, made of prime polymer, trade name: UZ2021L,
Density: 0.919 g/cm ³ Melting point: 120° C. MFR: 2.0 g/10 min LLDPE (2)
Linear low density polyethylene, manufactured by Dowchemical,
Product name: ELITE5400G,
Density: 0.916 g/cm ³ Melting point: 123° C. MFR: 1.0 g/10 min・bio-LLDPE
Plant-derived linear low-density polyethylene, manufactured by Braskem, trade name: SLL118,
Density: 0.916 g/cm ³ , MFR: 1.0 g/10 minutes

・Antistatic agent MB (1)
antistatic agent-containing masterbatch,
Boron Laboratory, trade name: Biomicelle BN-105,
Antistatic agent content: 10% by mass, base material: low density polyethylene (LDPE)
・Antistatic agent MB (2)
antistatic agent-containing masterbatch,
Boron Laboratory, trade name: Biomicelle BN-77,
Antistatic agent content: 10% by mass, base material: low density polyethylene (LDPE)
・Antistatic agent (3)
Polymer type antistatic agent, manufactured by Sanyo Chemical Industries, trade name: Plectron PVL,
Polyolefin/polyether copolymer, melting point: 135°C, MFR: 15 g/10 min Antistatic agent (4)
polymeric antistatic agents,
Mitsui Dow Polychemicals, trade name: Entira SD100,
Ionomer resin, density: 0.990 g/cm ³ , MFR: 5 g/10 min Antistatic agent MB (5)
antistatic agent (surfactant) containing masterbatch,
Takemoto oil, product name: ELECUT MASTER LM530,
Density: 0.920 g/cm ³ , MFR: 2.1 g/10 minutes,
Base material: low density polyethylene,
Antistatic agent content: 18% by mass

[Example 1-1]
LLDPE (1) as a laminate layer and a mixture of 97% by mass of LLDPE (2) and 3% by mass of antistatic agent MB (1) as a sealing layer were co-extruded into a film by inflation molding. As a result, a laminate film having a thickness of 50 μm and including a laminate layer having a thickness of 40 μm and a seal layer having a thickness of 10 μm was obtained. The laminate layer surface of the laminate film was subjected to corona treatment so that the wetness index was 48 dyn. This laminated film is hereinafter also referred to as "laminated film (A1)".

[Examples 1-2 to 1-8, Comparative Examples 1-1 to 1-6]
Example 1 except that at least one of the types and content of the ingredients in the seal layer, the thickness of the laminate layer, and the thickness of the seal layer were changed as described in Table 1-1 or Table 1-2. A laminated film was produced in the same manner as in -1. In Tables 1-1 and 1-2, the numerical value of each component in each layer indicates the content (% by mass).

[Example 2-1]
LLDPE (1) as a laminate layer, bio-LLDPE as an intermediate layer, and a mixture of 97% by mass of LLDPE (2) and 3% by mass of an antistatic agent MB (1) as a seal layer are co-extruded into a film by an inflation molding method. did. As a result, a laminated film with a thickness of 50 μm was obtained, which includes a laminate layer with a thickness of 10 μm, an intermediate layer with a thickness of 30 μm, and a sealing layer with a thickness of 10 μm in this order. The biomass degree was 52.2%. The laminate layer surface of the laminate film was subjected to corona treatment so that the wetness index was 48 dyn. This laminated film is hereinafter also referred to as "laminated film (A2)".

[Examples 2-2 to 2-4, Comparative Examples 2-1 to 2-3]
A laminated film was produced in the same manner as in Example 2-1, except that the types and content of the ingredients in the sealing layer were changed as shown in Table 2. In Table 2, the numerical value of each component in each layer indicates the content (% by mass).

[Preparation of laminate]
[Example 3-1]
A biaxially oriented PET film (manufactured by Toyobo Co., Ltd., T4100, thickness 12 μm) having one side subjected to corona treatment, an aluminum foil (manufactured by Toyo Aluminum Co., Ltd., JIS alloy number A8079, thickness 7 μm), and a laminated film (A1) were prepared. .

A two-component curing anchor coating agent (polyurethane adhesive, A3210/A3075, manufactured by Mitsui Chemicals) was applied to the corona-treated surface of the biaxially stretched PET film to a dry thickness of 0.3 μm, and the coated surface and aluminum foil were bonded together. , an extruded resin layer (thickness: 15 ^μm ). Next, the two-liquid curing anchor coating agent (A3210/A3075) was applied to the non-laminated surface of the aluminum foil to a dry thickness of 0.3 μm, and the coated surface and the corona-treated surface of the laminated film (A1) were separated by 300°C. The extruded resin layer (thickness: 15 µm) of the low-density polyethylene (LC602A) melted at °C was interposed between them.

As described above, a 12 μm thick biaxially stretched PET film, a 0.3 μm thick anchor coat layer, a 15 μm thick LDPE layer, a 7 μm thick aluminum foil, and a 0.3 μm thick A laminate comprising an anchor coat layer, a 15 μm-thick LDPE layer, and a 50 μm-thick laminated film (A1) as a sealant layer was obtained.

[Examples 3-2 to 3-4, Comparative Examples 3-1 to 3-3]
A laminate was produced in the same manner as in Example 3-1, except that the laminated film (A1) was changed to the laminated film shown in Table 3.

[Example 4-1]
A biaxially stretched PET film (hereinafter also referred to as “transparent vapor deposited PET film”; thickness 12 μm) in which a barrier coat layer is formed on the vapor deposited layer and an alumina-deposited biaxially stretched PET film (Toyobo E5200, thickness 12 μm) and a laminated film (A1) were prepared.

An adhesive layer with a thickness of 3 μm composed of a two-component curable urethane adhesive (RU-77T/H-7, manufactured by Rock Paint) was applied to the barrier coat layer surface of the transparent vapor-deposited PET film and the biaxially stretched PET film. pasted together through Next, the non-laminated surface of the biaxially stretched PET film and the corona-treated surface of the laminated film (A1) were bonded together with the above two-liquid curing urethane adhesive (RU-77T/H-7) having a thickness of 3 μm. were laminated via an adhesive layer.

As described above, a transparent vapor-deposited PET film with a thickness of 12 μm, an adhesive layer with a thickness of 3 μm, a biaxially stretched PET film with a thickness of 12 μm, an adhesive layer with a thickness of 3 μm, and a sealant layer with a thickness of A laminate comprising a 50 μm laminated film (A1) was obtained.

[Examples 4-2 to 4-4, Comparative Examples 4-1 to 4-3]
A laminate was produced in the same manner as in Example 4-1, except that the laminated film (A1) was changed to the laminated film shown in Table 4.

[Examples 5-1 to 5-4, Comparative Examples 5-1 to 5-3]
A laminate was produced in the same manner as in Example 3-1, except that the laminated film (A1) was changed to the laminated film shown in Table 5. The biomass degree of the laminate was 26%.

[Examples 6-1 to 6-4, Comparative Examples 6-1 to 6-3]
A laminate was produced in the same manner as in Example 4-1, except that the laminated film (A1) was changed to the laminated film shown in Table 6. The biomass degree of the laminate was 33%.

10... Sealant layer (laminated film)
DESCRIPTION OF SYMBOLS 12... 1st polyethylene layer 14... 2nd polyethylene layer 16... Intermediate layer 20... Base material 22... Resin film 24... Vapor-deposited film 30... Adhesive layer (extruded resin layer or adhesive layer)
32... Anchor coat layer 40... Metal foil 100... Laminate

Claims (7)

A laminate comprising at least a substrate and a sealant layer,
The sealant layer is
a first polyethylene layer;
at least a second polyethylene layer;
The second polyethylene layer is
polyethylene as the main component;
Containing a donor-acceptor type antistatic agent,
The second polyethylene layer constitutes one surface layer of the laminate,
laminate. 2. The laminate according to claim 1, wherein the donor-acceptor antistatic agent contains a semipolar organoboron compound as a donor component and a basic nitrogen compound as an acceptor component. The laminate according to claim 1 or 2, wherein the content of the donor-acceptor antistatic agent in the second polyethylene layer is 0.01% by mass or more and 5.0% by mass or less. The first polyethylene layer contains at least one polyethylene selected from linear low density polyethylene, high pressure low density polyethylene, medium density polyethylene and high density polyethylene,
The second polyethylene layer contains, as the polyethylene, at least one type of polyethylene selected from linear low-density polyethylene and high-pressure low-density polyethylene,
The laminate according to any one of claims 1-3. The laminate according to any one of claims 1 to 4, which has a haze of 15% or less as measured according to JIS K7136. The second polyethylene layer side surface has a half-life measured by a static voltage decay test of 10 seconds or less, and the second polyethylene layer side surface has a surface specific resistivity of 1.0×10 ⁸ Ω/. 6. The laminate according to any one of claims 1 to 5, wherein the resistance is □ or more and 9.0×10 ¹¹ Ω/□ or less. A packaging container comprising the laminate according to any one of claims 1 to 6.