Stacked body and packaging container

Abstract

The present application provides a laminate which is used in a case where contents filled in a packaging container using the laminate are greatly deteriorated due to the influence of humidity but not greatly deteriorated due to the influence of oxygen, and which is excellent in manufacturing cost reduction and reusability after use. The laminate of the present application is characterized in that the laminate has at least a first base material layer, a water vapor barrier layer, and a heat seal layer and is sequentially laminated from the outside toward the inside, and the first base material layer and the heat seal layer are composed of a polyolefin.

Description

Technical Field

[0001] This invention relates to laminates for manufacturing packaging containers and the like. Furthermore, it relates to packaging containers using said laminates. Background Technology

[0002] In the past, flexible resin packaging containers made in various ways were proposed for filling and packaging various beverages, foods, liquid detergents, cosmetics, medicines, groceries, industrial materials and other items.

[0003] For example, Patent Document 1 proposes a laminate containing a polyolefin of polyethylene or polypropylene as a sealant layer and including a light-shielding printing layer and a barrier coating, as well as a packaging bag using the laminate, which not only has the required strength and heat resistance during use, but also has excellent reusability and gas barrier properties after use from an environmental perspective.

[0004] Regarding gas barrier properties, when storing packaging containers in a normal atmospheric environment, it is important to focus on both oxygen and water vapor barrier properties. Furthermore, when the contents of the packaging container are common foods or other substances that are easily deteriorated or spoiled by atmospheric oxygen and humidity, both oxygen and water vapor barrier properties must be emphasized. However, when the contents are powders such as sugar, salt, or sports drink powders, which are significantly deteriorated or spoiled by humidity but not by oxygen, high water vapor barrier properties are sufficient, and high oxygen barrier properties are not required.

[0005] While emphasizing both oxygen and water vapor barrier properties, the use of high-barrier coatings, such as the barrier coating formed by a barrier coating film as described in Patent Document 1, has its limits in reducing the manufacturing cost of packaging containers. Furthermore, if the contents of the packaging container only require high water vapor barrier properties, the use of such barrier coatings results in excessive barrier properties, leading to a manufacturing cost exceeding the required level.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2020-157516 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The object of the present invention is to provide a laminate for use in situations where the contents of a packaging container using the laminate deteriorate significantly due to humidity but not due to oxygen. This laminate can reduce manufacturing costs and has excellent reusability after use.

[0011] Furthermore, a second objective of the present invention is to provide a packaging container using the aforementioned laminate.

[0012] Solution for solving the problem

[0013] According to the present invention, a laminate is provided, characterized in that the laminate has at least a first substrate layer, a water vapor barrier layer and a heat-sealing layer, and is formed by stacking them sequentially from the outside to the inside, wherein the first substrate layer and the heat-sealing layer are made of polyolefin.

[0014] Preferably, in the laminate, a light-shielding layer is provided between the first substrate layer and the water vapor barrier layer.

[0015] Preferably, in the laminate, a second substrate layer made of polyolefin is provided between the light-shielding layer and the water vapor barrier layer.

[0016] Preferably, in the laminate, a conventionally printed layer is present between the first substrate layer and the light-shielding layer.

[0017] Preferably, in the laminate, the light-shielding layer is a light-shielding printed layer or an inorganic vapor-deposited layer.

[0018] Preferably, the visible light transmittance of the laminate is below 90%.

[0019] Preferably, in the laminate, the xylene solubility of the polyolefin in the heat-sealing layer is 10-20% by mass, and the polyolefin has undergone stretching processing.

[0020] Preferably, in the laminate, the peak intensity ratio of the polyolefin in the heat-sealing layer, as observed by X-ray diffraction, is MD / TD>1 or TD / MD>1.

[0021] Preferably, in the laminate, the peak intensity ratio of the polyolefin in the first substrate layer and / or the second substrate layer, as observed by X-ray diffraction, is MD / TD>1 or TD / MD>1.

[0022] Preferably, the polyolefin in the first substrate layer and / or the second substrate layer has a heat shrinkage rate observed by heat shrinkage rate measurement as MD>TD or MD>TD. <TD。

[0023] Preferably, in the laminate, the polyolefin in the second substrate layer is partially cut to a depth of 10-90% in the thickness direction.

[0024] Furthermore, according to the present invention, a packaging container is provided that uses the aforementioned laminate.

[0025] Invention Effects

[0026] The laminate of the present invention is a laminate having at least a first substrate layer, a water vapor barrier layer, and a heat-sealing layer, which are sequentially stacked from the outside to the inside, wherein the first substrate layer and the heat-sealing layer are made of polyolefin; and a packaging container using the laminate. Therefore, when the contents filled in the packaging container, such as sugar, salt, or sports drink powder, are significantly degraded or deteriorated due to moisture but not significantly degraded or deteriorated due to oxygen, the gas barrier property of the packaging container will not be excessive, enabling the manufacture of a low-cost packaging container. Here, humidity is a numerical value representing the amount of water contained in the atmosphere in the form of water vapor, indicating the humidity level of the atmosphere.

[0027] Furthermore, since the first substrate layer and the heat-sealing layer are laminates made of polyolefin, a laminate with excellent reusability can be made when the water vapor barrier layer is made of a material that can be reused together with the polyolefin. Attached Figure Description

[0028] Figure 1 This is a schematic side sectional view showing the layer structure of the laminate according to the first embodiment of the present invention.

[0029] Figure 2 This is a schematic side sectional view showing the layer structure of the laminate according to the second embodiment of the present invention.

[0030] Figure 3 This is a schematic side sectional view showing the layer structure of the laminate according to the third embodiment of the present invention.

[0031] Figure 4 This is a schematic side sectional view showing the layer structure of the laminate according to the fourth embodiment of the present invention.

[0032] Figure 5 It means to use Figure 1 A schematic side sectional view of the layer structure of the packaging container formed by the laminate of the first embodiment.

[0033] Figure 6 It is a graph showing the weight change after using the storage stability tests of Examples 1, 2, 3 and Comparative Examples 1 and 2. Detailed Implementation

[0034] <Layered Body>

[0035] Figure 1 This is a schematic side sectional view showing the layer structure of the laminate 10 according to the first embodiment of the present invention. A first substrate layer 1, a water vapor barrier layer 3, and a heat-sealing layer 4 are sequentially laminated from the upper outer portion to the lower inner portion. The first substrate layer 1 and the heat-sealing layer 4 are each composed of a single layer or multiple layers of polyolefin. For ease of reuse, polyethylene or polypropylene is preferred among the polyolefins.

[0036] As the polyethylene, any of the known polyethylenes such as high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and mixtures thereof can be used. Furthermore, regarding the source of the raw materials, any of the following can be used: petroleum-based sources, plant-based sources, recycled polyethylene sources, and mixtures thereof. The heat-sealing layer 4 preferably uses any of the following: low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and mixtures thereof, which have excellent heat-sealing properties; linear low-density polyethylene (LLDPE) is particularly preferred.

[0037] Moreover, within the range that does not impair physical properties, it can be combined with lubricants, ultraviolet absorbers, plasticizers, crystal nucleating agents, fillers, hydrolysis inhibitors, flame retardants, antistatic agents, antifogging agents, and antiblocking agents.

[0038] As the polypropylene, known polypropylenes such as homopolymer polypropylene, atactic polypropylene (as a random copolymer of polypropylene and ethylene), high-impact polypropylene (CPP) obtained by uniformly and finely dispersing rubber component (EPR) in homopolymer polypropylene or atactic polypropylene, and biaxially oriented polypropylene (OPP) can be used. Furthermore, regarding the source of raw materials, any of the following can be used: petroleum-based raw materials, plant-based raw materials, recycled polypropylene, and mixtures thereof. The heat-sealing layer 4 preferably uses non-stretched polypropylene (CPP) with excellent heat-sealing properties.

[0039] The thickness of the first substrate layer 1 is 5–40 μm, preferably 8–30 μm, and more preferably 9–25 μm. If it is less than 5 μm, it may be difficult to manufacture the laminate; if it is more than 40 μm, it may not be able to provide the flexibility needed for use in packaging containers.

[0040] It should be noted that, from the viewpoint of excellent reusability, the resin of the first substrate layer 1 is preferably composed only of polyolefins. However, for the purpose of improving the rigidity, puncture strength, and gas barrier properties of the film, it may also include resins other than polyolefins, such as polyamide resin, polyester resin, polyvinyl alcohol resin, and ethylene-vinyl alcohol copolymer resin with an ethylene content of 20-50 mol%, at a rate of 20% or less, preferably 10% or less, relative to the first substrate layer 1 as a whole.

[0041] The thickness of the heat-sealing layer 4 is 10–300 μm, preferably 20–200 μm, and more preferably 25–150 μm. If it is less than 10 μm, heat-sealing properties may not be achieved, and if it exceeds 300 μm, flexibility for use in packaging containers may not be achieved. The heat-sealing layer 4 may also contain a reusable resin that can be used as a heat-sealing layer.

[0042] Polyolefins have a certain degree of water vapor permeability. Therefore, to block the permeation of water vapor from the laminate 10, a water vapor barrier layer 3 is provided on the upper surface of the heat-sealing layer 4. The water vapor barrier layer 3 can be a vapor-deposited film of inorganic materials or inorganic oxides, or a coating film containing inorganic materials or inorganic oxides. In the case of vapor deposition, the film is formed by using known vapor deposition methods such as chemical vapor deposition (CVD). In the case of coating, the film is formed by using known coating methods such as roll coating, spin coating, or dip coating to adhere the vapor-deposited film or coating film of inorganic materials or inorganic oxides to the upper surface of the heat-sealing layer 4.

[0043] As the inorganic material, silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y) and other inorganic materials can be used. As a suitable inorganic material for packaging containers, aluminum (Al) is preferred.

[0044] As the inorganic oxide, SiO can be used. X AlO X Wait until that by MO X(Where, M represents an inorganic element, and the value of X varies depending on the inorganic element.) represents an inorganic oxide. Here, the range of X values ​​is as follows: silicon (Si) can be 0–2, aluminum (Al) can be 0–1.5, magnesium (Mg) can be 0–1, calcium (Ca) can be 0–1, potassium (K) can be 0–0.5, tin (Sn) can be 0–2, sodium (Na) can be 0–0.5, boron (B) can be 0–1.5, titanium (Ti) can be 0–2, lead (Pb) can be 0–1, zirconium (Zr) can be 0–2, and yttrium (Y) can be 0–1.5. However, in the above case, when X=0, it is a completely inorganic substance, not an inorganic oxide, and is therefore excluded. As suitable inorganic oxides for packaging containers, silicon oxides or aluminum oxides are preferred, and SiO2 or AlO2 are particularly preferred from the perspective of transparency.

[0045] The thickness of the water vapor barrier layer 3 is 1–150 nm, preferably 5–60 nm, and more preferably 10–40 nm. If it is less than 1 nm, it may be difficult to block the water vapor from passing through the laminate 10. Furthermore, if it exceeds 150 nm, cracks may occur in the vapor-deposited film of the water vapor barrier layer 3, and it may be difficult to reuse the laminate 10.

[0046] In the laminate 10 of the first embodiment, the first substrate layer 1 and the water vapor barrier layer 3 are bonded together by an adhesive layer 2. Here, the adhesive layer 2 is not essential and can be arbitrarily placed; if the first substrate layer 1 and the water vapor barrier layer 3 are bonded together by heating or the like, the adhesive layer 2 is not required. However, when bonding is performed by heating or the like, peeling is easy, so the adhesive layer 2 is preferred to ensure reliable bonding.

[0047] As the adhesive used for the adhesive layer 2, known solvent-free adhesives and solvent-based adhesives can be used. From the viewpoint of environmental impact, solvent-free adhesives are preferred.

[0048] Examples of solvent-free adhesives include urethane adhesives, epoxy adhesives, polyether adhesives, polyester adhesives, and silicone adhesives. From the perspective of strong bonding strength and the ability to flexibly adapt to the shape deformation of packaging containers, urethane adhesives are preferred.

[0049] Examples of solvent-based adhesives include urethane adhesives, acrylic adhesives, rubber adhesives, vinyl adhesives, silicone adhesives, epoxy adhesives, phenolic adhesives, and olefin adhesives.

[0050] The thickness of the adhesive layer 2 is 0.1–10 μm, preferably 1–5 μm, and more preferably 1–3 μm. If it is less than 0.1 μm, sufficient adhesive force may not be obtained. Furthermore, if it exceeds 10 μm, it may not be able to flexibly accommodate the shape deformation of the packaging container, and the reuse of the laminate 10 may be difficult.

[0051] Figure 2 This is a schematic side sectional view showing the layer structure of the laminate 20 according to the second embodiment of the present invention. In addition to the layer structure of the laminate 10 of the first embodiment, a light-shielding layer 5 is laminated between the first substrate layer 1 and the adhesive layer 2.

[0052] The light-shielding layer 5 blocks ultraviolet light, visible light, and other light that are located on the outer side of the first substrate layer 1, which is the outer side of the laminate 20. This prevents the contents of the laminate 20 from being modified or deteriorated when it is used in a packaging container, and improves its storage stability.

[0053] As the light-shielding layer 5, either a light-shielding printed layer or an inorganic vapor-deposited layer can be used. The light-shielding printed layer is formed by printing a monochromatic light-shielding ink onto the lower surface of the first substrate layer 1. The color of the light-shielding ink can be black, white, gray, orange, red, yellow, silver, or brown, etc., without particular limitation; ideally, it can be varied depending on the type of content. Furthermore, as the coloring pigment used for the light-shielding ink, known pigments such as carbon black, acetylene black, lampblack, soot, iron black, aniline black, titanium dioxide, and zinc oxide can be used, without particular limitation. Moreover, it can be used not only as a single layer, but also as multiple layers of contrasting colors such as white and black layers, yellow and red layers, etc., as needed.

[0054] The printing method for the light-shielding printing layer can be any known printing method such as gravure printing, flexographic printing, inkjet printing, or offset printing. From the perspective of environmental impact, flexographic printing is preferred.

[0055] The thickness of the light-shielding printing layer is 0.1–10 μm, preferably 1–5 μm, and more preferably 1–3 μm. If it is less than 0.1 μm, it may not be able to prevent modification or deterioration of the contents when used in packaging containers, and thus cannot improve storage stability. In addition, if it exceeds 10 μm, it may not be able to flexibly cope with the shape deformation of the packaging container, and it may be difficult to reuse the laminate 10.

[0056] As the inorganic vapor-deposited layer, an inorganic vapor-deposited film described in the description of the water vapor barrier layer 3 can be used to form a film by adhering the vapor-deposited film tightly to the lower surface of the first substrate layer 1. Regarding the vapor deposition means, method, type of inorganic material, thickness, etc., the description related to the inorganic vapor-deposited film in the description of the water vapor barrier layer 3 is cited. Therefore, the inorganic vapor-deposited layer not only serves as the light-shielding layer 5 but also as the water vapor barrier layer 3. Here, from the perspective of suitability for packaging containers, aluminum (Al) is preferably used as the type of inorganic material.

[0057] By employing the light-shielding layer 5, the visible light transmittance (380–800 nm) of the laminate of the present invention, as measured using a UV-Vis spectrophotometer, can be arbitrarily controlled to be below 90%, preferably below 50%, and more preferably below 10%. If the transmittance exceeds 90%, the laminate 20 becomes almost transparent, which may prevent it from effectively preventing modification or deterioration of the contents when used in packaging containers, and thus hindering its ability to improve storage stability.

[0058] Figure 3 This is a schematic side sectional view showing the layer structure of the laminate 30 according to the third embodiment of the present invention. In addition to the layer structure of the laminate 20 of the second embodiment, the adhesive layer 2 is set as two layers, and a second substrate layer 6 is laminated between the two adhesive layers 2.

[0059] The second substrate layer 6 can use the same polyolefin as the first substrate layer 1, therefore, the description of the first substrate layer 1 relating to polyolefins is referenced. By laminating the second substrate layer 6, the laminate of the present invention can achieve higher water vapor barrier properties.

[0060] Figure 4 This is a schematic side sectional view showing the layer structure of the laminate 40 in the fourth embodiment of the present invention. In contrast to the layer structure of the laminate 30 in the third embodiment, the light-shielding layer 5 is not laminated on the lower surface of the first substrate layer 1, but on the upper surface of the second substrate layer 6.

[0061] A conventional printing layer 7 can be laminated on the lower surface of the first substrate layer 1. The conventional printing layer 7 can be a multi-color printing layer containing text, patterns, and images such as product names. The printing method for the light-shielding printing layer can be any known printing method such as gravure printing, flexographic printing, inkjet printing, or offset printing. By laminating the conventional printing layer 7, packaging containers using the laminate of this invention can be given added value such as improved recognizability and increased product value compared to other companies' products.

[0062] The means and methods for laminating the light-shielding layer 5 on the upper surface of the second substrate layer 6 are the same as those for laminating the light-shielding layer 5 on the lower surface of the first substrate layer 1 in the second embodiment. Therefore, the description related to the means and methods for laminating the light-shielding layer 5 on the lower surface of the first substrate layer 1 is cited. It should be noted that when the light-shielding layer 5 is a light-shielding printed layer, it is also possible not to laminate the light-shielding layer 5 on the upper surface of the substrate layer 6, but to laminate the light-shielding layer 5 on the lower surface of the normally printed layer 7.

[0063] In the first to fourth embodiments, the polyolefin in the heat-sealing layer 4 of the laminates 10, 20, 30, and 40 preferably has a xylene solubility of 10-20% by mass and has undergone stretching processing. Furthermore, it is more preferably that the xylene solubility is 12-18% by mass. Here, xylene solubility is the solubility ratio of the polyolefin after impregnation with xylene at room temperature to 100% of its initial mass, and is a physical property showing a correlation with stretch processability. Therefore, if the xylene solubility is within the specified range, the polyolefin in the heat-sealing layer 4 has appropriate stretch processability. If the xylene solubility is less than 10% by mass, sufficient stretch processability may not be obtained; if it exceeds 20% by mass, the anti-blocking properties of the polyolefin during storage may deteriorate.

[0064] The polyolefin in the heat-sealing layer 4 preferably exhibits a peak intensity ratio of MD / TD > 1 or TD / MD > 1, as observed by X-ray diffraction using Cu-Kα rays. For example, peaks derived from polypropylene crystals at 2θ = 14° or 17° are used. Here, MD refers to the stretching direction, and TD refers to the transverse direction orthogonal to the stretching direction. When the peak intensity ratio is MD / TD > 1 or TD / MD > 1, the polyolefin in the heat-sealing layer exhibits excellent linear cutoff in the MD or TD direction due to molecular orientation based on the stretching process, allowing for easy tearing of the laminate of the present invention with minimal force.

[0065] The polyolefins in the first substrate layer 1 and / or the second substrate layer 6 preferably exhibit a peak intensity ratio of MD / TD > 1 or TD / MD > 1 as observed by X-ray diffraction. Here, similar to the heat-sealing layer, when the peak intensity ratio is MD / TD > 1 or TD / MD > 1, the polyolefins in the first and second substrate layers exhibit excellent linear cutoff in the MD or TD direction due to molecular orientation based on stretching processing, allowing the laminate of the present invention to be easily torn with small force.

[0066] The polyolefin in the first base material layer 1 and / or the second base material layer 6 preferably has a heat shrinkage rate of MD > TD or MD < TD as observed by heat shrinkage rate measurement. Here, the heat shrinkage rate measurement is performed, for example, using a thermomechanical analysis device (TMA). When the initial size is set as L0 and the size after heating to 120 °C or 130 °C is set as L, the heat shrinkage rate is represented by (L0 - L) / L0 × 100 (%), and the larger the value, the greater the heat shrinkage. In the case where the heat shrinkage rate is MD > TD or MD < TD, excellent linear truncation in the MD direction or TD direction is shown by molecular orientation based on stretching processing, and the laminate of the present invention can be easily torn with a small force.

[0067] The polyolefin in the second base material layer 6 is preferably subjected to half-cut processing to a depth of 10 - 90% in the thickness direction, more preferably to a depth of 20 - 80%. Here, the half-cut processing refers to notch processing in the thickness direction using a stamping blade, laser, etc. By having the notch processing, the laminate of the present invention can be easily torn with a small force.

[0068] <Packaging container>

[0069] Figure 5 It represents the use of two Figure 1 The schematic side cross-sectional view of the layer structure of the packaging container 50 formed by welding the right half with a heat sealer in such a manner that the heat-sealing layer 4 of each of the laminates 10 shown in the first embodiment is on the inner side. Here, the water vapor barrier layer 3 in each laminate 10 blocks the water vapor gas present outside the packaging container, and the contents filled in the packaging container 50 can be kept in a dry state without being affected by humidity and stored for a long time.

[0070] Examples

[0071] Hereinafter, the present invention will be described in more detail by way of examples. It should be noted that the present invention is not limited to the examples.

[0072] The measurement methods of various physical properties used in the examples and comparative examples are shown below.

[0073] <Water vapor transmission rate>

[0074] Regarding the laminate as a specimen, using a water vapor transmission rate measuring device (PERMATRAN-W 3 / 34G manufactured by MOCON), the water vapor transmission rate (g / m 2 / day / atm) is measured under the conditions of 40 °C and 90% RH.

[0075] <Visible light transmittance>

[0076] The laminate was used as a sample, and the transmittance (%) of light in the range of 380–800 nm was measured using a UV-Vis-NIR spectrophotometer (Shimadzu Corporation UV-3600).

[0077] <Storage Stability Test>

[0078] Using a two-layer laminate, a heat-sealed container filled with 50g of sports drink powder was used as a test sample. A 90-day storage stability test was conducted using a constant temperature and humidity chamber at 30℃ / 80%RH. The weight (mg) of the container was measured appropriately midway through the 90 days. If moisture was absorbed, the weight increased, thus evaluating the water vapor barrier properties.

[0079] The following shows the types of membranes used in the examples and comparative examples.

[0080] <membrane>

[0081] (A) Substrate film A: Biaxially oriented polypropylene (OPP) is used as substrate film A. Thickness 20 μm.

[0082] (B) Substrate film with light-shielding layer (light-shielding printing layer): The film obtained by forming a white ink layer on one side of the substrate film through gravure printing, followed by the formation of a gray ink layer, is referred to as substrate film with light-shielding layer (light-shielding printing layer). Thickness: 20 μm.

[0083] (C) Substrate film with light-shielding layer (inorganic vapor deposition layer): A film with aluminum vapor deposition on one side of the substrate film is used as substrate film with light-shielding layer (inorganic vapor deposition layer) C. Thickness 25μm.

[0084] (D) Heat-sealing film D: Unstretched polypropylene (CPP) is used as the heat-sealing film D. Thickness 40μm.

[0085] (E) Heat-sealing film with water vapor barrier layer E: A film with silicon dioxide (SiO2) deposited on one side of the heat-sealing film is used as the heat-sealing film with water vapor barrier layer E. Thickness 25μm.

[0086] (Example 1)

[0087] In order to form Figure 1 The laminate 10 of the first embodiment shown uses a substrate film A as the outer substrate layer 1, and is coated using a doctor blade coater at approximately 4 g / m². 2A urethane adhesive is coated on the inner side to form an adhesive layer 2. With the urethane adhesive layer in a semi-dry state, a heat-sealing film E with a water vapor barrier layer is bonded to the adhesive layer with the water vapor barrier layer facing towards the adhesive layer, thus producing the laminate of Example 1. The laminate of Example 1 can be represented as “OPP (1) / urethane adhesive layer (2) / SiO2 vapor deposition layer (3) / CPP (4)”, where the values ​​in parentheses represent the layers corresponding to “1: first substrate layer”, “2: adhesive layer”, “3: water vapor barrier layer”, “4: heat-sealing layer”, “5: light-shielding layer”, and “6: second substrate layer”, respectively.

[0088] The laminate from Example 1 was used as a sample to measure water vapor transmittance and visible light transmittance. The results are shown in Table 2.

[0089] Furthermore, using two laminated bodies from Example 1, with their respective heat-sealing layers facing inwards, a heat-sealing machine was used to seal the containers under conditions of 180°C, 0.3 MPa, and 1.0 second, producing packaging containers with an internal dimension of 100 mm (vertical) × 100 mm (horizontal) and an opening on only one side. Next, 50 g of sports drink powder was filled into the packaging containers from one side of the opening, and then sealed using a heat-sealing machine under the same conditions as described above, thus sealing each packaging container. The sealed packaging containers were then used as samples for a storage stability test, and the results are shown below. Figure 6 .

[0090] (Example 2)

[0091] In order to form Figure 3 The laminate 30 of the third embodiment shown uses a substrate layer film B with a light-shielding layer (light-shielding printing layer) on the outside, a urethane adhesive, a substrate layer film A, a urethane adhesive, and a heat-sealing layer film E with a water vapor barrier layer. Except for this, the laminate of Example 2 is produced in the same way as in Example 1. The laminate of Example 2 can be represented as "OPP (1) / light-shielding layer (light-shielding printing layer) (5) / urethane adhesive layer (2) / OPP (6) / urethane adhesive layer (2) / SiO2 vapor deposition layer (3) / CPP (4)".

[0092] In addition, similar to Example 1, the laminate of Example 2 was used as a sample to measure water vapor transmittance and visible light transmittance, and the results are shown in Table 2. Furthermore, using two laminates of Example 2, a packaging container filled with sports drink powder was used as a sample to conduct a storage stability test, and the results are shown in Table 2. Figure 6 .

[0093] (Example 3)

[0094] In order to form Figure 4 The laminate 40 of the fourth embodiment shown uses a substrate layer film A as the outer substrate layer 1, a urethane adhesive, a substrate layer film C with a light-shielding layer (inorganic vapor deposition layer), a urethane adhesive, and a heat-sealing layer film E with a water vapor barrier layer. Except for this, the laminate of Example 3 is produced in the same manner as in Example 1. The laminate of Example 2 can be represented as "OPP (1) / urethane adhesive layer (2) / light-shielding layer (inorganic vapor deposition layer) (5) / OPP (6) / urethane adhesive layer (2) / SiO2 vapor deposition layer (3) / CPP (4)".

[0095] In addition, similar to Example 1, the laminate of Example 3 was used as a sample to measure water vapor transmittance and visible light transmittance, and the results are shown in Table 2. Furthermore, using two laminates of Example 3, a packaging container filled with sports drink powder was used as a sample to conduct a storage stability test, and the results are shown in Table 2. Figure 6 .

[0096] (Compare Examples 1 and 2)

[0097] In the laminates of Examples 1 and 3, the heat-sealing film D was used instead of the heat-sealing film E with the water vapor barrier layer, thus not including the "SiO2 vapor deposition film (3)" which is equivalent to the water vapor barrier layer. Otherwise, the laminates of Comparative Examples 1 and 2, which are the same as those of Examples 1 and 3, were produced.

[0098] Using the laminates of Comparative Examples 1 and 2 as samples, water vapor transmittance and visible light transmittance were measured, and the results are shown in Table 2. Furthermore, using two sheets each of the laminates of Comparative Examples 1 and 2, and packaging containers filled with sports drink powder as samples, a storage stability test (evaluation of water vapor barrier properties) was conducted, and the results are shown in Table 2. Figure 6 .

[0099] Table 1 shows the layer configurations of Examples 1-3 and Comparative Examples 1-2.

[0100] [Table 1]

[0101]

[0102] Table 2 shows the measurement results of water vapor transmittance and visible light transmittance of Examples 1-3 and Comparative Examples 1-2.

[0103] [Table 2]

[0104]

[0105] Table 2 shows the water vapor permeability (g / m³) of the laminates in Examples 1-3. 2 The permeability ( / day / atm) is all less than 0.2, indicating almost no water vapor transmission. However, Comparative Examples 1 and 2 have permeabilities greater than 1 and 0.4 respectively, clearly showing some water vapor transmission. Furthermore, the laminates of "Example 1 / Comparative Example 1" and "Example 3 / Comparative Example 2" differ in the presence or absence of the SiO2 vapor-deposited film as a water vapor barrier layer in the layer composition of the "Examples / Comparative Examples," but their visible light transmittance is almost the same at 93 / 92 and 0.8 / 0.9 respectively. Therefore, it can be concluded that the SiO2 vapor-deposited film is transparent, and the degree of transparency does not affect the visible light transmittance.

[0106] exist Figure 6 In the 90-day storage stability test shown, the packaging container of Example 1 showed a slight weight increase, while the packaging containers of Examples 2 and 3 showed almost no weight increase. Therefore, it can be concluded that the packaging containers of Examples 1-3 have high water vapor barrier properties. In contrast, the packaging containers of Comparative Examples 1 and 2 absorbed moisture from the environment and showed a greater weight increase. After 90 days of storage, the packaging containers were opened. The results showed that the sports drink powder of Examples 1-3 remained in the same dry state as when it was filled, and no agglomeration due to moisture was observed. However, the sports drink powder of Comparative Examples 1 and 2 agglomerated due to moisture, and strong agglomeration was observed in Comparative Example 1 in particular.

[0107] Industrial availability

[0108] The laminate of the present invention is a laminate having at least a first substrate layer, a water vapor barrier layer, and a heat-sealing layer, which are sequentially stacked from the outside to the inside, wherein the first substrate layer and the heat-sealing layer are made of polyolefin; and a packaging container using the laminate. When the contents filled in the packaging container, such as sugar, salt, or sports drink powder, are significantly degraded or deteriorated due to moisture but not due to oxygen, the gas barrier property of the packaging container is not excessive, enabling the production of a low-cost packaging container. Furthermore, since the first substrate layer and the heat-sealing layer are made of polyolefin, and the water vapor barrier layer is made of a material that can be reused along with the polyolefin, a laminate and packaging container with excellent reusability can be produced.

[0109] Explanation of reference numerals in the attached figures

[0110] 1: First substrate layer;

[0111] 2: Adhesive layer;

[0112] 3: Water vapor barrier layer;

[0113] 4: Heat-sealing layer;

[0114] 5: Light-blocking layer;

[0115] 6: Second substrate layer;

[0116] 10: The laminated body of the first embodiment;

[0117] 20: The laminated body of the second embodiment;

[0118] 30: The laminate of the third embodiment;

[0119] 40: The laminate of the fourth embodiment;

[0120] 50: Packaging containers.

Claims

1. A laminated body, characterized in that, The laminate has at least a first substrate layer, a water vapor barrier layer, and a heat-sealing layer, and is formed by stacking them sequentially from the outside to the inside. The first substrate layer and the heat-sealing layer are made of polyolefin.

2. The laminated body according to claim 1, wherein, A light-shielding layer is provided between the first substrate layer and the water vapor barrier layer.

3. The laminated body according to claim 2, wherein, Between the light-shielding layer and the water vapor barrier layer is a second substrate layer made of polyolefin.

4. The laminate according to claim 2, wherein, A conventional printed layer is present between the first substrate layer and the light-shielding layer.

5. The laminated body according to claim 2, wherein, The light-shielding layer is a light-shielding printed layer or an inorganic vapor-deposited layer.

6. The laminate according to claim 2, wherein, The visible light transmittance is below 90%.

7. The laminated body according to claim 1, wherein, The polyolefin in the heat-sealing layer has a xylene solubility of 10-20% by mass, and the polyolefin has undergone stretching processing.

8. The laminated body according to claim 1, wherein, The peak intensity ratio of the polyolefin in the heat-sealing layer, as observed by X-ray diffraction, is MD / TD>1 or TD / MD>1.

9. The laminate according to claim 3, wherein, The peak intensity ratio of the polyolefin in the first substrate layer and / or the second substrate layer, as observed by X-ray diffraction, is MD / TD>1 or TD / MD>1.

10. The laminate according to claim 3, wherein, The heat shrinkage rate of the polyolefin in the first substrate layer and / or the second substrate layer, as observed by heat shrinkage rate measurement, is MD>TD or MD <TD。 11. The laminate according to claim 3, wherein, The polyolefin in the second substrate layer is partially cut to a depth of 10-90% in the thickness direction.

12. A packaging container using a laminate according to any one of claims 1 to 11.

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