Laminate and packaging container

Abstract

To provide a laminate that is used when a content filled in a packaging container using a laminate does not largely denature and deteriorate due to the influence of humidity but does not largely denature and deteriorate due to the influence of oxygen, can reduce production cost, and is excellent in recyclability after use.SOLUTION: Provided is a laminate that has at least a first substrate layer, a water vapor gas barrier layer, and a heat seal layer, stacked in this order from the outside to the inside, characterized in that the first substrate layer and the heat seal layer are made of polyolefin.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate used in the manufacture of packaging containers and the like. The present invention also relates to a packaging container using the laminate.

Background Art

[0002] Conventionally, various flexible resin packaging containers have been proposed for filling and packaging various beverages, foods, liquid detergents, cosmetics, pharmaceuticals, miscellaneous goods, industrial materials, and other articles.

[0003] For example, Patent Document 1 proposes a laminate using a polyolefin such as polyethylene or polypropylene as a sealant layer, including a light-shielding printing layer and a barrier coat layer, and a packaging bag using the laminate. It is said to have not only the strength and heat resistance required during use, but also excellent recyclability and gas barrier properties after use in consideration of the environment.

[0004] Here, regarding the gas barrier property, when storing the packaging container in a general atmospheric environment, it is important to focus on the oxygen gas barrier property and the water vapor gas barrier property. And when the contents filled in the packaging container are likely to deteriorate due to both oxygen and humidity in the air, such as general foods, both the oxygen gas barrier property and the water vapor gas barrier property must be emphasized. However, for powders such as sugar, salt, and sports drink powder, which are greatly affected by humidity and deteriorate, but not greatly affected by oxygen, it is sufficient to have a high water vapor gas barrier property, and it is not necessary to have a high oxygen gas barrier property.

[0005] When attaching importance to the gas barrier properties for both oxygen gas and water vapor, a coating film with high gas barrier properties is often used, such as forming the barrier coating layer of Patent Document 1 with a gas barrier coating film. However, there has been a limit to reducing the manufacturing cost of the packaging container. And when the content filled in the packaging container only needs to have the high water vapor gas barrier property, using the gas barrier coating film or the like has the problem that the gas barrier property of the packaging container becomes an excessive performance, and the manufacturing cost of the packaging container becomes higher than necessary.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In view of the above circumstances, an object of the present invention is to provide a laminate used when the content filled in a packaging container using the laminate is greatly deteriorated or deteriorated due to the influence of humidity but not greatly deteriorated or deteriorated due to the influence of oxygen, which can reduce the manufacturing cost and has excellent recyclability after use. Another object of the present invention is to provide a packaging container using the laminate.

Means for Solving the Problems

[0008] According to the present invention, there is provided a laminate having at least a first base material layer, a water vapor gas barrier layer, and a heat seal layer, laminated in this order from the outside to the inside, wherein the first base material layer and the heat seal layer are made of polyolefin.

[0009] It is preferable that the laminate has a light-shielding layer between the first base material layer and the water vapor gas barrier layer.

[0010] It is preferable that the laminate has a second base material layer made of polyolefin between the light-shielding layer and the water vapor gas barrier layer.

[0011] It is preferable that the laminate has a normal printing layer between the first base material layer and the light-shielding layer.

[0012] It is preferable that the light-shielding layer of the laminate is a light-shielding printing layer or an inorganic vapor deposition layer.

[0013] It is preferable that the laminate has a visible light transmittance of 90% or less.

[0014] It is preferable that the polyolefin in the heat-sealing layer of the laminate has a xylene soluble content of 10 to 20% by mass and is subjected to stretching processing.

[0015] It is preferable that the polyolefin in the heat-sealing layer of the laminate has a peak intensity ratio of MD / TD > 1 or TD / MD > 1 observed by X-ray diffraction measurement.

[0016] It is preferable that the polyolefin in the first base material layer and the second base material layer of the laminate has a peak intensity ratio of MD / TD > 1 or TD / MD > 1 observed by X-ray diffraction measurement.

[0017] It is preferable that the polyolefin in the first base material layer and / or the second base material layer has a heat shrinkage rate of MD > TD or MD < TD observed by heat shrinkage rate measurement.

[0018] It is preferable that the polyolefin in the second base material layer of the laminate has a half-cut process with a depth of 10 to 90% in the thickness direction.

[0019] Further, according to the present invention, a packaging container using the laminate is provided.

Advantages of the Invention

[0020] The laminate of the present invention has at least a first base material layer, a water vapor gas barrier layer, and a heat seal layer, and is a laminate laminated in this order from the outside to the inside, wherein the first base material layer and the heat seal layer are made of polyolefin, and a packaging container using the laminate. Therefore, when the contents filled in the packaging container are greatly deteriorated or deteriorated due to humidity, such as sugar, salt, sports drink powder, etc., but not greatly deteriorated or deteriorated due to the influence of oxygen, the gas barrier property of the packaging container can be made a low-cost packaging container without being an excessive performance. Here, humidity is a numerical value representing the amount of water contained in the form of water vapor gas in the atmosphere as a ratio, and represents the humidity of the atmosphere.

[0021] Further, since the first base material layer and the heat seal layer are made of polyolefin, when the water vapor gas barrier layer is composed of a material that can be recycled together with polyolefin, a laminate excellent in recyclability can be obtained.

Brief Description of Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0023] <Laminate> FIG. 1 is a schematic side sectional view showing the layer structure of the laminate 10 according to the first embodiment of the present invention. From the outer upper part to the inner lower part, a first base material layer 1, a water vapor gas barrier layer 3, and a heat seal layer 4 are laminated in this order. Here, the first base material layer 1 and the heat seal layer 4 are each made of a single-layer or multi-layer polyolefin. Among polyolefins, it is preferable to use polyethylene or polypropylene because they are easy to recycle.

[0024] As the polyethylene, any of 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. Also, regarding the origin of the raw material, any of petroleum raw material origin, plant raw material origin, recycled polyethylene origin, and mixtures thereof can be used. For the heat seal layer 4, it is preferable to use any of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and mixtures thereof that have excellent heat sealability, and it is particularly preferable to use linear low-density polyethylene (LLDPE). Furthermore, lubricants, ultraviolet absorbers, plasticizers, crystal nucleating agents, fillers, hydrolysis inhibitors, flame retardants, antistatic agents, antifogging agents, antiblocking agents may be blended within a range that does not impair the physical properties.

[0025] As the polypropylene, homopolypropylene which is a homopolymer of polypropylene, random polypropylene which is a random copolymer with ethylene, high-impact polypropylene in which a rubber component (EPR) is uniformly and finely dispersed in homopolypropylene or random polypropylene, etc. are used, known polypropylenes such as unstretched polypropylene (CPP), biaxially stretched polypropylene (OPP), etc. Also, regarding the origin of the raw material, any of petroleum raw material origin, plant raw material origin, recycled polypropylene origin, and mixtures thereof can be used. For the heat seal layer 4, it is preferable to use unstretched polypropylene (CPP) which has excellent heat sealability.

[0026] The thickness of the first base material layer 1 is 5 to 40 μm, preferably 8 to 30 μm, and more preferably 9 to 25 μm. If it is less than 5 μm, it may be difficult to manufacture the laminate, and if it exceeds 40 μm, the flexibility when used for a packaging container may not be exhibited.

[0027] In addition, from the viewpoint of excellent recyclability, the resin of the first base material layer 1 is preferably composed only of polyolefin. However, for the purpose of enhancing the rigidity, puncture strength, gas barrier performance, etc. of the film, polyamide resin, polyester resin, polyvinyl alcohol-based resin, ethylene-vinyl alcohol copolymer resin with an ethylene content of 20 to 50 mol%, etc., resins other than polyolefin may be contained in the first base material layer 1 in an amount of 20% by mass or less, preferably 10% by mass or less, based on the whole first base material layer 1.

[0028] The thickness of the heat-sealing layer 4 is 10 to 300 μm, preferably 20 to 200 μm, and more preferably 25 to 150 μm. If it is less than 10 μm, the heat-sealing property may not be exhibited, and if it exceeds 300 μm, the flexibility when used for a packaging container may not be exhibited. The heat-sealing layer 4 may contain a recyclable resin that can be used as a heat-sealing layer.

[0029] Since polyolefin has a certain degree of water vapor gas permeability, a water vapor gas barrier layer 3 is provided on the upper surface of the heat-sealing layer 4 for the purpose of blocking the water vapor gas permeation of the laminate 10. As the water vapor gas barrier layer 3, a vapor deposition film of an inorganic substance or inorganic oxide, or a coating film in which an inorganic substance or inorganic oxide is dispersed can be used. In the case of a vapor deposition film, a known vapor deposition means or method such as chemical vapor deposition (CVD) method is used, and in the case of a coating film, a known coating means or method such as roll coating, spin coating, dip coating, etc. is used to form the vapor deposition film or coating film of the inorganic substance or inorganic oxide in close contact with the upper surface of the heat-sealing layer 4.

[0030] As the inorganic substance, inorganic substances such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc. can be used. However, as a suitable one for the packaging container, aluminum (Al) is preferable.

[0031] As the inorganic oxide, SiO X , AlO X etc., MO X (However, in the formula, M represents an inorganic element, and the value of X varies depending on the inorganic element.) can be used. Here, as the range of the value of X, for silicon (Si), it is 0 to 2, for aluminum (Al), it is 0 to 1.5, for magnesium (Mg), it is 0 to 1, for calcium (Ca), it is 0 to 1, for potassium (K), it is 0 to 0.5, for tin (Sn), it is 0 to 2, for sodium (Na), it is 0 to 0.5, for boron (B), it is 0 to 1.5, for titanium (Ti), it is 0 to 2, for lead (Pb), it is 0 to 1, for zirconium (Zr), it is 0 to 2, and for yttrium (Y), it can take values in the range of 0 to 1.5. However, in the above, when X = 0, it is a complete inorganic substance and not an inorganic oxide, so it is excluded. As a suitable one for the packaging container, silicon oxide or aluminum oxide is preferable, and since the appearance is transparent, SiO 2 or AlO 2 is particularly preferable.

[0032] The thickness of the water vapor gas barrier layer 3 is 1 to 150 nm, preferably 5 to 60 nm or less, and more preferably 10 to 40 nm. If it is less than 1 nm, it may be difficult to block the water vapor gas permeation of the laminate 10. Also, if it exceeds 150 nm, cracks may occur in the vapor deposition film of the water vapor gas barrier layer 3, and the recycling of the laminate 10 may be difficult.

[0033] In the laminate 10 of the first embodiment, the first base material layer 1 and the water vapor gas barrier layer 3 are adhered by the adhesive layer 2. Here, the adhesive layer 2 is not essential and is an arbitrarily provided layer. If the first base material layer 1 and the water vapor gas barrier layer 3 are bonded by heating or the like, the adhesive layer 2 is not necessary. However, when bonded by the heating or the like, since it is easy to peel off, it is preferable to use the adhesive layer 2 to ensure adhesion.

[0034] As the adhesive used for the adhesive layer 2, known solventless adhesives and solvent-based adhesives can be used. From the viewpoint of environmental impact, it is preferable to use a solventless adhesive.

[0035] Examples of the solventless adhesive include urethane-based adhesives, epoxy-based adhesives, polyether-based adhesives, polyester-based adhesives, and silicone-based adhesives. Since the adhesion strength is strong and the shape of the packaging container can be flexibly adapted to deformation, it is preferable to use a urethane-based adhesive.

[0036] Examples of the solvent-based adhesive include urethane-based adhesives, acrylic-based adhesives, rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

[0037] The thickness of the adhesive layer 2 is 0.1 to 10 μm, preferably 1 to 5 μm, and more preferably 1 to 3 μm. If it is less than 0.1 μm, it may not be possible to obtain sufficient adhesive strength. Further, if it exceeds 10 μm, it may not be possible to flexibly respond to deformation of the shape of the packaging container, and recycling of the laminate 10 may be difficult.

[0038] FIG. 2 is a schematic side sectional view showing the layer structure of the laminate 20 of the second embodiment in 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 base material layer 1 and the adhesive layer 2.

[0039] The light-shielding layer 5 has the function of preventing the contents from being denatured, deteriorated, etc. when the laminate 20 is used as a packaging container by shielding light such as ultraviolet rays and visible light existing further outside the upper first base material layer 1 on the outside of the laminate 20, and improving the storage stability.

[0040] As the light-shielding layer 5, either a light-shielding printing layer or an inorganic vapor deposition layer can be used. The light-shielding printing layer is a layer provided by printing a single-color light-shielding ink on the lower surface of the first base material layer 1. The color of the light-shielding ink is not particularly limited, such as black, white, gray, orange, red, yellow, silver, and brown, etc., and it is desirable to change according to the type of the contents. Further, as the coloring pigment used in the light-shielding ink, known pigments such as carbon black, acetylene black, lamp black, soot, iron black, aniline black, titanium oxide, and zinc oxide can be used, and it is not particularly limited. Furthermore, it can be used not only as a single layer, but also as a multi-layer of different-color layers such as a white layer and a black layer, a yellow layer and a red layer, etc. as needed.

[0041] As the printing method of the light-shielding printing layer, known printing methods such as a gravure printing method, a flexographic printing method, an inkjet printing method, and an offset printing method can be used. From the viewpoint of environmental load, it is preferable to use the flexographic printing method.

[0042] The thickness of the light-shielding printing layer is 0.1 to 10 μm, preferably 1 to 5 μm, and more preferably 1 to 3 μm. If it is less than 0.1 μm, it may be impossible to prevent the contents from being denatured, deteriorated, etc. when used as a packaging container and improve the storage stability. Also, if it exceeds 10 μm, it may be impossible to flexibly cope with the deformation of the shape of the packaging container, and it may be difficult to recycle the laminate 10.

[0043] As the inorganic vapor deposition layer, the vapor deposition film of the inorganic substance described in the description of the water vapor gas barrier layer 3 can be used, and the vapor deposition film is formed in close contact with the lower surface of the first base material layer 1. Regarding the vapor deposition means, method, type of inorganic substance, thickness, etc., the description content regarding the vapor deposition film of the inorganic substance in the description of the water vapor gas barrier layer 3 is incorporated by reference. Therefore, the inorganic vapor deposition layer not only has the action and function as the light shielding layer 5, but also has the action and function as the water vapor gas barrier layer 3. Here, as the type of inorganic substance, it is preferable to use aluminum (Al) because it is suitable for the packaging container.

[0044] By adopting the light shielding layer 5, the visible light transmittance (380 to 800 nm) measured using the ultraviolet-visible spectrophotometer of the laminate of the present invention can be arbitrarily controlled to 90% or less, preferably 50% or less, and more preferably 10% or less. When it exceeds 90%, the laminate 20 is almost transparent, and when the laminate 20 is used as a packaging container, it may not be able to exhibit the functions of preventing the modification and deterioration of the contents and improving the storage stability.

[0045] FIG. 3 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 according to the second embodiment, the adhesive layer 2 is provided in two layers, and a second base material layer 6 is laminated between the two adhesive layers 2.

[0046] Since the same polyolefin as the first base material layer 1 can be used for the second base material layer 6, the description content regarding the polyolefin in the description of the first base material layer 1 is incorporated by reference. By laminating the second base material layer 6, the laminate of the present invention can obtain a higher water vapor gas barrier property.

[0047] FIG. 4 is a schematic side sectional view showing the layer structure of the laminate 40 according to the fourth embodiment of the present invention. Instead of laminating the light shielding layer 5 on the lower surface of the first base material layer 1 with respect to the layer structure of the laminate 30 according to the third embodiment, the light shielding layer 5 is laminated on the upper surface of the second base material layer 6.

[0048] A normal printing layer 7 may be laminated on the lower surface of the first base material layer 1, and the normal printing layer 7 can be a multicolor printing layer of characters such as product names, patterns, and images. As the printing method of the light-shielding printing layer, known printing methods such as gravure printing, flexographic printing, inkjet printing, and offset printing can be used. By laminating the normal printing layer 7, added values such as improved distinguishability from other companies' products and improved product value can be imparted to the packaging container using the laminate of the present invention.

[0049] Regarding the means and method of laminating the light-shielding layer 5 on the upper surface of the second base material layer 6, since it is the same as the case of laminating the light-shielding layer 5 on the lower surface of the first base material layer 1 in the second embodiment, the description content regarding the means and method in the case of laminating the light-shielding layer 5 on the lower surface of the first base material layer 1 is incorporated by reference. In addition, when the light-shielding layer 5 is a light-shielding printing layer, instead of laminating the light-shielding layer 5 on the upper surface of the base material layer 6, the light-shielding layer 5 may be laminated on the lower surface of the normal printing layer 7.

[0050] The polyolefin in the heat-sealing layer 4 in the laminates 10, 20, 30, and 40 described in the first to fourth embodiments preferably has a xylene-soluble content ratio of 10 to 20% by mass and has been subjected to stretching processing. More preferably, the xylene-soluble content ratio is 12 to 18% by mass. Here, the xylene-soluble content ratio is the dissolution ratio of the mass after immersion to the mass before immersion when the polyolefin is immersed in xylene at normal temperature, and is a physical property showing a correlation with stretch processability. Therefore, if the xylene-soluble content ratio is within the above numerical range, the polyolefin in the heat-sealing layer 4 has appropriate stretch processability. If the xylene-soluble content ratio is less than 10% by mass, it may not be possible to obtain sufficient stretch processability, and if it exceeds 20% by mass, the blocking resistance during storage of the polyolefin may deteriorate.

[0051] It is preferable that the polyolefin in the heat seal layer 4 has a peak intensity ratio observed by X-ray diffraction measurement using Cu-Kα rays such that MD / TD > 1 or TD / MD > 1. For the peak, for example, peaks at 2θ = 14° or 17° derived from (110) and (040) of polypropylene crystals are used. Here, MD means the stretching direction, and TD means the transverse direction perpendicular to the stretching direction. When the peak intensity ratio is MD / TD > 1 or TD / MD > 1, it indicates that the polyolefin in the heat seal layer is excellent in linear cutability in the MD direction or TD direction due to molecular orientation by stretching processing, enabling the laminate of the present invention to be easily torn with a small force.

[0052] It is preferable that the polyolefin in the first base material layer 1 and / or the second base material layer 6 has a peak intensity ratio observed by the X-ray diffraction measurement such that MD / TD > 1 or TD / MD > 1. Here, similar to the heat seal layer, when the peak intensity ratio is MD / TD > 1 or TD / MD > 1, it indicates that the polyolefin in the first base material layer and the second base material layer is excellent in linear cutability in the MD direction or TD direction due to molecular orientation by stretching processing, enabling the laminate of the present invention to be easily torn with a small force.

[0053] It is preferable that the polyolefin in the first base material layer 1 and / or the second base material layer 6 has a heat shrinkage rate observed by heat shrinkage rate measurement such that MD > TD or MD < TD. Here, the heat shrinkage rate measurement is performed using, for example, a thermomechanical analyzer (TMA). The heat shrinkage rate is represented by (L0 - L) / L0 × 100 (%) when the initial dimension is L0 and the dimension after heating to 120°C or 130°C is L, and the larger the numerical value, the greater the heat shrinkage. When the heat shrinkage rate is MD > TD or MD < TD, it indicates that the polyolefin is excellent in linear cutability in the MD direction or TD direction due to molecular orientation by stretching processing, enabling the laminate of the present invention to be easily torn with a small force.

[0054] It is preferable that the polyolefin in the second base material layer 6 has a half-cut process with a depth of 10 to 90% in the thickness direction, and more preferably a depth of 20 to 80%. Here, the half-cut process means a cutting process in the thickness direction using a press blade, a laser, or the like. Due to the presence of the cutting process, the laminate of the present invention can be easily torn with a small force.

[0055] <Packaging container> FIG. 5 is a schematic side cross-sectional view showing the layer structure of a packaging container 50 formed by using two laminates 10 shown in FIG. 1, with their respective heat-seal layers 4 on the inside and fusing the right half using a heat sealer. Here, the water vapor gas barrier layer 3 in each laminate 10 blocks the water vapor gas existing outside the packaging container, so that the contents filled in the packaging container 50 can be stored for a long time while maintaining a dry state without being affected by humidity.

Examples

[0056] The present invention will be described in detail below with reference to examples. Note that the present invention is not limited to the examples.

[0057] The measurement methods for the respective physical properties used in the examples and comparative examples are shown below. <Water vapor permeability> Using the laminate as a sample, the water vapor permeability (g / m 2 / day / atm) was measured under the conditions of 40 ° C and 90% RH using a water vapor transmission rate measuring device (PERMATRAN-W 3 / 34 G manufactured by Mocon).

[0058] <Visible light transmittance> Using the laminate as a sample, the light transmittance (%) in the range of 380 to 800 nm was measured using an ultraviolet-visible-near-infrared spectrophotometer (UV-3600 manufactured by Shimadzu Corporation).

[0059] <Storage stability test> Using two laminates, a packaging container filled with 50 g of sports drink powder produced by heat sealing was used as a sample, and a storage stability test was conducted for 90 days in an environment of 30 °C / 80% RH using a thermostatic and high humidity chamber. During the 90 days, the weight (mg) of the packaging container was measured as appropriate. Since the weight increases when moisture is absorbed, the water vapor gas barrier property was evaluated.

[0060] The types of films used in the examples and comparative examples are shown below. <Film> (A) Substrate layer film A: Biaxially stretched polypropylene (OPP) was used as the substrate layer film A. Thickness 20 μm (B) Substrate layer film B with a light-shielding layer (light-shielding printing layer): A film in which a white ink layer was formed by gravure printing on one side of the substrate layer film and then a gray ink layer was further formed was used as the substrate layer film B with a light-shielding layer (light-shielding printing layer). Thickness 20 μm (C) Substrate layer film C with a light-shielding layer (inorganic vapor deposition layer): A film in which aluminum was vapor-deposited on one side of the substrate film was used as the substrate layer film C with a light-shielding layer (inorganic vapor deposition layer). Thickness 25 μm (D) Heat-sealing layer film D: Unstretched polypropylene (CPP) was used as the heat-sealing layer film D. Thickness 40 μm (E) Heat-sealing layer film E with a water vapor gas barrier layer: A film in which silicon dioxide (SiO 2 ) was vapor-deposited on one side of the heat-sealing layer film was used as the heat-sealing layer film E with a water vapor gas barrier layer. Thickness 25 μm

[0061] (Example 1) As shown in the layer structure of the laminate 10 of the first embodiment shown in FIG. 1, using the substrate layer film A as the outer substrate layer 1, a urethane-based adhesive was applied to the inner surface by a bar coater at about 4 g / m 2Coating was performed with the coating amount of 2 and this was used as the urethane-based adhesive layer as the adhesive layer 2. In a state where the urethane-based adhesive layer was semi-dried, as the water vapor gas barrier layer 3 and the heat seal layer 4, a heat seal layer film E with a water vapor gas barrier layer was adhered so that the water vapor gas barrier layer faced the adhesive layer, and the laminate of Example 1 was produced. The laminate of Example 1 can be represented as "OPP(1) / urethane adhesive layer(2) / SiO

[0062] Using the laminate of Example 1 as a sample, the water vapor permeability and the visible light transmittance were measured, and the measurement results are shown in Table 2. Also, using two laminates of Example 1, with each heat seal layer on the inside, sealing was performed using a heat sealer under the conditions of 180 °C, 0.3 MPa, and 1.0 second, and a packaging container with only one side of the inner dimension of 100 mm (vertical) × 100 mm (horizontal) open was produced. Subsequently, 50 g of sports drink powder was filled from the open side of the packaging container, and then sealing was performed using a heat sealer under the same conditions as above, and each packaging container was sealed. Using the sealed packaging container as a sample, a storage stability test was performed, and the measurement results are shown in FIG. 6.

[0063] (Example 2) A laminate of Example 2 was produced in the same manner as in Example 1, except that a base material layer film B with a light-shielding layer (light-shielding printing layer) using the base material layer on the outside, a urethane-based adhesive, a base material layer film A, a urethane-based adhesive, and a heat seal layer film E with a water vapor gas barrier layer were used so as to have the layer structure of the laminate 30 of the third embodiment shown in FIG. 3. The laminate of Example 2 can be represented as "OPP(1) / light-shielding printing layer(5) / urethane adhesive layer(2) / OPP(6) / urethane adhesive layer(2) / SiO 2 vapor deposition layer(3) / CPP(4)". Also, in the same manner as in Example 1, the laminate of Example 2 was used as a sample, and the water vapor transmission rate and visible light transmittance were measured, and the measurement results are shown in Table 2. Further, using two laminates of Example 2, a packaging container filled with sports drink powder was used as a sample, and a storage stability test was conducted, and the measurement results are shown in FIG. 6.

[0064] (Example 3) The laminate of Example 3 was produced in the same manner as in Example 1, except that a base material layer film A was used as the outer base material layer 1, a urethane-based adhesive, a base material layer film C with a light-shielding layer (inorganic vapor deposition layer), a urethane-based adhesive, and a heat-sealing layer film E with a water vapor gas barrier layer were used so as to have the layer structure of the laminate 40 of the fourth embodiment shown in FIG. 4. The laminate of Example 2 can be expressed as "OPP(1) / urethane adhesive layer(2) / inorganic vapor deposition layer(5) / OPP(6) / urethane adhesive layer(2) / SiO 2 vapor deposition layer(3) / CPP(4)". Also, in the same manner as in Example 1, the laminate of Example 3 was used as a sample, and the water vapor transmission rate and visible light transmittance were measured, and the measurement results are shown in Table 2. Further, using two laminates of Example 3, a packaging container filled with sports drink powder was used as a sample, and a storage stability test was conducted, and the measurement results are shown in FIG. 6.

[0065] (Comparative Examples 1 and 2) In the laminates of Examples 1 and 3, by using a heat-sealing layer film D instead of the heat-sealing layer film F with a water vapor gas barrier layer, Comparative Examples 1 and 2, which are the same as Examples 1 and 3 except that they do not include the "SiO 2 vapor deposition film(3)" corresponding to the water vapor gas barrier layer, were produced. The water vapor transmission rate and visible light transmittance of the laminates of Comparative Examples 1 and 2 were measured using the laminates as samples, and the measurement results are shown in Table 2. Further, using two laminates each of Comparative Examples 1 and 2, a packaging container filled with sports drink powder was used as a sample, and a storage stability test (evaluation of water vapor gas barrier property) was conducted, and the measurement results are shown in FIG. 6.

[0066] Table 1 shows the layer configurations of Examples 1 to 3 and Comparative Examples 1 and 2.

[0067]

Table 1

[0068] Table 2 shows the measurement results of the water vapor transmission rate and visible light transmittance of Examples 1 to 3 and Comparative Examples 1 and 2.

[0069]

Table 2

[0070] The water vapor transmission rate (g / m 2 / day / atm) of the laminates of Examples 1 to 3 in Table 2 was all less than 0.2, indicating that almost no water vapor permeated. However, Comparative Examples 1 and 2 were "greater than 1" and "0.4" respectively, indicating that water vapor permeated to a certain extent. Also, for the laminates of "Example 1 / Comparative Example 1" and "Example 3 / Comparative Example 2", although they differed in the presence or absence of the SiO 2 evaporated film, which is a water vapor gas barrier layer, in the "Example / Comparative Example" layer structure, the visible light transmittance was almost the same at "93 / 92" and "0.8 / 0.9" respectively. It can be seen that the SiO 2 evaporated film is transparent to such an extent that it does not affect the visible light transmittance.

[0071] In the 90-day storage stability test shown in Figure 6, the packaging container of Example 1 had a slight weight increase, but there was almost no weight increase for the packaging containers of Examples 2 and 3. It can be seen that the packaging containers of Examples 1 to 3 have high water vapor gas barrier properties. In contrast, the packaging containers of Comparative Examples 1 and 2 absorbed moisture in the environment and had a large weight increase. After 90 days of storage, when each packaging container was opened, the sports drink powders of Examples 1 to 3 maintained the same dry state as when filled, and no aggregation due to moisture was observed. However, for Comparative Examples 1 and 2, aggregation of the sports drink powder occurred due to moisture, and in particular, it was observed that Comparative Example 1 was strongly aggregated.

Industrial Applicability

[0072] The laminate of the present invention has at least a first base material layer, a water vapor gas barrier layer, and a heat seal layer, and is a laminate laminated in this order from the outside to the inside. The laminate in which the first base material layer and the heat seal layer are made of polyolefin, and a packaging container using the laminate. When the contents filled in the packaging container are greatly deteriorated or deteriorated due to the influence of humidity, such as sugar, salt, sports drink powder, etc., but are not greatly deteriorated or deteriorated due to the influence of oxygen, the gas barrier property of the packaging container can be a low-cost packaging container without being an excessive performance. Further, since the first base material layer and the heat seal layer are a laminate made of polyolefin, when the water vapor gas barrier layer is composed of a material that can be recycled together with polyolefin, a laminate and a packaging container excellent in recyclability can be obtained.

Explanation of Signs

[0073] 1 First base material layer 2 Adhesive layer 3 Water vapor gas barrier layer 4 Heat seal layer 5 Light shielding layer 6 Second base material layer 10 Laminate of the first embodiment 20 Laminate of the second embodiment 30 Laminate of the third embodiment 40 Laminate of the fourth embodiment 50 Packaging container

Claims

1. A laminate having at least a first base material layer, a water vapor gas barrier layer, and a heat seal layer, laminated in this order from the outside to the inside, wherein the first base material layer and the heat seal layer are made of polyolefin, and the polyolefin in the heat seal layer has a peak intensity ratio observed by X-ray diffraction measurement of MD / TD > 1 or TD / MD > 1.

2. The laminate according to claim 1, having a light-shielding layer between the first base material layer and the water vapor gas barrier layer.

3. The laminate according to claim 2, having a second base material layer made of polyolefin between the light-shielding layer and the water vapor gas barrier layer.

4. The laminate according to claim 2, having a normal printing layer between the first base material layer and the light-shielding layer.

5. The laminate according to claim 2, wherein the light-shielding layer is a light-shielding printing layer or an inorganic vapor deposition layer.

6. The laminate according to claim 2, having a visible light transmittance of 90% or less.

7. The laminate according to claim 1, wherein the polyolefin in the heat seal layer has a xylene soluble content of 10 to 20% by mass and has been subjected to stretching processing.

8. The laminate according to claim 3, wherein the polyolefin in the first base material layer and / or the second base material layer has a peak intensity ratio observed by X-ray diffraction measurement of MD / TD > 1 or TD / MD > 1.

9. The laminate according to claim 3, wherein the polyolefin in the first base material layer and / or the second base material layer has a heat shrinkage ratio observed by heat shrinkage ratio measurement of MD > TD or MD < TD.

10. The laminate according to claim 3, wherein the polyolefin in the second base material layer has a half-cut process with a depth of 10 to 90% in the thickness direction.

11. A packaging container using the laminate according to any one of claims 1 to 10.

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