JP7496070B2 - Laminate, packaging material, packaging bag and stand-up pouch - Google Patents

Description

The present invention relates to a laminate, a packaging material, a packaging bag, and a stand pouch.

Conventionally, resin films made of resin materials have been used as a constituent material of packaging materials. For example, resin films made of polyethylene have moderate flexibility and transparency, and also have excellent heat sealability, so they are widely used as packaging materials.

Normally, resin films made of polyethylene cannot be used as a base material because they are inferior in terms of strength and heat resistance, so ordinary packaging materials are made of laminated films in which the base material and the heat seal layer are made of different types of resin materials (for example, Patent Document 1).

For example, a laminated film having a polyester base material, a polyamide resin layer, and a heat seal layer has been widely used.

In recent years, with the growing demand for a recycling-oriented society, there is a demand for packaging materials with high recyclability. However, as mentioned above, conventional packaging materials are composed of multiple different types of resin materials, and because it is difficult to separate the individual resin materials, they are not currently recycled.

JP 2009-202519 A

The present inventors have found that by forming the polyethylene, which has conventionally been used as a heat seal layer, into a stretched film, it is possible to improve the strength and heat resistance, and even when the polyethylene is substituted for the polyamide resin layer of the above-mentioned laminate, the strength and heat resistance of the laminate can be maintained, and further, the recyclability of packaging materials and the like produced from the laminate can be significantly improved.
Furthermore, it was discovered that by using biomass-derived polyethylene as the polyethylene, the environmental impact of the produced packaging materials can be further reduced.

The present invention has been made in light of the above findings, and the problem to be solved by the present invention is to provide a laminate that can realize a packaging material that has excellent recyclability while also having the strength and other properties required for a packaging material.
Another problem to be solved by the present invention is to provide a packaging material formed from the laminate.

The laminate of the present invention comprises a substrate, an intermediate layer, and a heat seal layer,
The substrate is made of polyester,
The heat seal layer is made of polyethylene;
The intermediate layer is a stretched film,
At least one of the intermediate layer and the heat seal layer contains biomass-derived polyethylene as the polyethylene;
The thickness of the substrate is smaller than the sum of the thickness of the intermediate layer and the thickness of the heat seal layer.

In one embodiment of the present invention, the intermediate layer and the heat seal layer contain biomass-derived polyethylene as the polyethylene.

In one embodiment of the present invention, the laminate further comprises a vapor-deposited film between the substrate and the intermediate layer.

In one embodiment of the present invention, an adhesive layer is further provided between the vapor-deposited film and the intermediate layer,
the vapor-deposited film is an aluminum vapor-deposited film,
The adhesive layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound.

In one embodiment of the present invention, the difference between the thickness of the substrate and the sum of the thickness of the intermediate layer and the thickness of the heat seal layer is 40 μm or more.

In one embodiment of the present invention, the polyethylene content in the entire laminate is 80% by mass or more.

In one embodiment of the present invention, the laminate is used for packaging material applications.

The packaging material of the present invention is characterized by being made using the above laminate.

The packaging bag of the present invention is produced using the laminate,
The heat seal layer has a thickness of 20 μm or more and 60 μm or less.

The stand-up pouch of the present invention is produced using the laminate,
The heat seal layer has a thickness of 50 μm or more and 200 μm or less.

The present invention provides a laminate that can realize a packaging material that has the strength required for packaging and is also highly recyclable.

1 is a schematic cross-sectional view showing one embodiment of a laminate of the present invention. 1 is a schematic cross-sectional view showing one embodiment of a laminate of the present invention. 1 is a schematic cross-sectional view showing one embodiment of a laminate of the present invention. FIG. 1 is a perspective view showing one embodiment of a packaging material produced using a laminate of the present invention. FIG. 1 is a perspective view showing one embodiment of a packaging material produced using a laminate of the present invention.

<Laminate>
The laminate according to the present invention will now be described with reference to the drawings.
As shown in FIG. 1, the laminate 10 includes a substrate 11 , an intermediate layer 12 , and a heat seal layer 13 .

In one embodiment of the present invention, the laminate 10 may further include a vapor deposition film 14 between the substrate 11 and the intermediate layer 12, as shown in FIG. 2.

Furthermore, in one embodiment of the present invention, the laminate 10 may further include an adhesive layer 15 at least one between the substrate 11 or the vapor deposition film 14 and the intermediate layer 12, and between the intermediate layer 12 and the heat seal layer 13, as shown in FIG. 3.

In addition, the laminate of the present invention is characterized in that the thickness of the substrate is smaller than the sum of the thickness of the intermediate layer and the thickness of the heat seal layer, thereby improving the recyclability of packaging materials and the like produced using the laminate of the present invention.
The difference between the thickness of the substrate and the sum of the thickness of the intermediate layer and the thickness of the heat seal layer is preferably 40 μm or more, and more preferably 100 μm or more.

In the laminate of the present invention, the polyethylene content is preferably 80% by mass or more, and more preferably 80% by mass or more.
By making the content of polyethylene in the entire laminate of the present invention 80% by mass or more, the recyclability of the laminate of the present invention can be improved.
The content of polyethylene in the laminate means the ratio of the content of polyethylene to the sum of the contents of the resin materials in each layer constituting the laminate.

The layers constituting the laminate of the present invention are described below.

<Substrate>
The substrate included in the laminate of the present invention is characterized by being composed of polyester, which can improve the strength and heat resistance of the laminate of the present invention.

Examples of polyesters include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene isophthalate, polybutylene naphthalate (PBN), polypropylene terephthalate (PPT), polybutylene naphthalate (PBN), etc. Among these, polyethylene terephthalate (PET) is preferred from the viewpoint of the strength and heat resistance of the laminate.

The substrate may contain additives within the range that does not impair the characteristics of the present invention, such as crosslinking agents, antioxidants, antiblocking agents, slip agents, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

The substrate may be a stretched polyester film, which can improve the heat resistance and strength of the laminate and also improve the printability of the intermediate layer.
The stretched film may be a uniaxially stretched film or a biaxially stretched film.

The substrate may have an image formed on its surface.
It is preferable that an image is formed on the surface on which a heat seal layer described below is provided, since this can prevent contact with the outside air and deterioration over time.
The image to be formed is not particularly limited, and may be a character, a pattern, a symbol, or a combination thereof.
The image formation on the substrate is preferably carried out using ink derived from biomass, whereby the laminate of the present invention can be used to produce packaging materials with less environmental impact.
The method for forming the image is not particularly limited, and examples of the method include conventionally known printing methods such as gravure printing, offset printing, flexographic printing, etc. Among these, flexographic printing is preferred from the viewpoint of environmental load.
The method of the surface treatment is not particularly limited, and examples thereof include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and/or nitrogen gas, and glow discharge treatment, as well as chemical treatments such as oxidation treatment using chemicals.
Furthermore, an anchor coat layer may be formed on the surface of the substrate using a conventionally known anchor coat agent.

The thickness of the substrate is preferably 10 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less.
By making the thickness of the substrate 10 μm or more, the strength and heat resistance of the laminate of the present invention can be improved, and by making the thickness of the substrate 50 μm or less, the recyclability of the laminate of the present invention can be improved.

The substrate can be produced by forming a polyester film using a T-die method or an inflation method, etc., and then stretching the film.

The substrate is not limited to those prepared by the above method, and commercially available substrates may also be used.

<Middle class>
The intermediate layer provided in the laminate of the present invention is made of polyethylene, and the heat seal layer described below is also made of polyethylene.
By adopting such a configuration, the recyclability of the laminate can be improved.
Furthermore, in the present invention, at least one of the polyethylene constituting the intermediate layer and the polyethylene constituting the heat seal layer contains biomass-derived polyethylene as the polyethylene, thereby making it possible to make the packaging material produced from the laminate of the present invention more environmentally friendly.

The intermediate layer is a stretched film made of polyethylene, which improves the heat resistance and strength of the laminate and also improves the printability of the intermediate layer.
The stretched film may be a uniaxially stretched film or a biaxially stretched film.

The stretching ratio in the machine direction (MD) of the stretched film is preferably 2 times or more and 10 times or less, and more preferably 3 times or more and 7 times or less.
By making the stretching ratio in the machine direction (MD) of the stretched film 2 times or more, the strength and heat resistance of the laminate of the present invention can be improved. Furthermore, the printability of the intermediate layer can be improved. On the other hand, the upper limit of the stretching ratio in the machine direction (MD) of the stretched film is not particularly limited, but it is preferably 10 times or less from the viewpoint of the breaking limit of the stretched film.

The stretching ratio in the transverse direction (TD) of the stretched film is preferably 2 to 10 times, more preferably 3 to 7 times.
By setting the stretching ratio in the transverse direction (TD) of the stretched film to 2 times or more, the strength and heat resistance of the laminate of the present invention can be improved. On the other hand, the upper limit of the stretching ratio in the transverse direction (TD) of the stretched film is not particularly limited, but is preferably set to 10 times or less from the viewpoint of the breaking limit of the stretched film.

The intermediate layer may have an image formed on its surface. The method for forming the image is as described above.

The polyethylene contained in the intermediate layer may be high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE) or very low density polyethylene (VLDPE).
Here, the high-density polyethylene may be polyethylene having a density of 0.945 g/ ^cm3 or more, the medium-density polyethylene may be polyethylene having a density of 0.925 g/cm3 or ^more and less than 0.945 g/ ^cm3 , the low-density polyethylene may be polyethylene having a density of 0.900 g/ ^cm3 or more and less than 0.925 g/ ^cm3 , the linear low-density polyethylene may be polyethylene having a density of 0.900 g/ ^cm3 or more and less than 0.925 g/ ^cm3 , and the very low-density polyethylene may be polyethylene having a density less than 0.900 g/ ^cm3 .
Among these, high density polyethylene and medium density polyethylene are preferred from the viewpoints of the strength and heat resistance of the laminate of the present invention and suitability for stretching the film, and medium density polyethylene is more preferred from the viewpoint of suitability for stretching.

In one embodiment, the intermediate layer may be configured to include a layer made of high density polyethylene (hereinafter referred to as high density polyethylene layer) and a layer made of medium density polyethylene (hereinafter referred to as medium density polyethylene layer).
By providing a high-density polyethylene layer on the outer side of the intermediate layer, the strength and heat resistance of the laminate of the present invention can be further improved, and by providing a medium-density polyethylene layer, the stretchability of the resin film constituting the intermediate layer can be further improved.

For example, it has a structure of a co-extruded film of a high density polyethylene layer and a medium density polyethylene layer from the outside.
By adopting such a configuration, the stretchability of the resin film can be improved.
In addition, the strength and heat resistance of the laminate of the present invention can be improved.
In this case, the thickness of the high density polyethylene layer is preferably thinner than the thickness of the medium density polyethylene layer.
The ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer is preferably 1/10 or more and 1/1 or less, and more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer to be 1/10 or more, the strength and heat resistance of the laminate of the present invention can be further improved. Also, by setting the ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer to be 1/1 or less, the stretchability of the resin film can be further improved.

Also, for example, it may be configured as a three-layered co-extruded film having, from the outside, a high density polyethylene layer, a medium density polyethylene layer and a high density polyethylene layer.
By adopting such a constitution, the stretchability of the resin film can be further improved, the strength and heat resistance of the laminate of the present invention can be further improved, and curling in the intermediate layer can be prevented.
In this case, the thickness of the high density polyethylene layer is preferably thinner than the thickness of the medium density polyethylene layer.
The ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer is preferably 1/10 or more and 1/1 or less, and more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer to be 1/10 or more, the strength and heat resistance of the laminate of the present invention can be further improved. Also, by setting the ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer to be 1/1 or less, the stretchability of the resin film can be further improved.

Also, for example, the film may be configured as a five-layer co-extruded film having, from the outside, a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer or an ultra-low-density polyethylene layer (in this paragraph, for the sake of simplicity, these are collectively referred to as a low-density polyethylene layer), a medium-density polyethylene layer and a high-density polyethylene layer.
By adopting such a configuration, the stretchability of the resin film can be improved.
Furthermore, the strength and heat resistance of the laminate of the present invention can be improved, and curling in the intermediate layer can be prevented.
Furthermore, the production efficiency of the resin film can be improved as described below.
In this case, the thickness of the high density polyethylene layer is preferably thinner than the thickness of the medium density polyethylene layer.
The ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer is preferably 1/10 or more and 1/1 or less, and more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer to be 1/10 or more, the strength and heat resistance of the laminate of the present invention can be improved. Also, by setting the ratio of the thickness of the high density polyethylene layer to the thickness of the medium density polyethylene layer to be 1/1 or less, the stretchability of the resin film can be improved.
In addition, the thickness of the high density polyethylene layer is preferably the same as or greater than the thickness of the low density polyethylene layer.
The ratio of the thickness of the high density polyethylene layer to the thickness of the low density polyethylene layer is preferably 1/0.25 or more and 1/2 or less, and more preferably 1/0.5 or more and 1/1 or less.
By setting the ratio of the thickness of the high density polyethylene layer to the thickness of the low density polyethylene layer to be 1/0.25 or more, the heat resistance can be improved. Also, by setting the ratio of the thickness of the high density polyethylene layer to the thickness of the low density polyethylene layer to be 1/1 or less, the adhesion between the medium density polyethylene layers can be improved.
In one embodiment, the intermediate layer having such a configuration can be produced by, for example, an inflation method.
Specifically, the film can be produced by co-extruding, from the outside, a high-density polyethylene layer, a medium-density polyethylene layer, and a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer into a tubular shape, and then pressing the opposing low-density polyethylene layers, linear low-density polyethylene layers, or ultra-low-density polyethylene layers together using a rubber roll or the like.
By using such a method, the number of defective products during manufacturing can be significantly reduced, and ultimately, production efficiency can be improved.
In addition, the stretching can also be carried out in the inflation film forming machine, which can further improve the production efficiency.

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

The single-site catalyst is a catalyst capable of forming a uniform active species, and is usually prepared by contacting a metallocene transition metal compound or a nonmetallocene transition metal compound with an activating cocatalyst. Compared to multi-site catalysts, single-site catalysts have a uniform active site structure, and are therefore preferred because they can polymerize polymers with high molecular weights and highly uniform structures. As a single-site catalyst, it is particularly preferred to use a metallocene catalyst. A metallocene catalyst is a catalyst that contains each of the catalytic components of a transition metal compound of Group IV of the periodic table that contains a ligand having a cyclopentadienyl skeleton, a cocatalyst, and if necessary, an organometallic compound and a carrier.

In the above-mentioned transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. The substituted cyclopentadienyl group has at least one substituent selected from a hydrocarbon group having 1 to 30 carbon atoms, a silyl group, a silyl-substituted alkyl group, a silyl-substituted aryl group, a cyano group, a cyanoalkyl group, a cyanoaryl group, a halogen group, a haloalkyl group, a halosilyl group, or the like. The substituted cyclopentadienyl group may have two or more substituents, and the substituents may be bonded to each other to form a ring, such as an indenyl ring, a fluorenyl ring, an azulenyl ring, or a hydrogenated product thereof. The rings formed by bonding the substituents to each other may further have substituents.

In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the transition metal may be zirconium, titanium, hafnium, etc., and zirconium and hafnium are particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and it is preferred that the ligands having the cyclopentadienyl skeleton are bonded to each other by a bridging group. Examples of the bridging group include alkylene groups having 1 to 4 carbon atoms, silylene groups, substituted silylene groups such as dialkylsilylene groups and diarylsilylene groups, and substituted germylene groups such as dialkylgermylene groups and diarylgermylene groups. The substituted silylene group is preferred. The above transition metal compounds of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be used as a catalyst component, either alone or in a mixture of two or more types.

The co-catalyst refers to a catalyst that can effectively use the above-mentioned transition metal compound of Group IV of the periodic table as a polymerization catalyst, or can balance the ionic charge in a catalytically activated state. Examples of the co-catalyst include benzene-soluble aluminoxanes of organoaluminum oxy compounds and benzene-insoluble organoaluminum oxy compounds, ion-exchangeable layered silicates, boron compounds, ionic compounds consisting of cations with or without active hydrogen groups and non-coordinating anions, lanthanoid salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing fluoro groups.

The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be used by being supported on an inorganic or organic carrier. The carrier is preferably an inorganic or organic porous oxide, and specifically includes ion-exchange layered silicate such as montmorillonite, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO ₂ , and mixtures thereof. Furthermore, examples of the organometallic compound that is used as necessary include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organoaluminum compounds are preferably used.

In addition, copolymers of ethylene and other monomers can also be used as long as they do not impair the characteristics of the present invention. Examples of ethylene copolymers include copolymers of ethylene and α-olefins having 3 to 20 carbon atoms, and examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene. In addition, copolymers with vinyl acetate or acrylic esters can be used as long as they do not impair the object of the present invention.

In the present invention, the polyethylene constituting the intermediate layer is preferably polyethylene derived from biomass.
Biomass-derived polyethylene refers to polyethylene that uses biomass-derived ethylene as a raw material instead of ethylene obtained from fossil fuels.
Such biomass-derived polyethylene is a carbon-neutral material, and therefore can be used as a packaging material with even less environmental impact.

In one embodiment, plant-derived ethylene can be obtained by fermenting sugar liquid or starch obtained from plants such as sugar cane, corn, and sweet potato with a microorganism such as yeast to produce bioethanol, and then heating the bioethanol in the presence of a catalyst.
Furthermore, the biomass-derived polyethylene may be commercially available (for example, Green PE available from Braskem).

In one embodiment, polyethylene recycled by mechanical recycling can also be used as the polyethylene. Mechanical recycling generally refers to a method in which recovered polyethylene films are crushed and washed with an alkali to remove dirt and foreign matter from the film surface, and then dried at high temperature and reduced pressure for a certain period of time to diffuse contaminants remaining inside the film, thereby removing dirt from the polyethylene film and returning it to polyethylene.

The intermediate layer may contain the above additives as long as they do not impair the properties of the present invention.

It is also preferable that the intermediate layer is subjected to the above-mentioned surface treatment. This improves adhesion to adjacent layers.

The thickness of the intermediate layer is preferably 9 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less.
By making the thickness of the intermediate layer 9 μm or more, the strength of the laminate of the present invention can be improved, and by making the thickness of the intermediate layer 50 μm or less, the processability of the laminate of the present invention can be improved.

The intermediate layer can be produced by forming polyethylene into a film using a T-die method or an inflation method, etc., and then stretching the film.

When the intermediate layer is produced by the T-die method, the MFR of the polyethylene is preferably 3 g/10 min or more and 20 g/10 min or less.
By setting the MFR of the polyethylene to 3 g/10 min or more, the processability of the laminate of the present invention can be improved, and by setting the MFR of the polyethylene to 20 g/10 min or less, the resin film can be prevented from breaking.

When the intermediate layer is produced by an inflation method, the MFR of the polyethylene is preferably 0.5 g/10 min or more and 5 g/10 min or less.
By making the MFR of the polyethylene 0.5 g/10 min or more, the processability of the laminate of the present invention can be improved, and by making the MFR of the polyethylene 5 g/10 min or less, the film formability can be improved.

The intermediate layer is not limited to that produced by the above method, and a commercially available intermediate layer may be used.

<Heat seal layer>
The heat seal layer of the laminate of the present invention is characterized by being composed of polyethylene, like the intermediate layer described above. By using the laminate of the present invention, it is possible to produce a packaging material having sufficient strength and heat resistance and being recyclable.
In the present invention, from the viewpoint of environmental load, the heat seal layer preferably contains, as the polyethylene, polyethylene derived from biomass.
However, the intermediate layer is formed from an unstretched polyethylene resin film or by melt extrusion of polyethylene.

From the viewpoint of heat sealability, the polyethylene constituting the heat seal layer is preferably low density polyethylene (LDPE), linear low density polyethylene (LLDPE) or very high density polyethylene (VLDPE).
Copolymers of ethylene and other monomers can be used as long as they do not impair the characteristics of the present invention.
From the viewpoint of environmental load, recycled polyethylene can be used.

The heat seal layer may contain the above additives as long as they do not impair the properties of the present invention.

In one embodiment, the heat seal layer has a multi-layer structure and includes, as an intermediate layer, a layer containing at least one of medium density polyethylene and high density polyethylene.
Specifically, the laminate may be configured as a layer containing at least one of low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene/a layer containing at least one of medium-density polyethylene and high-density polyethylene/a layer containing at least one of low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene.
By adopting such a configuration, the bag-making suitability and strength of the laminate of the present invention can be further improved while maintaining the heat sealability.

It is preferable that the thickness of the heat seal layer is appropriately changed depending on the weight of the contents to be filled in the packaging material produced from the laminate of the present invention.
For example, when producing a packaging bag 20 as shown in FIG. 4 to be filled with a content of 1 g or more and 200 g or less, the thickness of the heat seal layer is preferably 20 μm or more and 60 μm or less.
By making the thickness of the heat seal layer 20 μm or more, it is possible to prevent the leakage of the filled contents due to the breakage of the heat seal layer, and by making the thickness of the heat seal layer 60 μm or less, it is possible to improve the processability of the laminate of the present invention.

Furthermore, for example, when producing a stand pouch 30 as shown in FIG. 5 for filling with a content of 50 g or more and 2000 g or less, the thickness of the heat seal layer is preferably 50 μm or more and 200 μm or less.
By making the thickness of the heat seal layer 50 μm or more, it is possible to prevent the leakage of the filled contents due to the breakage of the heat seal layer, and by making the thickness of the heat seal layer 200 μm or less, it is possible to improve the processability of the laminate of the present invention.
The shaded areas in Figures 4 and 5 are heat-sealed areas.

<Vapor-deposited film>
In one embodiment, the laminate of the present invention comprises a vapor-deposited film between the substrate and the intermediate layer.
This makes it possible to improve the gas barrier properties, particularly the oxygen barrier properties and water vapor barrier properties, of the laminate of the present invention.

Examples of vapor-deposited films include those composed of metals such as aluminum, and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide.

The thickness of the evaporated film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less.
By making the thickness of the vapor-deposited film 1 nm or more, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be further improved, and by making the thickness of the vapor-deposited film 150 nm or less, the occurrence of cracks in the vapor-deposited film can be prevented and the recyclability of the laminate of the present invention can be improved.

For the vapor-deposited film to be an aluminum vapor-deposited film, the OD value is preferably 2 or more and 3.5 or less. This makes it possible to improve the oxygen barrier property and water vapor barrier property while maintaining the productivity of the laminate of the present invention. In the present invention, the OD value can be measured in accordance with JIS-K-7361.

The vapor deposition film can be formed using a conventional method, for example, physical vapor deposition methods (PVD method) such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition methods (CVD method) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

Also, for example, a composite film consisting of two or more layers of vapor-deposited films of different inorganic oxides can be formed and used by combining both physical vapor deposition and chemical vapor deposition. The degree of vacuum in the vapor deposition chamber is preferably about 10 ^-2 to 10 ^-8 mbar before oxygen is introduced, and about 10 ^-1 to 10 ^-6 mbar after oxygen is introduced. The amount of oxygen introduced varies depending on the size of the vapor deposition machine. For the oxygen to be introduced, an inert gas such as argon gas, helium gas, or nitrogen gas may be used as a carrier gas to the extent that no problems occur. The film transport speed can be about 10 to 800 m/min.

It is preferable that the surface of the deposited film is subjected to the above-mentioned surface treatment. This can improve adhesion to adjacent layers.

<Adhesive Layer>
In one embodiment, the laminate of the present invention may include an adhesive layer between the substrate or the vapor-deposited film and the intermediate layer, or between the intermediate layer and the heat seal layer, thereby improving the adhesion between these layers.

The adhesive layer includes at least one adhesive, and may be a one-component curing type, a two-component curing type, or a non-curing type adhesive. The adhesive may be a solvent-free adhesive or a solvent-based adhesive, but from the viewpoint of environmental load, a solvent-free adhesive is preferably used.
Examples of solvent-free adhesives include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, two-component curing urethane adhesives can be preferably used.
Examples of the solvent-based adhesive include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

In addition, when a vapor-deposited film is provided between the vapor-deposited film and the intermediate layer and the vapor-deposited film is an aluminum vapor-deposited film, it is preferable that the adhesive layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound.
By configuring the adhesive layer in this way, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be further improved.
Furthermore, when a laminate having a vapor-deposited film is applied to a packaging material, a bending load is applied to the laminate by a molding machine, etc., which may cause cracks in the aluminum vapor-deposited film. By using the specific adhesive as described above, it is possible to suppress a decrease in the oxygen barrier property and water vapor barrier property even if cracks occur in the aluminum vapor-deposited film.

The polyester polyol has two or more hydroxyl groups as functional groups in one molecule, and the isocyanate compound has two or more isocyanate groups as functional groups in one molecule.
The polyester polyol has, for example, a polyester structure or a polyester polyurethane structure as a main skeleton.

Specific examples of resin compositions containing polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound include the PASLIM series sold by DIC Corporation.

The resin composition may further contain a plate-like inorganic compound, a coupling agent, cyclodextrin and/or its derivatives, etc.

As the polyester polyol having two or more hydroxyl groups in one molecule as a functional group, for example, the following [First Example] to [Third Example] can be used.
[Example 1] Polyester polyol obtained by polycondensation of an ortho-oriented polycarboxylic acid or its anhydride with a polyhydric alcohol. [Example 2] Polyester polyol having a glycerol skeleton. [Example 3] Polyester polyol having an isocyanuric ring. Each polyester polyol will be explained below.

The polyester polyol according to the first example is a polycondensate obtained by polycondensing a polycarboxylic acid component containing at least one or more types of orthophthalic acid and its anhydride, and a polyhydric alcohol component containing at least one type selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol.
In particular, polyester polyols in which the content of orthophthalic acid or its anhydride relative to the total amount of polyvalent carboxylic acids is 70 to 100% by mass are preferred.

The polyester polyol according to the first example essentially contains orthophthalic acid and its anhydride as the polycarboxylic acid component, but may be copolymerized with other polycarboxylic acid components as long as the effect of the present embodiment is not impaired.
Specifically, aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecane dicarboxylic acid, unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid, alicyclic polycarboxylic acids such as 1,3-cyclopentane dicarboxylic acid and 1,4-cyclohexane dicarboxylic acid, aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyl dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, anhydrides of these dicarboxylic acids, and ester-forming derivatives of these dicarboxylic acids, polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, etc. are exemplified. Among these, succinic acid, 1,3-cyclopentane dicarboxylic acid, and isophthalic acid are preferred.
Two or more of the above other polyvalent carboxylic acids may be used.

As a polyester polyol according to the second example, a polyester polyol having a glycerol skeleton represented by the general formula (1) can be mentioned.
In general formula (1), R ₁ , R ₂ and R ₃ each independently represent H (hydrogen atom) or a group represented by the following general formula (2).

In formula (2), n represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms.
However, at least one of R ₁ , R ₂ and R ₃ represents a group represented by formula (2).

In general formula (1), at least one of R ₁ , R ₂ and R ₃ must be a group represented by general formula (2). In particular, it is preferable that all of R ₁ , R ₂ and R ₃ are groups represented by general formula (2).

In addition, the compound may be a mixture _of two _{or more of a compound in which any one of R 1 ,} R ₂ , and R ₃ is a group represented by general formula (2), a compound in which any two of R 1, R ₂ , and R _{3 are groups represented by general formula (2), and a compound in which all of R 1, R 2, and R 3 are groups} represented by general formula (2).

X represents an optionally substituted arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group.
When X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. The substituents include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, a N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

In general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, or a dimethylbutylene group. Of these, a propylene group or an ethylene group is preferable, and an ethylene group is most preferable.

The polyester resin compound having a glycerol skeleton represented by general formula (1) can be synthesized by reacting glycerol, an aromatic polycarboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component as essential components.

Examples of aromatic polycarboxylic acids or anhydrides in which a carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride, naphthalene 2,3-dicarboxylic acid or anhydride, naphthalene 1,2-dicarboxylic acid or anhydride, anthraquinone 2,3-dicarboxylic acid or anhydride, and 2,3-anthracene carboxylic acid or anhydride.
These compounds may have a substituent at any carbon atom of the aromatic ring, such as a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, or a naphthyl group.

The polyhydric alcohol component may be an alkylene diol having 2 to 6 carbon atoms. Examples of such diols include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol.

The polyester polyol according to the third example is a polyester polyol having an isocyanuric ring represented by the following general formula (3).
In formula (3), R ₁ , R ₂ and R ₃ each independently represent "-(CH ₂ )n1-OH (wherein n1 represents an integer of 2 to 4)" or a structure represented by formula (4).

In general formula (4), n2 represents an integer of 2 to 4, n3 represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms), with the proviso that at least one of R ₁ , R ₂ , and R ₃ is a group represented by general formula (4).

In the general formula (3), the alkylene group represented by -(CH ₂ )n1- may be linear or branched. Among these, n1 is preferably 2 or 3, and most preferably 2.

In formula (4), n2 represents an integer of 2 to 4, and n3 represents an integer of 1 to 5.
X represents an optionally substituted arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group.

When X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. The substituents include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, a N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.
The substituent for X is preferably a hydroxyl group, a cyano group, a nitro group, an amino group, a phthalimido group, a carbamoyl group, an N-ethylcarbamoyl group, or a phenyl group, and most preferably a hydroxyl group, a phenoxy group, a cyano group, a nitro group, a phthalimido group, or a phenyl group.

In general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, or a dimethylbutylene group. Of these, a propylene group or an ethylene group is preferable, and an ethylene group is most preferable.

In formula (3), at least one of R ₁ , R ₂ and R ₃ is a group represented by formula (4). In particular, it is preferred that all of R ₁ , R ₂ and R ₃ are groups represented by formula (4).

In addition, the compound may be a mixture _of two or more _{of a compound in which any one of R 1 ,} R ₂ , and R ₃ is a group represented by general formula (4), a compound in which any two of R 1, R ₂ , and R _{3 are groups represented by general formula (4), and a compound in which all of R 1, R 2, and R 3 are groups} represented by general formula (4).

The polyester polyol having an isocyanuric ring represented by the general formula (3) can be synthesized by reacting a triol having an isocyanuric ring, an aromatic polycarboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component as essential components.

Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acid, such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.

Examples of aromatic polycarboxylic acids or anhydrides in which the carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride, naphthalene 2,3-dicarboxylic acid or anhydride, naphthalene 1,2-dicarboxylic acid or anhydride, anthraquinone 2,3-dicarboxylic acid or anhydride, and 2,3-anthracene carboxylic acid or anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring.

Such substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimido, carboxyl, carbamoyl, N-ethylcarbamoyl, phenyl, and naphthyl groups.

The polyhydric alcohol component may be an alkylene diol having 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol.
Among these, polyester polyol compounds having an isocyanuric ring, which use 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid as the triol compound having an isocyanuric ring, orthophthalic anhydride as the aromatic polycarboxylic acid or its anhydride in which the carboxylic acid is substituted at the ortho position, and ethylene glycol as the polyhydric alcohol, are particularly excellent in oxygen barrier properties and adhesive properties and are therefore preferred.

Isocyanuric rings are highly polar and trifunctional, and can increase the polarity of the entire system and increase the crosslinking density. From this perspective, it is preferable for the adhesive resin to contain 5% by mass or more of isocyanuric rings based on the total solid content.

The isocyanate compound has two or more isocyanate groups in the molecule.
The isocyanate compound may be either aromatic or aliphatic, and may be either a low molecular weight compound or a high molecular weight compound.
Furthermore, the isocyanate compound may be a blocked isocyanate compound obtained by subjecting a known isocyanate blocking agent to an addition reaction by a known, conventional appropriate method.
Among these, from the viewpoints of adhesiveness and retort resistance, polyisocyanate compounds having three or more isocyanate groups are preferred, and from the viewpoints of oxygen barrier property and water vapor barrier property, aromatic compounds are preferred.

Specific examples of the isocyanate compound include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, metaxylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds, as well as adducts, biurets, and allophanates obtained by reacting these isocyanate compounds with low-molecular-weight active hydrogen compounds or their alkylene oxide adducts, or high-molecular-weight active hydrogen compounds.
Examples of low molecular weight active hydrogen compounds include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine. Examples of molecular weight active hydrogen compounds include polymeric active hydrogen compounds such as various polyester resins, polyether polyols, and polyamides.

The phosphoric acid-modified compound is, for example, a compound represented by the following general formula (5) or (6).
In general formula (5), R ₁ , R ₂ and R ₃ are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms which has a (meth)acryloyloxy group, at least one of which is a hydrogen atom, and n is an integer of 1 to 4.
In the formula, R ₄ and R ₅ are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms and having a (meth)acryloyloxy group, n is an integer from 1 to 4, x is an integer from 0 to 30, and y is an integer from 0 to 30, except for the case where both x and y are 0.

More specifically, examples of such acids include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate, and one or more of these can be used.

The content of the phosphoric acid-modified compound in the resin composition is preferably from 0.005% by mass to 10% by mass, and more preferably from 0.01% by mass to 1% by mass.
By adjusting the content of the phosphoric acid-modified compound to 0.005% by mass or more, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be improved, and by adjusting the content of the phosphoric acid-modified compound to 10% by mass or less, the adhesiveness of the adhesive layer can be improved.

The resin composition containing the polyester polyol, the isocyanate compound and the phosphoric acid-modified compound may contain a plate-like inorganic compound, which can improve the adhesiveness of the adhesive layer and the bending load resistance of the laminate of the present invention.
Examples of the plate-like inorganic compounds include kaolinite-serpentine group clay minerals (such as halloysite, kaolinite, endelite, dickite, nacrite, antigorite, and chrysotile) and pyrophyllite-talc group (such as pyrophyllite, talc, and keroli).

Examples of the coupling agent include a silane-based coupling agent, a titanium-based coupling agent, and an aluminum-based coupling agent, which are represented by the following general formula (7). These coupling agents may be used alone or in combination of two or more kinds.

Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β(a Examples of such silanes include N-(aminoethyl) gamma-aminopropyl methyldimethoxysilane, N-β(aminoethyl) gamma-aminopropyl trimethoxysilane, N-β(aminoethyl) gamma-aminopropyl triethoxysilane, gamma-aminopropyl trimethoxysilane, gamma-aminopropyl triethoxysilane, N-phenyl-gamma-aminopropyl trimethoxysilane, gamma-chloropropyl trimethoxysilane, gamma-mercaptopropyl trimethoxysilane, 3-isocyanatopropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethyl-butylidene).

Examples of titanium-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(didodecyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctyl nor titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, diisostearoyl ethylene titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, and dicumyl phenyl oxyacetate titanate.

Specific examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethyl acetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkyl acetoacetate mono(dioctyl phosphate), aluminum 2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkyl acetoacetate aluminum oxide trimer.

The resin composition may contain cyclodextrin and/or a derivative thereof, which can improve the adhesiveness of the adhesive layer and the bending load resistance of the laminate of the present invention.
Specifically, for example, cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, hydroxyalkylated cyclodextrin, and other cyclodextrins in which the hydrogen atoms of the hydroxyl groups of the glucose units of cyclodextrin are substituted with other functional groups can be used. Branched cyclic dextrins can also be used.
Furthermore, the cyclodextrin skeleton in cyclodextrin and cyclodextrin derivatives may be any of α-cyclodextrin consisting of six glucose units, β-cyclodextrin consisting of seven glucose units, and γ-cyclodextrin consisting of eight glucose units.
These compounds may be used alone or in combination of two or more. Hereinafter, these cyclodextrins and/or their derivatives may be collectively referred to as dextrin compounds.

From the viewpoint of compatibility and dispersibility in the resin composition, it is preferable to use a cyclodextrin derivative as the cyclodextrin compound.

Examples of alkylated cyclodextrins include methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

Examples of acetylated cyclodextrins include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, and monoacetyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

Examples of hydroxyalkylated cyclodextrins include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

The thickness of the adhesive layer is preferably 0.5 μm or more and 6 μm or less, more preferably 0.8 μm or more and 5 μm or less, and even more preferably 1 μm or more and 4.5 μm or less.
By making the thickness of the adhesive layer 0.5 μm or more, the adhesiveness of the adhesive layer can be improved. In addition, when an adhesive layer made of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound is provided adjacent to an aluminum vapor deposition film, the bending load resistance of the laminate can be improved.
By setting the thickness of the adhesive layer to 6 μm or less, the processability of the laminate can be improved.

The adhesive layer can be formed by applying and drying onto a substrate or the like using a conventional method such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fontaine method, or transfer roll coating.

<Other demographics>
The laminate of the present invention may include a heat-resistant coating layer on the substrate.

The heat-resistant coating layer contains at least one resin material, such as polyester, polyolefin, cellulose resin, (meth)acrylic resin, urethane resin, and vinyl resin.

The ratio of the resin material contained in the heat-resistant coating layer to the sum of the resin materials contained in the laminate is preferably 3% by mass or less, and more preferably 1% by mass or less. This makes it possible to improve the heat resistance while maintaining the recyclability of the laminate of the present invention.

The thickness of the heat-resistant coating layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less. This allows the heat resistance of the laminate of the present invention to be improved while maintaining its recyclability.

<Applications>
The laminate of the present invention can be particularly suitably used for packaging material applications.
The shape of the packaging material is not particularly limited, and may be a packaging bag 20 as shown in Fig. 6, or a stand pouch 30 having a body 31 and a bottom 32 as shown in Fig. 7. In the stand pouch, only the body may be formed of the laminate, only the bottom may be formed of the laminate, or both the body and the bottom may be formed of the laminate.

The packaging bag can be produced by folding the laminate in half, overlapping the laminate so that the heat seal layer is on the inside, and heat sealing the ends.
Alternatively, the packaging bag can be produced by overlapping two laminates with their heat seal layers facing each other and heat sealing the ends thereof.

A stand pouch can be manufactured by heat sealing the laminate into a cylindrical shape with the heat seal layer on the inside to form a body, then folding the laminate into a V shape with the heat seal layer on the inside, sandwiching one end of the body, and heat sealing to form a bottom.

The heat sealing method is not particularly limited, and can be performed by known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, etc.

The contents filled in the packaging material are not particularly limited, and may be liquid, powder, or gel. In addition, the contents may be food or non-food.
After filling the container with the contents, the opening can be heat sealed to form a package.

The present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
Medium density polyethylene (density: 0.941 g/cm ³ , melting point: 129° C., MFR: 1.3 g/10 min, manufactured by Dow Chemical, trade name: Elite 5538G) was formed into a film by inflation molding to obtain a polyethylene film having a thickness of 100 μm.
This polyethylene film was stretched in the machine direction (MD) at a stretch ratio of 5 times to obtain an intermediate layer A having a thickness of 20 μm. The haze value of the intermediate layer A was measured and found to be 6.5%.

An image was formed on one side of the intermediate layer A by flexographic printing using the above water-based flexographic ink.

A 12 μm thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: E-5100) was prepared as the substrate, and the substrate and the image forming surface of the intermediate layer A were laminated using a two-component curing urethane adhesive (manufactured by Rock Paint Co., Ltd., product name: RU-77T/H-7). The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.

As the heat seal layer, linear low density polyethylene (density: 0.925, MFR: 1.9 g/10 min, manufactured by Prime Polymer, product name: SP2520) and biomass-derived linear low density polyethylene (density: 0.916 g/ ^cm3 , MFR: 1.3 g/10 min, biomass degree: 87%, manufactured by Braskem, product name: SLL18) were formed into a film by an inflation molding method to prepare a polyethylene film consisting of a linear low density polyethylene layer/biomass-derived linear low density polyethylene layer/linear low density polyethylene layer.
The linear low density polyethylene layer had a thickness of 30 μm, and the biomass-derived linear low density polyethylene layer had a thickness of 60 μm, resulting in a total thickness of 120 μm. This was laminated with intermediate layer A on the image forming surface of substrate A via a two-component curing urethane adhesive (manufactured by Rock Paint Co., Ltd., product name: RU-77T/H-7) to obtain a laminate of the present invention. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

Example 2
High density polyethylene (density: 0.961 g/ ^cm3 , melting point: 135°C, MFR: 0.7 g/10 min, ExxonMobil, product name: HTA108) and the above medium density polyethylene were formed into a polyethylene film by inflation molding, which was composed of a high density polyethylene layer/a medium density polyethylene layer/a high density polyethylene layer. The high density polyethylene layer had a thickness of 20 μm, and the medium density polyethylene layer had a thickness of 60 μm.
This polyethylene film was stretched in the longitudinal direction (MD) at a stretch ratio of 5 times to obtain an intermediate layer B having a total thickness of 20 μm, with the high density polyethylene layer being 4 μm thick and the medium density polyethylene layer being 12 μm thick. The haze value of intermediate layer B was measured and found to be 8.9%.

An image was formed on one side of the intermediate layer B by flexographic printing using the above water-based flexographic ink.

The above-mentioned polyethylene terephthalate film having a thickness of 12 μm was prepared as a substrate, and the substrate and the image forming surface of the above-mentioned intermediate layer B were laminated using the above-mentioned two-component curing urethane adhesive. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.

The above-mentioned polyethylene film having a thickness of 120 μm was prepared as a heat seal layer, and the heat seal layer and the intermediate layer B were laminated using the above-mentioned two-component curing urethane adhesive to obtain a laminate of the present invention. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

Example 3
The medium density polyethylene was formed into a film by inflation molding to obtain a polyethylene film having a thickness of 100 μm.
This polyethylene film was stretched in the machine direction (MD) and the transverse direction (TD) at a stretch ratio of 2.24 times to obtain an intermediate layer C having a thickness of 20 μm. The haze value of the intermediate layer C was measured and found to be 5.1%.

An image was formed on one surface of the intermediate layer C by flexographic printing using the above-mentioned water-based flexographic ink.

The above-mentioned polyethylene terephthalate film having a thickness of 12 μm was prepared as a substrate, and the substrate and the image forming surface of the above-mentioned intermediate layer C were laminated using the above-mentioned two-component curing urethane adhesive. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.

The above-mentioned polyethylene film having a thickness of 120 μm was prepared as a heat seal layer, and the heat seal layer and the intermediate layer C were laminated using the above-mentioned two-component curing urethane adhesive to obtain a laminate of the present invention. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

Example 4
The medium density polyethylene was formed into a film by inflation molding to obtain a polyethylene film having a thickness of 100 μm.
This polyethylene film was stretched in the machine direction (MD) at a stretch ratio of 5 times to obtain an intermediate layer D having a thickness of 20 μm. The haze value of the intermediate layer D was measured and found to be 6.5%.

An aluminum vapor deposition film with a thickness of 0.02 μm was formed on one side of the substrate by the PVD method.

The above-mentioned polyethylene terephthalate film having a thickness of 12 μm was prepared as a substrate, and the surface of the substrate on which the deposition film was formed and the above-mentioned intermediate layer D were laminated using the above-mentioned two-component curing urethane adhesive. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.

The above-mentioned polyethylene film having a thickness of 120 μm was prepared as a heat seal layer, and the heat seal layer and the intermediate layer D were laminated using the above-mentioned two-component urethane adhesive to obtain a laminate of the present invention. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

Example 5
A laminate of the present invention was produced in the same manner as in Example 4, except that the deposition film-formed surface of the substrate and the intermediate layer D were bonded together using a two-component curing adhesive containing an isocyanate compound and a phosphoric acid-modified compound (PASLIM VM001/VM102CP, manufactured by DIC Corporation).
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

<Comparative Example 1>
The medium density polyethylene was formed into a film by inflation molding to obtain an intermediate layer a having a thickness of 20 μm. The haze value of the intermediate layer a was measured and found to be 23.5%.

An image was formed on one surface of the intermediate layer a by flexographic printing using the above-mentioned water-based flexographic ink.

The above-mentioned polyethylene terephthalate film having a thickness of 12 μm was prepared as a substrate, and the substrate and the image forming surface of the above-mentioned intermediate layer a were laminated using the above-mentioned two-component curing urethane adhesive. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.

The above-mentioned polyethylene film having a thickness of 120 μm was prepared as a heat seal layer, and the heat seal layer and the intermediate layer a were laminated using the above-mentioned two-component curing urethane adhesive to obtain a laminate. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

<Comparative Example 2>
The high density polyethylene and the medium density polyethylene were formed into a film by inflation molding to prepare an intermediate layer b consisting of a high density polyethylene layer/a medium density polyethylene layer/a high density polyethylene layer. The high density polyethylene layer had a thickness of 4 μm, and the medium density polyethylene layer had a thickness of 12 μm. The haze value of the intermediate layer b was measured and found to be 28.8%.

An image was formed on one surface of the intermediate layer b by flexographic printing using the above-mentioned water-based flexographic ink.

The above-mentioned polyethylene terephthalate film having a thickness of 12 μm was prepared as a substrate, and the substrate and the image forming surface of the above-mentioned intermediate layer b were laminated using the above-mentioned two-component curing urethane adhesive. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.

The above-mentioned polyethylene film having a thickness of 120 μm was prepared as a heat seal layer, and the heat seal layer and the intermediate layer b were laminated using the above-mentioned two-component curing urethane adhesive to obtain a laminate. The thickness of the adhesive layer formed by the two-component curing urethane adhesive was 3.0 μm.
The proportion of polyethylene in the thus obtained laminate was 88% by mass.

<Comparative Example 3>
A laminate was obtained in the same manner as in Example 1, except that the intermediate layer A was changed to a nylon film having a thickness of 15 μm (manufactured by Unitika Ltd., product name: Emblem ONBC).
The proportion of polyethylene in the thus obtained laminate was 78% by mass.

<Recyclability evaluation>
The recyclability of the laminates obtained in the above Examples and Comparative Examples was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: The polyethylene content in the laminate was 80% by mass or more.
x: The polyethylene content in the laminate was less than 80% by mass.

<Heat resistance evaluation>
Two test pieces each having a length of 110 mm and a width of 150 mm were prepared from the laminates obtained in the above Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-3.
Two test pieces were overlapped with the heat seal layers facing each other, and two sides were heat sealed at 140° C. to form a cylindrical body.
Next, one test piece measuring 110 mm in length and 150 mm in width was prepared from the laminate obtained in the above Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-3, and this was folded in a V shape so that the heat-sealed layer was on the outside, and heat-sealed to the above cylindrical body at 140°C to form a bottom and produce a packaging material in the shape of a stand pouch.
The produced packaging materials were visually observed and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
◯: No wrinkles or the like were observed on the surface of the packaging material, and no adhesion to the heat seal bar was observed.
×: Wrinkles or the like were generated on the surface of the packaging material, and adhesion to the heat seal bar was observed, and bags could not be made.

<Printability evaluation>
The images formed on the polyethylene resin and nylon film of the laminates produced in the above Examples and Comparative Examples were visually observed, and their printability was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: The dimensional stability during printing was good, and a good image was formed without rubbing, bleeding, or the like.
×: The film expanded and contracted during printing, causing rubbing and bleeding in the formed image.

<Rigidity evaluation>
The laminates prepared in the above examples and comparative examples were cut into test pieces with a width of 10 mm, and their stiffness was measured using a loop stiffness measuring tester (manufactured by Toyo Seiki Seisakusho, product name: Loop Stiffness Tester). The length of the loop was 60 mm. The measurement results are summarized in Table 1.

<Strength test>
The laminates produced in the above Examples and Comparative Examples were measured for strength when pierced with a needle having a diameter of 0.5 mm using a tensile tester (manufactured by Orientec Co., Ltd., product name: RTC-1310A). The piercing speed was 50 mm/min. The measurement results are summarized in Table 1.

<Flexural load resistance test>
First, the oxygen permeability and water vapor permeability were measured for the laminates obtained in the above Examples 4 and 5. The oxygen permeability was measured using OXTRAN2/20 manufactured by MOCON under conditions of 23° C. and 90% RH, and the water vapor permeability was measured using PERMATRAN3/31 manufactured by MOCON under conditions of 40° C. and 90% RH.
Furthermore, the laminates obtained in Examples 4 and 5 were subjected to a bending load (stroke: 155 mm, bending motion: 440°) five times in accordance with ASTM F 392 using a Gelbo Flex Tester (manufactured by Tester Sangyo Co., Ltd., product name: BE1006BE).
After the bending load, the oxygen permeability and water vapor permeability of the laminate were measured.
The oxygen permeability and water vapor permeability of the laminate before and after the flex load test are shown in Table 1.

10: Laminate, 11: Base material, 12: Intermediate layer, 13: Heat seal layer, 14: Vapor deposition film, 15: Adhesive layer, 20: Packaging bag, 30: Stand pouch, 31: Body, 32: Bottom

Claims (8)

A laminate comprising at least a substrate, an intermediate layer, and a heat seal layer,
The substrate is made of polyester,
the intermediate layer and the heat seal layer are made of polyethylene;
the intermediate layer is a stretched film,
At least one of the polyethylenes constituting the intermediate layer and the heat seal layer contains polyethylene derived from biomass,
a vapor-deposited film is provided on at least one surface of the substrate, the intermediate layer, and the heat seal layer;
A laminate, characterized in that the thickness of the substrate is smaller than the sum of the thickness of the intermediate layer and the thickness of the heat seal layer, and the polyethylene content in the entire laminate is 80 mass% or more. The laminate according to claim 1, wherein both the polyethylene constituting the intermediate layer and the polyethylene constituting the heat seal layer contain polyethylene derived from biomass. The adhesive layer is provided between the vapor-deposited film and the intermediate layer,
the vapor-deposited film is an aluminum vapor-deposited film,
2. The laminate according to claim 1, wherein the adhesive layer is formed from a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. The laminate according to any one of claims 1 to 3, wherein the difference between the thickness of the substrate and the sum of the thickness of the intermediate layer and the thickness of the heat seal layer is 40 μm or more. The laminate according to any one of claims 1 to 4, which is used for packaging material applications. A packaging material made using the laminate according to any one of claims 1 to 5. A packaging bag,
A laminate according to any one of claims 1 to 5,
A packaging bag, characterized in that the heat seal layer has a thickness of 20 μm or more and 60 μm or less. It is a stand-up pouch,
A laminate according to any one of claims 1 to 5,
A stand pouch, characterized in that the heat seal layer has a thickness of 50 μm or more and 200 μm or less.