JP7494882B2 - Laminate and packaging material using same - Google Patents

Description

The present invention relates to a laminate having a paper base layer and a sealant layer having a vapor deposition layer, and a packaging body using the same.

Conventionally, in laminate packaging materials using a paper base layer, those that require barrier properties have been known to have a configuration in which a resin film having a vapor-deposited layer of metal or the like (e.g., an aluminum-deposited PET (polyethylene terephthalate) resin film) or the like is laminated between the paper base layer and a sealant layer (see, for example, Patent Document 1).
However, although a laminate packaging material having such a configuration can sufficiently ensure barrier properties, since a stretched resin film such as PET, which serves as the base material for the deposition layer, is interposed as an intermediate layer, there are problems in that, for example, when this laminate is used as a packaging material such as a packaging bag, it has poor hand-tearability and dead hold properties (shape retention).

JP 2008-094426 A

The object of the present invention is to provide a laminate that has high barrier properties and is excellent in hand tearability and dead hold properties, and a package using the same, in order to solve the above problems.

The present invention solves the above problems by the following means. Note that, for ease of understanding, the following description will use symbols corresponding to the embodiments of the present invention, but the present invention is not limited to these.

A first invention provides a sealant layer comprising a paper base layer, a sealant layer provided on one side of the paper base layer and including a vapor-deposited layer of a metal or inorganic oxide, and a solventless barrier adhesive layer provided between the paper base layer and the vapor-deposited layer to bond the paper base layer and the vapor-deposited layer,
The laminate has an oxygen permeability of 3.0 cc/ ^m2 /day/atm or less as measured at 23°C and 90% RH in accordance with JIS K 7126-2, and satisfies 1.0≦t1/t2≦5.0, where t1 is the mass per ^m2 of the paper base layer and t2 is the mass per m2 of the sealant layer having the vapor deposition layer.

A second invention is the laminate of the first invention, wherein the paper base layer has a basis weight of 30 g/ ^m2 or more and 100 g/ ^m2 or less.

A third invention is the laminate according to the first or second invention, wherein the sealant layer has a thickness of 20 μm or more and 40 μm or less .

The fourth invention is a laminate according to any one of the first to third inventions, in which the sealant layer is an unstretched polyolefin resin film.

The fifth invention is a laminate of the fourth invention, in which the unstretched polyolefin resin film is an unstretched polypropylene resin film, and the unstretched polypropylene resin film contains biomass polyethylene.

The sixth invention is a laminate according to any one of the first to fifth inventions, in which the barrier adhesive layer is a cured product of a resin composition containing a resin having two or more hydroxyl groups in one molecule and an isocyanate compound having two or more isocyanate groups in one molecule, the main skeleton of the resin being polyester or polyester polyurethane, and containing an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof as a polyester constituent monomer component.

The seventh invention is a package formed using any one of the laminates according to the first to sixth inventions.

The present invention provides a laminate that has high barrier properties, excellent hand tearability and dead hold properties, and a package using the same.

FIG. 2 is a cross-sectional view of a laminate according to an embodiment. 1A and 1B are diagrams showing examples of packaging bodies using the laminate of the embodiment. 11A and 11B are diagrams showing another example of a package using the laminate of the embodiment. 11A and 11B are diagrams showing another example of a package using the laminate of the embodiment. 11A and 11B are diagrams showing another example of a package using the laminate of the embodiment. 11A and 11B are diagrams showing another example of a package using the laminate of the embodiment.

The laminate according to the present invention will be described with reference to the drawings. An example of a cross-sectional view of the laminate according to the present invention is shown in FIG.
<Laminate of the embodiment>
The laminate 10 is, for example, a packaging material used for packaging food, etc. As shown in Fig. 1, the laminate 10 according to an embodiment of the present invention includes a paper base layer 11, a sealant layer 12 including a vapor deposition layer 13 provided on one side of the paper base layer 11, and a barrier adhesive layer 14 having barrier properties that bonds the vapor deposition layer 13 to the paper base layer 11. That is, the laminate 10 includes the paper base layer 11, the barrier adhesive layer 14, the vapor deposition layer 13, and the sealant layer 12 laminated in this order.
Each layer constituting the laminate 10 will now be described.

(Paper base layer)
The paper substrate layer 11 is a substrate layer supporting the sealant layer 12 having the deposition layer 13, and is a flexible paper substrate constituting so-called soft paper packaging, unlike cup base paper for paper cups having a basis weight of more than 100 g/m ² or milk carton base paper for paper containers. Specifically, the basis weight of the paper substrate layer is preferably 30 g/m ² or more and 100 g/m ² or less, and more preferably 35 g/m ² or more and 70 g/m ² or less. When the basis weight of the paper substrate layer is 30 g/m ² or more and 100 g/m ² or less, the mechanical strength is high, the paper substrate has excellent hand-tearability and deadholdability, and the paper substrate has flexibility as a packaging body such as a packaging bag. Examples of the paper substrate layer 11 include kraft paper, fine paper, coated paper, and paper with barrier properties (barrier coated paper).

Here, on the surface of the paper base layer 11 opposite the barrier adhesive layer 14, a design layer and a surface layer may be provided in this order, if necessary.
(Pattern layer)
The picture layer is a printed layer on which a picture is printed, and is provided on the surface of the paper base layer 11 opposite to the barrier adhesive layer 14. Here, the picture refers to a recording subject in various forms that can be recorded or printed on the paper base layer 11, and broadly includes, without being particularly limited, figures, characters, designs, patterns, symbols, patterns, marks, etc. In particular, when the laminate 10 is used for a package such as a packaging bag intended to contain food, a picture of the contents or characters showing information such as the product name, expiration date, production date, and production number of the contents are used as the picture.

(Surface layer)
The surface layer is a layer provided on the pattern layer, and is the layer located on the outermost side of the container when the laminate 10 is used for a package such as a packaging bag. The surface layer is formed of, for example, overprint varnish (OP varnish), and can prevent the pattern layer from being lost due to rubbing or the like, and can prevent the pattern from being tampered with.
In the above description, an example has been described in which the design layer and the surface layer are sequentially provided on the paper base layer 11. However, the design layer and the surface layer may be omitted as appropriate, if necessary.

(Sealant Layer)
The sealant layer 12 is a layer that appears on the surface of the laminate 10 opposite to the paper base layer 11. When a package such as a packaging bag is formed using the laminate 10, the sealant layer 12 is the innermost layer, and has heat sealability, which means adhesive properties when heated. The sealant layer 12 also has a vapor deposition layer 13 on the paper base layer 11 side. Details of the vapor deposition layer 13 will be described later.

The resin film constituting the sealant layer 12 is preferably an unstretched polyolefin resin film having heat sealability. In particular, in the present invention, an unstretched polyethylene resin film or an unstretched polypropylene resin film can be preferably used.

Examples of resins constituting the unstretched polyethylene resin film include low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), etc. In addition to these homopolymers, copolymerized polyolefins in which part of the ethylene has been replaced with other monomers may also be used.

Here, high density polyethylene refers to polyethylene having a density exceeding 0.942 g/ ^cm3 , and medium density polyethylene refers to polyethylene having a density exceeding 0.925 g/ ^cm3 and not more than 0.942 g/ ^cm3 . Low density polyethylene can also be called high pressure low density polyethylene, which is a high pressure ethylene homopolymer and can be obtained by a conventionally known high pressure radical polymerization method, and is a polyethylene having a density of not more than 0.925 g/ ^cm3 . Linear low density polyethylene is a copolymer of ethylene and an α-olefin polymerized using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and is a polyethylene having a density of not more than 0.925 g/ ^cm3 .
In the present invention, the density is measured by a method in accordance with JIS K7112.

Examples of resins constituting the unstretched polypropylene resin film (CPP film) include homopolypropylene, random polypropylene, and block polypropylene. Copolymer polypropylene in which part of the propylene is replaced with other monomers may also be used.

The polypropylene-based resin film may also contain polyethylene, and it is preferable that the polyethylene contained therein contains biomass polyethylene derived from plants. Here, when the unstretched polypropylene-based resin film contains biomass polyethylene, it is preferable that the biomass polyethylene is contained in the range of 5 to 30 parts by mass per 100 parts by mass of the polypropylene-based resin.

<Biomass-derived ethylene>
The method for producing biomass-derived ethylene, which is a raw material for biomass polyethylene, is not particularly limited, and it can be obtained by a conventionally known method. An example of the method for producing biomass-derived ethylene will be described below.

Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. The plant raw material is not particularly limited, and conventionally known plants can be used. For example, corn, sugar cane, beet, and manioc can be used.

Fermented ethanol derived from biomass refers to ethanol produced by contacting a culture solution containing a carbon source obtained from plant raw materials with an ethanol-producing microorganism or a product derived from its crushed material, and then purifying the ethanol. Conventional methods such as distillation, membrane separation, and extraction can be used to purify ethanol from the culture solution. For example, methods such as adding benzene, cyclohexane, etc. and removing water by azeotropy or membrane separation can be used.

To obtain the above ethylene, further advanced purification may be carried out at this stage, such as reducing the total amount of impurities in the ethanol to 1 ppm or less.

A catalyst is used to obtain ethylene by the dehydration reaction of ethanol, but there is no particular limitation on the catalyst, and any conventionally known catalyst can be used. From a process standpoint, a fixed-bed flow reaction is advantageous because it is easy to separate the catalyst from the product; for example, gamma-alumina is preferred.

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

In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in the ethanol supplied as a raw material. In general, when performing a dehydration reaction, it is preferable to have no water, considering the efficiency of removing water. However, in the case of the dehydration reaction of ethanol using a solid catalyst, it has been found that the amount of other olefins, especially butene, produced tends to increase if water is not present. This is probably because the ethylene dimerization after dehydration cannot be suppressed if a small amount of water is not present. The lower limit of the allowable water content is 0.1 mass% or more, preferably 0.5 mass% or more. There is no particular upper limit, but from the viewpoint of material balance and heat balance, 50 mass% or less is preferable, 30 mass% or less is more preferable, and 20 mass% or less is even more preferable.

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

The ethylene obtained by gas-liquid separation is further distilled, and there are no particular restrictions on the distillation method, operating temperature, residence time, etc., except that the operating pressure at this time must be normal pressure or higher.

When the raw material is biomass-derived ethanol, the ethylene obtained contains trace amounts of carbonyl compounds such as ketones, aldehydes, and esters, which are impurities mixed in during the ethanol fermentation process, as well as carbon dioxide, which is their decomposition product, and nitrogen-containing compounds such as amines and amino acids, which are enzyme decomposition products and impurities, as well as ammonia, which is their decomposition product. Depending on the use of ethylene, these trace amounts of impurities may be problematic, so they may be removed by purification. The purification method is not particularly limited, and can be performed by a conventionally known method. An example of a suitable purification operation is an adsorption purification method. The adsorbent used is not particularly limited, and conventionally known adsorbents can be used. For example, a material with a high surface area is preferable, and the type of adsorbent is selected according to the type and amount of impurities in the ethylene obtained by the dehydration reaction of biomass-derived ethanol.

Caustic water treatment may also be used in combination as a method for purifying impurities in ethylene. If caustic water treatment is used, it is preferable to carry it out before adsorption purification. In that case, it is necessary to carry out a moisture removal treatment after the caustic treatment and before adsorption purification.

<Biomass polyethylene>
Biomass polyethylene is obtained by polymerizing a monomer containing ethylene derived from biomass. It is preferable to use the ethylene derived from biomass obtained by the above-mentioned manufacturing method. Since biomass-derived ethylene is used as the raw material monomer, the polymerized polyethylene is derived from biomass. As the biomass polyethylene, for example, biomass linear low density polyethylene manufactured by Braskem (product name: SLL318, density: 0.918 g/cm ³ (918 kg/m ³ ), MFR: 2.7 g/10 min, biomass degree 87%), biomass low density polyethylene manufactured by Braskem (product name: SEB853, density: 0.923 g/cm ³ (923 kg/m ³ ), MFR: 2.7 g/10 min, biomass degree 95%), etc. can be used. Note that the raw material monomer of polyethylene does not have to contain 100% by mass of ethylene derived from biomass.
In the present invention, the melt flow rate (MFR) is measured in accordance with JIS K6921 (190° C.).

As long as the objective of the present invention is not impaired, the monomers that are the raw materials for biomass polyethylene may further contain ethylene derived from fossil fuels.

Atmospheric carbon dioxide contains a certain proportion of C14 (105.5 pMC), and it is known that plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, also contain about 105.5 pMC of C14. It is also known that fossil fuels contain very little C14. Therefore, by measuring the proportion of C14 in the total carbon atoms, the proportion of carbon derived from biomass can be calculated. In this invention, "biomass degree" refers to the weight ratio of biomass-derived components. Hereinafter, unless otherwise specified, "biomass degree" refers to the weight ratio of biomass-derived components.

In the present invention, theoretically, if all ethylene derived from biomass is used as the raw material for polyethylene, the concentration of biomass-derived ethylene is 100%, and the biomass degree of biomass polyethylene is 100%. In addition, the concentration of biomass-derived ethylene in fossil fuel polyethylene produced only from raw materials derived from fossil fuels is 0%, and the biomass degree of fossil fuel polyethylene is 0%.

In the present invention, the biomass polyethylene or biomass-derived resin layer does not need to be 100% biomass. If even a part of the resin film is made from biomass-derived raw materials, this is in line with the purpose of reducing the amount of fossil fuel used compared to conventional methods.

It is preferable that the resin film (sealant layer 12) has a biomass ratio of 5% or more. This allows for further improvement in reducing the environmental impact. It is more preferable that the biomass ratio of the resin film is 5% or more and 90% or less, even more preferable that it is 5% or more and 50% or less, and even more preferable that it is 10% or more and 25% or less.

The unstretched polyolefin resin film may be a single layer or a multilayer. When forming the unstretched polyolefin resin film, various plastic compounding agents and additives can be added to improve or modify the processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, mold resistance, electrical properties, strength, and other properties of the film. The amount of additives can range from a very small amount to several tens of percent, and can be added as desired depending on the purpose. Common additives include, for example, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, and the like.

The surface of the unstretched polyolefin resin film on which the vapor deposition layer is to be formed may be subjected to a surface treatment, the details of which will be described later.

Unstretched polyolefin resin films can be obtained by known means, such as a method of forming a film from each of the above resins alone using a film-forming method such as extrusion, cast molding, T-die method, cutting method, inflation method, or other film-forming method, a method of forming a multilayer film by co-extrusion using two or more types of various resins, or a method of using two or more types of resins and mixing them before forming into a film.

In addition, the resin film constituting the sealant layer 12 can be made of biodegradable polylactic acid (PLA) resin or polybutylene succinate (PBS) resin instead of an unstretched polyolefin resin film.

<Polylactic acid (PLA) resin>
For example, the sealant layer 12 may be made of polylactic acid resin, which is a polymer mainly composed of L-, D-, or DL-lactic acid units and has transparency, and a biodegradable polyester having physical properties similar to those of soft polyolefin resins can be used.

The polylactic acid resin has a melt flow rate (MFR) in the range of 1.0 to 20.0 g/10 min, preferably 1.5 to 12.0 g/10 min (190°C, 2.16 kg), a density in the range of approximately 1.10 to 1.30 g/ ^cm3 , a melting point in the range of 150 to 170°C, and, in the case of an amorphous type, a Tg in the range of 50 to 70°C.

Basically, polylactic acid resin is preferably one that is relatively flexible, melts when heated, has heat sealability, and has excellent melt tension and stretchability, and is suitable for coextrusion molding, as described below. For this reason, polylactic acid resin can be used alone, but from the viewpoint of improving flexibility, it is preferable to add a softening modifier to the extent that the function as the sealant layer 12 is not impaired. When a softening modifier is added, it is preferable to knead the polylactic acid resin and the softening modifier in a mixing ratio of 65 to 95% by mass of the former and 5 to 35% by mass of the latter. Specifically, for example, one or more of aliphatic polyester resins other than polylactic acid resin, plasticizers for polylactic acid resin, or polyester-based elastomers can be used.

As an aliphatic polyester resin other than polylactic acid resin, for example, a polymer mainly composed of aliphatic dicarboxylic acid units and aliphatic diol units can be used, specifically, for example, polybutylene succinate, polybutylene adipate, polybutylene sebacate, polybutylene succinate adipate, etc. can be used.

As a plasticizer for polylactic acid resin, for example, adipic acid esters can be used. As an adipic acid ester, for example, a plasticizer made of a diester of adipic acid and a higher alcohol can be used. Specifically, a plasticizer for polylactic acid resin made of adipic acid ester (product name: DAIFATTY-101) manufactured by Daihachi Chemical Industry Co., Ltd. can be used.

As the polyester-based elastomer, for example, a polyester-based elastomer having a high melting point (Tm) polyester portion as the hard segment and a polyether or polyester portion having a low melting point (Tm) or low glass transition temperature (Tg) as the soft segment can be used. Specifically, a polyester-based elastomer such as Hi-Retort 4057, a product name manufactured by DuPont-Toray Co., Ltd., can be used.

<Polybutylene succinate (PBS) resin>
Furthermore, when the sealant layer 12 is made of polybutylene succinate (PBS) resin, for example, polybutylene succinate having a melt flow rate (MFR) in the range of 1.0 to 30.0 g/10 min, preferably 3.0 to 20.0 g/10 min (190° C., 2.16 kg), a density in the range of approximately 1.20 to 1.30 g/cm ³ , and a melting point in the range of 80 to 120° C. can be used.
Specifically, the polybutylene succinate may be a biodegradable polyester having similar physical properties to polyolefin resins, which is made of an aliphatic polyester resin obtained by directly dehydrating and polycondensing 1,4-butanediol and succinic acid as the main components.
As the other component, for example, lactic acid can be used.

From the viewpoint of being heat-sealed without gaps by heating, the thickness of the sealant layer 12 is desirably 20 μm or more and 40 μm or less. If the thickness of the sealant layer 12 is 20 μm or more, for example, when the laminate 10 is used to produce a packaging bag 1A (see FIG. 2) described below, the heat seal strength can be maintained especially in the area where three or more laminates overlap (for example, the area where the back seal portion overlaps with the upper or lower seal portion). Furthermore, by making the thickness of the sealant layer 12 40 μm or less, excellent hand tearability and dead holdability can be maintained.

(Deposition layer)
The deposition layer 13 is a barrier layer provided to suppress the transmission of oxygen and water vapor through the laminate 10. As described above, the deposition layer 13 in this embodiment is provided on the surface of the sealant layer 12 facing the paper base layer 11, and is formed of a metal or an inorganic oxide. The deposition layer in the present invention means a film formed by a deposition method in a broad sense, and includes not only a vacuum deposition method but also a film formed by sputtering or the like.

Here, examples of metals that can be used for the deposition layer 13 include aluminum (Al), magnesium (Mg), tin (Sn), sodium (Na), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), gold (Au), and chromium (Cr). In particular, for packaging, it is preferable to have an aluminum deposition film.

Examples of inorganic oxides that can be used for the vapor deposition layer 13 include metal oxides of the above-mentioned metals such as aluminum oxide and titanium oxide, as well as silica, which is an oxide of silicon (Si). In particular, for packaging, it is preferable to have a vapor deposition film of aluminum oxide.

The thickness of the deposition layer 13 varies depending on the type of metal used, but is preferably selected from the range of 50 Å to 2000 Å, and preferably 100 Å to 1000 Å. More specifically, in the case of an aluminum deposition film, the thickness is preferably 50 Å to 600 Å, and more preferably 100 Å to 450 Å.

Methods for forming the deposition layer 13 include, for example, physical vapor deposition methods (PVD methods) such as vacuum deposition, sputtering, and ion plating, or chemical vapor deposition methods (CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

The deposition layer 13 can be formed, for example, by directly depositing the above-mentioned metal or inorganic oxide onto the sealant layer 12 using the above-mentioned vacuum deposition method or the like.
When the deposition layer 13 is provided directly on the sealant layer 12 as described above, the surface of the sealant layer 12 can be pretreated as necessary. Specifically, the surface of the sealant layer 12 can be pretreated by physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, or glow discharge treatment, or chemical treatments such as oxidation treatment using chemicals. When the deposition layer 13 is provided directly on the sealant layer 12, a commercially available product such as VM-CPP (aluminum-deposited CPP film) manufactured by Toray Advanced Film Co., Ltd. can be used as the sealant layer 12 having the deposition layer 13. The thickness of the sealant layer 12 on which the deposition layer 13 is directly formed is desirably 20 μm or more and 40 μm or less in total for both layers.
The sealant layer 12 including the vapor deposition layer 13 is not limited to the above-described form, and for example, an intermediate layer serving as an anchor layer for strengthening the adhesion between the sealant layer 12 and the vapor deposition layer 13 may be further provided between the sealant layer 12 and the vapor deposition layer 13.

The oxygen permeability of the sealant layer 12 including the vapor-deposited layer 13, measured at 23°C and 90% RH in accordance with JIS K 7126-2, is about 5 cc/ ^m2 /day/atm or more and 20 cc/ ^m2 /day/atm or less when the above-mentioned commercially available aluminum-deposited CPP film is used, and the oxygen barrier property is insufficient. Therefore, it is necessary to improve the oxygen barrier property by combining with a barrier adhesive layer described later.

(Barrier Adhesive Layer)
The barrier adhesive layer 14 is a layer made of an adhesive having barrier properties that suppress the transmission of oxygen and water vapor, and is provided between the paper base layer 11 and the vapor deposition layer 13 to bond the paper base layer 11 and the vapor deposition layer 13. The barrier adhesive layer 14 is provided to further suppress the oxygen and water vapor that permeate the laminate that cannot be suppressed by the vapor deposition layer 13. Specifically, a fine uneven shape is formed on the surface of the vapor deposition layer 13, and at a fine level, the thickness of the vapor deposition layer 13 is not uniform, and the barrier property of the relatively thin parts is low, resulting in non-uniform barrier property as a whole. However, when the barrier adhesive layer 14 comes into contact with the vapor deposition layer 13, the uneven shape is filled and flattened, making the barrier property uniform and further enhancing the effect of suppressing the transmission of oxygen and water vapor.

The barrier adhesive layer 14 is preferably a urethane-based adhesive having urethane bonds, which is a cured product of a resin composition containing a resin (polyol) having two or more hydroxyl groups in one molecule and an isocyanate compound (polyisocyanate) having two or more isocyanate groups in one molecule. The urethane-based adhesive is preferably a two-component curing type. Examples of configurations for imparting barrier properties to the resin composition include a method of introducing a skeleton having barrier properties into the resin constituting the resin composition (barrier organic adhesive), a method of adding a phosphoric acid-modified compound to the resin composition, and a method of adding a plate-shaped inorganic compound to the resin composition (barrier inorganic adhesive), and one or more of these can be combined.

As a method for introducing a skeleton having barrier properties into the resin constituting the above-mentioned resin composition, it is preferable that the main skeleton of the resin (polyol) is polyester or polyester polyurethane, and contains an ortho-oriented aromatic dicarboxylic acid or its anhydride as a polyester constituent monomer component.

The resin has two or more hydroxyl groups in one molecule, and the main skeleton has a polyester structure or a polyester polyurethane structure. The polyester portion of the main skeleton structure is obtained by polycondensation reaction of a polycarboxylic acid and a polyhydric alcohol by a known and commonly used method.
The polycarboxylic acid may be an aliphatic polycarboxylic acid or an aromatic polycarboxylic acid. Specific examples of the aliphatic polycarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

Specific examples of aromatic polycarboxylic acids include orthophthalic acid, terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,2-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid and anhydrides of these dicarboxylic acids; polybasic acids such as p-hydroxybenzoic acid and p-(2-hydroxyethoxy)benzoic acid. The polycarboxylic acids can be used alone or in combination of two or more.

In the present invention, as a configuration having barrier properties, it is preferable that the polycarboxylic acid contains an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof. The content of the ortho-oriented aromatic dicarboxylic acid or anhydride thereof is preferably 70 to 100 mass% relative to the total polycarboxylic acid components of the polyester constituent monomer components.

Specific examples of ortho-oriented aromatic dicarboxylic acids include orthophthalic acid, 1,2-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, and anhydrides of these dicarboxylic acids.

Examples of polyhydric alcohols include aliphatic polyhydric alcohols and aromatic polyhydric phenols. Specific examples of aliphatic polyhydric alcohols include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, cyclohexanedimethanol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol.

Specific examples of aromatic polyhydric phenols include hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, hisphenol F, tetramethylbiphenol, and their ethylene oxide-extended products and hydrogenated alicyclic derivatives.

The isocyanate compound (polyisocyanate) has two or more isocyanate groups in the molecule, and may be either aromatic or aliphatic, and may be either a low molecular weight compound or a high molecular weight compound. Known compounds such as diisocyanate compounds with two isocyanate groups and polyisocyanate compounds with three or more isocyanate groups can be used. The isocyanate compound may be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by a known, conventional, appropriate method.

Among these, polyisocyanate compounds are preferred from the viewpoint of adhesion and retort resistance, and from the viewpoint of imparting oxygen barrier properties, those having aromatic rings are preferred, and isocyanate compounds containing a meta-xylene skeleton are particularly preferred.

Specific examples of isocyanate compounds include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, meta-xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, or trimers of these isocyanate compounds, and adducts, biuret compounds, allophanate compounds, etc. obtained by reacting an excess amount of these isocyanate compounds with low molecular weight active hydrogen compounds such as ethylene glycol, propylene glycol, meta-xylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and meta-xylylenediamine, and alkylene oxide adducts thereof, various polyester resins, polyether polyols, and high molecular weight active hydrogen compounds of polyamides.

(Phosphate-modified compounds)
The resin composition may contain a phosphoric acid-modified compound in addition to the above-mentioned resin. The phosphoric acid-modified compound has the effect of improving the adhesive strength to inorganic members, and any known and commonly used phosphoric acid-modified compound can be used.

Specific examples 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, polyoxyethylene alkyl ether phosphate, and the like, and one or more of these can be used.

(Plate-shaped inorganic compound)
The resin composition may contain a plate-like inorganic compound in addition to the above resins. The plate-like inorganic compound has the effect of improving the lamination strength and oxygen barrier property of the laminate via the barrier adhesive layer 14.
Specific examples of the plate-like inorganic compound (M) include kaolinite-serpentine group clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, talc, kerolite, etc.), etc., and one or more of these can be used.

The thickness of the barrier adhesive layer 14 is 0.5 to 8.0 μm, preferably 1.0 to 5.0 μm, and more preferably 2.0 to 4.5 μm. If it is thinner than the above range, the gas barrier properties are likely to be insufficient, and if it is thicker than the above range, the bending resistance is likely to be poor, which is likely to lead to a decrease in the gas barrier properties after bending.

The barrier adhesive layer 14 may be composed of a solvent-based adhesive or a solventless (non-solvent-based) adhesive. When a solvent-based adhesive is used for the barrier adhesive layer 14, for example, PASLIM VM001/108CP, a barrier organic adhesive manufactured by DIC Corporation, can be applied, and the paper base layer 11 and the sealant layer 12 including the vapor deposition layer 13 can be bonded by a dry lamination method. When a solventless adhesive is used for the barrier adhesive layer 14, for example, PASLIM NSRD011/NSRD006, a barrier organic adhesive manufactured by DIC Corporation, can be applied, and the paper base layer 11 and the sealant layer 12 including the vapor deposition layer 13 can be bonded by a non-solvent lamination method.
Another example of an organic barrier adhesive that can be used is "Maxive (registered trademark)", which is disclosed in JP 2003-300271 A and JP 2010-012769 A and is an adhesive that uses a non-bisphenol A polyepoxy resin as a base resin and a polyamine as a curing agent, and is marketed by Mitsubishi Gas Chemical Company, Inc. as a gas barrier adhesive.

(Laminate)
The laminate 10 of the present embodiment has the barrier adhesive layer 14 having the above-mentioned barrier properties, and the sealant layer 12 including the vapor deposition layer 13, and therefore can significantly suppress the permeation of oxygen and water vapor through the laminate 10.
From the standpoint of more effectively ensuring the oxygen barrier properties, it is desirable for the laminate 10 as a whole to have an oxygen permeability measured in accordance with JIS K 7126-2 at 23° C. and 90% RH of 3.0 cc/m ² /day/atm or less.
Furthermore, from the viewpoint of more effectively ensuring the water vapor barrier properties, the laminate 10 as a whole has a water vapor permeability, measured in accordance with JIS K 7129 B method under measurement conditions of 40°C and 90% RH, of preferably 2.0 g/ ^m2 /day/atm or less when an unstretched polypropylene resin film is used for the sealant layer 12, and preferably 5.0 g/ ^m2 /day/atm or less when a polyethylene resin film is used for the sealant layer.

From the viewpoint of ensuring excellent hand tearability and dead holdability for the entire laminate, the laminate 10 of this embodiment desirably satisfies the relationship of the following formula (1), where t1 is the mass (basis weight) per ^m2 of the paper base layer 11 and t2 is the mass (basis weight) per ^m2 of the sealant layer 12 including the vapor deposition layer 13. Here, t2 indicates the basis weight of the sealant layer 12 and the vapor deposition layer 13 when the vapor deposition layer 13 is provided directly on the sealant layer 12, and indicates the combined basis weight of the sealant layer 12, the vapor deposition layer 13, and the intermediate layer when an intermediate layer such as an anchor layer is present between the sealant layer 12 and the vapor deposition layer 13.

Equation (1) 1.0≦t1/t2≦5.0

If t1/t2 is less than 1.0, the ratio of the sealant layer 12 including the vapor deposition layer 13 to the paper base layer 11 in the laminate 10 becomes too large, which is undesirable as it reduces the dead-holding ability of the laminate 10. If t1/t2 is greater than 5.0, the ratio of the sealant layer 12 including the vapor deposition layer 13 to the paper base layer 11 in the laminate 10 becomes too small, which is undesirable as it reduces the hand-tearability of the laminate 10 and makes the sealant layer 12 too thin, making it impossible to obtain sufficient heat-sealing performance.
As described above, if the thickness of the sealant layer 12 is 20 μm or more, sufficient heat sealability can be obtained.

In order to ensure better hand tearability and dead holdability, the paper base layer 11 of the laminate 10 has a basis weight of 30 g/ ^m2 or more and 100 g/ ^m2 or less, and preferably 35 g/ ^m2 or more and 70 g/ ^m2 or less, as described above.
If the basis weight of the paper base layer 11 is more than 100 g/ ^m2 , the paper base layer becomes too thick, which undesirably reduces the hand tearability of the laminate. Also, if the basis weight of the paper base layer 11 is less than 30 g/ ^m2 , the paper base layer becomes too thin, which undesirably reduces the deadhold ability of the laminate.

(Package using laminate)
Fig. 2 is a diagram showing a package using the laminate of the present embodiment. Fig. 2(A) is a diagram showing a packaging bag 1A which is an example of a package using the laminate 10 of the present embodiment, and Fig. 2(B) is a diagram showing a packaging bag 1B which is another example of a package using the laminate 10 of the present embodiment.
Fig. 3 is a diagram showing another example of a package using the laminate of this embodiment. Fig. 3(A) is a plan view showing a packaging bag 1C which is an example of a package using the laminate 10 of this embodiment, and Fig. 3(B) is a cross-sectional view of part B in Fig. 3(A).
Fig. 4 is a diagram showing another example of a package using the laminate of this embodiment. Fig. 4(A) is a plan view showing a packaging bag 1D, which is an example of a package using the laminate 10 of this embodiment, and Fig. 4(B) is a cross-sectional view of part B in Fig. 4(A).
Fig. 5 is a diagram showing another example of a package using the laminate of this embodiment. Fig. 5(A) is a diagram showing a packaging bag 1E which is an example of a package using the laminate 10 of this embodiment, Fig. 5(B) is a cross-sectional view of part B in Fig. 5(A), and Fig. 5(C) is a diagram explaining a usage form of the packaging bag 1E.
Fig. 6 is a diagram showing another example of a package using the laminate of this embodiment. Fig. 6(A) is a diagram showing a box-shaped package 1F, which is an example of a package using the laminate 10 of this embodiment, and Fig. 6(B) is a diagram showing a box-shaped package 1G, which is another example of a package using the laminate 10 of this embodiment.

The laminate 10 of this embodiment can be applied to, for example, a pillow-type packaging bag 1A shown in Fig. 2(A) or a flat pouch-type packaging bag 1B shown in Fig. 2(B). The pillow-type packaging bag 1A shown in Fig. 2(A) is produced by heat-sealing the sealant layers 12 on a pair of opposing sides of a single rectangular laminate 10 to form a back seal portion 2 to make it into a cylindrical shape, and then heat-sealing the upper and lower openings of the cylindrical shape to form an upper seal portion 3 and a lower seal portion 4, respectively.
In addition, the packaging bag 1B shown in FIG. 2(B) is produced by folding one rectangular laminate 10 in half with the sealant layers 12 facing each other, and heat-sealing the three sides other than the fold line 5 to form the seal portion 6.

The packaging bag 1C shown in Fig. 3 is a packaging bag in which a zipper-type opening/closing part is provided at the opening part of the flat pouch-type packaging bag shown in Fig. 2(B). Specifically, as shown in Fig. 3(A), a zipper part 24 is provided on the inside near the upper seal part 21 of the packaging bag 1C so as to follow the upper seal part 21. As shown in Fig. 3(B), the zipper part 24 is composed of, for example, a male member 24A and a female member 24B which can be fitted together, and the male member 24A is disposed on the inner surface of the laminate on the front side of the packaging bag 1C, and the female member 24B is disposed on the inner surface of the laminate on the opposing back side, and the zipper part 24 is closed by fitting together.
Furthermore, a notch 25 for opening is provided by cutting out a part of the side seals 22, 23 at both ends of the packaging bag 1C between the top seal 21 and the zipper 24. With this configuration, the packaging bag 1C can be opened and closed freely by the zipper 24 after the top seal 21 is separated from the main body of the packaging bag 1C by the notch 25 and opened.

The laminate of this embodiment can also be used for a stand-up pouch type packaging bag 1D as shown in Fig. 4. The packaging bag 1D shown in Fig. 4 is formed by stacking two rectangular laminates 10A and 10B with the sealant layers 12 facing each other, and heat-sealing the upper and both sides. The lower side is formed by sandwiching a laminate 10C folded in half between the two laminates 10A and 10B with the sealant layers 12 facing each other, and heat-sealing the outer edge of the laminate 10C and the laminates 10A and 10B. By using this form, the packaging bag 1D filled with the contents becomes a pouch that can stand on its own with the laminate 10C as the bottom surface, that is, a so-called standing pouch.
As with the packaging bag 1C shown in Figure 3 described above, a zipper portion 24 may be provided along the upper seal portion 21, and a notch portion 25 may be provided in a portion of the side seal portions 22, 23 between the zipper portion 24 and the upper seal portion 21, so that the opening can be opened and closed after the packaging bag is opened.

The laminate 10 of this embodiment can also be applied to a packaging bag 1E having an intermediate seal portion 31, as shown in FIG. 5. As shown in FIG. 5(A) and FIG. 5(B), the packaging bag 1E is formed by folding a long laminate 10A in half so that the front and back sides have different lengths, and joining the upper edge of the short side (front side) to the lower edge of the rectangular laminate 10B by heat sealing to form the intermediate seal portion 31. Also, the upper edge of the long side (back side) to the upper edge of the rectangular laminate 10B by heat sealing to form the upper seal portion 32, and joining both side edges of the joined laminates 10A and 10B by heat sealing to form the side seal portions 33 and 34.

The packaging bag 1E has a notch 35 for opening formed in a part of the side seals 33, 34 between the top seal 32 and the intermediate seal 31, and the packaging bag 1E can be opened by cutting the top seal 32 from the main body of the packaging bag using this notch 35 as a trigger. The opening part of the opened packaging bag 1E can be closed by folding the part above the intermediate seal 31 of the packaging bag 1E so that the intermediate seal 31 is located at the upper end, overlapping with the part below, as shown in Fig. 5(C). As described above, the laminate used for the packaging bag 1E has a paper base layer, and therefore has excellent dead hold properties, can properly maintain the folded state, and can minimize leakage of the contents of the packaging bag from the opening or exposure to the outside air.
Incidentally, the packaging bag 1E may be formed into a self-supporting standing type by providing a laminated body forming a bottom portion, as in the above-mentioned packaging bag 1D (see FIG. 4), if necessary.

The laminate 10 of this embodiment can also be applied to a box-shaped package 1F as shown in Fig. 6. The package 1F shown in Fig. 6(A) is a box-shaped package made up of five laminates 10, and is formed from a laminate 10A forming the bottom, laminates 10B and 10C forming the front and back parts, respectively, and laminates 10D and 10E forming the sides. The edges of adjacent laminates are joined by heat sealing with the sealant layer 12 on the inside of the package 1F, thereby forming the box-shaped package 1F.
In addition, the upper portion and the upper side edge of the package 1F shown in FIG. 6(A) are directly heat-sealed to the laminate 10B forming the front portion and the laminate 10C forming the back portion, forming an upper seal portion 41 and side seal portions 42, 43, and is formed in a shape that is tapered toward the upper side compared to the bottom side.
In addition, in the package 1F, an openable and closable chuck portion 44 and a notch portion 45 for opening the package 1F are provided along the upper seal portion 41 in parts of the side seal portions 42, 43 between the chuck portion 44 and the upper seal portion 41. As a result, after the upper seal portion 41 is separated from the main body of the package 1F by the notch portion 45 and opened, the package 1F can be opened and closed freely by the chuck portion 44.
The box-shaped packaging body 1F is not limited to the example shown in FIG. 6(A), but may be formed in a three-dimensional shape such as a rectangular parallelepiped or a cube as shown in FIG. 6(B).

The laminate 10 of the present embodiment has superior hand-tearability and dead-holdability as described above compared to conventional packaging materials, and therefore, by using the laminate 10 in such packaging bags, the opening of the packaging bag can be easily opened by cutting the opening by hand. In addition, the opened opening can be folded back to close and maintained closed.
The shape of the packaging bag is not limited to the pillow type or flat pouch (three-sided pouch) type described above, but may be a gusset type packaging bag.
The laminate 10 of the present embodiment can also be used as a lid member for closing the opening of a container as another example of a packaging material, and further, not only the lid member but also the three-dimensional container itself may be formed from the laminate. As described above, the laminate 10 of the present embodiment has excellent deadhold properties, so that the three-dimensional shape of the container or the like can be maintained.
In addition, the "packaging material" in the present invention is a general term for the case where the laminate of the present invention is used as a packaging material, and includes not only packaging bags but also container-shaped objects, and even components that constitute part of a packaging container, such as lid materials, are within the scope of the "packaging material".
<Other aspects>
In another aspect of the invention,
(1) A laminate may be provided which comprises a paper base layer, a sealant layer provided on one side of the paper base layer and having a vapor-deposited layer of a metal or inorganic oxide, and a barrier adhesive layer provided between the paper base layer and the vapor-deposited layer and bonding the paper base layer and the vapor-deposited layer, wherein the oxygen permeability measured in accordance with JIS K 7126-2 at 23°C and 90% RH is 3.0 cc/m2 ^/ day/atm or less, and where t1 is the mass per ^m2 of the paper base layer and t2 is the mass per ^m2 of the sealant layer having the vapor-deposited layer, the laminate satisfies 1.0≦t1/t2≦5.0.
(2) In the laminate of (1), the paper base layer may have a basis weight of 30 g/ ^m2 or more and 100 g/m2 ^or less.
(3) In the above (1) or (2), the sealant layer may be a laminate having a thickness of 20 μm or more.
(4) In any one of (1) to (3), the sealant layer may be an unstretched polyolefin resin film.
(5) In the above (4), the unstretched polyolefin resin film may be an unstretched polypropylene resin film, and the unstretched polypropylene resin film may be a laminate containing biomass polyethylene.
(6) In any one of (1) to (5), the barrier adhesive layer may be a cured product of a resin composition containing a resin having two or more hydroxyl groups in one molecule and an isocyanate compound having two or more isocyanate groups in one molecule, the main skeleton of the resin being polyester or polyester polyurethane, and the laminate containing an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof as a polyester constituent monomer component.
(7) It may be a package formed using the laminate of any one of (1) to (6).

The present invention will be described in further detail below with reference to examples.
[Example 1]
The laminate of Example 1 used coated paper 55 g/ ^m2 (Ryuo Coat, manufactured by Daio Paper Co., Ltd.) as the paper base layer, and a design layer was formed by gravure printing on the uncoated surface of this coated paper with gravure ink Sias HR (manufactured by DIC Graphics Co., Ltd.) to a dry thickness of 1 μm. Next, KS-10 (manufactured by DIC Graphics Co., Ltd.) was applied as an OP (overprint) varnish on the gravure print (design layer) to a dry thickness of 1 μm to form a surface layer.
Next, a non-solvent barrier adhesive (PASLIM NSRD011/NSRD006 manufactured by DIC Corporation) was applied to the non-printed surface (coated surface) of the paper base layer to a dry thickness of 3 μm to form a barrier adhesive layer. Thereafter, this was bonded to the vapor deposition surface of an aluminum vapor-deposited CPP film 25 μm thick (VM-CPP 2703 manufactured by Toray Advanced Film Co., Ltd.), which would serve as a sealant layer having a vapor deposition layer, by a non-solvent lamination method, and aged at 40° C. for 3 days to obtain a laminate of Example 1.

[Example 2]
The laminate of Example 2 was the same as that of Example 1, except that the paper base layer was changed to a coated paper of 37 g/m ² (grease-resistant coated paper manufactured by Daio Paper Corporation) and the thickness of the aluminum-deposited CPP film was changed to 40 μm.

[Example 3]
The laminate of Example 3 was the same as the laminate of Example 1, except that printing was performed on the coated layer side of the coated paper, which was the paper base layer, to form a picture layer, and a non-solvent barrier adhesive (PASLIM NSRD011/NSRD006, manufactured by DIC Corporation) was applied to the uncoated side.

[Example 4]
The laminate of Example 4 was similar to the laminate of Example 1, except that a solvent-based barrier adhesive (PASLIM VM001/108CP manufactured by DIC Corporation) was applied and dried to a dry thickness of 4 μm, and then bonded by a dry lamination method to the vapor-deposited surface of an aluminum-deposited CPP film of 25 μm (VM-CPP 2703 manufactured by Toray Advanced Film Co., Ltd.) which would serve as a sealant layer having a vapor deposition layer.

[Example 5]
The laminate of Example 5 was the same as the laminate of Example 4, except that printing was performed on the coated layer side of the coated paper, which was the paper base layer, to form a picture layer, and a solvent-based barrier adhesive (PASLIM VM001/108CP, manufactured by DIC Corporation) was applied to the uncoated side.

[Example 6]
The laminate of Example 6 used coated paper 55 g/ ^m2 (Ryuo Coat, manufactured by Daio Paper Co., Ltd.) as the paper base layer, and the coated surface of this coated paper was gravure printed with gravure ink Sias HR (manufactured by DIC Graphics Co., Ltd.) to a dry thickness of 1 μm to form a design layer. Next, KS-10 (manufactured by DIC Graphics Co., Ltd.) was applied as an OP (overprint) varnish on the gravure print (design layer) to a dry thickness of 1 μm to form a surface layer.
Next, a solvent-based barrier adhesive (PASLIM VM001/108CP manufactured by DIC Corporation) was applied to the deposition surface of an aluminum-deposited CPP film 25 μm thick (VM-CPP 2703 manufactured by Toray Advanced Film Co., Ltd.) as a sealant layer having a deposition layer to a dry thickness of 4 μm and dried, and then this was attached to the non-printed surface of coated paper by a dry lamination method and aged at 40° C. for 3 days to obtain a laminate of Example 6.

[Example 7]
The laminate of Example 7 is similar to the laminate of Example 1, except that the basis weight of the paper base layer was changed to 98 g/ ^m2 .

[Example 8]
The laminate of Example 8 is similar to the laminate of Example 1, except that the paper base layer was changed to a barrier coated paper (Nippon Paper Shield Plus) 66 g/ ^m2 .

[Comparative Example 1]
The laminate of Comparative Example 1 was the same as the laminate of Example 1, except that the paper base layer was changed to 34 g/ ^m2 coated paper (oil-resistant coated paper, manufactured by Daio Paper Corporation) and the thickness of the aluminum-vapor-deposited CPP film (sealant layer with a vapor-deposited layer) was changed to 40 μm.

[Comparative Example 2]
The laminate of Comparative Example 2 is similar to the laminate of Example 1, except that the basis weight of the paper base layer was changed to 120 g/m ² .

[Comparative Example 3]
The laminate of Comparative Example 3 was the same as the laminate of Example 1, except that the non-solvent barrier adhesive was changed to a general-purpose non-solvent ester adhesive (A-695/A-95, manufactured by Mitsui Chemicals, Inc.).

[Comparative Example 4]
The laminate of Comparative Example 4 was the same as the laminate of Example 4, except that the barrier adhesive was changed to a general-purpose solvent-based ester adhesive (A-315/A-50, manufactured by Mitsui Chemicals, Inc.).

The evaluation results of each of the laminates of the Examples and Comparative Examples are summarized in Table 1 below.

[Evaluation of Barrier Properties]
The oxygen permeability of the laminates of the examples and comparative examples prepared was measured at 23°C and 90% RH in accordance with JIS K 7126-2, and it was confirmed that, as shown in Table 1, the laminates of Comparative Examples 3 and 4, which used a general-purpose non-solvent adhesive that is not a barrier adhesive and a general-purpose solvent-based adhesive, had significantly higher oxygen permeability than the laminates of the other examples, Comparative Examples 1 and 2. This confirmed that the oxygen permeability of the laminates of each example was significantly improved by the barrier adhesive layer. An oxygen permeability measuring device (manufactured by Mocon, product name "OXTRAN") was used.

When the water vapor permeability of the laminates of the Examples and Comparative Examples was measured at 40°C and 90% RH in accordance with JIS K 7129 B method, it was confirmed that, as in the case of oxygen, the laminates of Comparative Examples 3 and 4, which do not have a barrier adhesive layer, have a significantly higher water vapor permeability than the laminates of the other Examples, Comparative Examples 1 and 2. This confirmed that the laminates of each Example have a significantly improved water vapor permeability due to the barrier adhesive layer. A water vapor permeability measuring device (manufactured by Mocon, product name "Permatran") was used.

[Evaluation of hand tearability]
The evaluation of hand tearability was a sensory evaluation in which an experimenter judged whether the laminate of each Example and Comparative Example created could be properly cut by hand. In Table 1, a case in which it was properly cut along the planned line was marked with "◎", a case in which it was cut to some extent along the planned line was marked with "◯", and a case in which it could not be cut or it was cut in an unexpected direction was marked with "X".

As shown in Table 1, the laminate of Comparative Example 2 had a ratio (t1/t2) of the basis weight t1 of the paper base layer to the basis weight t2 of the sealant layer with a vapor deposition layer of 5.33, and the basis weight t1 of the paper base layer was too large compared with the basis weight t2 of the sealant layer with a vapor deposition layer, so the hand-tearability was rated as "X".
In contrast, the laminates of each Example were evaluated as "good" or "good", and it was confirmed that the t1/t2 of each Example was within the preferred range (1.00 to 5.00). It was also confirmed that the basis weight of each paper base layer of each Example Example was within the preferred range (30 g/ ^m2 to 100 g/ ^m2 ).

[Dead hold evaluation]
The evaluation of the dead hold property was a sensory evaluation in which the laminate of each Example and Comparative Example prepared was folded in half, left to stand for 5 minutes, and then judged by an experimenter whether the folded shape was maintained or not. In Table 1, the case where the folded shape was maintained even after being folded in half and left to stand was marked with "◎", the case where the folded shape returned slightly to the shape before folding when left to stand was marked with "◯", and the case where the folded shape returned to its original shape after folding, or where some creases remained but the shape before folding was almost completely returned to its original shape was marked with "X".

As shown in Table 1, the laminate of Comparative Example 1 had a ratio (t1/t2) of the basis weight t1 of the paper base layer to the basis weight t2 of the sealant layer with a vapor deposition layer of 0.94. It is believed that the basis weight t1 of the paper base layer was too small compared with the basis weight t2 of the sealant layer with a vapor deposition layer, which was why the dead hold ability was rated as "x".
In contrast, the laminates of the respective Examples were rated as "good" or "excellent" in terms of dead hold property, and it was confirmed that the respective t1/t2 ratios fell within the preferred range (1.00 or more and 5.00 or less).

1 (1A, 1B, 1C, 1D, 1E, 1F, 1G) Packaging bag (packaging body)
REFERENCE SIGNS LIST 10 Laminate 11 Paper base layer 12 Sealant layer 13 Vapor deposition layer 14 Barrier adhesive layer

Claims (7)

A paper base layer (excluding those using lightly coated paper as the paper base layer) ;
a sealant layer provided on one side of the paper base layer and having a vapor-deposited layer of a metal or an inorganic oxide;
a solventless barrier adhesive layer provided between the paper base layer and the vapor deposition layer to bond the paper base layer and the vapor deposition layer,
The oxygen transmission rate measured in accordance with JIS K 7126-2 at 23°C and 90% RH is 3.0 cc/m ² /day/atm or less;
The mass per ^m2 of the paper base layer is t1,
When the mass per ^m2 of the sealant layer including the vapor deposition layer is t2,
A laminate satisfying 1.0≦t1/t2≦2.44. The laminate according to claim 1 , wherein the paper base layer has a basis weight of 30 g/m ² or more and 100 g/m ² or less. The laminate according to claim 1 or 2, wherein the sealant layer has a thickness of 20 μm or more and 40 μm or less. The laminate according to claim 1 , wherein the sealant layer is an unstretched polyolefin resin film. The unstretched polyolefin resin film is an unstretched polypropylene resin film,
The laminate according to claim 4 , wherein the unstretched polypropylene resin film contains biomass polyethylene. the barrier adhesive layer is a cured product of a resin composition containing a resin having two or more hydroxyl groups per molecule and an isocyanate compound having two or more isocyanate groups per molecule,
The laminate according to any one of claims 1 to 5, wherein the main skeleton of the resin is a polyester or a polyester polyurethane, and contains an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof as a polyester constituent monomer component. A packaging body formed using the laminate according to any one of claims 1 to 6.

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