JP2023111996A - laminate - Google Patents

Abstract

To provide a laminate that is better in CO2 reduction effect than a laminate made of a polyethylene terephthalate that is not recycled, and that has excellent hygiene property.SOLUTION: The laminate includes at least an adhesive-agent layer, a barrier layer and a sealant layer in this order. A substrate layer is a biaxially stretched film comprising a first layer, a second layer and a third layer in this order. The first layer and the third layer are layers composed only of virgin polyethylene terephthalate. The second layer is a layer composed only of recycled polyethylene terephthalate or a mixed layer of recycled polyethylene terephthalate and virgin polyethylene terephthalate. The thickness of the substrate layer is 5 μm or more and 25 μm or less. The barrier layer includes a transparent vapor deposition layer provided on the substrate layer and a gas barrier coating film provided on the surface of the transparent vapor deposition layer. The transparent vapor deposition layer is made of aluminum oxide.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a laminate, and more particularly to a laminate using as a raw material a recycled polyester resin recovered from a packaging material or the like so as to be reused.

Plastics, which are materials derived from fossil fuels, are mainly used in the manufacture of packaging materials for filling products such as pharmaceuticals, cosmetics, and foods, from the viewpoints of ease of molding and cost. Polyester-based resins, polyolefin-based resins, polyamide-based resins, and the like are used as plastic materials widely used as materials for packaging containers. Among them, polyester-based resins are widely used in various industrial applications such as films, sheets, and packaging containers because they are excellent in mechanical properties, chemical stability, heat resistance, transparency, etc., and are inexpensive.

Polyester is obtained by polycondensation of diol units and dicarboxylic acid units. For example, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is produced by using ethylene glycol and terephthalic acid as raw materials and subjecting them to an esterification reaction and then a polycondensation reaction. These raw materials are produced from petroleum, which is a fossil resource. For example, ethylene glycol is industrially produced from ethylene, and terephthalic acid is industrially produced from xylene.

In recent years, with respect to such fossil fuel-derived materials, there has been an increasing trend year by year to reduce the use of fossil fuels in various applications and to reduce CO ₂ emissions in consideration of the environment. As an attempt to reduce the use of fossil fuels, a method has been proposed in which polyester resin recovered from used packaging materials such as PET bottles can be reused and recycled as recycled polyester for molding packaging materials ( For example, see Patent Documents 1 and 2). In Patent Documents 1 and 2, CO ₂ emissions are reduced by using polyester, which is made from polyester derived from fossil fuels and which has been recovered and made reusable, as part of the packaging material. It is proposed that

JP 2011-256328 A JP 2012-41463 A

However, packaging materials using recycled PET, which is mechanically recycled by pulverizing, washing, and reusing polyester resin products such as collected PET bottles, are contaminated due to foreign substances adhering to the recycled PET. There is an impression that there is a possibility that nations and the like are occurring. For this reason, packaging materials manufactured using a laminate made of recycled PET, particularly packaging materials for filling products such as foods, are in a situation where it is difficult to gain trust from consumers.

An object of the present invention is to provide a laminate that can effectively solve such problems.

The present invention provides a laminate comprising at least a substrate layer, an adhesive layer, a barrier layer, and a sealant layer in this order, wherein the substrate layer comprises a first layer, a second layer, and a third layer. A biaxially stretched film comprising layers in this order, wherein the first layer and the third layer are layers composed only of virgin polyethylene terephthalate, and the second layer is a layer composed only of recycled polyethylene terephthalate. Alternatively, a mixed layer of recycled polyethylene terephthalate and virgin polyethylene terephthalate, wherein the recycled polyethylene terephthalate includes polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units, and the substrate The thickness of the layer is 5 μm or more and 25 μm or less, and the barrier layer includes a transparent deposition layer provided on the base material layer and a gas barrier coating film provided on the surface of the transparent deposition layer. , the transparent deposition layer is a laminate made of aluminum oxide.

In the laminate according to the present invention, the adhesive layer may have a cured product of a polyester polyol and an isocyanate compound.

In the laminate according to the present invention, the sealant layer may have a thickness of 30 μm or more and 130 μm or less.

The laminate according to the invention may comprise a printed layer between the substrate layer and the barrier layer.

ADVANTAGE OF THE INVENTION According to this invention, the laminated body which is excellent in a sanitary property while being excellent in a _CO2 reduction effect compared with the laminated body which consists of polyethylene terephthalate which is not recycled can be provided.

1 is a schematic cross-sectional view showing an example of a laminate according to this embodiment; FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to this embodiment; FIG. It is a schematic cross section which shows an example of a base material layer.

<Laminate>
The laminate according to this embodiment includes at least a substrate layer, a barrier layer, and a sealant layer in this order. The laminate may further comprise adhesive layers, printing layers, other layers and the like.

A laminate according to this embodiment will be described with reference to the drawings. Examples of schematic cross-sectional views of the laminate according to the present embodiment are shown in FIGS. 1 and 2. FIG.

The laminate 10 shown in FIG. 1 includes a substrate layer 11, an adhesive layer 14, a barrier layer 12, and a sealant layer 13 in this order. As shown in FIG. 1, the barrier layer 12 includes a deposited layer 121 provided on the sealant layer 13 . Although not shown, the laminate 10 may further include a printed layer provided on the base material layer 11 . In the packaging bag comprising the laminate 10 shown in FIG. 1, the sealant layer 13 constitutes the inner surface of the packaging bag.

The laminate 10 shown in FIG. 2 includes a substrate layer 11, a barrier layer 12, an adhesive layer 14, and a sealant layer 13 in this order. As shown in FIG. 2 , the barrier layer 12 includes at least a deposition layer 121 provided on the base material layer 11 . The barrier layer 12 may further include a gas barrier coating film 122 provided on the surface of the vapor deposition layer 121 . Although not shown, laminate 10 may further comprise a printing layer positioned between barrier layer 12 and adhesive layer 14 . In the packaging bag including the laminate 10 shown in FIG. 2 as well, the sealant layer 13 constitutes the inner surface of the packaging bag.

Each layer constituting the laminate will be described below.

[Base material layer]
The base material layer contains polyethylene terephthalate recycled by mechanical recycling (hereinafter polyethylene terephthalate is also referred to as PET). Specifically, the base material layer contains PET obtained by mechanically recycling PET bottles, and this PET contains ethylene glycol as the diol unit and terephthalic acid and isophthalic acid as the dicarboxylic acid unit. Here, mechanical recycling generally refers to the process of pulverizing collected PET bottles and other polyethylene terephthalate resin products, washing with alkali to remove dirt and foreign matter from the surface of the PET resin products, and then drying for a certain period of time under high temperature and reduced pressure. This method decontaminates the PET resin by diffusing the contaminants remaining inside the PET resin, removes dirt from the resin product made of the PET resin, and returns it to the PET resin. Hereinafter, in this specification, polyethylene terephthalate obtained by recycling PET bottles is referred to as "recycled polyethylene terephthalate (hereinafter also referred to as recycled PET)", and polyethylene terephthalate that is not recycled is referred to as "virgin polyethylene terephthalate (hereinafter also referred to as virgin PET). )”.

Among the PET contained in the base material layer, the content of isophthalic acid is preferably 0.5 mol% or more and 5 mol% or less, and 1.0 mol%, based on the total dicarboxylic acid units constituting the PET. It is more preferable that the content is at least 2.5 mol % or less. When the content of isophthalic acid is less than 0.5 mol %, the flexibility may not be improved. PET may be biomass PET in addition to PET derived from ordinary fossil fuels. “Biomass PET” contains biomass-derived ethylene glycol as a diol unit and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit. This biomass PET may be formed only of PET having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit, or may be formed from biomass-derived ethylene glycol and fossil fuel-derived diol. It may be formed of PET having a diol unit and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit.

PET used for PET bottles can be obtained by a conventionally known method of polycondensing the diol units and dicarboxylic acid units described above. Specifically, a general method of melt polymerization such as conducting an esterification reaction and/or a transesterification reaction between the diol unit and the dicarboxylic acid unit and then conducting a polycondensation reaction under reduced pressure, or an organic solvent can be produced by a known solution heating dehydration condensation method using

The amount of the diol unit used in the production of the PET is substantially equimolar with respect to 100 mol of the dicarboxylic acid or derivative thereof. Since there is distillation during the reaction, it is used in excess of 0.1 mol % or more and 20 mol % or less.

Moreover, the polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added at the time of charging the raw materials or at the start of depressurization.

After the PET recycled from PET bottles is polymerized and solidified as described above, solid phase polymerization is performed as necessary to further increase the degree of polymerization and remove oligomers such as cyclic trimers. you can go Specifically, in the solid state polymerization, PET is chipped and dried, and then heated at a temperature of 100° C. or higher and 180° C. or lower for about 1 to 8 hours to pre-crystallize the PET, followed by 190° C. It is carried out by heating at a temperature of 230° C. or less in an inert gas atmosphere or under reduced pressure for 1 hour to several tens of hours.

The intrinsic viscosity of PET contained in the base material layer is preferably 0.58 dl/g or more and 0.80 dl/g or less. If the intrinsic viscosity is less than 0.58 dl/g, the mechanical properties required for the PET film as the substrate may be insufficient. On the other hand, when the intrinsic viscosity exceeds 0.80 dl/g, the productivity in the film forming process may be impaired. In addition, the intrinsic viscosity is measured at 35° C. with an orthochlorophenol solution.

The base material layer preferably contains recycled PET at a ratio of 50% by weight or more and 95% by weight or less, and may contain virgin PET in addition to recycled PET. The virgin PET may be PET containing ethylene glycol as the diol unit and containing terephthalic acid and isophthalic acid as the dicarboxylic acid unit as described above, or PET containing no isophthalic acid as the dicarboxylic acid unit. good too. Moreover, the base material layer may contain polyester other than PET. For example, dicarboxylic acid units may include aliphatic dicarboxylic acids and the like in addition to aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid.

Specific examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid, which usually have 2 to 40 carbon atoms. cyclic or alicyclic dicarboxylic acids. Derivatives of aliphatic dicarboxylic acids include lower alkyl esters such as methyl esters, ethyl esters, propyl esters and butyl esters of the above aliphatic dicarboxylic acids, and cyclic acid anhydrides of the above aliphatic dicarboxylic acids such as succinic anhydride. . Among these, as the aliphatic dicarboxylic acid, adipic acid, succinic acid, dimer acid, or a mixture thereof is preferred, and those containing succinic acid as a main component are particularly preferred. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

The substrate layer composed of such PET may be a single layer or multiple layers. As shown in FIG. 3, when the recycled PET as described above is used for the base material layer, the base material layer may have three layers of a first layer 31, a second layer 32 and a third layer 33. FIG. In this case, in the laminate, the third layer 33 of the base material layers is located on the sealant layer side. In this case, the second layer 32 is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 31 and the third layer 33 are layers composed only of virgin PET. preferably. By using only virgin PET for the first layer 31 and the third layer 33 in this way, it is possible to prevent the recycled PET from being exposed from the front surface or the rear surface of the base material layer. Therefore, the sanitation of the laminate can be ensured. Moreover, the base layer may be a base layer having two layers, the second layer 32 and the third layer 33, without providing the first layer 31 shown in FIG. Furthermore, the base layer may be a base layer having two layers, the first layer 31 and the second layer 32, without providing the third layer 33 shown in FIG. Also in these cases, the second layer 32 is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 31 and the third layer 33 are layers composed only of virgin PET. It is preferable to

When recycled PET and virgin PET are mixed and molded into one layer, there are a method of feeding them separately to a molding machine, a method of feeding them after mixing by dry blending, and the like. Among them, the method of mixing by dry blending is preferable from the viewpoint of simple operation.

Various additives can be added to the PET constituting the base material layer during the production process or after the production, as long as the properties are not impaired. Additives such as plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, release agents, antioxidants, ions exchange agents, color pigments, and the like. The additive is preferably added in a range of 5% by mass to 50% by mass, preferably 5% by mass to 20% by mass, based on the total resin composition containing PET.

The substrate layer can be formed by forming a film from the PET described above, for example, by a T-die method. Specifically, after drying the above PET, it is supplied to a melt extruder heated to a temperature (Tm) above the melting point of PET to Tm + 70 ° C. to melt the resin composition, for example, a T die A film can be formed by extruding a sheet from a die such as the above, and rapidly cooling and solidifying the extruded sheet with a rotating cooling drum or the like. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

The film obtained as described above is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to obtain a longitudinally stretched film. This stretching is preferably carried out using a difference in peripheral speed between two or more rolls. Longitudinal stretching is usually performed in a temperature range of 50°C or higher and 100°C or lower. Further, the longitudinal stretching ratio is preferably 2.5 times or more and 4.2 times or less, although it depends on the properties required for the film application. If the draw ratio is less than 2.5 times, the thickness unevenness of the PET film becomes large, making it difficult to obtain a good film.

The longitudinally stretched film is then successively subjected to transverse stretching, heat setting, and heat relaxation steps to obtain a biaxially stretched film. Lateral stretching is usually performed in a temperature range of 50°C or higher and 100°C or lower. The lateral stretching ratio is preferably 2.5 times or more and 5.0 times or less, although it depends on the properties required for the application. If it is less than 2.5 times, the thickness of the film becomes uneven, making it difficult to obtain a good film.

After the transverse stretching, heat setting treatment is carried out, and the preferable temperature range for heat setting is Tg+70 to Tm−10° C. of PET. Moreover, the heat setting time is preferably 1 second or more and 60 seconds or less. Furthermore, for applications that require a reduction in heat shrinkage, heat relaxation treatment may be performed as necessary.

The thickness of the PET film obtained as described above is arbitrary according to its use, but is usually about 5 μm to 100 μm, preferably 5 μm to 25 μm. The breaking strength of the PET film is 5 kg/mm ² or more and 40 kg/mm ² or less in the MD direction, and 5 kg/mm ² or more and 35 kg/mm ^{2 or} less in the TD direction. % or more and 350% or less, and 50% or more and 300% or less in the TD direction. Moreover, the shrinkage ratio when left in a temperature environment of 150° C. for 30 minutes is 0.1% or more and 5% or less.

Virgin PET may be fossil fuel polyethylene terephthalate (hereinafter also referred to as fossil fuel PET) or biomass PET. As used herein, “fossil fuel PET” has a diol unit derived from a fossil fuel and a dicarboxylic acid derived from a fossil fuel as a dicarboxylic acid unit. Recycled PET may be obtained by recycling PET resin products formed using fossil fuel PET, or obtained by recycling PET resin products formed using biomass PET. There may be.

[Barrier layer]
Next, the barrier layer will be explained. The barrier layer is a layer for suppressing the problem that even if foreign matter adheres to the recycled PET used for the base material layer, the foreign matter is exposed to the sealant layer side rather than the barrier layer. As a result, it is possible to prevent foreign matter from appearing on the inner surface side of the barrier layer in the packaging bag constructed using the laminate, so that the sanitation of the contents can be ensured.

(evaporation layer)
Next, the deposited layer of the barrier layer will be described. The vapor deposition layer is a layer made of a vapor deposition film that can be formed by a conventionally known method. By providing the vapor deposition layer, it is possible to impart or improve gas barrier properties that prevent permeation of oxygen gas, water vapor, and the like. In addition, the vapor deposition film which comprises a barrier layer may be provided with two or more layers of vapor deposition layers. When two or more deposited layers are provided, they may have the same composition or may have different compositions.

The vapor-deposited film may be a metal vapor-deposited layer made of a metal vapor-deposited film, or may be a transparent vapor-deposited layer made of an inorganic oxide vapor-deposited film.

When the barrier layer contains a vapor-deposited metal layer, in addition to the above-described gas barrier properties, it is possible to impart or improve light-shielding properties that block the transmission of visible light, ultraviolet rays, and the like. Moreover, since it is possible to impart a metallic luster to the packaging bag, it is possible to improve the design.
When the barrier layer includes a transparent deposited layer, it is possible to impart or improve gas barrier properties that prevent permeation of oxygen gas, water vapor, etc., while maintaining the permeability of the contents.

In the laminate 10 shown in FIG. 1 , the printed layer can be provided on the base material layer 11 located on the outer surface side of the barrier layer 12 . Therefore, the barrier layer 12 may have a light shielding property. Therefore, in the layered product 10 shown in FIG. 1, the vapor deposition layer 121 is preferably a metal vapor deposition layer.

Examples of metal deposition layers include aluminum (Al), magnesium (Mg), tin (Sn), sodium (Na), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), gold ( Au), chromium (Cr), etc. can be used. In particular, for packaging bags, it is preferable to have an aluminum deposition layer.

The film thickness of the vapor-deposited metal layer varies depending on the type of metal used, but it is desirable to select and form it within the range of, for example, 50 Å or more and 2000 Å or less, preferably 100 Å or more and 1000 Å or less. More specifically, in the case of an aluminum deposition layer, the film thickness is desirably 50 Å or more and 600 Å or less, more preferably 100 Å or more and 450 Å or less.

When the vapor deposited layer of the barrier layer is a transparent vapor deposited layer, the printed layer can be visually recognized from the outer surface side even when the printed layer is located closer to the sealant layer than the barrier layer. Therefore, as shown in FIG. 2, when the barrier layer 12 is provided on the substrate layer 11, the deposited layer 121 of the barrier layer 12 is preferably a transparent deposited layer.

Examples of transparent deposited layers include silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium ( Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc. can be used. In particular, for packaging bags, it is preferable to have a deposited layer of aluminum oxide or silicon oxide.

Inorganic oxides are represented by MO _X such as SiO _X and AlO _X (wherein M represents an inorganic element, and the value of X varies depending on the inorganic element). expressed. The range of values of X is 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), 0 to 1 for calcium (Ca), Potassium (K) is 0 to 0.5, Tin (Sn) is 0 to 2, Sodium (Na) is 0 to 0.5, Boron (B) is 0 to 1.5, Titanium (Ti) can range from 0 to 2, lead (Pb) from 0 to 2, zirconium (Zr) from 0 to 2, and yttrium (Y) from 0 to 1.5. In the above, when X=0, it is a completely inorganic substance (pure substance) and not transparent, and the upper limit of the range of X is the fully oxidized value. Silicon (Si) and aluminum (Al) are preferably used as packaging materials, with silicon (Si) in the range of 1.0 to 2.0 and aluminum (Al) in the range of 0.5 to 1.5. values can be used.

Although the film thickness of the transparent deposition layer varies depending on the type of inorganic oxide used, it is desirable to form the layer by selecting it within the range of, for example, 50 Å or more and 2000 Å or less, preferably 100 Å or more and 1000 Å or less. For example, in the case of a deposited layer of aluminum oxide or silicon oxide, the film thickness is desirably 50 Å or more and 500 Å or less, more preferably 100 Å or more and 300 Å or less.

The vapor deposition layer can be formed on the substrate layer or the sealant layer using the following formation method. Examples of the method for forming the deposited layer include physical vapor deposition methods such as vacuum deposition, sputtering, and ion plating (Physical Vapor Deposition, PVD), plasma chemical vapor deposition, thermochemical A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a chemical vapor deposition method and a photochemical vapor deposition method can be used.

(Gas barrier coating film)
A gas barrier coating film is provided on the surface of the vapor deposition layer as required. In particular, when the vapor deposition layer is a transparent vapor deposition layer, it is preferable to provide a gas barrier coating film on the surface of the transparent vapor deposition layer.

The gas barrier coating film is a coating film that functions as a layer that suppresses permeation of oxygen gas and water vapor. The gas barrier coating film has the general formula R ¹ _n M (OR ² ) _m (wherein R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) and at least one or more alkoxides represented by a polyvinyl alcohol-based resin and / or It contains an ethylene-vinyl alcohol copolymer and is obtained by polycondensation by the sol-gel method in the presence of a sol-gel catalyst, acid, water and an organic solvent.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , at least one of partial hydrolyzate of alkoxide and condensate of hydrolysis of alkoxide can be used. The partial hydrolyzate of the above alkoxide does not need to have all of the alkoxy groups hydrolyzed, and may be those in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. As the condensate obtained by hydrolysis of alkoxide, a partially hydrolyzed alkoxide dimer or higher, specifically a dimer to hexamer, is used.

In the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , the metal atom represented by M can be silicon, zirconium, titanium, aluminum, or the like. In this embodiment, preferred metals include, for example, silicon and titanium. In addition, in the present embodiment, alkoxides can be used singly or as a mixture of alkoxides of two or more different metal atoms in the same solution.

Further, in the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ¹ include a methyl group, an ethyl group, an n-propyl group, i -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group, and the like. Further, in the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ² include a methyl group, an ethyl group, an n-propyl group, i -propyl group, n-butyl group, sec-butyl group, and the like. These alkyl groups may be the same or different in the same molecule.

For example, a silane coupling agent may be added when preparing the gas barrier composition. Known organic reactive group-containing organoalkoxysilanes can be used as the silane coupling agent. In this embodiment, organoalkoxysilanes having an epoxy group are particularly preferably used. Specifically, examples include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β -(3,4-Epoxycyclohexyl)ethyltrimethoxysilane and the like can be used. The above silane coupling agents may be used singly or in combination of two or more.

[Sealant layer]
The sealant layer is the innermost layer in the package. The sealant layer is a layer made of a thermoplastic resin that can be fused together by heat. The sealant layer may contain a resin material derived from fossil fuel, or may contain a resin material derived from biomass.

The resin material forming the sealant layer is not particularly limited as long as it is a resin that can be mutually fused by heat. High-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), ethylene-α-olefin copolymer polymerized using a metallocene catalyst, random or block copolymer of ethylene-polypropylene, polypropylene, Ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate Copolymers (EMMA), ionomer resins, heat-sealable ethylene-vinyl alcohol resins, or polyolefins such as methylpentene-based resins, ethylene-propylene copolymers, methylpentene polymers, polybutene polymers, polyethylene, polypropylene or cyclic olefin copolymers acid-modified polyolefin resins, poly(vinyl acetate) resins, poly(meth)acryl resins, polyvinyl chloride resins, and other resins. These may be used alone or as a mixture of two or more. The sealant layer can be used as a resin film or sheet as described above, or as a coating film thereof.

When polyethylene is used as the resin material for forming the sealant layer, the raw material may be obtained by polymerizing ethylene derived from biomass in addition to ethylene obtained from fossil fuels. As the biomass-derived ethylene, specifically, for example, one described in JP-A-2012-251006 can be used. By using polyethylene obtained by polymerizing biomass-derived ethylene as a material for forming the sealant layer, it is possible to form a layer made of a carbon-neutral material. can reduce the amount used and reduce the environmental load.

As the biomass-derived ethylene, commercially available ones may be used, for example, Braskem's "C4LL-LL118 (d = 0.916, MFR = 1.0 g / 10 minutes)" sugarcane-derived linear A low-density polyethylene-based resin or a sugarcane-derived low-density polyethylene-based resin such as "SBC118 (d=0.918, MFR=8.1 g/10 min)" can be used.

In this embodiment, one sealant layer is provided, but two or more sealant layers may be provided. When there are two or more sealant layers, each layer may have the same composition or different compositions. For example, the sealant layer is composed of three layers in which a first layer, a second layer and a third layer are laminated in order, the first layer and the third layer are made of a fossil fuel-derived resin material, and the second layer is made of a resin material derived from fossil fuel. The layer may be made of a resin material containing a biomass-derived resin material. When the sealant layer is composed of two or more layers, they can be laminated using a co-extrusion method.

The thickness of the sealant layer is preferably 20 μm or more and 200 μm or less, more preferably 30 μm or more and 130 μm or less.

[Adhesive layer]
The adhesive layer is a layer formed by applying an adhesive to the surface of the laminated film of the film including the base layer 11 and the film including the sealant layer 13 and drying the adhesive. Examples of adhesives include one-component or two-component curing or non-curing vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, and others. A solvent-type, water-based, or emulsion-type adhesive can be used. A cured product of a polyol and an isocyanate compound can be used as the two-liquid curing adhesive. Examples of coating methods for the lamination adhesive include a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, a transfer roll coating method, and other methods. .

The adhesive layer may be configured to reinforce the barrier properties of the barrier layer. In the following description, among adhesive layers containing a cured product of a polyol and an isocyanate compound, an adhesive layer configured to reinforce the barrier properties of the barrier layer is particularly referred to as a barrier adhesive layer. The barrier adhesive layer will be described below.

(Barrier adhesive layer)
The barrier adhesive layer has gas barrier properties, particularly oxygen and water vapor barrier properties. The thickness of the barrier adhesive layer is, for example, 0.5 μm or more and 6.0 μm or less, preferably 0.8 μm or more and 5.0 μm or less, and more preferably 1.0 μm or more and 4.5 μm or less. If it is thinner than the above range, the gas barrier properties tend to be insufficient, and if it is thicker than the above range, the bending resistance tends to be inferior, which tends to lead to a decrease in the gas barrier properties after bending.

The barrier adhesive layer contains a cured product of a polyester polyol and an isocyanate compound. A polyester polyol has two or more hydroxyl groups in one molecule as a functional group. Also, the isocyanate compound has two or more isocyanate groups in one molecule as functional groups. A polyester polyol has, for example, a polyester structure or a polyester polyurethane structure as a main skeleton.

The resin composition for forming a cured product of polyester polyol and isocyanate compound may further contain a plate-like inorganic compound, a phosphoric acid-modified compound, a coupling agent, cyclodextrin and/or a derivative thereof, and the like. .

The glass transition temperature of the cured coating film of the adhesive resin composition is preferably in the range of -30°C or higher and 80°C or lower. More preferably, the temperature is 0°C or higher and 70°C or lower. More preferably, the temperature is 25°C or higher and 70°C or lower. If the glass transition temperature is higher than 80° C., the flexibility of the cured coating film at around room temperature may be low, resulting in poor adhesion to the film and reduced adhesive strength. On the other hand, when the temperature is lower than −30° C., there is a risk that sufficient oxygen barrier properties may not be obtained due to vigorous molecular movement of the cured coating film near room temperature, and that adhesive strength may be reduced due to insufficient cohesive strength.

As a specific example of the resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound, a series of oxygen-barrier adhesives (PASLIM) sold by DIC Corporation can be used. PASLIM VM001/VM102CP or the like, which is a compound having a polyester skeleton and a curing agent having two or more isocyanate groups, is preferably used.

(polyester polyol)
As polyester polyols having two or more hydroxyl groups in one molecule as functional groups, for example, the following [first example] to [third example] can be used.
[Example 1] A polyester polyol obtained by polycondensation of an ortho-oriented polycarboxylic acid or its anhydride and a polyhydric alcohol [Example 2] Polyester polyol having a glycerol skeleton [Example 3] Having an isocyanuric ring Polyester Polyol Each polyester polyol will be described below.

[Example 1] Polyester polyol obtained by polycondensation of ortho-oriented polyvalent carboxylic acid or its anhydride and polyhydric alcohol The polyester polyol according to Example 1 contains at least one kind of ortho-phthalic acid and its anhydride. Polycondensation obtained by polycondensation of a polyhydric carboxylic acid component containing ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and a polyhydric alcohol component containing at least one selected from the group consisting of cyclohexanedimethanol It can be a body. In particular, a polyester polyol having a content of 70 to 100% by mass of the orthophthalic acid and its anhydride relative to the total polyvalent carboxylic acid component is preferred.

The polyester polyol according to the first example essentially contains the orthophthalic acid and its anhydride as the polyvalent carboxylic acid component, but other polyvalent carboxylic acid components are copolymerized to the extent that the effects of the present embodiment are not impaired. You may let Specifically, aliphatic polycarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc., and unsaturated bond-containing polycarboxylic acids include maleic anhydride, maleic acid, Fumaric acid and the like, 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid as alicyclic polycarboxylic acids, and terephthalic acid, isophthalic acid and pyromellitic acid as aromatic polycarboxylic acids acid, trimellitic 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 acids and anhydrides or 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 They can be used singly or in mixtures of two or more. Among them, succinic acid, 1,3-cyclopentanedicarboxylic acid and isophthalic acid are preferred.

Examples of the polyhydric alcohol component and other components include those described above.

一般式（１）において、Ｒ_１、Ｒ_２、Ｒ_３は、各々独立に、Ｈ（水素原子）又は下記の一般式（２）で表される化合物である。

[Second Example] Polyester Polyol Having a Glycerol Skeleton 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 are each independently H (hydrogen atom) or a compound represented by general formula (2) below.

In formula (2), n represents an integer of 1 to 5, X is a 1,2-phenylene group which may have a substituent, a 1,2-naphthylene group, a 2,3-naphthylene group, 2, represents an arylene group selected from the group consisting of a 3-anthraquinonediyl group and a 2,3-anthracenediyl group, 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 general 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). Among them, it is preferable that all of R ₁ , R ₂ and R ₃ are groups represented by the general formula (2).

Further, a compound in which any one of R ₁ , R ₂ and R ₃ is a group represented by the general formula (2) and any two of R ₁ , R ₂ and R ₃ are represented by the general formula (2) and a compound in which all of R ₁ , R ₂ and R ₃ are groups represented by the general formula (2), and any two or more compounds are a mixture. good too.

X is 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; represents an arylene group which may be present. When X is substituted by substituents, it may be substituted by one or more substituents, which are attached to any carbon atom on X that is different from the radical. The substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimido group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, naphthyl group and the like.

In the general formula (2), Y is 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, methylpentylene. It represents an alkylene group having 2 to 6 carbon atoms such as a len group and a dimethylbutylene group. Among them, Y is preferably a propylene group or an ethylene group, and most preferably an ethylene group.

The polyester resin compound having a glycerol skeleton represented by the general formula (1) includes glycerol, an aromatic polycarboxylic acid or an anhydride thereof in which the carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component. It is obtained by reacting as a component.

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

Further, the polyhydric alcohol component includes alkylenediol having 2 to 6 carbon atoms. Diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol and dimethylbutanediol can be exemplified.

一般式（３）において、Ｒ_１、Ｒ_２、Ｒ_３は、各々独立に、「－（ＣＨ_２）ｎ１－ＯＨ（但しｎ１は２～４の整数を表す）」、又は、一般式（４）の構造を表す。

[Third Example] Polyester polyol having an isocyanuric ring The polyester polyol according to the third example is a polyester polyol having an isocyanuric ring represented by the following general formula (3).

In general formula (3), R ₁ , R ₂ and R ₃ are each independently “—(CH ₂ )n1-OH (n1 represents an integer of 2 to 4)” or general formula (4 ) represents the structure of

In general formula (4), n2 represents an integer of 2 to 4, n3 represents an integer of 1 to 5, X represents a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, represents an optionally substituted arylene group selected from the group consisting of a 2,3-anthraquinonediyl group and a 2,3-anthracenediyl group, and Y represents an alkylene group having 2 to 6 carbon atoms; ) represents a group represented by However, at least one of R ₁ , R ₂ and R ₃ is a group represented by the general formula (4)

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

In the general formula (4), n2 represents an integer of 2-4, and n3 represents an integer of 1-5. X is 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, and has a substituent; represents an arylene group which may be

When X is substituted by substituents, it may be substituted by one or more substituents, which are attached to any carbon atom on X that is different from the radical. The substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimido group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, naphthyl group and the like.

Among the substituents of X, hydroxyl group, cyano group, nitro group, amino group, phthalimido group, carbamoyl group, N-ethylcarbamoyl group and phenyl group are preferable. , the phenyl group is most preferred.

In the general formula (4), Y is 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, methylpentylene. It represents an alkylene group having 2 to 6 carbon atoms such as a len group and a dimethylbutylene group. Among them, Y is preferably a propylene group or an ethylene group, and most preferably an ethylene group.

In the general formula (3), at least one of R ₁ , R ₂ and R ₃ is a group represented by the general formula (4). Among them, it is preferable that all of R ₁ , R ₂ and R ₃ are groups represented by the general formula (4).

Further, a compound in which any one of R ₁ , R ₂ and R ₃ is a group represented by the general formula (4), and any two of R ₁ , R ₂ and R ₃ are represented by the general formula (4) and a compound in which all of R ₁ , R ₂ , and R ₃ are groups represented by the general formula (4), and two or more compounds are a mixture. good too.

The polyester polyol having an isocyanuric ring represented by the general formula (3) includes a triol having an isocyanuric ring, an aromatic polycarboxylic acid in which the carboxylic acid is substituted at the ortho position or an anhydride thereof, and a polyhydric alcohol component. are reacted 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. etc.

Further, the aromatic polyvalent carboxylic acid or its anhydride in which the carboxylic acid is substituted at the ortho-position includes orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, and naphthalene 1,2-dicarboxylic acid. or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracenecarboxylic acid or its anhydride. These compounds may have a substituent at any carbon atom of the aromatic ring.

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

Further, the polyhydric alcohol component includes alkylenediol having 2 to 6 carbon atoms. Diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol and dimethylbutanediol can be exemplified.

Among them, 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid is used as a triol compound having an isocyanuric ring, and the carboxylic acid is at the ortho position. A polyester polyol compound with an isocyanuric ring that uses orthophthalic anhydride as the substituted aromatic polycarboxylic acid or its anhydride and ethylene glycol as the polyhydric alcohol has particularly excellent oxygen barrier properties and adhesion. preferable.

The isocyanuric ring is highly polar and trifunctional. Therefore, the whole system can be made highly polar and the crosslink density can be increased. From this point of view, it is preferable that the isocyanuric ring content is 5% by mass or more based on the total solid content of the adhesive resin.

The reason why an adhesive having an isocyanuric ring can ensure oxygen barrier properties and dry lamination adhesiveness is presumed as follows.

Isocyanuric rings are highly polar and do not form hydrogen bonds. In general, as a technique for improving adhesion, it is known to add highly polar functional groups such as hydroxyl groups, urethane bonds, ureido bonds, and amide bonds, but resins with these bonds do not form intermolecular hydrogen bonds. However, polyester resins with isocyanuric rings do not impair the solubility and can be easily diluted. is.

Further, since the isocyanuric ring is trifunctional, a polyester polyol compound having an isocyanuric ring as the center of the resin skeleton and a polyester skeleton having a specific structure in its branched chain can obtain a high crosslink density. It is presumed that the gaps through which gases such as oxygen pass can be reduced by increasing the crosslink density. Thus, the isocyanuric ring is highly polar without forming intermolecular hydrogen bonds and provides a high crosslink density, so it is presumed that oxygen barrier properties and dry laminate adhesiveness can be ensured.

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

Among them, polyisocyanate compounds are preferred from the viewpoint of adhesiveness and retort resistance, and those having an aromatic ring are preferred from the viewpoint of imparting oxygen barrier properties. It is preferable because oxygen barrier properties can be improved not only by hydrogen bonding but also by π-π stacking between aromatic rings.

Specific isocyanate compounds include, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, meta-xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, or isocyanate compounds thereof. Trimers and excess amounts of these isocyanate compounds, such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol , erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, metaxylylenediamine and other low-molecular-weight active hydrogen compounds and their alkylene oxide adducts, various polyester resins, polyether polyols, and polyamides. Examples include adducts, burettes, and allophanates obtained by reacting with active hydrogen compounds and the like.

(Plate-like inorganic compound)
The plate-like inorganic compound has the effect of improving the lamination strength and gas barrier properties of the barrier adhesive layer formed by curing the adhesive resin composition.
Specific examples of plate-like inorganic compounds include kaolinite-serpentine clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, etc.). light, talc, kerorai, etc.), and one or more of these can be used.

(Phosphate modified compound)
A phosphoric acid-modified compound is, for example, a compound represented by the following general formula (5) or (6).

一般式（５）において、Ｒ_１、Ｒ_２、Ｒ_３は、水素原子、炭素数１～３０のアルキル基、（メタ）アクリロイル基、置換基を有してもよいフェニル基、（メタ）アクリロイルオキシ基を有する炭素数１～４のアルキル基から選ばれる基であるが、少なくとも一つは水素原子であり、ｎは、１～４の整数を表す。

In general formula (5), R ₁ , R ₂ and R ₃ are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, (meth)acryloyl A group selected from alkyl groups having 1 to 4 carbon atoms and having an oxy group, at least one of which is a hydrogen atom, and n represents an integer of 1 to 4.

式中、Ｒ_４、Ｒ_５は、水素原子、炭素数１～３０のアルキル基、（メタ）アクリロイル基、置換基を有してもよいフェニル基、（メタ）アクリロイルオキシ基を有する炭素数１～４のアルキル基から選ばれる基であり、ｎは１～４の整数、ｘは０～３０の整数、ｙは０～３０の整数を表すが、ｘとｙが共に０である場合を除く。

In the formula, R ₄ and R ₅ are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, or a (meth)acryloyloxy group having 1 carbon atoms. a group selected from alkyl groups of 1 to 4, n is an integer of 1 to 4, x is an integer of 0 to 30, and y is an integer of 0 to 30, except when both x and y are 0 .

The above phosphoric acid-modified compound has an effect of improving the laminate strength to the inorganic member of the present embodiment, and a known and commonly used compound can be used.

More specifically, 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, butoxy Ethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, polyoxyethylene alkyl ether phosphoric acid and the like can be mentioned, and one or more of these can be used.

The content of the phosphoric acid-modified compound is preferably 0.005% by mass or more and 10% by mass or less in the adhesive resin composition of the present embodiment. More preferably, it is 0.01% by mass or more and 1% by mass or less. If it is less than 0.005% by mass, good adhesion cannot be obtained. If the amount is more than 10% by mass, the barrier properties may deteriorate.

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

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxysilane oxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercapto propyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene) and the like.

Examples of the titanium-based coupling agent include isopropyltriisostearoyl titanate, isopropyltri(N-aminoethyl-aminoethyl)titanate, isopropyltridodecylbenzenesulfonyltitanate, isopropyltris(dioctylpyrophosphate)titanate, and tetraoctyl. Bis(didodecylphosphite) titanate, tetraoctylbis(ditridecylphosphite) titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, isopropyltrioctynortitanate, isopropyldimethacrylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, diisostearoyl ethylene titanate, isopropyl tri(dioctylphosphate) titanate, isopropyl tricumylphenyl titanate, dicumylphenyloxyacetate titanate and the like.

Specific examples of the aluminum-based coupling agent include acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethylacetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkylacetoacetate mono(dioctylphosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, alkylacetoacetate aluminum oxide trimer and the like.

(Cyclodextrin and/or its derivative)
Said cyclodextrin and/or its derivatives are preferred components for obtaining 1) excellent adhesion to films with inorganic layers and 2) excellent oxygen barrier enhancement. Specifically, for example, in addition to cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, hydroxyalkylated cyclodextrin, etc., in which the hydrogen atom of the hydroxyl group of the glucose unit of cyclodextrin is substituted with another functional group, etc. are used. be able to. Branched cyclic dextrins can also be used. In addition, cyclodextrin skeletons in cyclodextrins and cyclodextrin derivatives include α-cyclodextrin consisting of 6 glucose units, β-cyclodextrin consisting of 7 glucose units, and γ-cyclodextrin consisting of 8 glucose units. can be used. These compounds may be used alone or in combination of two or more. Moreover, hereinafter, these cyclodextrins and/or derivatives thereof may be collectively referred to as dextrin compounds.

From the viewpoint of compatibility and dispersibility in the adhesive resin composition, it is preferable to use a cyclodextrin derivative as the cyclodextrin compound. The degree of substitution is preferably in the range of 0.1 to 14/glucose, more preferably in the range of 0.3 to 8/glucose, from the viewpoint of the polarity of the various resins. .

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

As the acetylated cyclodextrin, for example, monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, monoacetyl-γ-cyclodextrin and the like can be used. These compounds may be used alone or in combination of two or more.

As the hydroxyalkylated cyclodextrin, for example, hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroxypropyl-γ-cyclodextrin and the like can be used. These compounds may be used alone or in combination of two or more.

The content of the cyclodextrin and/or derivative thereof is not particularly limited, but from the viewpoints of compatibility with resins, solvents, and isocyanate compounds, improvement of adhesive strength, and improvement of barrier properties, the content of the cyclodextrin and/or derivative thereof is 0.00% in the barrier adhesive layer. It is preferably in the range of 01 to 20 parts by mass, more preferably in the range of 0.05 to 10 parts by mass, and even more preferably in the range of 0.1 to 5 parts by mass.

When the adhesive resin composition contains cyclodextrin and/or its derivative, the cyclic and regularly arranged hydroxyl groups and ether groups of the cyclodextrin and/or its derivative have multiple interaction points with the inorganic surface. By having coordinate bonds and hydrogen bonds, it is assumed that an adhesive with strong adhesive strength can be produced when films with inorganic layers, especially various films such as metal foil, metal vapor deposition film, and transparent vapor deposition film are laminated. are doing. In addition, it is assumed that a large number of hydroxyl groups possessed by cyclodextrin and/or its derivatives interact intermolecularly to narrow the free volume pores through which gas permeates, thereby improving the barrier function.

(solvent)
If the polyester polyol and the isocyanate compound are dissolved, the phosphoric acid-modified compound, the plate-like inorganic compound, etc. can be uniformly dispersed, and the boiling point and volatility are appropriate from the viewpoint of the process of forming the barrier adhesive layer, There are no particular restrictions.

[Print layer]
The printed layer contains letters, numbers, pictures, figures, symbols, patterns, etc. It is a layer that forms any desired printed pattern. The printed layer can be provided as necessary, for example, it can be provided between the base material layer and the barrier layer or between the barrier layer and the sealant layer. The printed layer may be provided on the entire surface of the base material layer, or may be provided on a part thereof. The print layer can be formed using conventionally known pigments and dyes, and the formation method is not particularly limited.

The print layer preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, still more preferably 1 μm or more and 3 μm or less.

Examples of the layer structure of the laminate formed by combining the layers described above are listed below.
Structure example 1: base material layer/adhesive layer/metal vapor deposition layer/sealant layer Structure example 2: base material layer/barrier adhesive layer/metal vapor deposition layer/sealant layer Structure example 3: base material layer/transparent vapor deposition layer/ Adhesive layer/sealant layer configuration example 4: substrate layer/transparent vapor deposition layer/barrier adhesive layer/sealant layer Configuration example 5: substrate layer/transparent vapor deposition layer/gas barrier coating film/adhesive layer/sealant layer configuration Example 6: Base material layer/transparent vapor deposition layer/gas barrier coating film/barrier adhesive layer/sealant layer "/" represents the boundary between layers.

As described above, the base material layer contains recycled PET at a ratio of, for example, 50% by weight or more and 95% by weight or less. According to the present embodiment, since the base material layer contains recycled PET, it is possible to provide a laminate that is more effective in reducing CO ₂ than a laminate that does not contain recycled PET. In addition, according to the present embodiment, since the laminate includes the above-described barrier layer, it is possible to provide a laminate excellent in sanitation.

<Method for manufacturing laminate>
The method for manufacturing the laminate according to the present embodiment is not particularly limited, and it can be manufactured using a conventionally known method such as a dry lamination method.

The laminate according to the present embodiment has chemical functions, electrical functions, magnetic functions, mechanical functions, friction/wear/lubricating functions, optical functions, thermal functions, surface functions such as biocompatibility, and the like. It is also possible to apply secondary processing for the purpose of imparting. Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Also, the laminated body according to the present embodiment can be subjected to lamination (dry lamination or extrusion lamination), bag making, and other post-treatments to produce a molded product.

The laminate can be used, for example, as a packaging bag filled with products such as food. For example, using the above laminate, folding it in two, or preparing two laminates, overlapping the sealant surfaces with each other, and further sealing the peripheral edge thereof, for example, a side seal type , 2-side seal type, 3-side seal type, 4-side seal type, envelope seal type, palm seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset type, etc. By heat-sealing with, various forms of packaging bags can be produced.

In the above, as the heat sealing method, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing can be used.

Since the packaging bag has excellent hygienic properties while reducing the burden on the environment, it can be suitably used as a packaging bag for hermetically packaging foods and the like.

(Other aspects)
In another aspect of the present invention, there is provided a laminate comprising at least a substrate layer, an adhesive layer, a barrier layer and a sealant layer in this order, wherein the substrate layer contains ethylene glycol as a diol unit. , polyethylene terephthalate having terephthalic acid and isophthalic acid as dicarboxylic acid units, and the barrier layer includes a vapor deposition layer provided on the sealant layer.

In the laminate according to another aspect of the present invention, the vapor deposition layer may be a metal vapor deposition layer.

Another aspect of the present invention is a laminate comprising at least a base layer, a barrier layer, an adhesive layer, and a sealant layer in this order, wherein the base layer contains ethylene glycol as a diol unit, The laminate is a laminate including polyethylene terephthalate having terephthalic acid and isophthalic acid as dicarboxylic acid units, and the barrier layer including a vapor deposition layer provided on the base material layer.

In the laminate according to another aspect of the present invention, the vapor deposition layer may be a transparent vapor deposition layer.

In the laminate according to another aspect of the present invention, the barrier layer may further include a gas-barrier coating film provided on the surface of the transparent deposition layer.

In the laminate according to another aspect of the present invention, the adhesive layer may have a cured product of a polyester polyol and an aliphatic isocyanate compound.

In the laminate according to another aspect of the present invention, the polyester polyol has two or more hydroxyl groups in one molecule as functional groups, and the isocyanate compound has two or more isocyanate groups in one molecule as functional groups. The polyester polyol may be a polycondensate of an ortho-oriented polycarboxylic acid or its anhydride and a polyhydric alcohol.

一般式（１）において、Ｒ_１、Ｒ_２、Ｒ_３は、各々独立に、Ｈ（水素原子）又は下記の一般式（２）で表される化合物であってもよい。

In the laminate according to another aspect of the present invention, the polyester polyol has two or more hydroxyl groups in one molecule as functional groups, and the isocyanate compound has two or more isocyanate groups in one molecule as functional groups. and the polyester polyol is a compound represented by the following general formula (1),

In general formula (1), R ₁ , R ₂ and R ₃ may each independently be H (hydrogen atom) or a compound represented by general formula (2) below.

In the laminate according to another aspect of the present invention, the polyester polyol has two or more hydroxyl groups in one molecule as functional groups, and the isocyanate compound has two or more isocyanate groups in one molecule as functional groups. However, the polyester polyol may have an isocyanuric ring.

In the laminate according to another aspect of the present invention, the isophthalic acid content may be 0.5 mol % or more and 5.0 mol % or less with respect to all dicarboxylic acid units constituting the polyethylene terephthalate. .

In the laminate according to another aspect of the present invention, the intrinsic viscosity of the polyethylene terephthalate may be 0.58 dl/g or more and 0.80 dl/g or less.

10 Laminate 11 Base Material Layer 12 Barrier Layer 121 Vapor Deposition Layer 122 Gas Barrier Coating Film 13 Sealant Layer 14 Adhesive Layer

Claims (4)

A laminate comprising at least a substrate layer, a barrier layer, an adhesive layer, and a sealant layer in this order,
The base layer is a biaxially stretched film comprising a first layer, a second layer, and a third layer in this order,
The first layer and the third layer are layers composed only of virgin polyethylene terephthalate,
The second layer is a layer composed only of recycled polyethylene terephthalate, or a mixed layer of recycled polyethylene terephthalate and virgin polyethylene terephthalate,
The recycled polyethylene terephthalate includes polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units,
The thickness of the base material layer is 5 μm or more and 25 μm or less,
The barrier layer includes a transparent deposition layer provided on the base material layer and a gas barrier coating film provided on the surface of the transparent deposition layer,
The laminated body, wherein the transparent deposition layer is made of aluminum oxide. The laminate according to claim 1, wherein the adhesive layer has a cured product of a polyester polyol and an isocyanate compound. The laminate according to claim 1 or 2, wherein the sealant layer has a thickness of 30 µm or more and 130 µm or less. The laminate according to any one of claims 1 to 3, comprising a printed layer between the base material layer and the barrier layer.