JP2023065359A - Laminate and packaging material composed of the laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having high recycling suitability, printability and strength.

SOLUTION: A laminate includes a substrate and a heat seal layer. The substrate and the heat seal layer are configured with a same material. The substrate has received a drawing process. The same material is polyethylene.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a laminate and a packaging material comprising the laminate.

BACKGROUND ART Polyethylene films have appropriate flexibility, are excellent in transparency, moisture resistance, chemical resistance, etc., and are inexpensive, and are therefore used for various packaging materials. In particular, since the melting point of polyethylene is generally about 100 to 140° C., although it varies somewhat depending on the type, it is generally used as a heat-sealable film in the field of packaging materials.

On the other hand, polyethylene films are inferior in rigidity to other thermoplastic resin films, and thus have poor printability and cannot form clear images on their surfaces. In addition, the polyethylene film does not have high strength and cannot satisfy the durability required as the exterior of the packaging material. Therefore, a laminate is formed by laminating a resin film with excellent rigidity and strength such as a polyester film or nylon film and a polyethylene film, and the edges of the laminate are heat-sealed so that the polyethylene film side of the laminate faces the inside. A packaging material is manufactured by doing so (for example, Japanese Unexamined Patent Application Publication No. 2005-104525).

By the way, in recent years, along with the increasing demand for building a recycling-oriented society, attempts have been made to recycle and use packaging materials. However, when different types of resin films are laminated together as described above, it is difficult to separate the resin films from each other, and thus the resin films are not suitable for recycling.

JP 2005-104525 A

The present invention has been made to solve the above problems, and an object of the present invention is to provide a laminate having high recyclability, printability and strength.

The laminate of the present invention comprises a substrate and a heat-seal layer, the substrate and the heat-seal layer are made of the same material, the substrate is stretched, and the same material is polyethylene. characterized by being

In one embodiment, the substrate comprises at least one of high density polyethylene (HDPE) and medium density polyethylene (MDPE).

In one embodiment, the draw ratio in the longitudinal direction (MD) of the substrate is 2 times or more and 10 times or less.

In one embodiment, the thickness of the substrate is greater than or equal to 9 μm and less than or equal to 50 μm.

In one embodiment, the substrate has a construction of a high density polyethylene layer, a medium density polyethylene layer and a high density polyethylene layer.

In one embodiment, the substrate comprises a layer of high density polyethylene, a layer of medium density polyethylene, a layer of low density polyethylene, a layer of linear low density polyethylene or a layer of ultra low density polyethylene, a layer of medium density polyethylene and a layer of high density polyethylene. It is a five-layer co-extruded film consisting of layers.

In one embodiment, the substrate comprises a high density polyethylene layer, a blended resin layer of high density and medium density polyethylene, a medium density polyethylene layer, a low density polyethylene layer, a linear low density polyethylene layer or an ultra low density polyethylene layer. It is a seven-layer coextruded film comprising a polyethylene layer, a medium density polyethylene layer, a blended resin layer of high density polyethylene and medium density polyethylene, and a high density polyethylene layer.

In one embodiment, at least one side of the substrate is imaged.

In one embodiment, the substrate is made by a blown film method.

In one embodiment, the heat seal layer comprises at least one of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE).

A packaging material of the present invention is characterized by comprising the laminate described above.

According to the present invention, a laminate having high recyclability, printability and strength can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic which shows one Embodiment of the laminated body by this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic which shows one Embodiment of the laminated body by this invention.

<Laminate for packaging material>
A laminate according to the present invention will be described with reference to the drawings.
As shown in FIG. 1 , the laminate 10 includes at least a substrate 20 and a heat seal layer 30 .
Also, in one embodiment, between the substrate 20 and the heat seal layer 30 is provided a polyethylene layer 40 with a deposited film.
Each layer included in the laminate will be described below.

<Base material>
The substrate is subjected to stretching treatment, and may be uniaxially stretched or biaxially stretched, but from the viewpoint of strength, biaxially stretched is preferred.

The stretching ratio in the longitudinal direction (MD) of the substrate is preferably 2 times or more and 10 times or less, and preferably 3 times or more and 7 times or less. This can further improve the printability and strength of the laminate. Moreover, this can improve the transparency of the substrate.
The draw ratio in the transverse direction (TD) is preferably 2 times or more and 10 times or less, and preferably 3 times or more and 7 times or less. This can further improve the printability and strength of the laminate. Moreover, this can improve the transparency of the substrate.

The substrate is composed of polyethylene, including high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). Moreover, the base material can contain 2 or more types of these.
Among these, high-density polyethylene (HDPE) and medium-density polyethylene (MDPE) are preferable from the viewpoint of printability, strength, heat resistance, and stretching suitability of the laminate, and medium-density polyethylene is more preferable from the viewpoint of stretching suitability.
In the present invention, high-density polyethylene has a density of 0.945 g/cm ³ or more, medium-density polyethylene has a density of 0.925 to 0.944 g/cm ³ , and low-density polyethylene has a density of 0. 0.900 g/cm ³ or more and less than 0.925 g/cm ³ , and ultra-low density polyethylene has a density of less than 0.900 g/cm ³ .

Polyethylenes having different densities and branches as described above can be obtained by appropriately selecting a polymerization method. For example, using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst, by any method of gas phase polymerization, slurry polymerization, solution polymerization, and high pressure ion polymerization, It is preferable to carry out in one stage or in multiple stages of two or more stages.

The above-mentioned single-site catalyst is a catalyst capable of forming uniform active species, and is usually prepared by contacting a metallocene-based transition metal compound or a non-metallocene-based transition metal compound with an activating cocatalyst. . A single-site catalyst has a more uniform active site structure than a multi-site catalyst, and is therefore preferable because it can polymerize a polymer having a high molecular weight and a highly uniform structure. As the single-site catalyst, it is particularly preferable to use a metallocene-based catalyst. The metallocene catalyst is a catalyst containing a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organometallic compound if necessary, and each catalyst component of a carrier. be.

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

In the transition metal compound of group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, examples of the transition metal include zirconium, titanium, hafnium and the like, with zirconium and hafnium being particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and each ligand having a cyclopentadienyl skeleton is preferably bonded to each other by a bridging group. The bridging group includes an alkylene group having 1 to 4 carbon atoms, a silylene group, a dialkylsilylene group, a substituted silylene group such as a diarylsilylene group, and a substituted germylene group such as a dialkylgermylene group and a diarylgermylene group. A substituted silylene group is preferred. One or a mixture of two or more of the transition metal compounds of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton can be used as a catalyst component.

The co-catalyst is one that can make the above Group IV transition metal compound of the periodic table effective as a polymerization catalyst, or one that can balance the ionic charges in a catalytically activated state. Examples of co-catalysts include benzene-soluble aluminoxanes of organoaluminumoxy compounds, benzene-insoluble organoaluminumoxy compounds, ion-exchange layered silicates, boron compounds, cations containing or not containing active hydrogen groups, and non-coordinating anions. ionic compounds, lanthanide salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing a fluoro group.

The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be supported on an inorganic or organic compound carrier and used. As the carrier, porous oxides of inorganic or organic compounds are preferred, and specific examples include ion-exchange layered silicates such as montmorillonite, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ and B ₂ O. ₃ , CaO, ZnO, BaO, _ThO2 , etc. or mixtures thereof. Examples of organometallic compounds that may be used if necessary include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organic aluminum is preferably used.

Copolymers of ethylene and other monomers can also be used as long as the properties of the present invention are not impaired. Ethylene copolymers include copolymers composed of ethylene and α-olefins having 3 to 20 carbon atoms, and α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, 6-methyl- 1-heptene and the like. Moreover, it may be a copolymer with vinyl acetate, acrylic acid ester, or the like, as long as it does not impair the object of the present invention.

Further, in the present invention, biomass-derived ethylene may be used instead of ethylene obtained from fossil fuels as a raw material for obtaining the high-density polyethylene or the like. Since such biomass-derived polyethylene is a carbon-neutral material, it can be used as a packaging material with even less environmental impact. Such biomass-derived polyethylene can be produced, for example, by a method as described in JP-A-2013-177531. Also, commercially available biomass-derived polyethylene (eg, Green PE, commercially available from Braskem, etc.) may be used.

The content of polyethylene in the substrate is preferably 50% by mass or more, more preferably 70% by mass or more.

The base material may contain additives as long as they do not impair the characteristics of the present invention. agents, reinforcing agents, antistatic agents, pigments, modifying resins, and the like.

In one embodiment, the substrate has a multilayer structure.
In one embodiment, as a substrate, a structure comprising a layer composed of high-density polyethylene (hereinafter referred to as a high-density polyethylene layer) and a layer composed of medium-density polyethylene (hereinafter referred to as a medium-density polyethylene layer). can be used.
By providing the high-density polyethylene layer on the outside of the substrate, the strength and heat resistance of the laminate of the present invention can be further improved. In addition, by providing the medium-density polyethylene layer, the stretchability of the base material can be further improved.

For example, it has a structure consisting of a coextruded film of a high-density polyethylene layer and a medium-density polyethylene layer from the outside.
With such a configuration, the stretchability of the base material can be improved. Moreover, the strength and heat resistance of the laminate of the present invention can be improved.
At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer.
The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably 1/10 or more and 1/1 or less, more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate of the present invention can be further improved. Further, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/1 or less, the stretchability of the substrate can be further improved.

Further, for example, it is possible to adopt a configuration of a three-layer co-extruded film of a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer from the outside.
With such a configuration, the stretchability of the substrate can be further improved. Moreover, the strength and heat resistance of the laminate of the present invention can be further improved. Furthermore, curling of the substrate can be prevented.
At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer.
The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably 1/10 or more and 1/1 or less, more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate of the present invention can be further improved. Further, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/1 or less, the stretchability of the substrate can be further improved.

Also, for example, from the outside, a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer (in this paragraph, for simplification of the description, the low-density It is also possible to configure a five-layer coextruded film consisting of a density polyethylene layer), a medium density polyethylene layer and a high density polyethylene layer.
With such a configuration, the stretchability of the base material can be improved. Moreover, the strength and heat resistance of the laminate of the present invention can be improved. Moreover, it is possible to prevent curling in the base material.
Furthermore, the production efficiency of the base material can be improved as described below.
At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer.
The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably 1/10 or more and 1/1 or less, more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate of the present invention can be improved. Further, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/1 or less, the stretchability of the substrate can be improved.
Also, the thickness of the high-density polyethylene layer is preferably the same as or thicker than the thickness of the low-density polyethylene layer.
The ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer is preferably 1/0.25 or more and 1/2 or less, more preferably 1/0.5 or more and 1/1 or less. preferable.
Heat resistance can be improved by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer to 1/0.25 or more. Further, by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer to 1/1 or less, the adhesion between the medium-density polyethylene layers can be improved.
The thickness of each high-density polyethylene layer is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less. By setting the thickness of the high-density polyethylene layer to 1 μm or more, the strength and heat resistance of the laminate of the present invention can be further improved. Further, by setting the thickness of the high-density polyethylene layer to 20 μm or less, the processability of the laminate of the present invention can be further improved.
The thickness of the medium-density polyethylene layer is preferably 1 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less. By setting the thickness of the medium-density polyethylene layer to 1 μm or more, the stretchability of the substrate can be further improved. Further, by setting the thickness of the medium-density polyethylene layer to 30 μm or less, the processability of the laminate of the present invention can be further improved.
The thickness of the low-density polyethylene layer is preferably 1 μm or more and 10 μm or less, more preferably 2 μm or more and 5 μm or less. By setting the thickness of the low-density polyethylene layer to 1 μm or more, the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer can be further improved. By setting the thickness of the low-density polyethylene layer to 5 μm or less, the processability of the laminate of the present invention can be further improved.
In one embodiment, a substrate having such a configuration can be produced, for example, by an inflation method.
Specifically, from the outside, a high-density polyethylene, a medium-density polyethylene layer, and a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer are coextruded into a tubular shape, and then facing each other. A low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer can be produced by pressing them together with a rubber roll or the like.
By manufacturing by such a method, the number of defective products in manufacturing can be remarkably reduced, and finally the production efficiency can be improved.
In addition, stretching can also be performed in the inflation film forming machine, thereby further improving production efficiency.

In one embodiment, from the outside, a high-density polyethylene layer, a high-density polyethylene and medium-density polyethylene blend resin layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer. layer (in this paragraph, for simplicity of description, it will be collectively referred to as a low-density polyethylene layer), a medium-density polyethylene layer, a blend resin layer of high-density polyethylene and medium-density polyethylene, and a high-density polyethylene layer It is also possible to configure a seven-layer co-extruded film.
With such a configuration, the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer can be improved. Moreover, the processability of the laminate of the present invention can be improved.
The thickness of each high-density polyethylene layer is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less. By setting the thickness of the high-density polyethylene layer to 1 μm or more, the strength and heat resistance of the laminate of the present invention can be further improved. Further, by setting the thickness of the high-density polyethylene layer to 20 μm or less, the processability of the laminate of the present invention can be further improved.
The thickness of each of the high-density polyethylene and medium-density polyethylene blend resin layers is preferably 1 μm or more and 20 μm or less, and more preferably 2 μm or more and 10 μm or less. This can improve the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer. Moreover, the processability of the laminate of the present invention can be improved.
The blending ratio of high-density polyethylene and medium-density polyethylene in the blend resin layer is preferably 1:9 to 9:1, more preferably 3:7 to 7:3, based on mass. This can improve the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer. Moreover, the processability of the laminate of the present invention can be improved.
The thickness of the medium-density polyethylene layer is preferably 1 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less. By setting the thickness of the medium-density polyethylene layer to 1 μm or more, the stretchability of the substrate can be further improved. Further, by setting the thickness of the medium-density polyethylene layer to 30 μm or less, the processability of the laminate of the present invention can be further improved.
The thickness of the low-density polyethylene layer is preferably 1 μm or more and 10 μm or less, more preferably 2 μm or more and 5 μm or less.
By setting the thickness of the low-density polyethylene layer to 1 μm or more, the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer can be further improved. By setting the thickness of the low-density polyethylene layer to 5 μm or less, the processability of the laminate of the present invention can be further improved.
In one embodiment, a substrate having such a configuration can be produced by the inflation method described above.
By manufacturing by such a method, the number of defective products in manufacturing can be remarkably reduced, and finally the production efficiency can be improved.
In addition, stretching can also be performed in the inflation film forming machine, thereby further improving production efficiency.

The thickness of the substrate is preferably 9 μm or more and 50 μm or less, more preferably 12 μm or more and 30 μm or less. By setting the thickness of the substrate within the above numerical range, the printability, strength and heat resistance of the laminate can be further improved.

In one embodiment, the substrate has a metal such as aluminum or an inorganic oxide such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide on one surface. provided with a deposited film containing Thereby, the gas barrier property of the laminate according to the present invention can be improved.
As a vapor deposition method, a conventionally known method can be employed, for example, a physical vapor deposition method (physical vapor deposition method, PVD method) such as a vacuum deposition method, a sputtering method, an ion plating method, or a plasma chemical vapor deposition method. , a thermal chemical vapor deposition method, a chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a photochemical vapor deposition method, and the like.

Moreover, the film thickness of the deposited film is preferably 0.002 μm or more and 0.4 μm or less, and more preferably 0.005 μm or more and 0.1 μm or less. By setting the thickness of the vapor deposition film within the above numerical range, it is possible to prevent cracks and the like from occurring in the vapor deposition film while maintaining gas barrier properties.

Further, for example, both physical vapor deposition and chemical vapor deposition may be used in combination to form a composite film composed of two or more layers of deposited films of different inorganic oxides. The degree of vacuum in the deposition chamber is preferably about 10-2 to 10-8 mbar, particularly preferably about 10-3 to 10-7 mbar, before introducing oxygen, and about 10-1 to 10-6 mbar after introducing oxygen. , particularly about 10-2 to 10-5 mbar. The amount of oxygen to be introduced and the like differ depending on the size of the vapor deposition machine and the like. As the oxygen to be introduced, an inert gas such as argon gas, helium gas, nitrogen gas, or the like may be used as a carrier gas as long as there is no problem. The transport speed of the film is preferably about 10 to 800 m/min, more preferably about 50 to 600 m/min.

The substrate may have an image such as letters, patterns, or symbols formed on its surface. It is preferable to form an image on the side of the base material on which the heat seal layer is laminated, since this can prevent deterioration of the image over time.
The image forming method is not particularly limited, and conventionally known printing methods such as gravure printing, offset printing, and flexographic printing can be used. Among these, the flexographic printing method is preferable from the viewpoint of environmental load.

The substrate can be obtained by melting a resin material containing polyethylene, forming a film by a melt extrusion molding method such as an inflation molding method or a T-die molding method, and then stretching the film. The film is preferably produced by the inflation molding method because the stretching process can be performed more easily. A substrate having a multilayer structure can be produced by melt-coextrusion of a plurality of resin materials.

The melt flow rate (MFR) of the resin material is preferably 0.5 g/10 minutes or more and 20 g/10 minutes or less, more preferably 0.8 g/10 minutes or more and 5 g/10 minutes or less. By setting the MFR of the resin material within the above numerical range, the stretching process can be performed more easily.

In one embodiment, the substrate can be provided with a barrier coat layer, which can improve oxygen and water vapor barrier properties.
When the base material has a vapor deposition film, the barrier coat layer may be provided on the vapor deposition film or under the vapor deposition film.

In one embodiment, the barrier coat layer comprises ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, polyamides such as nylon 6, nylon 6,6 and polymetaxylylene adipamide (MXD6), polyesters, Gas barrier resins such as polyurethane and (meth)acrylic resins are included. Among these, polyvinyl alcohol is preferable from the viewpoint of oxygen barrier properties and water vapor barrier properties.
In addition, when the base material has a deposited film composed of an inorganic oxide, the inclusion of polyvinyl alcohol in the barrier coat layer can effectively prevent the generation of cracks in the deposited film.

The content of the gas barrier resin in the barrier coat layer is preferably 50% by mass or more and 95% by mass or less, more preferably 75% by mass or more and 90% by mass or less. By setting the content of the gas barrier resin in the barrier coat layer to 50% by mass or more, the oxygen barrier properties and water vapor barrier properties can be further improved.

The barrier coat layer can contain additives as long as the properties of the present invention are not impaired.

The thickness of the barrier coat layer is preferably 0.01 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less.
By setting the thickness of the barrier coat layer to 0.01 μm or more, the oxygen barrier property and the water vapor barrier property can be further improved. Recyclability can be maintained by setting the thickness of the barrier coat layer to 10 μm or less.

The barrier coat layer can be formed by dissolving or dispersing the above materials in water or a suitable solvent, coating and drying. The barrier coat layer can also be formed by coating and drying a commercially available barrier coat agent.

In another embodiment, the barrier coat layer is a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel catalyst, water, an organic solvent, or the like. or a hydrolyzed condensate of a metal alkoxide.
When the substrate is provided with a vapor deposited film composed of an inorganic oxide, by providing a barrier coat layer of this form adjacent to the vapor deposited film, the occurrence of cracks in the vapor deposited film can be effectively prevented. can.

In one embodiment, the metal alkoxide is represented by the following general formula.
R ¹ _n M (OR ² ) _m
(In the formula, R ¹ and R ² each represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, and m represents an integer of 1 or more. , n+m represents the valence of M.)

As the metal atom M, for example, silicon, zirconium, titanium and aluminum can be used.
Examples of organic groups represented by R ¹ and R ² include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group and i-butyl group. can be done.

Examples of metal alkoxides satisfying the above general formula include tetramethoxysilane (Si(OCH ₃ ) ₄ ), tetraethoxysilane (% by mass) Si(OC ₂ H ₅ ) ₄ ), tetrapropoxysilane (Si(OC ₃ H ₇ ) _{4 )} , tetrabutoxysilane (Si( _OC4H9 ) ₄ ), and the like.

A silane coupling agent is preferably used together with the metal alkoxide.
As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used, but organoalkoxysilanes having an epoxy group are particularly preferred. Examples of organoalkoxysilanes having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. be done.

Two or more of the above silane coupling agents may be used, and the silane coupling agent is used in an amount of about 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the alkoxide. is preferred.

As the water-soluble polymer, polyvinyl alcohol and ethylene-vinyl alcohol copolymer are preferable, and from the viewpoint of oxygen barrier properties, water vapor barrier properties, water resistance and weather resistance, it is preferable to use these together.

The content of the water-soluble polymer in the gas barrier coating film is preferably 5 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the metal alkoxide.
By setting the content of the water-soluble polymer in the gas barrier coating film to 5 parts by mass or more with respect to 100 parts by mass of the metal alkoxide, the oxygen barrier properties and water vapor barrier properties of the substrate can be further improved. In addition, by setting the content of the water-soluble polymer in the gas barrier coating film to 500 parts by mass or less per 100 parts by mass of the metal alkoxide, the film formability of the gas barrier coating film can be improved.

The thickness of the gas barrier coating film is preferably 0.01 μm or more and 100 μm or less, more preferably 0.1 μm or more and 50 μm or less. Thereby, the oxygen barrier property and the water vapor barrier property can be further improved while maintaining the recyclability.
By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the substrate can be improved. Moreover, when it is provided so as to be adjacent to a vapor deposition film made of an inorganic oxide, it is possible to prevent the generation of cracks in the vapor deposition film.

The gas barrier coating film is formed by applying a composition containing the above materials by conventionally known means such as roll coating such as gravure roll coater, spray coating, spin coating, dipping, brush, bar code, and applicator. can be formed by polycondensation by the sol-gel method.
As the sol-gel process catalyst, an acid or amine compound is suitable. As the amine compound, tertiary amines that are substantially insoluble in water and soluble in organic solvents are suitable. amines and the like. Among these, N,N-dimethylbenzylamine is preferred.
The sol-gel catalyst is preferably used in the range of 0.01 parts by mass or more and 1.0 parts by mass or less, and is used in the range of 0.03 parts by mass or more and 0.3 parts by mass or less per 100 parts by mass of the metal alkoxide. is more preferable.
By setting the amount of the sol-gel catalyst to be used to 0.01 parts by mass or more per 100 parts by mass of the metal alkoxide, the catalytic effect can be improved. Further, by setting the amount of the sol-gel process catalyst used to 1.0 parts by mass or less per 100 parts by mass of the metal alkoxide, the thickness of the gas barrier coating film formed can be made uniform.

The composition may further contain an acid. Acids are used as catalysts for sol-gel processes, mainly for hydrolysis of alkoxides and silane coupling agents.
As the acid, mineral acids such as sulfuric acid, hydrochloric acid and nitric acid, and organic acids such as acetic acid and tartaric acid are used. The amount of the acid used is preferably 0.001 mol or more and 0.05 mol or less with respect to the total molar amount of the alkoxide and the alkoxide portion (for example, silicate portion) of the silane coupling agent.
By setting the amount of the acid used to be 0.001 mol or more with respect to the total molar amount of the alkoxide and the alkoxide portion (for example, silicate portion) of the silane coupling agent, the catalytic effect can be improved. Further, by setting the amount to 0.05 mol or less with respect to the total molar amount of the alkoxide and the alkoxide portion (for example, silicate portion) of the silane coupling agent, the thickness of the gas barrier coating film to be formed can be made uniform. can.

In addition, the above composition may contain water in a ratio of preferably 0.1 mol or more and 100 mol or less, more preferably 0.8 mol or more and 2 mol or less, per 1 mol of the total molar amount of the alkoxide. preferable.
By setting the water content to 0.1 mol or more per 1 mol of the total molar amount of the alkoxide, the oxygen barrier property and the water vapor barrier property can be improved. Further, by setting the content of water to 100 mol or more per 1 mol of the total molar amount of the alkoxide, the hydrolysis reaction can be carried out quickly.

Moreover, the composition may contain an organic solvent. Examples of organic solvents that can be used include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butanol.

An embodiment of a method for forming a gas barrier coating film will be described below.
First, a composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel process catalyst, water, an organic solvent, and optionally a silane coupling agent. A polycondensation reaction proceeds gradually in the composition.
Then, the composition is applied and dried by the conventionally known method described above. Due to this drying, the polycondensation reaction of the alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains a silane coupling agent) further proceeds to form a composite polymer layer.
Finally, the composition is heated at a temperature of 20 to 250° C., preferably 50 to 220° C. for 1 second to 10 minutes to form a gas barrier coating film.

The barrier coat layer may have an image formed on its surface. The image forming method and the like are as described above.

<Heat seal layer>
The heat-seal layer is made of the same material as the base material, namely polyethylene. Such a configuration can improve the recyclability of the laminate.
The heat seal layer is at least one of high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE), copolymers of ethylene and other monomers. including. Among these, low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) are preferable from the viewpoint of heat sealability. From the viewpoint of environmental load, these polyethylenes are preferably derived from biomass.

The content of polyethylene in the heat seal layer is preferably 50% by mass or more, more preferably 70% by mass or more.

The heat seal layer can contain additives within the range that does not impair the properties of the present invention, such as cross-linking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, Examples include pigments and modifying resins.

The thickness of the heat seal layer is preferably 20 μm or more and 200 μm or less, more preferably 30 μm or more and 150 μm or less. By setting the thickness of the heat seal layer within the above numerical range, the heat sealability can be improved.

The heat seal layer is made of a resin material containing polyethylene by a melt extrusion molding method such as inflation molding or T-die molding to prepare a polyethylene film, which is attached to a substrate or a deposited film via an adhesive layer. can be formed by lamination on a polyethylene layer comprising
The adhesive layer includes an adhesive, the adhesive comprising:
The adhesive may be a one-component curing type, a two-component curing type, or a non-curing type. The adhesive may be a non-solvent type adhesive or a solvent type adhesive, but the non-solvent type adhesive can be preferably used from the viewpoint of environmental load.
Examples of solventless adhesives include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives and urethane adhesives. system adhesives can be preferably used.
Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

Further, when the base material is provided with an aluminum vapor deposition film and an adhesive layer is provided so as to be adjacent to the vapor deposition film, the adhesive layer is a cured product of a resin composition containing a polyester polyol, an isocyanate compound and a phosphoric acid modified compound. It is preferable to configure by
When a laminate having a vapor deposition film is applied to a packaging material, a bending load is applied to the laminate by a molding machine or the like, which may cause cracks or the like in the aluminum vapor deposition film. By using the specific adhesive as described above, it is possible to suppress deterioration of oxygen barrier properties and water vapor barrier properties even when cracks occur in the aluminum deposition film.

A polyester polyol has two or more hydroxyl groups in one molecule as a functional group. Moreover, 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.

As a specific example of the resin composition containing a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound, the PASLIM series sold by DIC Corporation can be used.

The resin composition may further contain plate-like inorganic compounds, coupling agents, cyclodextrins and/or derivatives thereof, and the like.

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] 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.

The polyester polyol according to the first example is selected from the group consisting of a polyvalent carboxylic acid component containing at least one or more of orthophthalic acid and its anhydride, and ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. It is a polycondensate obtained by polycondensation with a polyhydric alcohol component containing at least one of the polycondensates.
Particularly preferred is a polyester polyol containing 70 to 100% by mass of orthophthalic acid and its anhydride relative to the total polyvalent carboxylic acid component.

The polyester polyol according to the first example essentially contains orthophthalic acid and its anhydride as the polyvalent carboxylic acid component. may
Specifically, aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid and fumaric acid, 1, Alicyclic polycarboxylic acids such as 3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, pyromellitic 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 acid, anhydrides of these dicarboxylic acids and ester formation of these dicarboxylic acids polybasic acids such as aromatic polycarboxylic acids such as polyvalent derivatives, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid and isophthalic acid are preferred.
In addition, you may use 2 or more types of said other polyhydric carboxylic acid.

一般式（１）において、Ｒ１、Ｒ２、Ｒ３は、各々独立に、Ｈ（水素原子）または下記の一般式（２）で表される基である。

As a polyester polyol according to the second example, a polyester polyol having a glycerol skeleton represented by general formula (1) can be mentioned.

In general formula (1), R1, R2 and R3 are each independently H (hydrogen atom) or a group 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).
At least one of R1, R2 and R3 represents a group represented by general formula (2).

In general formula (1), at least one of R1, R2 and R3 must be a group represented by general formula (2). Among them, it is preferable that all of R1, R2 and R3 are groups represented by general formula (2).

Further, a compound in which any one of R1, R2, and R3 is a group represented by general formula (2), and a compound in which any two of R1, R2, and R3 are groups represented by general formula (2) and a compound in which all of R1, R2, and R3 are groups represented by general formula (2).

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.

In 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. and alkylene groups having 2 to 6 carbon atoms such as dimethylbutylene group. Among them, Y is preferably a propylene group or an ethylene group, most preferably an ethylene group.

A 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 as essential components. It can be synthesized by reacting as

Examples of aromatic polyvalent carboxylic acids or anhydrides thereof in which the carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride thereof, naphthalene 2,3-dicarboxylic acid or anhydride thereof, naphthalene 1,2-dicarboxylic acid or anhydride thereof. 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, for example, 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、Ｒ１、Ｒ２、Ｒ３は、各々独立に、「－（ＣＨ２）ｎ１－ＯＨ（但しｎ１は２～４の整数を表す）」、または、一般式（４）の構造を表す。

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), R1, R2, and R3 each independently represent "-(CH2)n1-OH (where n1 represents an integer of 2 to 4)", or the structure of general formula (4) show.

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 R1, R2 and R3 is a group represented by general formula (4).

In general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. n1 is preferably 2 or 3, most preferably 2.

In 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. Phenyl groups are most preferred.

In 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. and alkylene groups having 2 to 6 carbon atoms such as dimethylbutylene group. Among them, Y is preferably a propylene group or an ethylene group, most preferably an ethylene group.

In general formula (3), at least one of R1, R2 and R3 is a group represented by general formula (4). Among them, it is preferable that all of R1, R2 and R3 are groups represented by general formula (4).

Further, a compound in which any one of R1, R2, and R3 is a group represented by general formula (4), and a compound in which any two of R1, R2, and R3 are groups represented by general formula (4) and a compound in which all of R1, R2, and R3 are groups represented by general formula (4), and any two or more compounds may form a mixture.

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

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 and naphthyl group;

Further, the polyhydric alcohol component includes alkylenediol having 2 to 6 carbon atoms. Diols such as, for example, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol and dimethylbutanediol is mentioned.
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, which can increase the polarity of the overall system and increase the crosslink density. 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 isocyanate compound has two or more isocyanate groups in its molecule.
Also, the isocyanate compound may be aromatic or aliphatic, and may be a low-molecular-weight compound or a high-molecular-weight compound.
Furthermore, the isocyanate compound 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, a polyisocyanate compound having 3 or more isocyanate groups is preferable from the viewpoint of adhesiveness and retort resistance, and an aromatic compound is preferable from the viewpoint of oxygen barrier properties and water vapor barrier properties.

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, and these isocyanate compounds. trimers, and these isocyanate compounds and low-molecular-weight active hydrogen compounds or their alkylene oxide adducts, or adducts obtained by reacting high-molecular-weight active hydrogen compounds, burettes and allophanates.
Low-molecular-weight active hydrogen compounds include, for example, ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, Examples thereof include ethylenediamine, monoethanolamine, diethanolamine, triethanolamine and m-xylylenediamine. Examples of molecularly active hydrogen compounds include polymeric active hydrogen compounds of various polyester resins, polyether polyols and polyamides.

一般式（５）において、Ｒ１、Ｒ２、Ｒ３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および（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。

式中、Ｒ４、Ｒ５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および（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。 A phosphoric acid-modified compound is, for example, a compound represented by the following general formula (5) or (6).

In general formula (5), R1, R2, and R3 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, and a (meth)acryloyloxy group. A group selected from alkyl groups having 1 to 4 carbon atoms, at least one of which is a hydrogen atom, and n represents an integer of 1 to 4.

In the formula, R4 and R5 are hydrogen atoms, alkyl groups having 1 to 30 carbon atoms, (meth)acryloyl groups, optionally substituted phenyl groups and (meth)acryloyloxy groups having 1 to 4 carbon atoms. wherein 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.

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

A resin composition containing a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound may contain a plate-like inorganic compound, thereby improving the adhesiveness of the adhesive layer. Moreover, the bending load resistance of the laminate of the present invention can be improved.
Plate-like inorganic compounds include, for example, kaolinite-serpentine clay minerals (halloysite, kaolinite, endellite, dickite, nacrite, antigorite, chrysotile, etc.) and pyrophyllite-talcs (pyrophyllite, talc, Kerorai, etc.).

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

Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxy Propylmethyldiethoxysilane, γ-Methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (amino ethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyl trimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane and 3-triethoxysilyl-N-(1,3-dimethyl-butylidene), and the like.

Examples of titanium-based coupling agents include isopropyltriisostearoyl titanate, isopropyltri(N-aminoethyl-aminoethyl)titanate, isopropyltridodecylbenzenesulfonyltitanate, isopropyltris(dioctylpyrophosphate)titanate, tetraoctylbis (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(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate and dicumylphenyloxyacetate titanate.

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

The resin composition can contain cyclodextrin and/or its derivatives, which can improve the adhesion of the adhesive layer. In addition, the bending load resistance of the laminate of the present invention can be further improved.
Specifically, for example, cyclodextrins such as cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin and hydroxyalkylated cyclodextrin in which the hydrogen atom of the hydroxyl group of the glucose unit of the cyclodextrin is substituted with another functional group can be used. can be done. Branched cyclic dextrins can also be used.
The cyclodextrin backbone in cyclodextrins and cyclodextrin derivatives is α-cyclodextrin consisting of 6 glucose units, β-cyclodextrin consisting of 7 glucose units, and γ-cyclodextrin consisting of 8 glucose units. Either 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 resin composition, it is preferable to use a cyclodextrin derivative as the cyclodextrin compound.

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

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

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

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

The heat seal layer can also be formed by extruding a resin material containing polyethylene onto a base material or a polyethylene layer provided with a deposited film and drying it.

<Polyethylene layer with deposited film>
In one embodiment, the laminate according to the invention comprises a polyethylene layer comprising a deposited film between the substrate and the heat seal layer. Thereby, the gas barrier property of the laminate according to the present invention can be improved.

The polyethylene layer provided with the vapor deposition film may be composed of a stretched film or an unstretched film. It is preferable that the In addition, it may be uniaxially stretched or biaxially stretched, but from the viewpoint of strength, biaxially stretched is preferred.

The polyethylene layer with the vapor deposited film can be made of high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE), copolymers of ethylene and other monomers. At least one. Among these, from the viewpoint of printability, strength and heat resistance, high density polyethylene (HDPE) and medium density polyethylene (MDPE) are preferred, and high density polyethylene (HDPE) is more preferred. From the viewpoint of environmental load, these polyethylenes are preferably derived from biomass.

The content of polyethylene in the polyethylene layer provided with the vapor-deposited film is preferably 50% by mass or more, more preferably 70% by mass or more.

The polyethylene layer provided with the deposited film may contain additives within the range that does not impair the characteristics of the present invention. Examples include inhibitors, pigments, and modifying resins.

From the viewpoint of productivity and economy, the thickness of the polyethylene layer provided with the deposited film is preferably 9 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less.
Moreover, the thickness of the deposited film is preferably 0.002 μm or more and 0.4 μm or less, and more preferably 0.005 μm or more and 0.1 μm or less. By setting the thickness of the vapor deposition film within the above numerical range, it is possible to prevent cracks and the like from occurring in the vapor deposition film while maintaining gas barrier properties.

The polyethylene layer with the vapor deposited film may have an image formed on its surface. The image forming method is as described above.

The polyethylene layer provided with a vapor-deposited film is produced by forming a polyethylene film from a resin material containing polyethylene by a melt extrusion molding method such as inflation molding or T-die molding. After forming a vapor deposition film by the method described above, it can be formed by laminating it on a substrate via an adhesive. In this case, the polyethylene film may be stretched before vapor deposition and before lamination.
A polyethylene layer having a deposited film can also be formed by extruding a resin material containing polyethylene onto a base material, drying it, and then forming a deposited film.

<Packaging material>
In one embodiment, the packaging material according to the present invention can be produced by folding the laminate in two and overlapping them with the heat-seal layer of the laminate on the inside, and heat-sealing the ends thereof.
Alternatively, two laminates can be produced by stacking two laminates so that the heat-seal layers face each other and heat-sealing the edges.
Depending on the sealing method, for example, side seal type, two side seal type, three side seal type, four side seal type, envelope seal type, palm joint seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type Various forms of packaging material can be produced by heat-sealing by heat-sealing forms such as molds, gussets, and the like.
In addition, for example, a self-supporting packaging bag (standing pouch) or the like is also possible. 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.

In the laminate according to the present invention, even if the laminate is made of only one type of resin (that is, polyethylene), the base material satisfies the strength and printability required as the outer film of the packaging material, and the heat seal layer facilitates packaging. make it possible. Therefore, it is extremely suitable as a material constituting a packaging material that requires recyclability.

EXAMPLES The present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

<Example 1>
Medium-density polyethylene (density: 0.941 g/cm ³ , melting point: 129° C., MFR: 1.3 g/10 min, manufactured by Dowchemical, trade name: Elite 5538G) was formed by an inflation molding method to form a polyethylene film having a thickness of 100 μm. got
This polyethylene film was stretched in the machine direction (MD) at a draw ratio of 5 times to obtain a substrate having a thickness of 20 µm.

The base material and an unstretched linear low-density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) with a thickness of 40 μm are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Example 2>
High density polyethylene (density: 0.961 g/cm ³ , melting point: 135°C, MFR: 0.7 g/10 min, manufactured by ExxonMobil, trade name: HTA108) and medium density polyethylene (density: 0.941 g/cm ³ , melting point) 129 ° C., MFR: 1.3 g / 10 minutes, manufactured by Dowchemical, product name: Elite 5538G) is formed into a film by an inflation molding method, and consists of a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer. A polyethylene film was produced. The thickness of the high-density polyethylene layers was 20 μm each, and the thickness of the medium-density polyethylene layers was 60 μm.
This polyethylene film was stretched in the machine direction (MD) at a draw ratio of 5 times to obtain a substrate having a thickness of 20 µm.

The base material and an unstretched linear low-density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) with a thickness of 40 μm are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Example 3>
Medium-density polyethylene (density: 0.941 g/cm ³ , melting point: 129° C., MFR: 1.3 g/10 min, manufactured by Dowchemical, trade name: Elite 5538G) was formed by an inflation molding method to form a polyethylene film having a thickness of 100 μm. got
This polyethylene film was stretched in the machine direction (MD) and the width direction (TD) at a draw ratio of 2.24 times to obtain a substrate having a thickness of 20 μm.
The base material and an unstretched linear low-density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) with a thickness of 40 μm are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Example 4>
high-density polyethylene (density: 0.960 g/cm3, melting point: 130°C, MFR: 0.85 g/10 min, manufactured by Dowchemical, trade name: Elite5960);
A blend resin (mass ratio 4:6) of the above high-density polyethylene and medium-density polyethylene (density: 0.940 g / cm, melting point: 126 ° C., MFR: 0.85 g / 10 minutes, manufactured by Dowchemical, trade name Elite 5940),
the medium density polyethylene;
Ultra-low density polyethylene (density 0.870 g / cm 3, melting point 55 ° C., MFR: 1.0 g / 10 minutes, manufactured by Dowchemical, trade name: Affinity EG8100G) and a high-density polyethylene layer from the outside by an inflation molding method (12.5 μm), as a tubular film comprising a blend resin layer of high and medium density polyethylene (12.5 μm), a medium density polyethylene layer (31.25 μm) and an ultra low density polyethylene layer (6.25 μm). After extrusion, the inner ultra-low-density polyethylene layers were pressed against each other with a rubber roll to form a high-density polyethylene layer (12.5 μm), a blended resin layer (12.5 μm), and a medium-density polyethylene layer (31.25 μm). , a 125 μm thick polyethylene film comprising an ultra-low density polyethylene layer (12.5 μm), a medium density polyethylene layer (31.25 μm) and a blended resin layer (12.5 μm).
This polyethylene film was stretched in the longitudinal direction (MD) at a draw ratio of 5 times to obtain a substrate having a thickness of 25 µm.

The base material and an unstretched linear low-density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) with a thickness of 40 μm are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Example 5>
high-density polyethylene (density: 0.960 g/cm3, melting point: 130°C, MFR: 0.85 g/10 min, manufactured by Dowchemical, trade name: Elite5960);
Medium density polyethylene (density: 0.940 g/cm3, melting point: 126°C, MFR: 0.85 g/10 min, manufactured by Dowchemical, trade name: Elite5940),
Ultra-low density polyethylene (density: 0.870 g / cm 3, melting point 55 ° C., MFR: 1.0 g / 10 minutes, manufactured by Dowchemical, trade name: Affinity EG8100G) and high-density polyethylene from the outside by an inflation molding method After extrusion as a tubular film comprising a layer (12.5 μm), a medium density polyethylene layer (43.75 μm) and an ultra-low density polyethylene layer (6.25 μm), the inner ultra-low density polyethylene layers were rolled together by a rubber roll. , a high-density polyethylene layer (12.5 μm), a medium-density polyethylene layer (43.75 μm), an ultra-low-density polyethylene layer (12.5 μm), a medium-density polyethylene layer (43.75 μm), and a high-density polyethylene layer (43.75 μm). A 125 μm thick polyethylene film was obtained with a density polyethylene layer (12.5 μm).
This polyethylene film was stretched in the longitudinal direction (MD) at a draw ratio of 5 times to obtain a substrate having a thickness of 25 µm.

The base material and an unstretched linear low-density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) with a thickness of 40 μm are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Comparative Example 1>
Medium-density polyethylene (density: 0.941 g/cm ³ , melting point: 129° C., MFR: 1.3 g/10 min, manufactured by Dowchemical, trade name: Elite 5538G) was formed by an inflation molding method to form a 20 μm thick polyethylene film. got

The above polyethylene film and a 40 μm thick unstretched linear low density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Comparative Example 2>
High density polyethylene (density: 0.961 g/cm ³ , melting point: 135°C, MFR: 0.7 g/10 min, manufactured by ExxonMobil, trade name: HTA108) and medium density polyethylene (density: 0.941 g/cm ³ , melting point) 129° C., MFR: 1.3 g/10 min, manufactured by Dowchemical, trade name: Elite 5538G) is formed by an inflation molding method to form a polyethylene film consisting of a high-density polyethylene layer/medium-density polyethylene layer/high-density polyethylene layer. made. The thickness of the high-density polyethylene layers was 4 μm, and the thickness of the medium-density polyethylene layers was 12 μm.

The above polyethylene film and a 40 μm thick unstretched linear low density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Comparative Example 3>
high-density polyethylene (density: 0.960 g/cm3, melting point: 130°C, MFR: 0.85 g/10 min, manufactured by Dowchemical, trade name: Elite5960);
Medium density polyethylene (density: 0.940 g/cm3, melting point: 126°C, MFR: 0.85 g/10 min, manufactured by Dowchemical, trade name: Elite5940),
Ultra-low density polyethylene (density: 0.870 g/cm3, melting point: 55°C, MFR: 1.0 g/10 min, manufactured by Dowchemical, trade name: Affinity EG8100G) is blown from the outside by a high-density polyethylene layer, After extruding as a tube-shaped film comprising a medium density polyethylene layer and an ultra-low density polyethylene layer, the inner ultra-low density polyethylene layers were crimped together with a rubber roll to obtain a high density polyethylene layer (2.5 μm) and a medium density polyethylene layer. A 25 μm thick polyethylene film was obtained comprising a layer (8.75 μm), an ultra-low density polyethylene layer (2.5 μm), a medium density polyethylene layer (8.75 μm) and a high density polyethylene layer (2.5 μm).

The above polyethylene film and a 40 μm thick unstretched linear low density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd., trade name: L6100) are combined with a two-component curable urethane adhesive (Rock Paint Co., Ltd. ), trade name: RU-77T/H-7) to obtain a laminate.

<Printability evaluation>
An image was formed on one surface of the base material and polyethylene film prepared in the above examples and comparative examples by flexographic printing using a water-based flexographic ink (manufactured by Toyo Ink Co., Ltd., trade name: Aquariona). The formed image was visually observed, and the printability of the substrate and the polyethylene film was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
◯: Dimensional stability during printing was good, and a good image free from rubbing, blurring, etc. could be formed.
x: Expansion and contraction of the film occurred during printing, and rubbing and blurring occurred in the formed image.

<Rigidity evaluation>
The substrates and polyethylene films prepared in the above examples and comparative examples were used as test pieces with a width of 15 mm, and the stiffness was measured using a loop stiffness measurement tester (manufactured by Toyo Seiki Seisakusho, trade name: loop stiffness tester). In addition, the length of the loop was set to 60 mm. Table 1 summarizes the measurement results.

<Strength evaluation>
A dumbbell-shaped test piece with a width of 10 mm was made from the base material and the polyethylene film produced in the above examples and comparative examples. The tensile strength of this test piece in the MD direction was measured using a tensile tester (RTC-1310A manufactured by Orientec). The chuck-to-chuck distance was 10 mm, and the pulling speed was 300 mm/min. Table 1 summarizes the measurement results.

10: Laminate 20: Base material 30: Heat seal layer 40: Polyethylene layer provided with vapor deposition film

Claims (11)

comprising a base material and a heat seal layer,
The base material is made of polyethylene, the heat seal layer is made of polyethylene,
The base material is stretched,
The heat seal layer is unstretched,
Recyclable laminate. 2. The recyclable laminate of Claim 1, wherein the substrate comprises at least one of high density polyethylene (HDPE) and medium density polyethylene (MDPE). The recyclable laminate according to claim 1 or 2, wherein the stretch ratio in the longitudinal direction (MD) of the substrate is 2 times or more and 10 times or less. A recyclable laminate according to any one of claims 1 to 3, wherein the substrate has a thickness of 9 µm or more and 50 µm or less. A recyclable laminate according to any one of claims 1 to 4, wherein the substrate has a structure consisting of a high density polyethylene layer, a medium density polyethylene layer and a high density polyethylene layer. 5. The substrate comprises a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer or an ultra-low-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer. A recyclable laminate according to any one of claims 1 to 4, which is a layer-coextruded film. The substrate comprises a high-density polyethylene layer, a blend resin layer of high-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer; The recyclable material according to any one of claims 1 to 4, which is a seven-layer co-extruded film comprising a medium density polyethylene layer, a high density polyethylene and medium density polyethylene blend resin layer, and a high density polyethylene layer. laminate. A recyclable laminate according to any preceding claim, wherein at least one side of the substrate is imaged. The recyclable laminate according to any one of claims 1 to 8, wherein the substrate is produced by a blown film method. A recyclable laminate according to any preceding claim, wherein the heat seal layer comprises at least one of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). A packaging material composed of a recyclable laminate according to any one of claims 1-10.

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