JP2023071675A - Base material, laminate, packaging material, packaging bag and stand pouch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base material that enables production of a packaging material which has sufficient strength and barrier property as a packaging material, and is excellent in recyclability.

SOLUTION: A base material is formed of a film composed of polyethylene, in which the film is subjected to stretching treatment, at least one surface of the film is subjected to electron beam irradiation treatment, and the base material has a vapor-deposited film provided on at least one surface of the film.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a substrate, a laminate comprising the substrate, and packaging materials, packaging bags and stand pouches composed of the laminate.

2. Description of the Related Art Conventionally, a resin film made of a resin material has been used as a material constituting a packaging material. For example, a resin film made of polyolefin is widely used as a packaging material because it has appropriate flexibility and transparency and excellent heat-sealing properties.

Generally, resin films made of polyolefin are inferior in terms of strength and heat resistance, so they cannot be used as base materials for packaging materials. For this reason, ordinary packaging materials are composed of laminates in which the base material and the heat-seal layer are made of different resin materials (for example, Patent Document 1).

In recent years, with the increasing demand for building a recycling-oriented society, packaging materials and the like are required to be highly recyclable. However, conventional packaging materials are composed of different types of resin materials, as described above, and it is difficult to separate them by resin material, so currently they are not recycled.

JP 2009-202519 A

The present inventors have found that the strength and heat resistance of a polyolefin film conventionally used as a heat seal layer, specifically a polyethylene film, can be significantly improved by stretching and electron beam irradiation. It has been found that it can be used as a base material for packaging materials and the like.
Furthermore, by laminating the base material with a heat seal layer composed of polyethylene to form a laminate, a laminate having high strength and heat resistance and capable of producing a recyclable packaging material can be obtained. I have learned that it is possible.

The present invention has been made in view of the above findings, and the problem to be solved is to produce a packaging material that has sufficient strength and barrier properties as a base material for packaging materials and is also excellent in recyclability. It is to provide a base material that makes it possible.

Moreover, the problem to be solved by the present invention is to provide a laminate comprising the substrate.

Furthermore, the problem to be solved by the present invention is to provide a packaging material, a packaging bag and a stand-up pouch which are composed of the laminate.

The substrate of the present invention consists of a film made of polyethylene,
The film is stretched,
At least one surface of the film is subjected to electron beam irradiation treatment,
At least one surface of the film is provided with a deposited film.

In one embodiment, the thickness of the substrate of the present invention is 10 μm or more and 50 μm or less.

In one embodiment, the stretch ratio in the longitudinal direction and/or transverse direction of the substrate of the present invention is 2 times or more and 10 times or less.

In one embodiment, the density of the polyethylene before electron beam irradiation is 0.935 g/cm ³ or more and 0.957 g/cm ³ or less.

In one embodiment, the thickness of the deposited film is 1 nm or more and 150 nm or less.

The laminate of the present invention is
the base material;
a heat seal layer and
The substrate is provided so that the electron beam irradiation surface of the substrate is the outermost surface and the vapor deposition film forming surface of the substrate is the heat seal layer side,
The heat seal layer is characterized by being made of polyethylene.

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

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

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

The stand pouch of the present invention is composed of the above laminate,
The thickness of the heat seal layer is 50 μm or more and 200 μm or less.

According to the present invention, it is possible to provide a base material that has sufficient strength and barrier properties to be applied as a base material for packaging materials, and that enables the production of packaging materials that are excellent in recyclability.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic which shows one Embodiment of the base material of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic which shows one Embodiment of the base material of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the cross-sectional schematic which shows one Embodiment of the laminated body of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the cross-sectional schematic which shows one Embodiment of the laminated body of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view showing one Embodiment of the packaging material produced using the laminated body of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view showing one Embodiment of the packaging material produced using the laminated body of this invention.

(Base material)
As shown in FIG. 1, the substrate 10 of the present invention is a film 11 made of polyethylene, and is characterized by being subjected to stretching treatment and at least one surface thereof to electron beam irradiation treatment.
Thus, by stretching a film composed of polyethylene and irradiating at least one surface of the film with an electron beam to improve the crosslink density of the polyethylene, the heat resistance and strength of the film can be significantly improved. It can satisfy the physical properties required for outer layers of packaging materials and the like.
Further, the substrate 10 of the present invention has a deposited film 12 on at least one surface.

As polyethylene, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and ultra low density polyethylene can be used.
Among these, high-density polyethylene and medium-density polyethylene are preferable from the viewpoint of strength and heat resistance of the substrate, and medium-density polyethylene is more preferable from the viewpoint of stretchability.

In the present invention, as the high-density polyethylene, polyethylene having a density of 0.945 g/cm ³ or more can be used, and as the medium-density polyethylene, a density of 0.925 g/cm ³ or more and less than 0.945 g/cm ³ can be used. As the low-density polyethylene, polyethylene having a density of 0.900 g/cm ³ or more and less than 0.925 g/cm ³ can be used, and as the linear low-density polyethylene, the density of 0.900 g/cm ³ or more and less than 0.925 g/cm ³ can be used, and polyethylene with a density of less than 0.900 g/cm ³ can be used as the ultra-low density polyethylene.
In the present invention, it is preferable to use polyethylene having a density of 0.935 g/cm ³ or more and 0.950 g/cm ³ or less. By using polyethylene having such a density, the cross-linking reaction proceeds more favorably, and the strength and heat resistance of the substrate can be further improved.

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 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, and hydrogenated forms thereof. 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 and hafnium, 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 and 6-methyl- 1-heptene and the like can be mentioned. In addition, it may be a copolymer with vinyl acetate or acrylic acid ester as long as it does not impair the purpose of the present invention.

In the present invention, biomass-derived ethylene may be used instead of ethylene obtained from fossil fuels as a raw material for obtaining the polyethylene. Since such biomass-derived polyethylene is a carbon-neutral material, it is possible to reduce the environmental load of packaging materials and the like produced from laminates comprising the multilayer base material. Such biomass-derived polyethylene can be produced, for example, by a method as described in JP-A-2013-177531. Also, commercially available biomass-derived polyethylenes, such as Green PE from Braskem, may be used.

Polyethylene recycled by mechanical recycling can also be used. Here, mechanical recycling generally means that the recovered polyethylene film or the like is pulverized and washed with alkali to remove dirt and foreign matter from the film surface, and then dried for a certain period of time under high temperature and reduced pressure to remain inside the film. In this method, the contaminants are diffused to decontaminate the polyethylene film, and then the dirt is removed from the polyethylene film, which is then returned to polyethylene.

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 and modifying resins.

In one embodiment, the substrate of the invention has a multilayer structure.
In one embodiment, the substrate of the present invention comprises a layer composed of high-density polyethylene (hereinafter referred to as a high-density polyethylene layer), a layer composed of medium-density polyethylene (hereinafter referred to as a medium-density polyethylene layer), and a layer made of high-density polyethylene (hereinafter referred to as a high-density polyethylene layer).
With such a configuration, the strength and heat resistance of the base material can be further improved while maintaining the stretchability of the base material.
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 substrate 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.

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 (for simplicity in this paragraph, , collectively referred to as a low-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. Also, the strength and heat resistance of the substrate can be improved. Moreover, it is possible to prevent curling in the base material. Furthermore, the production efficiency of the substrate 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 substrate 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.
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, the heat resistance of the substrate can be improved. 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.
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.

The substrate may be a uniaxially stretched film or a biaxially stretched film.
The draw 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.
By setting the stretching ratio in the longitudinal direction (MD) of the substrate to 2 times or more, the strength and heat resistance of the substrate of the present invention can be improved. Furthermore, the printability to the base material can be improved. Moreover, the transparency of the substrate can be improved. On the other hand, the upper limit of the draw ratio in the longitudinal direction (MD) of the substrate is not particularly limited, but is preferably 10 times or less from the viewpoint of the breaking limit of the substrate.
The draw ratio in the transverse direction (TD) of the base material is preferably 2 times or more and 10 times or less, and preferably 3 times or more and 7 times or less.
The strength and heat resistance of the substrate of the present invention can be improved by setting the stretch ratio in the transverse direction (TD) of the substrate to 2 times or more. Furthermore, the printability to the base material can be improved. Moreover, the transparency of the substrate can be improved. On the other hand, the upper limit of the stretch ratio in the transverse direction (TD) of the base material is not particularly limited, but is preferably 10 times or less from the viewpoint of the breaking limit of the base material.

As shown in FIG. 1, the base material 10 may be one in which the polyethylene on one side is irradiated with an electron beam to improve the crosslink density, and as shown in FIG. Some may have improved densities.
Moreover, when the base material has a multilayer structure, it is sufficient that at least the polyethylene in the outermost layer has an improved crosslink density by electron beam irradiation.
From the viewpoint of strength and heat resistance, it is preferable that the crosslink density of the polyethylene as a whole is improved by electron beam irradiation.

As a device that can be used for electron beam irradiation to the substrate, conventionally known devices can be used, for example, curtain type electron irradiation device (LB1023, manufactured by I Electron Beam Co., Ltd.), line irradiation type low energy An electron beam irradiation device (EB-ENGINE, manufactured by Hamamatsu Photonics Co., Ltd.), a drum roll type electron beam irradiation device (EZ-CURE, manufactured by I Electron Beam Co., Ltd.), and the like can be preferably used.

The dose of the electron beam irradiated to the substrate is preferably in the range of 10 kGy or more and 2000 kGy or less, and more preferably in the range of 20 kGy or more and 1000 kGy or less.
The electron beam acceleration voltage is preferably in the range of 30 kV to 300 kV, more preferably in the range of 50 kV to 300 kV, and even more preferably in the range of 50 kV to 250 kV.
The irradiation energy of the electron beam is preferably in the range of 20 keV to 750 keV, more preferably in the range of 25 keV to 500 keV, even more preferably in the range of 30 keV to 400 keV, and 20 keV to 200 keV. The following ranges are particularly preferred.

The oxygen concentration in the electron beam irradiation device is preferably 500 ppm or less, more preferably 100 ppm or less. By performing the electron beam irradiation under such conditions, it is possible to suppress the generation of ozone and to suppress the deactivation of the radicals generated by the electron beam irradiation due to the oxygen in the atmosphere. can. Such conditions can be achieved, for example, by setting the inside of the apparatus to an inert gas (nitrogen, argon, etc.) atmosphere.

In one embodiment, electron beam irradiation can be performed simultaneously with cooling using a cooling drum or the like.

Moreover, the base material may be surface-treated. As a result, when a laminate described below is formed, the adhesion between adjacent layers can be improved.
The method of surface treatment is not particularly limited, and examples include corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas and/or nitrogen gas, physical treatment such as glow discharge treatment, and oxidation using chemicals. Chemical treatments such as treatments are included.
Moreover, you may form an anchor-coat layer on the base-material surface using a conventionally well-known anchor-coat agent.

The substrate of the present invention may have an image formed on its surface, and the formed image is not particularly limited, and may be characters, patterns, symbols, combinations thereof, or the like.
Image formation on the substrate is preferably carried out using a biomass-derived ink, so that the substrate of the present invention can be used to produce packaging materials with less environmental impact.
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 10 of the present invention has a deposited film 12 on at least one surface, as shown in FIGS. This can improve the gas barrier properties, specifically oxygen barrier properties and water vapor barrier properties.
Note that when only the polyethylene on one side of the polyethylene film 11 has its crosslink density improved by electron beam irradiation, as in the base material shown in FIG. 1, the deposited film is provided on the other side of the base material. is preferred.

The deposited film includes metals such as aluminum and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. can be mentioned.

Also, the thickness of the deposited film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less.
By setting the thickness of the deposited film to 1 nm or more, the oxygen barrier properties and water vapor barrier properties of the substrate can be further improved. Also, by setting the thickness of the vapor deposition film to 150 nm or less, it is possible to prevent the generation of cracks in the vapor deposition film. Moreover, when the base material of the present invention is applied to a laminate described below, its recyclability can be maintained.

In one embodiment, the substrate of the present invention comprises a barrier coat layer, which can improve the oxygen and water vapor barrier properties of the substrate.
The barrier coat layer may be provided on the vapor deposition film or may be provided 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.
Moreover, when the vapor deposition film is composed of an inorganic oxide, the occurrence of cracks in the vapor deposition film can be effectively prevented by including polyvinyl alcohol in the barrier coat layer.

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 of the substrate of the present invention can be further improved.

The barrier coat layer can contain the above additives within a range that does not impair the properties of the present invention.

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 properties and water vapor barrier properties of the substrate of the present invention can be further improved. By setting the thickness of the barrier coat layer to 10 μm or less, the recyclability can be maintained when the base material of the present invention is applied to the laminate described below.

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 metal alkoxide.
When the base material of the present invention is provided with a vapor-deposited film composed of an inorganic oxide, the formation of cracks in the vapor-deposited film can be effectively prevented by providing a barrier coat layer of this form adjacent to the vapor-deposited film. can do.

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 of the present invention can be further improved. can. 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 properties and water vapor barrier properties of the substrate of the present invention 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. In addition, 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, the 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 properties and water vapor barrier properties of the laminate of the present invention 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 onto the polyolefin resin layer by the conventionally known method and dried. By this drying, the polycondensation reaction of the alkoxide and the water-soluble polymer (and the silane coupling agent when 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.

The thickness of the substrate is preferably 10 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 base material to 10 μm or more, the strength required as a base material such as a packaging material can be sufficiently satisfied. Further, by setting the thickness of the base material to 50 μm or less, the workability of the base material can be improved.

The base material can be produced by forming a resin composition containing at least polyethylene using a T-die method, an inflation method, or the like to form a resin film, followed by stretching and electron beam irradiation.
By forming the film by the inflation method, the resin film can be stretched at the same time.
Either the stretching of the resin film or the electron beam irradiation may be carried out first, but the stretching is preferably carried out first from the viewpoint of suitability for stretching.

When the substrate is produced by the T-die method, the MFR of the resin composition is preferably 3 g/10 minutes or more and 20 g/10 minutes or less.
By setting the MFR of the resin composition to 3 g/10 minutes or more, the processability of the substrate of the present invention can be improved. Further, by setting the MFR of the resin composition to 20 g/10 minutes or less, it is possible to prevent the substrate from breaking.

When the substrate is produced by the inflation method, the MFR of the resin composition is preferably 0.5 g/10 minutes or more and 5 g/10 minutes or less.
By setting the MFR of the resin composition to 0.5 g/10 minutes or more, the processability of the substrate of the present invention can be improved. Also, by setting the MFR of the resin composition to 5 g/10 minutes or less, the film formability can be improved.

Formation of the deposited film can be performed using a conventionally known method, for example, a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum deposition method, a sputtering method and an ion plating method, and a plasma A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a chemical vapor deposition method, a thermal chemical vapor deposition method, and a photochemical vapor deposition method can be used.

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 vapor deposition chamber is preferably about 10 ⁻² to 10 ⁻⁸ mbar before oxygen is introduced, and is preferably about 10 ⁻¹ to 10 ⁻⁶ mbar after oxygen is introduced. 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 it does not interfere. The transport speed of the film can be about 10 to 800 m/min.

The surface of the deposited film is preferably subjected to the surface treatment described above. As a result, when applied to a laminate described below, adhesion to adjacent layers can be improved.

(Laminate)
The laminate 13 of the present invention comprises the base material 10 and the heat seal layer 14, as shown in FIG.
Moreover, the heat-sealing layer included in the laminate of the present invention is made of polyethylene, and with such a configuration, the recyclability of the laminate can be improved.

In one embodiment, laminate 13 of the present invention comprises intermediate layer 15 between substrate 10 and heat seal layer 14, as shown in FIG.

In one embodiment, laminates of the present invention can include adhesive layers 16 between any of the layers, as shown in FIGS.

The content of polyethylene in the entire laminate of the present invention is preferably 90% by mass or more, more preferably 90% by mass or more.
By setting the content of polyethylene in the entire laminate of the present invention to 90% by mass or more, the recyclability of the laminate of the present invention can be improved.

Each layer constituting the laminate of the present invention will be described below.

(Base material)
In the laminate, the substrate is provided so that the electron beam irradiation surface is the outermost surface and the vapor deposition film formation surface is the heat seal layer side. Since the details of the structure of the base material have been described above, they are omitted here.

(Heat seal layer)
The heat seal layer is characterized by being made of polyethylene. Since the laminate of the present invention comprises a base material made of polyethylene and a heat seal layer, it is possible to improve the recyclability of packaging materials and the like produced using the laminate.
However, the heat seal layer is formed of an unstretched polyolefin resin film or formed by melt extrusion of polyolefin.

From the viewpoint of heat-sealability, it is preferable to use low-density polyethylene, linear low-density polyethylene and ultra-low-density polyethylene as polyethylene.
In addition, polyethylene derived from biomass and mechanically recycled polyethylene can also be used.

It is preferable that the thickness of the heat seal layer is appropriately changed according to the weight of the contents to be filled in the packaging material produced from the laminate of the present invention.
For example, when producing a packaging bag as shown in FIG. 5 filled with contents of 1 g or more and 200 g or less, the thickness of the heat seal layer is preferably 20 μm or more and 60 μm or less.
By setting the thickness of the heat-seal layer to 20 μm or more, it is possible to prevent the filled content from leaking due to breakage of the heat-seal layer. Further, by setting the heat seal layer to 60 μm or less, the workability of the laminate of the present invention can be improved.

Moreover, for example, when producing a stand pouch as shown in FIG.
By setting the thickness of the heat-seal layer to 50 μm or more, it is possible to prevent the filled content from leaking due to breakage of the heat-seal layer. Further, by setting the thickness of the heat seal layer to 200 μm or less, the workability of the laminate of the present invention can be improved.
5 and 6 are heat-sealed portions.

The heat seal layer may have a deposited film on its substrate-side surface. Oxygen barrier properties and water vapor barrier properties can be improved by providing a vapor deposition film.

The deposited film includes metals such as aluminum and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. can be mentioned.

Also, the thickness of the deposited film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less.

The method for forming the deposited film is as described above.

The surface of the deposited film is preferably subjected to the surface treatment described above. This can improve adhesion with adjacent layers.

(middle layer)
In one embodiment, the intermediate layer comprises a stretched polyethylene film, which can further improve the strength of the laminate of the present invention.
The oriented polyethylene film is composed of polyethylene, and high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and ultra low density polyethylene can be used.
Biomass-derived polyethylene and mechanically recycled polyethylene can also be used.

Moreover, the stretched polyethylene film may have the multilayer structure described above.

The stretched polyethylene film may be a uniaxially stretched film or a biaxially stretched film, and the preferred stretch ratio is as described above.

The thickness of the stretched polyethylene film is preferably 10 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 stretched polyethylene film to 10 μm or more, the strength and heat resistance of the laminate of the present invention can be improved. Also, by setting the thickness of the stretched polyethylene film to 50 μm or less, the workability of the laminate can be improved.

In one embodiment, the intermediate layer comprises a gas barrier layer composed of a gas barrier resin. By including such an intermediate layer in the laminate of the present invention, the oxygen barrier properties and water vapor barrier properties can be improved.
Gas barrier resins include, for example, ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, polyamides such as nylon 6, nylon 6,6 and polymetaxylylene adipamide (MXD6), polyesters, polyurethanes, and (meth)acrylic resins.

The thickness of the gas barrier 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 gas barrier layer to 0.01 μm or more, the oxygen barrier properties and water vapor barrier properties of the laminate of the present invention can be further improved. By setting the thickness of the gas barrier layer to 10 μm or less, it is possible to maintain the recyclability of the laminate of the present invention.

In one embodiment, the intermediate layer comprises a deposited film. The mode, preferred thickness, formation method, etc. of the vapor deposition film that can be used are as described above.

In one embodiment, the intermediate layer comprises a barrier coat layer. The structure, preferred thickness, formation method, etc. of the barrier coat layer are as described above.

(adhesive layer)
The laminate of the present invention can have an adhesive layer between any layers. Thereby, the adhesion between layers can be improved.

The adhesive layer may be formed using a conventionally known adhesive. 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.

In addition, when the adhesive layer is provided adjacent to the vapor deposited aluminum film, the adhesive layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. is preferred.
In addition, when a laminate having a vapor deposition film is formed into 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 configuring the adhesive layer as described above, it is possible to suppress deterioration of oxygen barrier properties and water vapor barrier properties (flex load resistance) 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. 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.

As a specific example of the resin composition (adhesive) 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.
In particular, a polyester polyol having a content of 70 to 100% by mass of 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 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、Ｒ_１、Ｒ_２、Ｒ_３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), R ₁ , R ₂ and R ₃ 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).
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 general formula (2).

Further, a compound in which any one of R ₁ , R ₂ and R ₃ is a group represented by general formula (2), and a compound in which any two of R ₁ , R ₂ and R ₃ are represented by general formula (2) and a compound in which all of R ₁ , R ₂ and R ₃ are groups represented by general formula (2).

X 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、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）」、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), R ₁ , R ₂ and R ₃ are each independently “—(CH ₂ )n1-OH (where 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 general formula (4).

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

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

The polyester polyol having an isocyanuric ring represented by the general formula (3) 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、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、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), 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, and (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.

In the formula, R ₄ and R ₅ are hydrogen atoms, alkyl groups having 1 to 30 carbon atoms, (meth)acryloyl groups, optionally substituted phenyl groups and (meth)acryloyloxy groups 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 .

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 the adhesive layer is composed of a cured product of a resin composition containing a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound, the bending load resistance of the laminate can be improved.
By setting the thickness of the adhesive layer to 6 μm or less, the workability of the laminate can be improved.

The adhesive layer is applied onto a substrate or the like by a conventionally known method such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, fonten method and transfer roll coating, and then dried. can be formed by

The laminate of the present invention can be particularly preferably used for packaging materials as described below.

(packaging material)
A packaging material of the present invention is characterized by comprising the laminate described above.
The shape of the packaging material is not particularly limited, and may be bag-like as shown in FIG.
In the drawing, the hatched portion represents the heat-sealed portion.

In one embodiment, a bag-like packaging material can be produced by folding the laminate of the present invention in two and overlapping them so that the heat-seal layer is on the inside, and heat-sealing the ends thereof. .
In another embodiment, the bag-like packaging material can also be produced by stacking two laminates so that the heat-seal layers face each other and heat-sealing the edges.

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

Also, in one embodiment, the packaging material has a standing pouch-like shape with a body and a bottom, as shown in FIG.

The stand pouch-shaped packaging material is heat-sealed into a cylindrical shape so that the heat-seal layer of the laminate is on the inside to form a body, and then another laminate is heat-sealed. It can be manufactured by folding in a V shape with the layer on the inside, pinching one end of the trunk, and heat-sealing to form the bottom.

The content filled in the packaging material is not particularly limited, and the content may be liquid, powder, or gel. Moreover, it may be food or non-food.
After the contents are filled, the opening can be heat-sealed to form a package.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1
A medium-density polyethylene (density: 0.941 g/cm3, 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. Obtained.
This polyethylene film was stretched in the longitudinal direction (MD) at a draw ratio of 5 times to obtain a film with a thickness of 20 µm.

Then, one surface of the film was irradiated with an electron beam under the following conditions using an electron beam irradiation device (line irradiation type irradiation device EZ-CURE, manufactured by Iwasaki Electric Co., Ltd.).
Voltage: 100kV
Irradiation dose: 280 kGy
Oxygen concentration in the device: 100 ppm or less Line speed: 25 m / min

On the other surface of the film, a 20 nm-thick aluminum deposition film was formed by PVD method to obtain the substrate of the present invention.

As a heat seal layer, an unstretched linear low-density polyethylene film (Mitsui Chemicals Tohcello Co., Ltd., trade name: TUX-TCS) having a thickness of 40 μm was prepared, and the two-component curable urethane film was applied to the image forming surface of the substrate. A laminate of the present invention was obtained by laminating via an adhesive (trade name: RU-77T/H-7 manufactured by Rock Paint Co., Ltd.).
The thickness of the adhesive layer formed by the two-component curable urethane adhesive was 3.0 μm.

Example 2
A medium-density polyethylene (density: 0.941 g/cm3, 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. Obtained.
This polyethylene film was stretched in the longitudinal direction (MD) at a draw ratio of 5 times to obtain a film with a thickness of 20 μm.

On one surface of the polyethylene film thus obtained, a 20 nm-thick aluminum vapor-deposited film was formed by PVD to prepare an intermediate layer.

The above-mentioned adhesive was applied to the vapor-deposited film forming surface of the intermediate layer, and the image forming surface of the substrate prepared in Example 1 was laminated.

The above adhesive was applied to the surface of the intermediate layer on which no deposited film was formed, and the above LLDPE film having a thickness of 40 μm was laminated to obtain the laminate of the present invention.

Example 3
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 the medium-density polyethylene are film-formed by an inflation molding method, A polyethylene film consisting of a high-density polyethylene layer/medium-density polyethylene layer/high-density polyethylene layer 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 longitudinal direction (MD) at a draw ratio of 5 times to obtain a film with a total thickness of 20 μm, in which the thickness of each high-density polyethylene layer was 4 μm and the thickness of the medium-density polyethylene layer was 12 μm. Obtained.
The resulting film was irradiated with an electron beam under the same conditions as in Example 1, and a 20 nm-thick aluminum deposition film was formed on the other surface of the film by PVD to prepare a substrate.
A laminate of the present invention was obtained in the same manner as in Example 1, except that the substrate prepared by the above method was used.

Comparative example 1
A polyethylene film having a thickness of 20 μm was obtained by forming the medium density polyethylene into a film by an inflation molding method.

On the other surface of the film, a vapor-deposited aluminum film having a thickness of 20 nm was formed by PVD method to obtain a vapor-deposited film.

A laminate was produced in the same manner as in Example 1, except that the deposited film produced as described above was used instead of the substrate.

Comparative example 2
A laminate was produced in the same manner as in Comparative Example 1, except that one surface of the polyethylene film produced in Comparative Example 1 was subjected to electron beam irradiation in the same manner as in Example 1 and then a vapor deposited film was formed.

Comparative example 3
A polyethylene film having a thickness of 100 μm was obtained by forming the medium-density polyethylene into a film by an inflation molding method.
This polyethylene film was stretched in the longitudinal direction (MD) at a draw ratio of 5 times to obtain a polyethylene film having a thickness of 20 µm.

A 20 nm-thick aluminum vapor deposition film was formed on one surface of the film by PVD to obtain a vapor deposition film.

A laminate was produced in the same manner as in Example 1, except that the vapor-deposited film produced as described above was used instead of the substrate.

Comparative example 4
In the same manner as in Example 1, except that the substrate was a biaxially stretched polyester film (manufactured by Toyobo Co., Ltd., trade name: E5100) provided with an aluminum deposition film having a thickness of 12 μm and a thickness of 20 nm on one side. A laminate was obtained.

<<Recyclability Evaluation>>
The recyclability of the laminates obtained in the above examples and comparative examples was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
○: The content of polyethylene in the laminate was 90% by mass or more.
x: The content of polyethylene in the laminate was less than 90% by mass.

<<Strength evaluation>>
The laminates produced in the above examples and comparative examples were measured for strength when a needle with a diameter of 0.5 mm was pierced by a tensile tester (trade name: RTC-1310A manufactured by Orientec). The puncture speed was set to 50 mm/min. The measurement results are summarized in Table 1

<<Heat resistance evaluation>>
Two test pieces each having a length of 80 mm and a width of 80 mm were produced from the laminates obtained in the above examples and comparative examples.
Two test pieces were superimposed so that the heat-seal layers faced each other, and three sides were heat-sealed at 150° C. to prepare a small bag-like packaging material.
The produced packaging material was visually observed, and the heat resistance of the laminate was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
○: No wrinkles occurred on the surface of the packaging material, and no adhesion to the heat seal bar was observed.
x: Wrinkles occurred on the surface of the packaging material, and adhesion to the heat seal bar was observed, and the bag could not be made.

<<Oxygen barrier property evaluation>>
The laminates obtained in the above examples and comparative examples were cut into A4 size, and oxygen permeability (cc/m ² /day/atm) was measured. Table 1 summarizes the measurement results.

<<Water vapor barrier property evaluation>>
The laminates obtained in the above examples and comparative examples were cut into A4 size, and using PERMATRAN 3/31 manufactured by MOCON in the United States, the water vapor permeability (g/m ² /day/atm) was measured. Table 1 summarizes the measurement results.

<<Heat sealability test>>
The laminates obtained in the above examples and comparative examples were cut into pieces of 10 cm×10 cm to prepare sample pieces. This sample piece was folded in half so that the heat-seal layer was on the inside, and a 1 cm×10 cm area was heat-sealed under the conditions of a temperature of 140° C., a pressure of 1 kgf/cm ² and 1 second.
Cut the heat-sealed sample piece into strips with a width of 15 mm, hold both ends that were not heat-sealed in a tensile tester, and measure the peel strength (N / 15 mm) under the conditions of a speed of 300 mm / min and a load range of 50 N. It was measured. Table 1 summarizes the measurement results.
The laminate obtained in Comparative Example 1 adhered to the heat seal bar and could not be measured for peel strength.

10: Base material, 11: Film composed of polyethylene, 12: Vapor-deposited film, 13: Laminate, 14: Heat seal layer, 15: Intermediate layer, 16: Adhesive layer

Claims (9)

a substrate;
A laminate comprising a heat seal layer,
The base material is made of a film made of polyethylene,
The film is stretched,
At least one surface of the film is subjected to electron beam irradiation treatment,
A vapor-deposited film is provided on at least one surface of the film,
The film does not have a multilayer structure,
The substrate is provided so that the electron beam irradiation surface of the substrate is the outermost surface and the vapor deposition film forming surface of the substrate is the heat seal layer side,
The heat seal layer is made of polyethylene,
A recyclable laminate, wherein the content of polyethylene in the entire laminate is 90% by mass or more. 2. A recyclable laminate according to claim 1, wherein the substrate has a thickness of 10 [mu]m to 50 [mu]m. 3. The recyclable laminate according to claim 1, wherein the stretch ratio in the longitudinal direction and/or the lateral direction of the film is 2 times or more and 10 times or less. The recyclable laminate according to any one of claims 1 to 3, wherein the polyethylene in the film has a density of 0.935 g/cm ³ or more and 0.950 g/cm ³ or less before electron beam irradiation. The recyclable laminate according to any one of claims 1 to 4, wherein the vapor deposited film has a thickness of 1 nm or more and 150 nm or less. The recyclable laminate according to any one of claims 1 to 5, which is used for packaging material applications. A packaging material characterized in that it is constituted by the recyclable laminate according to any one of claims 1-6. A packaging bag,
Composed of the recyclable laminate according to any one of claims 1 to 6,
A packaging bag, wherein the heat seal layer has a thickness of 20 μm or more and 60 μm or less. It is a standing pouch,
Composed of the recyclable laminate according to any one of claims 1 to 6,
A stand-up pouch, wherein the heat seal layer has a thickness of 50 μm or more and 200 μm or less.

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