JP2020157715A - Laminate for packaging material, and packaging material - Google Patents

Abstract

To provide a laminate for packaging material that can achieve a packaging material excellent in recyclability while having high strength and heat resistance.SOLUTION: A laminate 10 for packaging bag includes at least a base material 11, an intermediate layer 12 and a heat seal layer 13, in which the base material, the intermediate layer and the heat seal layer are composed of the same material, the base material and the intermediate layer are subjected to stretching treatment, and the same material is polyolefin.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminate for packaging materials and a packaging material composed of the laminate.

Conventionally, a resin film composed of a resin material has been used as a constituent material of a packaging material. For example, a resin film composed of polyolefin is widely used as a packaging material because it has appropriate flexibility and transparency and is excellent in heat-sealing property.

Normally, a resin film made of polyolefin is inferior in strength and heat resistance, so it cannot be used as a base material for packaging materials, and is attached to a resin film made of polyester, polyamide, etc. Therefore, the usual packaging material is composed of a laminated film in which the base material and the heat-sealing layer are made of different materials (for example, Patent Document 1).

In recent years, with the growing demand for the construction of a recycling-oriented society, packaging materials with high recyclability are required. However, the conventional packaging is composed of different types of resin materials as described above, and it is difficult to separate each resin material, so that the packaging is not recycled at present.

Japanese Unexamined Patent Publication No. 2009-202519

The present inventors use a polyolefin resin conventionally used as a heat seal layer as a base material by forming a stretched resin film, and use the base material by laminating it with a heat seal layer composed of polyolefin. By doing so, it was found that a recyclable packaging material can be obtained while maintaining the strength and heat resistance of the packaging material.
Further, it was found that the strength can be improved by providing an intermediate layer, which is a stretched resin film, between the base material and the heat seal layer.

The present invention has been made in view of the above findings, and the problem to be solved is to obtain a packaging material laminate capable of realizing a packaging material having high strength and heat resistance and excellent recyclability. Is to provide.
Further, an object to be solved by the present invention is to provide a packaging material composed of a laminate for the packaging material.

The packaging material laminate of the present invention is a packaging material laminate including at least a base material, an intermediate layer, and a heat seal layer, and the base material, the intermediate layer, and the heat seal layer are made of the same material. It is characterized in that the base material and the intermediate layer are stretched and the same material is polyolefin.

In one embodiment, the intermediate layer comprises a thin film.

In one embodiment, an adhesive layer is provided between the substrate and the intermediate layer, and at least one between the intermediate layer and the heat seal layer.

In one embodiment, the adhesive layer comprises a cured product of a resin composition comprising a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound.

In one embodiment, the content of the polyolefin in the entire packaging material laminate is 90% by mass or more.

The packaging material of the present invention is characterized by being composed of the above-mentioned laminate.

According to the present invention, it is possible to provide a laminate for a packaging material which can realize a packaging material having high strength and heat resistance and also excellent in recyclability.

Further, according to the present invention, it is possible to provide a packaging material composed of the laminate for the packaging material.

It is sectional drawing which shows one Embodiment of the laminated body for packaging material of this invention. It is sectional drawing which shows one Embodiment of the laminated body for packaging material of this invention. It is a perspective view which shows one Embodiment of the packaging material produced using the laminate for packaging material of this invention. It is a perspective view which shows one Embodiment of the packaging material produced using the laminate for packaging material of this invention.

(Laminate for packaging material)
As shown in FIG. 1, the packaging material laminate 10 of the present invention includes at least a base material 11, an intermediate layer 12, and a heat seal layer 13.
In the present invention, the base material, the intermediate layer and the heat seal layer are made of the same material, that is, polyolefin, whereby the recyclability of the laminate for packaging material of the present invention can be improved.

Further, in one embodiment of the present invention, as shown in FIG. 2, the packaging material laminate 10 is located between the base material 11 and the intermediate layer 12, and between the intermediate layer 12 and the heat seal layer 13. An adhesive layer 14 can be further provided.

The content of the same polyolefin in the entire laminate for packaging materials of the present invention is preferably 90% by mass or more.
By setting the content of the same polyolefin in the entire packaging material laminate of the present invention to 90% by mass or more, the recyclability of the packaging material laminate of the present invention can be improved.

Hereinafter, each layer constituting the packaging material laminate of the present invention will be described.

(Base material)
The base material provided in the laminate for packaging material of the present invention is composed of polyolefin, and this polyolefin is the same as the polyolefin constituting the following intermediate layer and heat seal layer. With such a configuration, the recyclability of the laminated body for packaging materials can be improved.

The base material provided in the laminate for packaging material of the present invention has been stretched. Thereby, the strength and heat resistance of the base material can be improved. Such a base material may be a uniaxially stretched resin film or a biaxially stretched resin film.

The stretching ratio in the longitudinal direction (MD) 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.
By setting the draw ratio in the longitudinal direction (MD) of the base material to 2 times or more, the strength and heat resistance of the laminate for packaging material of the present invention can be improved. Further, since the transparency of the base material can be improved, the visibility can be improved when an image is formed on the surface of the base material on the adhesive layer side. On the other hand, the upper limit of the draw ratio in the longitudinal direction (MD) of the base material is not particularly limited, but is preferably 10 times or less from the viewpoint of the breaking limit of the stretched film.

Further, the stretching ratio in the lateral 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.
By setting the stretching ratio of the base material in the lateral direction (TD) to 2 times or more, the strength and heat resistance of the laminate for packaging material of the present invention can be improved. Further, since the transparency of the base material can be improved, the visibility can be improved when an image is formed on the surface of the base material on the adhesive layer side. On the other hand, the upper limit of the stretching ratio in the lateral 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 stretched film.

As the polyolefin that can be used as the base material, it is necessary to use the same polyolefin that constitutes the intermediate layer and the heat seal layer as described above, and examples of such polyolefin include polyethylene, polypropylene, polymethylpentene, and ethylene. Examples thereof include a-propylene copolymer and a propylene-butene copolymer, and among these, polyethylene and polypropylene are preferable.

As polyethylene, high density polyethylene (HDPE) with a density of more than 0.945 g / cm ³ , medium density polyethylene (MDPE) with a density of 0.925 to 0.945 g / cm ³ , and a density of less than 0.925 g / cm ³ Low density polyethylene (LDPE) and linear low density polyethylene (LLDPE).

In one embodiment, as the base material, a structure including a layer containing high-density polyethylene and a layer containing medium-density polyethylene can be used.
By providing the high-density polyethylene layer on the outside of the base material, the strength and heat resistance of the laminate for packaging material of the present invention can be improved. Further, by providing the medium-density polyethylene layer, the stretchability of the resin film constituting the base material can be improved.

For example, it has a structure composed of a high-density polyethylene layer and a medium-density polyethylene layer from the outside.
With such a configuration, the stretchability of the film can be improved. In addition, the strength and heat resistance of the laminate for packaging materials 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, and more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate for packaging material 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 film can be improved.

Further, for example, from the outside, a configuration including a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer can be used.
With such a configuration, the stretchability of the film can be improved. In addition, the strength and heat resistance of the laminate for packaging materials of the present invention can be improved. Further, it is possible to prevent the occurrence of curl on 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, and more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate for packaging material 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 film can be improved.

Further, for example, from the outside, it may be composed of a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer or a linear low-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer. it can.
With such a configuration, the stretchability of the film can be improved. In addition, the strength and heat resistance of the laminate for packaging materials of the present invention can be improved. In addition, it is possible to prevent the occurrence of curl on the base material. Further, the processability of the film 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, and more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate for packaging material 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 film can be improved.
Further, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the low-density polyethylene layer or the linear low-density polyethylene layer.
The ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer or the linear low-density polyethylene layer is preferably 1/10 or more and 1/1 or less, preferably 1/5 or more and 1/2 or less. More preferably.
Heat resistance can be improved by making the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer or the linear low-density polyethylene layer 1/10 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 or the linear low-density polyethylene layer to 1/1 or less, the processability of stretching can be improved.

Polypropylene may be a homopolymer, a random copolymer or a block copolymer.
The polypropylene homopolymer is a polymer containing only propylene, and the polypropylene random copolymer is a polymer of propylene and other α-olefins other than propylene (for example, ethylene, butene-1, 4-methyl-1-pentene, etc.). It is a random copolymer, and the polypropylene block copolymer is a copolymer having a polymer block made of propylene and a polymer block made of α-olefin other than the above-mentioned propylene.
Among these polypropylenes, homopolymers or randoms can be used from the viewpoint of improving the transparency of the base material and improving the visibility when an image is formed on the surface of the base material on the adhesive layer side. It is preferable to use a copolymer. A homopolymer can be used when the rigidity and heat resistance of the packaging material are important, and a random copolymer can be used when the impact resistance and the like are important.

Further, as a raw material for obtaining polyolefin, a biomass-derived olefin monomer may be used instead of the olefin monomer obtained from fossil fuel. Since such a biomass-derived olefin monomer is a carbon-neutral material, it can be used as a packaging material having an even lower environmental load.
Such a biomass-derived polyolefin, for example, polyethylene, can be produced by a method as described in JP2013-177531A. Further, a commercially available biomass-derived polyolefin (for example, green PE commercially available from Braskem) may be used.

It is also possible to use polyolefins recycled by mechanical recycling. Here, mechanical recycling generally refers to crushing a recovered polyolefin film or the like, alkaline cleaning to remove stains and foreign substances on the film surface, and then drying the film under high temperature and reduced pressure for a certain period of time to stay inside the film. This is a method of diffusing pollutants, decontaminating, removing stains on the polyolefin film, and returning the polyolefin to polyolefin.

An image may be formed on the surface of the base material. The image may be formed on any surface of the base material, but it is preferable to form the image on the surface on the adhesive layer side because it can prevent contact with the outside air and prevent deterioration over time.
The image to be formed is not particularly limited, and characters, patterns, symbols, combinations thereof, and the like are represented.
The image formation can be performed using a conventionally known ink, but it is preferably performed using a biomass-derived ink. Thereby, the packaging material having less environmental load can be produced by using the laminate of the present invention.
The method for forming an image is not particularly limited, and examples thereof include conventionally known printing methods such as a gravure printing method, an offset printing method, and a flexographic printing method. Among these, the flexographic printing method is preferable because it can reduce the environmental load.

Further, the base material is preferably surface-treated. As a result, the adhesion to the adjacent layer can be improved.
The surface treatment method is not particularly limited, and for example, 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. Examples include chemical treatment such as treatment.
Further, an anchor coat layer may be formed on the surface of the base material by using a conventionally known anchor coat agent.

The thickness of the base material is preferably 5 μm or more and 300 μm or less, and more preferably 7 μm or more and 100 μm or less.
By setting the thickness of the base material to 5 μm or more, the strength of the laminate for packaging materials of the present invention can be improved. Further, by setting the thickness of the base material to 300 μm or less, the processability of the laminate for packaging material of the present invention can be improved.

The base material can be produced by forming a film of polyolefin by a T-die method, an inflation method, or the like, producing a film, and then stretching the film.
According to the inflation method, film formation and stretching can be performed at the same time.

When the base material is prepared by the T-die method, the MFR of the polyolefin is preferably 5 g / 10 minutes or more and 20 g / 10 minutes or less.
By setting the MFR of the polyolefin to 5 g / 10 minutes or more, the processability of the laminate for packaging materials of the present invention can be improved. Further, by setting the MFR of the polyolefin to 20 g / 10 minutes or less, it is possible to prevent the resin film from breaking.

When the base material is prepared by the inflation method, the MFR of the polyolefin is preferably 0.5 g / 10 minutes or more and 5 g / 10 minutes or less.
By setting the MFR of the polyolefin to 0.5 g / 10 minutes or more, the processability of the laminate for packaging materials of the present invention can be improved. Further, by setting the MFR of the polyolefin to 5 g / 10 minutes or less, the film forming property can be improved.

The base material is not limited to the one produced by the above method, and a commercially available material may be used.

(Mesosphere)
The laminate for packaging materials of the present invention includes an intermediate layer between the base material and the heat seal layer. Thereby, the strength of the laminate for packaging material of the present invention can be improved.
The intermediate layer contains the same polyolefin as the polyolefin contained in the substrate and the heat seal layer.
Further, the intermediate layer has been stretched in the same manner as the base material.
The stretching to the intermediate layer may be uniaxial stretching or biaxial stretching. Further, the preferable draw ratio and the like are as described above.

The thickness of the intermediate layer is preferably 10 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less. By setting the thickness of the intermediate layer to 10 μm or more, the strength of the laminate for packaging materials of the present invention can be further improved. By setting the thickness of the intermediate layer to 50 μm or less, the processability of the laminate for packaging materials of the present invention can be improved.

In one embodiment, the intermediate layer may include a thin film. Thereby, the gas barrier property, particularly the oxygen barrier property and the water vapor barrier property, of the laminate for packaging material of the present invention can be further improved.

The vapor-deposited film includes a metal such as aluminum and an inorganic oxide such as aluminum oxide, silicon oxide, magsium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. Can be mentioned.

The thickness of the thin-film deposition film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and further preferably 10 nm or more and 40 nm or less.
By setting the thickness of the thin-film deposition film to 1 nm or more, the oxygen barrier property and the water vapor barrier property of the laminate for packaging materials of the present invention can be further improved. Further, by setting the thickness of the thin-film deposition film to 150 nm or less, it is possible to prevent the occurrence of cracks in the thin-film deposition film and improve the recyclability of the laminate for packaging materials of the present invention.

In order for the vapor-deposited film to be an aluminum-deposited film, its OD value is preferably 2 or more and 3.5 or less. Thereby, the oxygen barrier property and the water vapor barrier property can be improved while maintaining the productivity of the laminate for packaging material of the present invention. In the present invention, the OD value can be measured according to JIS-K-7361.

The vapor deposition film can be formed by using a conventionally known method, for example, a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum vapor deposition method, a sputtering method and an ion plating method, and plasma chemistry. Examples thereof include chemical vapor deposition methods (Chemical Vapor Deposition methods, CVD methods) such as a vapor phase growth method, a thermochemical vapor phase growth method, and a photochemical vapor deposition method.

Further, for example, both the physical vapor deposition method and the chemical vapor deposition method can be used in combination to form a composite film composed of two or more layers of vapor-deposited films of different kinds of inorganic oxides. The degree of vacuum deposition chamber, before introduction of ^oxygen, preferably about 10 ^-2 to 10 -8 mbar, in the after introduction of ^oxygen, preferably about 10 ^-1 ~10 -6 mbar. The amount of oxygen introduced differs 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, or nitrogen gas may be used as the carrier gas within a range that does not hinder. The transport speed of the film can be about 10 to 800 m / min.

The surface of the vapor-deposited film is preferably subjected to the above surface treatment. As a result, the adhesion to the adjacent layer can be improved.

In one embodiment, the intermediate layer is a hydrolyzate of 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 method catalyst, water and an organic solvent. Alternatively, a gas barrier coating film containing at least one resin composition such as a hydrolyzed condensate of a metal alkoxide may be provided.
Thereby, the oxygen barrier property and the water vapor barrier property of the laminate for packaging material of the present invention can be further improved.
Further, when the vapor-deposited film is composed of an inorganic oxide, the occurrence of cracks in the vapor-deposited film can be effectively prevented by providing the gas barrier coating film so as to be adjacent to the vapor-deposited film.

In one embodiment, the metal alkoxide is represented by the following general formula.
R ¹ _n M (OR ² ) _m
(However, 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, aluminum and the like can be used.
Examples of the organic group 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 the metal alkoxide satisfying the above general formula include tetramethoxysilane (Si (OCH ₃ ) ₄ ), tetraethoxysilane (mass%) Si (OC ₂ H ₅ ) ₄ ), and tetrapropoxysilane (Si (OC ₃ H)). ₇ ) ₄ ), tetrabutoxysilane (Si (OC ₄ H ₉ ) ₄ ) and the like can be mentioned.

Further, it is preferable to use a silane coupling agent together with the above metal alkoxide.
As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used, but organoalkoxysilanes having an epoxy group are particularly preferable. Examples of the organoalkoxysilane having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Be done.

Two or more kinds of the above-mentioned silane coupling agent may be used, and the silane coupling agent is used within the range of about 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the above-mentioned alkoxide. Is preferable.

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

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 property and the water vapor barrier property of the packaging material laminate of the present invention are further improved. can do. Further, by setting the content of the water-soluble polymer in the gas barrier coating film to 500 parts by mass or less with respect to 100 parts by mass of the metal alkoxide, the film forming property 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, and more preferably 0.1 μm or more and 50 μm or less.
By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier property and the water vapor barrier property of the packaging material laminate of the present invention can be improved. Further, when it is provided adjacent to the thin-film deposition film composed of an inorganic oxide, it is possible to prevent the occurrence of cracks in the thin-film deposition film.
Further, by setting the thickness of the gas barrier coating film to 100 μm or less, the recyclability and processability of the laminate for packaging materials of the present invention can be improved.

In the gas barrier coating film, a composition containing the above materials is coated on a substrate by a conventionally known means such as a roll coating such as a gravure roll coater, a spray coating, a spin coating, dipping, a brush, a barcode, and an applicator. The composition can be formed by polycondensation by the sol-gel method.
As the sol-gel method catalyst, an acid or amine compound is suitable. As the amine compound, a tertiary amine which is substantially insoluble in water and soluble in an organic solvent is preferable, and for example, N, N-dimethylbenzylamine, tripropylamine, tributylamine, and trypentyl are preferable. Amine and the like can be mentioned. Among these, N, N-dimethylbenzylamine is preferable.
The sol-gel method catalyst is preferably used in the range of 0.01 parts by mass or more and 1.0 parts by mass or less, and 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 method catalyst to be 0.01 part 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 method catalyst to be 1.0 part by mass or less per 100 parts by mass of the metal alkoxide, the thickness of the formed gas barrier coating film can be made uniform.

The composition may further contain an acid. The acid is used as a catalyst for the sol-gel process, mainly as a catalyst for hydrolysis of alkoxides, silane coupling agents and the like.
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 content (for example, the silicate portion) of the alkoxide and the silane coupling agent.
The catalytic effect can be improved by setting the amount of the acid to be 0.001 mol or more with respect to the total molar amount of the alkoxide content (for example, the silicate portion) of the alkoxide and the silane coupling agent.
Further, the thickness of the gas barrier coating film formed can be made uniform by setting the total molar amount of the alkoxide and the silane coupling agent (for example, the silicate portion) to 0.05 mol or less. it can.

Further, the composition may contain water at 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, based on 1 mol of the total molar amount of alkoxide. preferable.
By setting the water content to 0.1 mol or more with respect to 1 mol of the total molar amount of alkoxide, the oxygen barrier property and the water vapor barrier property of the laminate for packaging material of the present invention can be improved.
Further, by setting the water content to 100 mol or more with respect to 1 mol of the total molar amount of alkoxide, the hydrolysis reaction can be carried out rapidly.

Moreover, the said composition may contain an organic solvent. As the organic solvent, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol and the like can be used.

Hereinafter, 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 method catalyst, water, an organic solvent and, if necessary, a silane coupling agent. The polycondensation reaction gradually proceeds in the composition.
Next, the composition is applied and dried on the substrate by the above-mentioned conventionally known method.
By 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 layer of the composite polymer.
Finally, the gas barrier coating film can be formed by heating the composition at a temperature of 20 to 250 ° C., preferably 50 to 220 ° C. for 1 second to 10 minutes.

(Heat seal layer)
The heat-sealing layer is characterized in that it is made of the same material (same polyolefin) as the polyolefin constituting the above-mentioned base material and the intermediate layer.
The heat seal layer is formed of an unstretched polyolefin resin film or is formed by melt extrusion.

Further, when polypropylene is used as the resin constituting the heat seal layer, a heat seal modifier can be contained in order to improve the heat seal property. The heat seal modifier is not particularly limited as long as it has excellent compatibility with the polyolefin constituting the heat seal layer, and examples thereof include an olefin copolymer and the like.

The thickness of the heat seal layer is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.
By setting the thickness of the heat seal layer to 5 μm or more, the heat seal property and recyclability of the heat seal layer can be improved. Further, by setting the thickness of the heat seal layer to 100 μm or less, the processability of the laminate for packaging material of the present invention can be improved.

In one embodiment, the heat seal layer may have a multi-layer structure. In particular, when a heat seal modifier is added to polypropylene as the heat seal layer, the modifier may migrate (leak out) to the gas barrier laminate side, so that the heat seal layer is composed of two or more layers. The heat-sealed side (the innermost layer side of the laminate) can be a layer containing a polyolefin and a heat-sealing modifier, and the outer layer thereof can be a layer made of polyolefin.
That is, examples of the multilayer structure include a multilayer structure composed of a first heat-sealing layer composed of polyolefin and a second heat-sealing layer composed of polyolefin and a heat-sealing modifier.

The content of the heat seal modifier in the second heat seal layer is preferably 10% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 40% by mass or less.
By setting the content of the heat seal modifier in the second heat seal layer to 10% by mass or more, the heat seal property of the second heat seal layer can be improved. Further, by setting the content of the heat seal modifier in the second heat seal layer to 50% by mass or less, the recyclability of the laminate for packaging material of the present invention can be improved.

When the heat seal layer has the above two-layer structure, the thickness of the first heat seal layer is preferably 5 μm or more and 50 μm or less, and more preferably 7 μm or more and 45 μm or less.
By setting the thickness of the first heat-sealing layer to 5 μm or more, the recyclability of the laminate for packaging materials of the present invention and the heat-sealing property of the first heat-sealing layer can be improved. Further, by setting the thickness of the first heat seal layer to 50 μm or less, the processability of the laminate for packaging material of the present invention can be improved.
The thickness of the second heat seal layer is preferably 5 μm or more and 20 μm or less, and more preferably 7 μm or more and 15 μm or less.
By setting the thickness of the second heat seal layer to 5 μm or more, the heat seal property of the second heat seal layer can be improved. Further, by setting the thickness of the second heat seal layer to 20 μm or less, it is possible to achieve both the recyclability and the processability of the laminate for packaging material of the present invention.

(Adhesive layer)
The laminate for packaging materials of the present invention may be provided with an adhesive layer between the base material and the intermediate layer and between the intermediate layer and the heat seal layer, thereby improving the adhesion between these layers. be able to.

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

When the intermediate layer includes an aluminum vapor deposition film, an adhesive layer adjacent to the vapor deposition film is formed by using a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. Is preferable.
When a laminate provided with a vapor-deposited film is applied to a packaging material, a bending load is applied to the laminate by a molding machine or the like, so that the aluminum vapor-deposited film may crack. By using the specific adhesive as described above, it is possible to suppress the deterioration of the oxygen barrier property and the water vapor barrier property even when the aluminum vapor deposition film is cracked.

The polyester polyol has two or more hydroxyl groups in one molecule as a functional group. Further, the isocyanate compound has two or more isocyanate groups in one molecule as a functional group.
The 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, a series of PASLIM sold by DIC Corporation can be used.

The resin composition may further contain a plate-like inorganic compound, a coupling agent, cyclodextrin and / or a derivative thereof and the like.

As the polyester polyol having two or more hydroxyl groups in one molecule as a functional group, for example, the following [1st example] to [3rd example] can be used.
[Example] Polyester polyol obtained by polycondensing an ortho-oriented polyvalent carboxylic acid or its anhydride and a polyhydric alcohol [Example] Polyester polyol having a glycerol skeleton [Example] Having an isocyanul ring Polyester polyols 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 orthophthalic acid and an anhydride thereof, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. It is a polycondensate obtained by polycondensing with a polyhydric alcohol component containing at least one of these.
In particular, a polyester polyol having an orthophthalic acid and its anhydride content of 70 to 100% by mass with respect to all the components of the polyvalent carboxylic acid is preferable.

The polyester polyol according to the first example requires orthophthalic acid and its anhydride as the polyvalent carboxylic acid component, but other polyvalent carboxylic acid components are copolymerized as long as the effects of the present embodiment are not impaired. You may.
Specifically, aliphatic polyvalent carboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanediocarboxylic acid, unsaturated bond-containing polyvalent carboxylic acids such as maleic anhydride, maleic acid and fumaric acid, 1, Alicyclic polyvalent carboxylic 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. Examples thereof include aromatic polyvalent carboxylic acids such as sex derivatives, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid and polybasic acids such as ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid and isophthalic acid are preferable.
In addition, you may use 2 or more kinds of the above-mentioned other polyvalent carboxylic acids.

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

In the formula (2), n represents an integer of 1 to 5, and X is a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, 2, which may have a substituent. It represents an arylene group selected from the group consisting of a 3-anthraquinonediyl group and a 2,3-anthracendyl group, and Y represents a group represented by 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 the general formula (2).

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

_Also, tables in the compound R _1, R 2, one of _{R 3} is a group represented by the general formula _(2), R _1, R 2, either _{R 3} 2 two generally formula (2) Any two or more compounds of the compound which is the group to be used and the compound which is the group in which all of R ₁ , R ₂ and R ₃ are represented by the general formula (2) may be a mixture.

X is selected from the group consisting of 1,2-phenylene group, 1,2-naphthylene group, 2,3-naphthylene group, 2,3-anthraquinone diyl group and 2,3-anthracene diyl group, and has a substituent. Represents an allylene group that may be present.
When X is substituted with a substituent, it may be substituted with one or more substituents, the substituent being attached to any carbon atom on X different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group and an amino group. Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group and a naphthyl group.

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

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

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

Further, examples of the polyhydric alcohol component include an alkylene diol having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol and dimethylbutanediol. Can be exemplified.

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

In the 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, It represents an arylene group selected from the group consisting of a 2,3-anthraquinonediyl group and a 2,3-anthracendyl group and may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms). Represents a group represented by. However, at least one of R ₁ , R ₂ , and R ₃ is a group represented by the general formula (4).

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

In the general formula (4), n2 represents an integer of 2 to 4, and n3 represents an integer of 1 to 5.
X is selected from the group consisting of 1,2-phenylene group, 1,2-naphthylene group, 2,3-naphthylene group, 2,3-anthraquinonediyl group, and 2,3-anthracenediyl group and has a substituent. Represents an allylene group that may be present.

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

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

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

_Also, tables in the compound R _1, R 2, one of _{R 3} is a group represented by the general formula _(4), R _1, R 2, either _{R 3} 2 two generally formula (4) Any two or more compounds of the compound which is the group to be used and the compound which is the group in which all of R ₁ , R ₂ and R ₃ are represented by the general formula (4) may be a mixture.

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

Triols having an isocyanuric ring include, for example, 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. And so on.

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

Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group and an amino group. Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group and a naphthyl group.

Further, examples of the polyhydric alcohol component include an alkylene diol having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol and dimethylbutanediol. Can be mentioned.
Among them, 1,3,5-tris (2-hydroxyethyl) isocyanuric acid or 1,3,5-tris (2-hydroxypropyl) isocyanuric acid is used as the triol compound having an isocyanul ring, and the carboxylic acid is in the ortho position. A polyester polyol compound having an isocyanul ring using an aromatic polyvalent carboxylic acid substituted with or using orthophthalic anhydride as its anhydride and ethylene glycol as the polyhydric alcohol is particularly excellent in oxygen barrier property and adhesiveness. preferable.

The isocyanul ring is highly polar and trifunctional, and can increase the polarity of the entire system and increase the crosslink density. From this point of view, it is preferable to contain isocyanul ring in an amount of 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 the molecule.
Further, the isocyanate compound may be aromatic, aliphatic, low molecular weight compound, or high molecular weight compound.
Further, the isocyanate compound may be a blocked isocyanate compound obtained by an addition reaction using a known isocyanate blocking agent by a known and commonly used appropriate method.
Among them, a polyisocyanate compound having three 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 property and water vapor barrier property.

Specific examples of the isocyanate compound include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydride diphenylmethane diisocyanate, metaxylylene diisocyanate, hydride hydride diisocyanate, isophorone diisocyanate, and these isocyanate compounds. Examples thereof include an adduct, a burette, and an allophanate obtained by reacting these isocyanate compounds with a low molecular weight active hydrogen compound or an alkylene oxide adduct thereof, or a high molecular weight active hydrogen compound.
Examples of the low molecular weight active hydrogen compound include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, and sorbitol. Examples thereof include ethylenediamine, monoethanolamine, diethanolamine, triethanolamine and metaxylylene diamine, and examples of the molecularly active hydrogen compound include various polyester resins, polyether polyols and high molecular weight active hydrogen compounds of polyamide.

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

More specifically, phosphoric acid, pyrophosphate, triphosphate, 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 oxygen barrier property and the water vapor barrier property of the laminate for packaging materials of the present invention can be improved. Further, 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.

The resin composition containing the polyester polyol, the isocyanate compound, and the phosphoric acid-modified compound may contain a plate-like inorganic compound, whereby the adhesiveness of the adhesive layer can be improved. In addition, the bending load resistance of the laminate for packaging materials of the present invention can be improved.
Plate-like inorganic compounds include, for example, kaolinite-serpentinite clay minerals (haloisite, kaolinite, enderite, dicite, nacrite, antigolite, chrysotile, etc.) and pyrophyllite-talc (pyrophilite, talc, etc.). Kerorai, etc.).

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

Examples of the silane coupling agent include vinyl trichlorosilane, vinyl trimethoxysilane, vinyl triethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ. -Glysidoxypropylmethyldiethoxysilane, 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 Examples thereof include trimethoxysilane, 3-isocyanuspropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane and 3-triethoxysilyl-N- (1,3-dimethyl-butylidene).

Examples of titanium-based coupling agents include isopropyltriisostearoyl titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropyltris (dioctylpyrophosphate) titanate, and tetraoctylbis. (Didodecylphosphite) titanate, tetraoctylbis (ditridecylphosphite) titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctainoltitanate, isopropyldimethacrylisostearoyl titanate , Isostatearoyl diacrylic titanate, diisostearoyl ethylene titanate, isopropyltri (dioctyl phosphate) titanate, isopropyltricylphenyl titanate and dicumylphenyloxyacetate titanate and the like.

Specific examples of the aluminum-based coupling agent include acetalkoxyaluminum diisopropyrate, diisopropoxyaluminum ethylacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkylacetate monomethacrylate, and aluminum. Examples thereof include -2-ethylhexanoate oxide trimmer, aluminum stearate oxide trimmer and alkylacetate aluminum oxide trimmer.

The resin composition can include cyclodextrin and / or its derivatives, which can improve the adhesiveness of the adhesive layer. In addition, the bending load resistance of the laminate for packaging materials of the present invention can be further improved.
Specifically, for example, a cyclodextrin such as cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, and hydroxyalkylated cyclodextrin in which the hydrogen atom of the hydroxyl group of the glucose unit is replaced with another functional group is used. Can be done. A branched cyclic dextrin can also be used.
The cyclodextrin skeleton of cyclodextrin 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. It may be either.
These compounds may be used alone or in combination of two or more. In addition, these cyclodextrins and / or derivatives thereof may be collectively referred to as dextrin compounds hereafter.

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

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

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

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

The thickness of the adhesive layer is preferably 0.5 μm or more and 6 μm or less, more preferably 0.8 μm or more and 5 μm or less, and further 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 a cured product of a resin composition containing a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound is used, the bending load resistance of the laminate for packaging material can be improved.
By setting the thickness of the adhesive layer to 6 μm or less, the processability of the laminated body for packaging materials can be improved.

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

(Packaging material)
The packaging material of the present invention is characterized by being composed of the above-mentioned laminate for packaging material.
The shape of the packaging material is not particularly limited, and may be a bag-like shape as shown in FIG.

In one embodiment, the bag-shaped packaging material can be produced by folding and stacking the laminates of the present invention in half so that the heat-sealing layer is on the inside, and heat-sealing the ends thereof. ..
In another embodiment, the bag-shaped packaging material can also be produced by stacking two laminates so that the heat-sealing layers face each other and heat-sealing the ends thereof.
In the figure, the shaded area represents the heat-sealed part.

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

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

The stand pouch-shaped packaging material is heat-sealed in a tubular 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. The bottom can be formed and manufactured by folding it in a V shape so that the layer is on the inside, sandwiching it from one end of the body, and heat-sealing it.

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

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
As a base material, a biaxially stretched polypropylene film having a thickness of 18 μm (manufactured by Toyobo Co., Ltd., trade name: P2108) was prepared.
An image was formed on one surface of the base material by a gravure printing method using a solvent-type gravure ink (Finato, manufactured by DIC Graphics Corporation).

A biaxially stretched polypropylene film having a thickness of 18 μm (manufactured by Toyobo Co., Ltd., trade name: P2108) was prepared, and an aluminum vapor-deposited film having a thickness of 30 nm was formed on one surface of the film by the PVD method. The vapor deposition concentration (OD value) of the formed vapor deposition film was measured and found to be 3.0.
Further, a polyvinyl alcohol-based barrier coating agent (MFB7010 manufactured by Michelman Co., Ltd.) was applied on the aluminum vapor-deposited film by a gravure method and dried to form a barrier coating layer having a thickness of 1 μm to prepare an intermediate layer.

As a heat seal layer, polypropylene (manufactured by TPC Co., Ltd., trade name: FL7540L, density: 0.90 g / cm ³ , melting point: 138 ° C., MFR: 7.0 g / 10 minutes) is extruded by the T-die method. , An unstretched polypropylene film having a thickness of 35 μm was prepared.

The printed surface of the base material and the barrier coat layer forming surface of the intermediate layer were laminated via a two-component curable polyurethane adhesive (manufactured by Rock Paint Co., Ltd., trade name: RU-3600 / H-689).
Further, the intermediate layer surface of the laminated film bonded above and the heat seal layer were bonded with the above adhesive to obtain the laminated body of the present invention. The proportion of the same polyolefin (PP) in the laminate thus obtained was 92% by mass.

Example 2
The laminate for packaging material of the present invention was produced in the same manner as in Example 1 except that the thickness of the aluminum vapor-deposited film was changed to 20 nm and the OD value of the thin-film film was changed to 2.0. The proportion of the same polyolefin (PP) in the laminate for packaging materials thus obtained was 92% by mass.

Example 3
A laminate for a packaging material of the present invention was produced in the same manner as in Example 1 except that the barrier coat layer was not provided. The proportion of the same polyolefin (PP) in the laminate for packaging materials thus obtained was 93% by mass.

Example 4
Examples except that the two-component curable polyurethane adhesive was changed to a two-component curable adhesive containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound (manufactured by DIC Co., Ltd., trade name: PASLIM VM001 / VM102CP). The laminate for packaging material of the present invention was produced in the same manner as in 3. The proportion of the same polyolefin (PP) in the laminate for packaging materials thus obtained was 92% by mass.

Comparative Example 1
A laminate for packaging material was obtained in the same manner as in Example 1 except that an unstretched polypropylene film having a thickness of 18 μm (manufactured by Toyobo Co., Ltd., trade name: P1108) was used as a base material. The proportion of the same polyolefin (PP) in the laminate thus obtained was 92% by mass.

Comparative Example 2
A laminate for packaging material was obtained in the same manner as in Example 1 except that the vapor deposition film was not provided. The proportion of the same polyolefin (PP) in the laminate thus obtained was 92% by mass.

Comparative Example 3
A laminate for packaging material was obtained in the same manner as in Example 1 except that the base material was a biaxially stretched polyester film having a thickness of 12 μm (manufactured by Toyobo Co., Ltd., trade name: E5100). The proportion of the same polyolefin (PP) in the laminate thus obtained was 69% by mass.

<< Recyclability Evaluation >>
The recyclability of the laminates for packaging materials 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 the same polyolefin in the laminate for packaging material was 80% by mass or more.
X: The content of the same polyolefin in the laminate for packaging material was less than 80% by mass.

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

<< Heat resistance evaluation >>
From the packaging material laminates obtained in the above Examples and Comparative Examples, two test pieces each having a length of 80 mm and a width of 80 mm were prepared.
The two test pieces were superposed so that the heat-sealing layers faced each other, and the three sides were heat-sealed at 150 ° C. to prepare a pouch-shaped packaging material.
The prepared packaging material was visually observed, and the heat resistance of the packaging material laminate was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
◯: No wrinkles were generated on the surface of the packaging material, and no adhesion to the heat seal bar was observed.
X: Wrinkles were generated on the surface of the packaging material, and adhesion to the heat seal bar was observed, so that the bag could not be made.

<< Printability Evaluation >>
In the above Examples and Comparative Examples, the images formed on the base material were visually observed, and the printability was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
◯: The dimensional stability at the time of printing was good, and a good image without rubbing or bleeding could be formed.
X: Stretching or shrinkage of the film occurred during printing, and the formed image was rubbed or blurred.

<< Oxygen barrier evaluation >>
The laminate for packaging material obtained in the above Examples and Comparative Examples was cut into A4 size, and using OXTRAN2 / 20 manufactured by MOCON of the United States, oxygen permeability (cc) in an environment of 23 ° C. and 90% relative humidity. / M ² / day / atm) was measured. The measurement results are summarized in Table 1.
Those exceeding the measurement upper limit of 200 cc / m ² / day / atm are described as "-".

<< Evaluation of water vapor barrier property >>
The laminates obtained in the above Examples and Comparative Examples were cut into A4 size, and using PERMATRAN 3/31 manufactured by MOCON of the United States, water vapor permeability (g / m ^{2) in} an environment of 40 ° C. and 90% relative humidity. / Day / atm) was measured. The measurement results are summarized in Table 1.

<Bending load resistance evaluation>
For the laminate for packaging materials obtained above, using Gelboflex Tetter (Tester Sangyo Co., Ltd., trade name: BE1006BE), bending load (stroke: 155 mm, bending operation: 440) in accordance with ASTM F 392. °) Was given 5 times.
After the bending load, the oxygen permeability and water vapor permeability of the laminate were measured. The measurement results are summarized in Table 1.

<< Heat sealability test >>
The laminates for packaging materials obtained in the above Examples and Comparative Examples were cut into 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 region was heat-sealed under the conditions of a temperature of 150 ° C., a pressure of 1 kgf / cm ² , and 1 second.
Cut the sample piece after heat sealing into strips with a width of 15 mm, grasp both ends that were not heat-sealed with a tensile tester, and determine 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. The measurement results are summarized in Table 1.
The laminate for packaging material obtained in Comparative Example 1 adhered to the heat seal bar, and the peel strength could not be measured. Therefore, the value was set to "-".

10: Laminate for packaging material, 11: Base material, 12: Intermediate layer, 13: Heat seal layer, 14: Adhesive layer

Claims (6)

A laminate for packaging materials including at least a base material, an intermediate layer, and a heat seal layer.
The base material, the intermediate layer, and the heat seal layer are made of the same material.
The base material and the intermediate layer have been stretched and have been stretched.
A laminate for packaging materials, wherein the same material is polyolefin. The laminate for packaging materials according to claim 1, wherein the intermediate layer includes a vapor-deposited film. The laminate for packaging material according to claim 1 or 2, wherein an adhesive layer is provided between the base material and the intermediate layer, and at least one of the intermediate layer and the heat seal layer. The laminate for packaging material according to claim 3, wherein the adhesive layer contains a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. The laminate for packaging materials according to any one of claims 1 to 4, wherein the content of the polyolefin in the entire laminate for packaging materials is 90% by mass or more. A packaging material composed of the laminate for packaging material according to any one of claims 1 to 5.