JP2023016859A - Laminate for packaging material and packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate for a packaging material capable of realizing a packaging material excellent in recyclability while having strength and barrier properties as a packaging material.

SOLUTION: A laminate for a packaging material includes a base material and a heat seal layer. The heat seal layer includes a gas barrier resin layer and a polyolefin resin layer. The base material and the polyolefin resin layer are composed of the same polyolefin. The base material is a stretched resin film composed of a polyolefin. The thickness of the gas barrier resin layer is smaller than the thickness of the polyolefin resin layer.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

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

Conventionally, a resin film made of a resin material has been used as a constituent material of 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, and are used by being laminated with resin films made of polyester, polyamide, etc. A typical packaging body is composed of a laminated film in which a base material and a heat seal layer are made of different materials (for example, Patent Document 1).

In recent years, along with the increasing demand for building a recycling-oriented society, packaging materials with high recyclability are in demand. However, as described above, conventional packages are made of different types of resin materials, and it is difficult to separate them into different resin materials, so currently they are not recycled.

JP 2009-202519 A

The present inventors have found that polyolefin resin, which has been conventionally used as a heat-seal layer, is used as a base material by making it into a stretched resin film, and the base material is laminated with a heat-seal layer and used as a packaging material. It was found that it can be used as a recyclable packaging material while maintaining the strength and heat resistance as. In addition, as a heat seal layer, a polyolefin resin layer and a barrier resin layer such as an ethylene-vinyl alcohol copolymer layer are laminated to form a recyclable packaging material while imparting barrier properties. I have learned that I can.

The present invention has been made in view of the above findings, and the problem to be solved is for packaging materials that can realize packaging materials that are excellent in recyclability while having strength and barrier properties as packaging materials. It is to provide a laminate.
Another problem to be solved by the present invention is to provide a packaging material composed of the laminate for packaging material.

The laminate for packaging material of the present invention comprises a substrate and a heat seal layer,
The heat seal layer comprises a gas barrier resin layer and a polyolefin resin layer,
The base material and the polyolefin resin layer are made of the same polyolefin,
The substrate is a stretched resin film made of polyolefin,
The thickness of the gas-barrier resin layer is characterized by being smaller than the thickness of the polyolefin resin layer.

In one embodiment, the content of polyolefin in the laminate for packaging materials is 80% by mass or more.

In one embodiment, the laminate for packaging material of the present invention comprises an adhesive layer between the substrate and the heat seal layer.

In one embodiment, the laminate for packaging material of the present invention comprises a vapor deposition film between the adhesive layer and the heat seal layer.

In one embodiment, the deposited film is an aluminum deposited film,
The adhesive layer contains a cured product of a resin composition containing a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound.

In one embodiment, the heat seal layer comprises an adhesive resin layer between the gas barrier resin layer and the polyolefin resin layer.

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

ADVANTAGE OF THE INVENTION According to this invention, the laminated body for packaging materials which has high recyclability can be provided.

Moreover, according to the present invention, it is possible to provide a laminate for packaging materials having high strength, heat resistance, printability, oxygen barrier properties and water vapor barrier properties.

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

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

(Laminate for packaging material)
As shown in FIG. 1, the laminate 10 for packaging materials of the present invention comprises a substrate 11 and a heat-sealing layer 12. The heat-sealing layer 12 comprises a gas barrier resin layer 13 and a polyolefin resin layer 14. .

In one embodiment of the present invention, the laminate for packaging material 10 may include an adhesive layer 15 between the substrate 11 and the heat seal layer 12, as shown in FIG.

Further, in one embodiment of the present invention, the laminate for packaging material 10 has an adhesive layer 15 between the substrate 11 and the heat seal layer 12 as shown in FIG. 3 or an adhesive layer 15 as shown in FIG. and the heat seal layer 12, a vapor deposition film 16 may be further provided.

In one embodiment of the present invention, the laminate for packaging material 10 includes an adhesive resin layer 17 between the gas barrier resin layer 13 and the polyolefin resin layer 14, as shown in FIG. may

Moreover, in one embodiment of the present invention, as shown in FIG. may

Furthermore, in one embodiment of the present invention, the laminate for packaging material 10 may be provided with a gas barrier coating film between arbitrary layers (not shown).

The polyolefin content in the entire laminate for packaging materials of the present invention is preferably 80% by mass or more, more preferably 90% by mass or more.
By setting the polyolefin content in the entire laminate for packaging materials of the present invention to 80% by mass or more, the recyclability of the laminate for packaging materials of the present invention can be improved.
The content of polyolefin in the laminate for packaging materials means the ratio of the content of polyolefin to the sum of the contents of the resin materials in the layers constituting the laminate.

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

(Base material)
The base material of the laminate for packaging material of the present invention is composed of polyolefin, and the polyolefin used is the same as the polyolefin that constitutes the polyolefin resin layer described later. By using the same type of polyolefin for the base material and the heat seal layer, the recyclability of the laminate for packaging materials can be improved.

A stretched resin film made of polyolefin is used as the base material in order to maintain strength and heat resistance as a packaging material. The stretched resin film may be a uniaxially stretched resin film or a biaxially stretched resin film.

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

Moreover, the draw ratio in the transverse direction (TD) of the stretched resin film 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 stretch ratio of the stretched resin film in the transverse direction (TD) to 2 times or more, the strength and heat resistance of the laminate for packaging materials of the present invention can be improved. Moreover, since the transparency of the base material can be improved, the visibility of an image formed on the adhesive layer side surface of the base material can be improved. On the other hand, the upper limit of the stretch ratio in the transverse direction (TD) of the stretched resin film 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 resin that constitutes the heat seal layer as described above. Such polyolefins include, for example, polyethylene, polypropylene, polymethylpentene, and ethylene-propylene. Examples include copolymers and propylene-butene copolymers, among which polyethylene and polypropylene are preferred.

Polyethylene includes high density polyethylene (HDPE) with a density greater than 0.945 g/cm ³ , medium density polyethylene (MDPE) with a density between 0.925 and 0.945 g/cm ³ , density less than 0.925 g/cm ³ low density polyethylene (LDPE) and linear low density polyethylene (LLDPE).

In one embodiment, a substrate having a structure comprising a layer containing high density polyethylene and a layer containing medium density polyethylene can be used.
By providing a high-density polyethylene layer on the outside of the substrate, the strength and heat resistance of the laminate for packaging materials of the present invention can be improved. Further, by providing the medium-density polyethylene layer, it is possible to improve the stretchability of the resin film that constitutes the substrate.

For example, it has a structure consisting of a high-density polyethylene layer/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 or less, more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate for packaging materials 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, it is possible to have a configuration consisting of, from the outside, a high-density polyethylene layer/medium-density polyethylene layer/high-density polyethylene layer.
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. Furthermore, curling of the substrate can be prevented.
At this time, the thickness of the high-density polyethylene layer is preferably thinner than the thickness of the medium-density polyethylene layer.
The ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer is preferably 1/10 or more and 1/1 or less, more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate for packaging materials 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, it is possible to have a configuration of, from the outside, a high-density polyethylene layer/medium-density polyethylene layer/low-density polyethylene layer or a linear low-density polyethylene layer/medium-density polyethylene layer/high-density polyethylene layer.
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. Moreover, it is possible to prevent curling in the base material. Furthermore, the workability 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 or less, more preferably 1/5 or more and 1/2 or less.
By setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the medium-density polyethylene layer to 1/10 or more, the strength and heat resistance of the laminate for packaging materials 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.
Moreover, 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, and 1/5 or more and 1/2 or less. It is more preferable to have
Heat resistance can be improved by setting the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer or the linear low-density polyethylene layer to 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, it is possible to improve the processability of stretching.

Polypropylene can be homopolymers, random copolymers and block copolymers.
A polypropylene homopolymer is a polymer of propylene only, and a polypropylene random copolymer is a polymer of propylene and other α-olefins other than propylene (eg, ethylene, butene-1, 4-methyl-1-pentene, etc.). A polypropylene block copolymer, which is a random copolymer, is a copolymer having a polymer block composed of propylene and a polymer block composed of an α-olefin other than the above-mentioned propylene.
Among these polypropylenes, homopolymer or random polypropylene can improve the transparency of the base material and can improve the visibility when an image is formed on the adhesive layer side surface of the base material. Copolymers are preferably used. A homopolymer can be used when importance is attached to the rigidity and heat resistance of the packaging material, and a random copolymer can be used when importance is attached to impact resistance and the like.

As a raw material for obtaining polyolefin, a biomass-derived olefin monomer may be used in place of the olefin monomer obtained from fossil fuels. Since such a biomass-derived olefin monomer is a carbon-neutral material, it can be used as a packaging material with even less environmental impact.
Such biomass-derived polyolefins, such as polyethylene, can be produced by the method described in JP-A-2013-177531. Also, commercially available biomass-derived polyolefins, such as Green PE from Braskem, may be used.

Polyolefins recycled by mechanical recycling can also be used. Here, mechanical recycling generally means that the collected polyolefin film is pulverized and washed with alkali to remove dirt and foreign matter on the film surface, and then dried for a certain period of time under high temperature and reduced pressure to remain inside the film. It is a method of decontaminating by diffusing contaminants, removing dirt from the polyolefin film, and returning it to polyolefin again.

The substrate may have an image formed on its surface. Although the image may be formed on any surface of the base material, it is preferable to form the image on the surface of the adhesive layer, since contact with the outside air can be prevented and deterioration over time can be prevented.
Also, the image to be formed is not particularly limited, and may represent characters, patterns, symbols, combinations thereof, and the like.
Image formation can be performed using conventionally known inks, but is preferably performed using biomass-derived inks. As a result, the laminate of the present invention can be used to produce a packaging material 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 because it can reduce the environmental load.

The base material may have a deposited film on its surface, which will be described later.

Moreover, it is preferable that the base material is surface-treated. This can improve adhesion with adjacent layers.
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 thickness of the substrate is preferably 5 μm or more and 300 μm or less, more preferably 7 μm or more and 100 μm or less.
By setting the thickness of the substrate 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 materials of the present invention can be improved.

The substrate can be produced by forming a polyolefin into a film 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 simultaneously.

When the substrate is produced 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. Moreover, 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 produced 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. Also, by setting the MFR of the polyolefin to 5 g/10 minutes or less, the film formability can be improved.

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

(Heat seal layer)
The laminate for packaging material of the present invention comprises a heat seal layer comprising a gas barrier resin layer and a polyolefin resin layer.

In one embodiment, the heat seal layer can further include an adhesive resin layer between the gas barrier resin layer and the polyolefin resin layer.
By further providing an adhesive resin layer between the gas barrier resin layer and the polyolefin resin layer, the adhesion between these layers can be further improved.

The present invention is characterized in that the thickness of the gas barrier resin layer is smaller than the thickness of the polyolefin resin layer. With such a configuration, the recyclability of the laminate for packaging materials of the present invention can be improved.
The thickness of the gas barrier resin layer is preferably 5 μm or more, more preferably 10 μm or more, less than the thickness of the polyolefin resin layer. When the thickness of the gas-barrier resin layer is smaller than the thickness of the polyolefin resin layer by 5 μm or more, the recyclability of the laminate for packaging materials of the present invention can be further improved.

(Polyolefin resin layer)
The polyolefin resin layer constituting the heat seal layer is characterized by being composed of the same polyolefin as the polyolefin constituting the base material. That is, as the resin that can be used for the polyolefin resin layer, the polyolefin that is used for the above base material is used. With such a configuration, a recyclable packaging material can be obtained while maintaining strength and heat resistance as a packaging material. However, the polyolefin resin layer is formed from an unstretched polyolefin resin film, or formed by melt extrusion.

Moreover, when polypropylene is used as the polyolefin resin layer, a heat-sealing modifier can be included in order to improve the heat-sealing property. The heat seal modifier is not particularly limited as long as it is highly compatible with the polyolefin forming the polyolefin resin layer, and examples thereof include olefin copolymers.

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

In one embodiment, the polyolefin resin layer may have a multilayer structure. In particular, when a heat seal modifier is added to polypropylene as the polyolefin resin layer, the modifier may migrate (bleed out) to the gas barrier resin layer side, so the polyolefin resin layer is formed of two or more layers. A layer containing a polyolefin resin and a heat seal modifier can be used as the side to be heat-sealed (the innermost layer side of the laminate), and a layer made of polypropylene resin can be used as the outer layer. That is, the multi-layer structure includes a multi-layer structure comprising a first polyolefin resin layer composed of polyolefin and a second polyolefin resin layer composed of polyolefin and a heat seal modifier.

The content of the heat seal modifier in the second polyolefin resin layer is preferably 10% by mass or more and 50% by mass or less, 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 polyolefin resin layer to 10% by mass or more, the heat sealability of the second polyolefin resin layer can be improved. Further, by setting the content of the heat seal modifier in the second polyolefin resin layer to 50% by mass or less, the recyclability of the laminate for packaging materials of the present invention can be improved.

When the polyolefin resin layer has the two-layer structure, the thickness of the first polyolefin resin layer is preferably 5 μm or more and 50 μm or less, more preferably 7 μm or more and 45 μm or less.
By setting the thickness of the first polyolefin resin layer to 5 μm or more, the recyclability of the laminate for packaging materials of the present invention and the heat sealability of the first polyolefin resin layer can be improved. Further, by setting the thickness of the first polyolefin resin layer to 50 μm or less, the processability of the laminate for packaging materials of the present invention can be improved.
The thickness of the second polyolefin resin layer is preferably 5 μm or more and 20 μm or less, more preferably 7 μm or more and 15 μm or less.
By setting the thickness of the second polyolefin resin layer to 5 μm or more, the heat sealability of the second polyolefin resin layer can be improved. Further, by setting the thickness of the second polyolefin resin layer to 20 μm or less, both recyclability and processability of the laminate for packaging materials of the present invention can be achieved.

(Gas barrier resin layer)
The gas barrier resin layer constituting the heat seal layer contains at least one gas barrier resin, such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, nylon 6, nylon 6,6 and polymer. Examples include polyamides such as taxylylene adipamide (MXD6), polyesters, polyurethanes, and (meth)acrylic resins. Among these, EVOH is preferred from the viewpoint of oxygen barrier properties and water vapor barrier properties.

The ethylene content in EVOH is preferably 20% by mass or more and 60% by mass or less, more preferably 27% by mass or more and 48% by mass or less.
By setting the ethylene content in EVOH to 20% by mass or more, the processability of the laminate for packaging materials of the present invention can be improved. By setting the ethylene content in EVOH to 60% by mass or less, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be improved.

The content of the gas barrier resin in the gas barrier resin layer is preferably 50% by mass or more, more preferably 75% by mass or more.
By setting the content of the gas barrier resin in the gas barrier resin layer to 50% by mass or more, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be further improved.

The content of the gas barrier resin in the laminate for packaging material of the present invention is preferably 20% by mass or less, more preferably 10% by mass or less.
By setting the content of the gas barrier resin in the laminate for packaging material to 20% by mass or less, the recyclability of the laminate for packaging material of the present invention can be improved.

The gas-barrier resin layer may contain an additive within a range that does not impair the properties of the present invention. Examples of additives include cross-linking agents, antioxidants, anti-blocking agents, slip agents, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, compatibilizers and pigments. be done.

The thickness of the gas barrier resin layer is preferably 0.5 μm or more and 10 μm or less, more preferably 1 μm or more and 7 μm or less.
By setting the thickness of the gas barrier resin layer to 0.5 μm or more, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be improved. Further, by setting the thickness of the gas-barrier resin layer to 10 μm or less, the recyclability of the laminate for packaging materials of the present invention can be improved.

(Adhesive resin layer)
In one embodiment, the heat seal layer may include an adhesive resin layer between the gas barrier resin layer and the polyolefin resin layer. Thereby, the adhesion between the gas barrier resin layer and the polyolefin resin layer can be improved.

The adhesive resin layer contains at least one resin material, examples of which include polyolefins, modified polyolefins, polyesters, vinyl resins and polyamides. Among these, polyolefins and modified polyolefins are preferred from the viewpoint of recyclability and adhesion.

The adhesive resin layer can contain the above additives within a range that does not impair the characteristics of the present invention.

The thickness of the adhesive resin is preferably 0.5 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less.
By setting the thickness of the adhesive resin layer to 0.5 μm or more, the adhesion between the gas barrier resin layer and the polyolefin resin layer can be improved. Further, by setting the thickness of the adhesive resin layer to 10 μm or less, the recyclability of the laminate for packaging materials of the present invention can be improved.

In a particularly preferred embodiment of the present invention, there is provided a laminate for packaging materials, wherein the heat seal layer comprises a gas barrier resin layer containing EVOH, an adhesive resin layer containing at least one of polyolefin and modified polyolefin, and polyolefin. and a second heat seal layer comprising a polyolefin and a heat seal modifier. With the above configuration, the laminate for packaging materials of the present invention can have extremely good oxygen barrier properties, water vapor barrier properties, and heat seal properties. Moreover, the adhesion between each layer constituting the heat seal layer can be improved.

The heat seal layer is formed by combining the material constituting the gas barrier resin layer, the material constituting the polyolefin resin layer (and the material constituting the layer when an adhesive resin layer is provided) by a T-die method or It is an unstretched resin film that can be produced by co-extrusion film formation by a conventionally known method such as an inflation method.
The unstretched resin film produced in this manner can be laminated on a substrate via an adhesive layer described below.

(evaporation film)
The laminate for packaging material of the present invention may further comprise a vapor deposition film between the substrate and the heat seal layer. By providing the deposited film, gas barrier properties, especially oxygen barrier properties and water vapor barrier properties can be further improved.

As the deposited film, a deposited film composed of a metal such as aluminum and an inorganic oxide such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide is used. 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 vapor-deposited film to 1 nm or more, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be further improved. Moreover, 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 and improve the recyclability of the laminate for packaging materials of the present invention.

In order for the deposited film to be an aluminum deposited film, the 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 materials of the present invention. In the present invention, the OD value can be measured according to JIS-K-7361.

The deposited film can be formed 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 chemical method. Chemical vapor deposition methods (Chemical Vapor Deposition method, CVD method) such as vapor deposition method, thermal chemical vapor deposition method, and photochemical vapor deposition method can be mentioned.

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. This can improve adhesion with adjacent layers.

(adhesive layer)
The laminate for packaging materials of the present invention may be provided with an adhesive layer for the purpose of improving the adhesion between the surface on which the vapor deposition layer is provided and the surface to which the vapor deposition layer is adhered (attachment surface). That is, when a vapor-deposited layer is provided on the substrate surface, an adhesive layer can be provided between the vapor-deposited layer and the heat-sealing layer, and when a vapor-deposited layer is provided on the surface of the gas barrier resin layer of the heat-sealing layer, can provide an adhesive layer between the deposited layer and the substrate.

The adhesive layer contains at least one kind of adhesive, and may be either a one-component curing type, a two-component curing type, or a non-curing type adhesive. 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 vapor-deposited film is an aluminum vapor-deposited film, the laminate for packaging materials of the present invention includes a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound as a two-liquid curing adhesive. It is preferred to use a cured product.
By configuring the adhesive layer in this manner, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be further improved. When a laminate having a vapor deposition film is applied to a packaging material, a bending load is applied to the laminate by a molding machine or the like, which may cause cracks or the like in the aluminum vapor deposition film. By using the specific adhesive as described above, it is possible to suppress deterioration of oxygen barrier properties and water vapor barrier properties even when cracks occur in the aluminum deposition film.

A polyester polyol has two or more hydroxyl groups in one molecule as a functional group. Moreover, the isocyanate compound has two or more isocyanate groups in one molecule as functional groups.
A polyester polyol has, for example, a polyester structure or a polyester polyurethane structure as a main skeleton.

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

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

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

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

The polyester polyol according to the first example essentially contains orthophthalic acid and its anhydride as the polyvalent carboxylic acid component. may
Specifically, aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid and fumaric acid, 1, Alicyclic polycarboxylic acids such as 3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5- naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, anhydrides of these dicarboxylic acids and ester formation of these dicarboxylic acids polybasic acids such as aromatic polycarboxylic acids such as polyvalent derivatives, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid and isophthalic acid are preferred.
In addition, you may use 2 or more types of said other polyhydric carboxylic acid.

一般式（１）において、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 oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be improved. 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. 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-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 for packaging materials 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. Moreover, 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 materials can be improved.
By setting the thickness of the adhesive layer to 6 μm or less, the processability of the laminate for packaging materials can be improved.

The adhesive layer is applied onto a base material 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, and then dried. can be formed by

(Gas barrier coating film)
In the packaging laminate of the present invention, a mixture of a metal alkoxide and a water-soluble polymer is added between arbitrary layers in the presence of a sol-gel catalyst, water, an organic solvent, etc., as long as the characteristics of the present invention are not impaired. A gas barrier coating film containing at least one resin composition such as a metal alkoxide hydrolyzate or a metal alkoxide hydrolysis condensate obtained by polycondensation by a sol-gel method may be provided.
Thereby, the oxygen barrier property and water vapor barrier property of the laminate for packaging materials of the present invention can be further improved.
Furthermore, when the vapor deposition film is composed of an inorganic oxide, it is possible to effectively prevent the generation of cracks in the vapor deposition film by providing the gas barrier coating film so as to be adjacent to the vapor deposition film.

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 per 100 parts by mass of the metal alkoxide, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention are further improved. can do. 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.
By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the laminate for packaging material 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.
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.

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

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

In addition, the above composition may contain water in a ratio of preferably 0.1 mol or more and 100 mol or less, more preferably 0.8 mol or more and 2 mol or less, per 1 mol of the total molar amount of the alkoxide. preferable.
By setting the water content to 0.1 mol or more per 1 mol of the total molar amount of the alkoxide, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials 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 base material and dried by the above-described conventionally known method.
Due to this drying, the polycondensation reaction of the alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains a silane coupling agent) further proceeds to form a composite polymer layer.
Finally, the composition is heated at a temperature of 20 to 250° C., preferably 50 to 220° C. for 1 second to 10 minutes to form a gas barrier coating film.

(packaging material)
The packaging material of the present invention is characterized by comprising the laminate for packaging materials described above.
The shape of the packaging material is not particularly limited, and may be bag-like as shown in FIG.

In one embodiment, the bag-like packaging material is produced by folding the laminate of the present invention in two and overlapping them so that the heat-sealable laminate is on the inside, and heat-sealing the ends thereof. can be done.
In another embodiment, the bag-like packaging material can also be produced by stacking two laminates so that the heat-sealable laminates face each other and heat-sealing the edges.
In the drawing, the hatched portion represents the heat-sealed portion.

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-like packaging material is heat-sealed into a cylindrical shape so that the heat-sealable laminate of the laminate is on the inside to form a body, and then another laminate is attached, It can be produced by folding in a V-shape so that the heat-sealable laminate is on the inside, sandwiching one end of the body, 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
Ethylene-vinyl alcohol copolymer (EVOH, manufactured by Kuraray Co., Ltd., trade name: EVAL E171B, density: 1.14 g/cm ³ , melting point: 165°C, MFR: 1.7 g/ 10 minutes, ethylene content: 44% by mass),
Polyolefin (manufactured by Mitsui Chemicals, Inc., trade name: ADMER QF551, density: 0.89 g/cm ³ , melting point: 135° C., MFR: 2.5 g/10 minutes), which constitutes the adhesive resin layer,
polypropylene (manufactured by TPC Corporation, trade name: FL7540L, density: 0.90 g/cm ³ , melting point: 138° C., MFR: 7.0 g/10 minutes), which constitutes the first polyolefin resin 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) and heat seal modified A mixture ⁽ polypropylene: heat seal modified Particle = 60:40 (mass standard)) and
are co-extruded by a T-die method to form a gas barrier resin layer (2 μm)/adhesive resin layer (3 μm)/first polyolefin resin layer (15 μm)/second polyolefin resin layer (10 μm). A heat seal layer having

A 30 nm-thick aluminum deposition film was formed by PVD on the gas-barrier resin layer of the heat seal layer produced as described above. Incidentally, when the vapor deposition concentration (OD value) of the formed vapor deposition film was measured, it was 3.0.

A biaxially oriented polypropylene film (manufactured by Toyobo Co., Ltd., trade name: P2108) having a thickness of 25 μm was prepared as a base material.
An image was formed on one surface of the biaxially stretched polypropylene film by gravure printing using a solvent type gravure ink (manufactured by DIC Graphics Co., Ltd., Finart).
The aluminum deposition film forming surface of the heat seal layer and the image forming surface of the biaxially oriented polypropylene film were bonded together with a two-component curable polyurethane adhesive (manufactured by Rock Paint Co., Ltd., trade name: RU-3600/H-689). to obtain a laminate for packaging materials of the present invention. The ratio of the same polyolefin (PP) in the laminate thus obtained was 84% by mass.

Example 2
A laminate for packaging materials of the present invention was produced in the same manner as in Example 1, except that the thickness of the vapor-deposited aluminum film was changed to 20 nm and the OD value of the vapor-deposited film was changed to 2.0. The ratio of the same polyolefin (PP) in the laminate thus obtained was 84% by mass.

Example 3
A two-component curable polyurethane adhesive containing a polyester polyol, an isocyanate compound and a phosphoric acid-modified compound (manufactured by DIC Corporation, trade name: PASLIM
A laminate for packaging materials of the present invention was produced in the same manner as in Example 1, except for changing to VM001/VM102CP). The ratio of the same polyolefin (PP) in the laminate thus obtained was 84% by mass.

Comparative example 1
A laminate for packaging materials was obtained in the same manner as in Example 1, except that a 25 μm-thick unstretched polypropylene film (manufactured by Toyobo Co., Ltd., trade name: P1108) was used as the base material. The ratio of the same polyolefin (PP) in the laminate thus obtained was 84% by mass.

Comparative example 2
polypropylene (manufactured by TPC Corporation, trade name: FL7540L, density: 0.90 g/cm ³ , melting point: 138° C., MFR: 7.0 g/10 minutes), which constitutes the first polyolefin resin 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) and heat seal modified A mixture ⁽ polypropylene: heat seal modified Particle = 60:40 (mass standard)) and
were co-extruded into a film by a T-die method to prepare a heat seal layer having a structure consisting of a first polyolefin resin layer (20 μm)/a second polyolefin resin layer (10 μm).

On the first polyolefin resin layer of the heat seal layer produced as described above, a 30 nm-thick aluminum deposition film was formed by the PVD method. Incidentally, when the vapor deposition concentration (OD value) of the formed vapor deposition film was measured, it was 3.0.

A biaxially oriented polypropylene film (manufactured by Toyobo Co., Ltd., trade name: P2108) having a thickness of 25 μm was prepared as a base material. An image was formed on one surface of the biaxially stretched polypropylene film by gravure printing using a solvent type gravure ink (manufactured by DIC Graphics Co., Ltd., Finart).
The aluminum deposition film forming surface of the heat seal layer and the image forming surface of the biaxially oriented polypropylene film were bonded together with a two-component curable polyurethane adhesive (manufactured by Rock Paint Co., Ltd., trade name: RU-3600/H-689). to obtain a laminate for packaging materials. The ratio of the same polyolefin (PP) in the laminate thus obtained was 88% by mass.

Comparative example 3
A laminate for packaging materials was obtained in the same manner as in Example 1, except that a 12 μm-thick biaxially stretched polyester film (manufactured by Toyobo Co., Ltd., trade name: E5100) was used as the base material. The ratio of the same polyolefin (PP) in the laminate thus obtained was 53% 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)
Good: 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 laminates for packaging materials prepared 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 prepared from the laminates for packaging materials obtained in the above Examples and Comparative Examples.
Two test pieces were superimposed so that the second polyolefin resin layers faced each other, and three sides were heat-sealed at 140° C. to prepare a small bag-like packaging material.
The produced packaging material was visually observed, and the heat resistance of the laminate for packaging material 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.

<<Printability Evaluation>>
In the above examples and comparative examples, the images formed on the substrates were visually observed, and the printability was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
◯: Dimensional stability during printing was good, and a good image free from rubbing and bleeding could be formed.
x: The film stretched or shrunk during printing, and the formed image was rubbed or smudged.

<<Oxygen barrier property evaluation>>
The laminates for packaging materials obtained in the above Examples and Comparative Examples were cut into A4 size, and using OXTRAN 2/20 manufactured by MOCON in the United States, the 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.

<Bending load resistance evaluation>
The laminate for packaging materials obtained above was subjected to a bending load (stroke: 155 mm, bending motion: 440 mm) in accordance with ASTM F 392 using a Gelboflex tester (manufactured by Tester Sangyo Co., Ltd., trade name: BE1006BE). °) was given 5 times.
After bending load, the oxygen permeability and water vapor permeability of the laminate were measured. Table 1 summarizes the measurement results.

<<Heat sealability test>>
The laminates for packaging materials 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 second polyolefin resin layer was on the inside, and a 1 cm×10 cm area was heat-sealed under 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 for packaging material obtained in Comparative Example 1 adhered to the heat-seal bar, and the peel strength could not be measured.

10: Laminate for packaging material, 11: Base material, 12: Heat-sealable laminate, 13: Gas barrier resin layer, 14: Polyolefin resin layer, 15: Adhesive layer, 16: Deposited film, 17: Adhesive resin layer , 18: first polyolefin resin layer, 19: second polyolefin resin layer

Claims (7)

A laminate for packaging material comprising at least a substrate and a heat seal layer,
The heat seal layer is a resin film comprising a gas barrier resin layer and a polyolefin resin layer and formed by co-extrusion,
The base material and the polyolefin resin layer are made of the same polyolefin,
The base material is a stretched resin film composed of the polyolefin,
A laminate for packaging material, wherein the thickness of the gas barrier resin layer is smaller than the thickness of the polyolefin resin layer. The laminate according to claim 1, wherein the content of the polyolefin in the entire laminate for packaging materials is 80% by mass or more. The laminate according to claim 1 or 2, comprising an adhesive layer between the base material and the heat seal layer. 4. The laminate according to claim 3, comprising a deposited film between said adhesive layer and said heat seal layer. The vapor deposited film is an aluminum vapor deposited film,
5. The laminate according to claim 4, 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 according to any one of claims 1 to 5, wherein the heat seal layer comprises an adhesive resin layer between the gas barrier resin layer and the polyolefin resin layer. A packaging material composed of the laminate according to any one of claims 1-6.

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