JP7779064B2 - Laminates and packages - Google Patents

Description

This disclosure relates to a laminate and a package using the same.

Flexible packaging using resin film is known for packaging food, toiletries, cosmetics, pharmaceuticals, quasi-drugs, etc.

Flexible packaging requires safety, such as virginity, tamper-evidentness, and hygiene, environmental friendliness, such as recyclability and ease of disposal, and design.

Recently, the novel coronavirus disease (COVID-19) has become a global pandemic, and hygiene awareness in society has increased. As a result, there is a strong demand not only for the safety of the contents of packaging, but also for the safety of the packaging itself.

For example, Patent Document 1 proposes that, for the purpose of recyclability, in a laminate in which a paper layer and a thermoplastic resin layer are stacked, the peel strength between the paper layer and the thermoplastic resin layer be set within a specified range. In such a laminate, the thermoplastic resin layer can be peeled from the paper layer to separate the paper and plastic, allowing them to be reused.

Patent No. 4852913

In the above laminate, the thermoplastic resin layer is laminated onto the paper layer by extrusion coating, so the thermoplastic resin layer is disposed over the entire surface of the paper layer. This can make it difficult to peel the paper layer and thermoplastic resin layer from each other.

This disclosure was made in light of the above-mentioned circumstances, and its primary purpose is to provide a laminate and packaging body that can improve the safety, environmental conservation, and design of the packaging itself.

One embodiment of the present disclosure provides a laminate having, in this order, a first substrate layer, a patterned heat seal layer having easy peelability, a second substrate layer, and a seal layer.

In the laminate of the present disclosure, it is preferable that the peel strength when peeled between the first substrate layer and the second substrate layer is 0.1 N/15 mm or more and 3.5 N/15 mm or less.

Furthermore, the laminate of the present disclosure may have a first printed layer between the first base material layer and the heat seal layer, or on the surface of the first base material layer opposite the heat seal layer.

The laminate of the present disclosure may also have a second printed layer between the second base layer and the heat seal layer, or between the second base layer and the seal layer.

The laminate of the present disclosure may also have a barrier layer located anywhere between the heat seal layer and the seal layer.

Another embodiment of the present disclosure provides a package having the above-described laminate.

The present disclosure has the effect of providing a laminate and packaging body that can improve the safety, environmental friendliness, and design of the packaging itself.

1A and 1B are a schematic plan view and a cross-sectional view illustrating a laminate according to the present disclosure. 1A and 1B are a schematic plan view and a cross-sectional view illustrating a laminate according to the present disclosure. 1A and 1B are a schematic plan view and a cross-sectional view illustrating a laminate according to the present disclosure. 1 is a schematic plan view illustrating a laminate according to the present disclosure. 1A and 1B are a schematic plan view and a cross-sectional view illustrating a laminate according to the present disclosure. 1A and 1B are a schematic plan view and a cross-sectional view illustrating a laminate according to the present disclosure. 1 is a schematic cross-sectional view illustrating a laminate according to the present disclosure. 1 is a schematic cross-sectional view illustrating a laminate according to the present disclosure. 1A and 1B are schematic plan and cross-sectional views illustrating a packaging body according to the present disclosure. 1A and 1B are schematic plan and cross-sectional views illustrating a packaging body according to the present disclosure. 1A and 1B are schematic plan and cross-sectional views illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure. 1 is a schematic plan view illustrating a packaging body according to the present disclosure.

Embodiments of the present disclosure are described below with reference to the drawings. However, the present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form, but these are merely examples and do not limit the interpretation of the present disclosure. Furthermore, in this specification and each figure, elements similar to those previously described with reference to the previous figures are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

In this specification, when describing the arrangement of another component on a component, the terms "above" or "below" are used, unless otherwise specified, to include both the case where another component is placed directly above or below the component so as to be in contact with the component, and the case where another component is placed above or below the component with another component interposed between them. Furthermore, in this specification, when describing the arrangement of another component on the surface of a component, the term "on the surface" is used, unless otherwise specified, to include both the case where another component is placed directly above or below the component so as to be in contact with the component, and the case where another component is placed above or below the component with another component interposed between them.

The laminate and packaging material in this disclosure are described in detail below.

A. Laminate The laminate according to the present disclosure has, in this order, a first base material layer, a patterned heat seal layer having easy peelability, a second base material layer, and a seal layer.

The laminate of the present disclosure will be described with reference to the drawings. FIGS. 1(a) and 1(b) are a schematic plan view and cross-sectional view showing an example of a laminate of the present disclosure, with FIG. 1(a) being a plan view from the first substrate layer side of the laminate, and FIG. 1(b) being a cross-sectional view taken along line A-A of FIG. 1(a). As shown in FIGS. 1(a) and 1(b), the laminate 1 comprises, in this order, a first substrate layer 2, a patterned heat-seal layer 3 having easy peelability, a second substrate layer 4, and a seal layer 6. In the example shown in FIGS. 1(a) and 1(b), the heat-seal layer 3 has a circular dot pattern. Furthermore, as shown in FIG. 1(a), an adhesive layer 5 can be disposed between the second substrate layer 4 and the seal layer 6.

Because the heat seal layer 3 is easily peelable, the first base material layer 2 and heat seal layer 3 can be peeled from the laminate 1, as shown in Figures 2(a) and 2(b), for example. Note that Figure 2(a) is a plan view of the laminate viewed from the first base material layer side when the first base material layer and part of the heat seal layer have been peeled from the laminate, and Figure 2(b) is a cross-sectional view of the laminate when the first base material layer and the heat seal layer have all been peeled from the laminate.

In the laminate of the present disclosure, a patterned heat seal layer having easy peelability is disposed between the first base material layer and the second base material layer, allowing the first base material layer and the heat seal layer to be peeled from the laminate. Therefore, when the laminate of the present disclosure is used in, for example, a package, the first base material layer and the heat seal layer can be peeled from the laminate constituting the package and discarded, ensuring the hygiene of the surface of the package after peeling. This ensures the virginity of the package. Furthermore, even if the first base material layer and the heat seal layer are peeled from the laminate, the second base material layer and the seal layer remain, allowing the package to fulfill its function as a packaging material. Therefore, for example, after obtaining a package filled with contents, the first base material layer and the heat seal layer can be peeled from the laminate constituting the package and discarded, allowing the package to be stored and used hygienically and safely. This improves the safety, such as the virginity and hygiene, of the package itself.

Furthermore, in the laminate of the present disclosure, for example, if the first substrate layer and second substrate layer are made of different materials, the first substrate layer and second substrate layer can be separated by peeling the first substrate layer and heat seal layer from the laminate. This improves environmental conservation, such as recyclability and ease of separate disposal.

Furthermore, in the laminate of the present disclosure, for example, when the first substrate layer and the second substrate layer are different colors, or when the first substrate layer or the heat seal layer contains a colorant, the design and color can be changed by peeling the first substrate layer and the heat seal layer from the laminate. Furthermore, in the laminate of the present disclosure, as described below, when a first printed layer is disposed between the first substrate layer and the heat seal layer or on the surface of the first substrate layer opposite the heat seal layer, or when a second printed layer is disposed between the second substrate layer and the heat seal layer or between the second substrate layer and the seal layer, the design and color can also be changed by peeling the first substrate layer and the heat seal layer from the laminate. This allows for improved design.

The following describes each component of the laminate in this disclosure.

1. Heat Seal Layer The heat seal layer in the present disclosure is a member that is easily peelable and is arranged in a pattern on one surface of the first base material layer.

Here, "easily peelable" refers to the property that allows two layers that contact both sides of the heat seal layer to be bonded via the heat seal layer, and that the heat seal layer can be easily peeled from the layer that contacts the surface of the heat seal layer facing the second substrate layer.

The heat seal layer may be arranged in a pattern on one surface of the first base layer, and may be arranged in a pattern over the entire surface of the first base layer, or in a localized pattern. For example, Figure 1(a) shows an example in which the heat seal layer 3 is arranged in a pattern over the entire surface of the first base layer 2, and Figure 3(a) shows an example in which the heat seal layer 3 is arranged in a pattern over the entire surface of the first base layer 2.

In particular, it is preferable that the heat seal layer be arranged in a pattern on one surface of the first base material layer. The first base material layer and the second base material layer can be uniformly bonded via the heat seal layer. This makes it difficult for the heat seal layer to peel from the laminate until the first base material layer and the heat seal layer are peeled from the laminate. Furthermore, when the laminate is used for packaging or labels, the arrangement of the patterned heat seal layer does not need to be adjusted to the size of the packaging or label, and the laminate can be used regardless of the size of the packaging or label.

Furthermore, when the heat seal layer is locally arranged in a pattern on one surface of the first base material layer, it is preferably arranged on the peripheral edge of the first base material layer. In this case, when the laminate has a rectangular shape in plan view, the heat seal layer is preferably arranged on the peripheral edge of three or four sides of the first base material layer, and more preferably on the peripheral edge of four sides of the first base material layer. By arranging the heat seal layer on the peripheral edge of four sides of the first base material layer, it is possible to make the heat seal layer less likely to peel from the laminate until the first base material layer and heat seal layer are peeled from the laminate.

Furthermore, when the heat seal layer is locally arranged in a pattern on one surface of the first base material layer, it is preferable that the heat seal layer be arranged continuously. When the heat seal layer is arranged continuously, it is more difficult for the heat seal layer to peel from the laminate until the first base material layer and heat seal layer are peeled from the laminate, compared to when the heat seal layer is arranged discontinuously.

For example, in Figure 3(a), the heat seal layer 3 is continuously disposed around the four peripheral edges of the first base layer 2. Note that Figure 3(b) is a cross-sectional view taken along line A-A in Figure 3(a).

Furthermore, the ratio of the total area of the patterned heat seal layer to the area of the first base layer, i.e., the area ratio of the patterned heat seal layer, is, for example, 10% or more and 95% or less, or may be 20% or more and 60% or less, or 30% or more and 50% or less.

The pattern shape of the heat seal layer in plan view may be, for example, a regular pattern or a random pattern. Examples of regular patterns include dots, lines, stripes, lattice patterns, spiral patterns, concentric shapes, and frame patterns.

In a dot pattern, the dots may be in a variety of shapes, including, for example, a circle, an ellipse, a rectangle, a polygon, a cross, a Y-shape, a star, or a heart. The dot pattern may also be in the form of letters. For example, Figure 1(a) shows an example in which the pattern shape of the heat seal layer 3 in a planar view is a circular dot shape, while Figure 4 shows an example in which the pattern shape of the heat seal layer 3 in a planar view is a dot shape, forming the letters "ABC."

In addition, in dot patterns, examples of dot arrangements include a square lattice arrangement, a rectangular lattice arrangement, a triangular lattice arrangement, a hexagonal lattice arrangement, a rhombic lattice arrangement, and a parallelogram lattice arrangement.

Examples of line or stripe patterns include straight lines; curved lines such as wavy lines of sine waves, triangular waves, rectangular waves, and sawtooth waves; and other patterns. For example, Figure 5(a) shows an example in which the pattern shape of the heat seal layer 3 in a plan view is a straight stripe shape. Note that Figure 5(b) is a cross-sectional view taken along line A-A in Figure 5(a).

Examples of lattice patterns include square lattice, rectangular lattice, triangular lattice, hexagonal lattice, rhombic lattice, and parallelogram lattice. For example, Figure 6(a) shows an example in which the pattern shape of the heat seal layer 3 in plan view is a square lattice. Note that Figure 6(b) is a cross-sectional view taken along line A-A in Figure 6(a).

Examples of concentric geometric patterns include concentric circles, concentric triangles, concentric squares, and concentric hexagons.

For example, Figure 3(a) shows an example in which the pattern shape of the heat seal layer 3 in plan view is frame-shaped.

Furthermore, when the heat seal layer has a dot-like pattern in plan view, the size of the dots in plan view may be, for example, 1 mm or more and 15 mm or less, and may be 3 mm or more and 8 mm or less. If the dot size is too small, the adhesion between the first base material layer and the second base material layer via the heat seal layer may be reduced, or formation may be difficult. If the dot size is too large, it may be difficult to peel the first base material layer and the heat seal layer from the laminate.

Here, the planar size of a dot refers to, for example, the diameter if the dot is circular, the major axis if the dot is elliptical, the length of the diagonal if the dot is rectangular, or the diameter of the circle or the diagonal of the rectangle when the dot is some other shape and is approximated to a circle or rectangle.

Furthermore, when the heat seal layer has a dotted pattern in plan view, the dot pitch can be, for example, 1.5 to less than 10 times the size of the dots in plan view. If the dot pitch is too small, formation may be difficult. If the dot pitch is too large, adhesion between the first base material layer and the second base material layer via the heat seal layer may decrease.

Here, dot pitch refers to the distance between adjacent dots.

When the heat seal layer has a line or stripe pattern in plan view, the line width is, for example, 1 mm or more and 15 mm or less, and may be 2 mm or more and 8 mm or less. If the line width is too small, the adhesion between the first base material layer and the second base material layer via the heat seal layer may be reduced, or formation may be difficult. Furthermore, if the line width is too large, it may be difficult to peel the first base material layer and the heat seal layer from the laminate.

Furthermore, when the heat seal layer has a striped pattern in plan view, the pitch of the stripes may be, for example, 1 mm or more and 20 mm or less, or 3 mm or more and 10 mm or less. If the stripe pitch is too small, formation may be difficult. If the stripe pitch is too large, adhesion between the first base material layer and the second base material layer via the heat seal layer may decrease.

Here, the stripe pitch refers to the distance between adjacent lines.

Furthermore, when the pattern shape of the heat seal layer in plan view is a grid, the line width may be, for example, 1 mm or more and 15 mm or less, or 2 mm or more and 8 mm or less. If the line width is too small, the adhesion between the first base material layer and the second base material layer via the heat seal layer may decrease, or formation may become difficult. If the line width is too large, it may become difficult to peel the first base material layer and the heat seal layer from the laminate.

Furthermore, when the heat seal layer has a grid-like pattern in plan view, the grid spacing may be, for example, 1 mm or more and 20 mm or less, or 3 mm or more and 10 mm or less. If the grid spacing is too small, it may be difficult to form. If the grid spacing is too large, the adhesion between the first base material layer and the second base material layer via the heat seal layer may decrease.

Furthermore, when the heat seal layer is locally arranged in a pattern on one surface of the first base material layer and is arranged on the periphery of the first base material layer, the width of the heat seal layer may be, for example, 1 mm to 15 mm, or 2 mm to 8 mm. If the line width is too small, the adhesion between the first base material layer and the second base material layer via the heat seal layer may be reduced, or formation may be difficult. Furthermore, if the width of the heat seal layer is too large, it may be difficult to peel the first base material layer and the heat seal layer from the laminate.

The dimensions of the heat seal layer can be measured by observing the surface of the laminate using a laser microscope, a stylus surface profiler, or a scanning electron microscope (SEM).

The thickness of the heat seal layer is, for example, 0.3 μm or more and 5.0 μm or less, or alternatively 0.5 μm or more and 4.0 μm or less, or 0.7 μm or more and 3.0 μm or less. If the heat seal layer is too thin, the adhesion between the first base layer and the second base layer via the heat seal layer may be reduced. Furthermore, if the heat seal layer is too thick, it may be difficult to peel the first base layer and the heat seal layer from the laminate.

The heat seal layer can be made from a heat seal agent commonly used in packaging applications. Examples of the main components of heat seal agents include ethylene-vinyl acetate copolymer (EVA), acrylic resin, vinyl chloride resin, polyester resin, ethylene-methacrylic acid copolymer, acid-modified polyolefin resin, chlorinated polyolefin resin, and styrene-butadiene copolymer. These may be used alone or in combination of two or more.

The heat seal layer may contain additives as needed. For example, if the heat seal layer contains a colorant, peeling the first base layer and heat seal layer from the laminate allows the design and color to be changed, and peeling of the first base layer and heat seal layer from the laminate can be visually confirmed. This can improve design and provide tamper-evident properties.

One method for forming the heat seal layer is to apply a heat sealant in a pattern to one surface of the first base material layer, and then thermally laminate the surface of the first base material layer to which the heat sealant has been applied and the second base material layer. Examples of methods for applying the heat sealant in a pattern include gravure printing, flexographic printing, offset printing, and screen printing.

2. First Base Material Layer The first base material layer in the present disclosure is a member that supports the heat seal layer.

The first substrate layer is not particularly limited as long as it is a substrate layer capable of supporting the heat seal layer, and examples include a resin substrate, a paper substrate, and a metal foil.

Among these, resin substrates are preferred. Because the first substrate layer is peeled off and removed, inexpensive resin substrates are preferably used. Resin substrates also have good processability for printing and lamination.

The resin substrate may be, for example, a stretched film or a non-stretched film. Stretched films are preferably used due to their good processability.

The resin that constitutes the resin substrate is not particularly limited, but examples include polyester-based resins such as polyethylene terephthalate; polyamide-based resins such as nylon; and polyolefin-based resins such as polypropylene.

When the first substrate layer is a resin substrate or a paper substrate, it may contain additives as needed. If the first substrate layer contains, for example, a colorant, the design or color can be changed by peeling the first substrate layer and heat seal layer from the laminate, and peeling of the first substrate layer and heat seal layer from the laminate can be visually confirmed. This can therefore improve design and impart tamper-evident properties.

The first substrate layer may be transparent or opaque.

The first substrate layer may be composed of a single layer, or may be composed of multiple layers.

The thickness of the first substrate layer can be similar to that of substrate layers generally used in flexible packaging, and can be selected appropriately depending on the type of first substrate layer, etc. The thickness of the first substrate layer can be, for example, 10 μm or more and 150 μm or less. If the thickness of the first substrate layer is within the above range, the first substrate layer can have sufficient strength and flexibility.

3. Second Base Layer The second base layer in the present disclosure is a member that supports the sealing layer.

The second substrate layer is not particularly limited as long as it is a substrate layer capable of supporting the sealing layer, and examples include a resin substrate, a paper substrate, and a metal foil.

The resin substrate may be, for example, a stretched film or a non-stretched film. Of these, stretched films are preferred due to their excellent mechanical and optical properties.

The resin substrate is not particularly limited, and resin substrates used in flexible packaging can be used. The resin that constitutes the resin substrate can be the same as that used for the first substrate layer described above.

The paper substrate is not particularly limited, and any paper substrate used in flexible packaging can be used. Examples of paper substrates include kraft paper, fine paper, glassine paper, rayon paper, coated paper, and barrier paper (paper that has been given barrier properties through coating or inorganic metal vapor deposition).

There are no particular limitations on the metal foil, and a paper substrate used in flexible packaging can be used. Examples of metals that can be used to make the metal foil include aluminum and aluminum alloys.

When the second substrate layer is a resin substrate or a paper substrate, it may contain additives as needed. If the second substrate layer contains, for example, a colorant, the design and color can be changed by peeling the first substrate layer and the heat seal layer from the laminate, thereby improving the design.

The second substrate layer may be transparent or opaque.

The second substrate layer may be composed of a single layer, or may be composed of multiple layers.

The thickness of the second substrate layer can be the same as that of substrate layers generally used in flexible packaging, and can be selected appropriately depending on the type of second substrate layer, etc. The thickness of the second substrate layer can be, for example, 6 μm or more and 150 μm or less. When the thickness of the second substrate layer is within the above range, the laminate has high mechanical strength, good hand-tearability and dead-holdability, and is flexible enough for use as a package.

4. Sealing Layer The sealing layer in the present disclosure is a member located on the outermost surface of the laminate opposite the first base layer, and serves as the innermost layer when a package is manufactured using the laminate.

The sealing layer may be, for example, a heat-seal type sealing layer, a hot-melt type sealing layer, a cold-seal type sealing layer, etc., and is selected appropriately depending on the intended use of the laminate.

Of these, heat-sealable sealing layers are preferred for their versatility.

(1) Heat-sealable seal layer The heat-sealable seal layer has heat-sealing properties that allow it to fuse with heat.

Examples of heat-sealable sealing layers include films containing thermoplastic resins. Specific examples include films containing polyolefin resins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, and ethylene-methacrylic acid copolymer.

Among these, polyethylene and polypropylene are preferably used.

Examples of polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE). Polyethylene may be a homopolymer or a copolymer in which part of the ethylene is replaced with another monomer.

Examples of polypropylene include homopolypropylene, random polypropylene, and block polypropylene. Polypropylene may be a homopolymer or a copolymer in which part of the propylene is replaced with another monomer.

Specifically, it is preferable to use unstretched polypropylene (CPP) or low-density polyethylene (LDPE) such as linear low-density polyethylene (LLDPE).

In addition, the heat-sealable seal layer can contain various additives during film formation to improve or modify the film's processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slip resistance, release properties, flame retardancy, mildew resistance, electrical properties, strength, and other properties. Common additives include crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, and the like. The amount of additives contained can be set appropriately depending on the purpose.

The heat-sealable sealing layer may be composed of a single layer, or may be composed of multiple layers.

The thickness of the heat-sealable sealing layer can be, for example, 15 μm or more and 200 μm or less.

Methods for producing a heat-sealable seal layer include, for example, extrusion molding, cast molding, T-die molding, cutting, inflation molding, etc., to produce a film using a single resin or a mixture of two or more resins, or multi-layer co-extrusion using two or more resins.

Methods for laminating a heat-sealable seal layer and a second base layer include, for example, laminating a heat-sealable seal layer onto one side of the second base layer via an adhesive layer (described below), or laminating a heat-sealable seal layer onto one side of the second base layer without an adhesive layer. Examples of lamination methods using an adhesive layer include dry lamination, solventless lamination, and extrusion lamination (sand lamination). Examples of lamination methods not using an adhesive layer include extrusion lamination.

(2) Hot-melt type sealing layer The hot-melt type sealing layer is a sealing layer made of a hot-melt adhesive.

When the laminate of this disclosure is used for a label, a hot-melt type seal layer is preferably used.

Hot melt adhesives are adhesives containing thermoplastic resins that are solid at room temperature (23°C), liquefied by heating and melting, applied, and solidified by cooling to exert their adhesive properties. Hot melt adhesives contain thermoplastic resins as their main component, optionally blended with additives, and are 100% solids, containing no solvents.

Examples of hot melt adhesives include ethylene-vinyl acetate copolymer (EVA)-based hot melt adhesives, olefin-based hot melt adhesives, rubber-based hot melt adhesives, polyester-based hot melt adhesives, polyamide-based hot melt adhesives, and polyurethane-based hot melt adhesives.

Hot melt adhesives can contain any additives. Examples of additives include waxes, tackifiers, plasticizers, stabilizers, antioxidants, UV absorbers, antistatic agents, colorants, inorganic fillers, flame retardants, lubricants, reinforcing materials, processing aids, slip agents, anti-blocking agents, and release agents. The amount of additives contained can be set appropriately depending on the purpose.

The thickness of the hot melt seal layer is, for example, 1 μm or more and 20 μm or less, and may be 5 μm or more and 10 μm or less. If the hot melt seal layer is too thin, the dead hold properties may be impaired. Furthermore, if the hot melt seal layer is too thick, manufacturing and processing may become difficult or the costs may increase.

One method for forming a hot-melt seal layer is to apply a hot-melt adhesive to one surface of the second base layer by heating and melting it to form a liquid.

(3) Cold-seal-type sealing layer The cold-seal-type sealing layer is a sealing layer made of a cold-sealing agent.

The cold seal type sealing layer does not exhibit adhesiveness, but can be bonded by placing two cold seal type sealing layers face to face and applying pressure. No heating is required.

Examples of the main component of cold seal agents include rubber latex.

The cold sealant may contain optional additives as needed.

The thickness of the cold seal type sealing layer is, for example, 1 μm or more and 20 μm or less, and may be 5 μm or more and 10 μm or less.

One method for forming a cold seal type sealing layer is to apply a cold seal agent to one surface of the second base material layer.

5. Adhesive Layer In the laminate of the present disclosure, an adhesive layer 5 can be disposed between the second base material layer 4 and the seal layer 6, as shown in FIG. 1(b), for example.

Examples of materials for the adhesive layer include adhesives and sand lamination resins.

General laminating adhesives can be used as the adhesive that makes up the adhesive layer, including, for example, ester-based adhesives, ether-based adhesives, and urethane-based adhesives.

Sand lamination resins include, for example, low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). Among these, low-density polyethylene (LDPE) is preferred due to its versatility and processability.

The thickness of the adhesive layer is selected appropriately depending on the material of the adhesive layer, etc. In the case of an adhesive layer using an adhesive, the thickness of the adhesive layer is, for example, 1 μm to 6 μm, or may be 2 μm to 5 μm. In the case of an adhesive layer using a sand lamination resin, the thickness of the adhesive layer is, for example, 5 μm to 30 μm, or may be 10 μm to 20 μm.

6. First Printed Layer The laminate of the present disclosure preferably has a first printed layer between the first base layer and the heat seal layer, or on the surface of the first base layer opposite the heat seal layer. The presence of the first printed layer allows visual confirmation of the peeling of the first base layer, the first printed layer, and the heat seal layer from the laminate, thereby providing tamper-evident properties. This allows the virginity of the package to be easily and reliably confirmed when the laminate is used in a package. Furthermore, when the first printed layer is present, the design and color can be changed by peeling the first base layer, the first printed layer, and the heat seal layer from the laminate, thereby improving the design.

The first printed layer is a layer on which information, pictures, etc. are printed. When the laminate is used for packaging or labels, information printed on the first printed layer may include, for example, a diagram of the contents, the product name of the contents, a manufacturing number, ingredient labeling, identification markings, barcodes, etc. When the laminate is used for food packaging or labels, information such as the expiration date of the contents and the date of manufacture may also be included. Examples of pictures printed on the first printed layer include figures, patterns, letters, symbols, designs, marks, etc.

When the laminate of the present disclosure has a second printed layer (described below) in addition to the first printed layer, it is preferable that the information, design, etc. printed on the first printed layer be different from the information, design, etc. printed on the second printed layer. This can improve design and tamper-evident properties.

The first printed layer 7a may be disposed between the first base material layer 2 and the heat seal layer 3, as shown in FIG. 7(a), for example, or, although not shown, may be disposed on the surface of the first base material layer opposite the heat seal layer. When the first printed layer is disposed between the first base material layer and the heat seal layer, the first printed layer can be protected by the first base material layer, preventing the information and image on the first printed layer from being lost due to rubbing, etc., and preventing the information and image on the first printed layer from being tampered with.

The first printing layer may contain a colorant and a binder resin.

Pigments and dyes can be used as colorants. The colorant may be one type or two or more types. The content of the colorant in the first printed layer is, for example, 5% by mass or more and 70% by mass or less, 15% by mass or more and 60% by mass or less, or 20% by mass or more and 60% by mass or less.

The binder resin can be the same as that used in general film laminating inks.

The first printing layer may contain any additives as needed. Examples of additives include fillers, stabilizers, plasticizers, antioxidants, UV absorbers, light stabilizers, dispersants, thickeners, desiccants, lubricants, antistatic agents, and crosslinking agents.

One method for forming the first printed layer is to print ink on one surface of the first base layer. Examples of printing methods include gravure printing, flexographic printing, digital printing, offset printing, screen printing, and inkjet printing.

Inks typically contain a colorant, a binder resin, and a solvent. Solvents commonly used in inks can be used. A single solvent may be used, or two or more solvents may be used in combination.

The thickness of the first printing layer is not particularly limited and may be, for example, 1 μm or more and 5 μm or less, or 1 μm or more and 3 μm or less.

7. Second Printed Layer The laminate of the present disclosure may have a second printed layer between the second base material layer and the heat seal layer, or between the second base material layer and the seal layer. When the laminate is used for packaging, labels, etc., the presence of the second printed layer makes it possible to check information about the contents even after peeling the first base material layer and the heat seal layer from the laminate.

The second printing layer is a layer on which information, images, etc. are printed. The information and images can be the same as the information and images printed on the first printing layer.

The second printed layer may be disposed between the second substrate layer and the heat seal layer, or between the second substrate layer and the seal layer. When the second printed layer is disposed between the second substrate layer and the heat seal layer, the placement of the second printed layer between the second substrate layer and the seal layer can prevent a decrease in the laminate strength between the second substrate layer and the seal layer. On the other hand, when the second printed layer is disposed between the second substrate layer and the seal layer, damage to the adherend can be prevented when the first substrate layer and the heat seal layer are peeled from the laminate.

When the second printed layer is disposed between the second base material layer and the sealing layer, and an adhesive layer is disposed between the second base material layer and the sealing layer, the second printed layer 7b is disposed between the second base material layer 4 and the adhesive layer 5, as shown in Figure 7(b), for example.

The material, thickness, and formation method of the second printed layer can be the same as those of the first printed layer.

The laminate of the present disclosure may have, as the printed layer, only the first printed layer 7a, as shown in FIG. 7(a), or only the second printed layer 7b, as shown in FIG. 7(b), or may have both the first printed layer 7a and the second printed layer 7b, as shown in FIG. 7(c).

8. First Protective Layer In the present disclosure, when the first printed layer is disposed on the surface of the first base layer opposite to the heat seal layer, a first protective layer may be disposed on the surface of the first printed layer opposite to the first base layer.

The first protective layer is a member that protects the first printed layer. The presence of the first protective layer prevents the information and image on the first printed layer from being lost due to rubbing, etc., and also prevents the information and image on the first printed layer from being tampered with.

Examples of materials for the first protective layer include overprint varnish (OP varnish).

One method for forming the first protective layer is to print OP varnish on the first printed layer.

9. Second Protective Layer In the present disclosure, when the second printed layer is disposed between the second base material layer and the heat seal layer, a second protective layer may be disposed between the second printed layer and the heat seal layer.

The second protective layer is a member that protects the second printed layer. The presence of the second protective layer prevents the information or image on the second printed layer from being lost due to rubbing or the like after the first base material layer and heat seal layer are peeled from the laminate, and also prevents the second printed layer from being damaged or peeled off, i.e., the adherend from being damaged, when the first base material layer and heat seal layer are peeled from the laminate.

Examples of materials for the second protective layer include overprint varnish (OP varnish).

One method for forming the second protective layer is to print OP varnish on the second printed layer.

10. Barrier Layer The laminate according to the present disclosure may have a barrier layer 8 at any position between the heat seal layer 3 and the seal layer 6, as shown in Figures 8(a) and 8(b), for example. By providing the barrier layer, it is possible to impart barrier properties to the laminate.

Examples of materials for the barrier layer include metals, inorganic oxides, organic-inorganic composite materials, and organic materials.

Examples of metals include aluminum, magnesium, tin, sodium, titanium, lead, zirconium, yttrium, gold, chromium, and alloys thereof. Among these, aluminum or its alloys are preferred when the laminate is used as a packaging material. The metal-containing barrier layer may be, for example, a metal film such as a vapor-deposited film, or a metal foil.

Examples of inorganic oxides include aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, tin oxide, sodium oxide, titanium oxide, lead oxide, zirconium oxide, yttrium oxide, and silicon oxide. Among these, aluminum oxide is preferably used when the laminate is used as a packaging material.

Examples of organic materials include ethylene-vinyl alcohol copolymer and polyvinylidene chloride resin.

An example of an organic-inorganic composite material is a material containing a condensate of a hydrolyzed metal alkoxide and a water-soluble resin. Examples of metal alkoxides include silicon alkoxide, zirconium alkoxide, titanium alkoxide, and aluminum alkoxide. Examples of water-soluble resins include polyvinyl alcohol resin and ethylene-vinyl alcohol copolymer. Such organic-inorganic composite materials can be formed using the sol-gel method.

The barrier layer may be located anywhere between the heat seal layer and the sealing layer, such as between the heat seal layer and the second base material layer, or between the second base material layer and the sealing layer. When the barrier layer is located between the heat seal layer and the second base material layer and a second printed layer is located between the heat seal layer and the second base material layer, the barrier layer may be located between the heat seal layer and the second printed layer, or between the second printed layer and the second base material layer. When the barrier layer is located between the second base material layer and the sealing layer and a second printed layer is located between the second base material layer and the sealing layer, the barrier layer may be located between the second base material layer and the second printed layer, or between the second printed layer and the sealing layer.

When the barrier layer is disposed in contact with the sealing layer, the surface of the sealing layer on which the barrier layer is disposed can be subjected to a surface treatment, if necessary. Examples of surface treatments include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, and glow discharge treatment, as well as chemical treatments such as oxidation treatment using chemicals.

Furthermore, if a barrier layer is disposed between the second substrate layer and the seal layer, an anchor layer may be disposed between the barrier layer and the seal layer to improve adhesion between the barrier layer and the seal layer.

The thickness of the barrier layer is selected appropriately depending on the material, etc. The thickness of the barrier layer is, for example, 5 nm or more and 200 nm or less, and may be 10 nm or more and 100 nm or less.

The method for forming the barrier layer is appropriately selected depending on the material of the barrier layer, and examples include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. The barrier layer may also be formed by applying the above-mentioned material to the first substrate layer, second substrate layer, or sealing layer. When the barrier layer is, for example, a metal foil, the barrier layer may be disposed on the first substrate layer, second substrate layer, or sealing layer via an adhesive layer.

11. Second Barrier Layer The laminate according to the present disclosure may have a second barrier layer between the first base material layer and the heat seal layer, or on the surface of the first base material layer opposite to the heat seal layer.

The second barrier layer can be the same as the barrier layer described above.

12. Peel Strength In the laminate of the present disclosure, the peel strength when peeled between the first base layer and the second base layer is, for example, preferably 0.1 N/15 mm or more, more preferably 0.5 N/15 mm or more. Furthermore, the peel strength is, for example, preferably 3.5 N/15 mm or less, more preferably 3.0 N/15 mm or less, even more preferably 2.5 N/15 mm or less, particularly preferably 2.0 N/15 mm or less, and most preferably 1.5 N/15 mm or less. Specifically, the peel strength is preferably 0.1 N/15 mm or more and 3.5 N/15 mm or less, more preferably 0.5 N/15 mm or more and 3.5 N/15 mm or less, even more preferably 0.5 N/15 mm or more and 2.5 N/15 mm or less, particularly preferably 0.5 N/15 mm or more and 2.0 N/15 mm or less, and most preferably 0.5 N/15 mm or more and 1.5 N/15 mm or less. When the peel strength is within the above range, the first base layer and the heat seal layer can be easily peeled from the laminate.

The peel strength between the first and second base layers of the laminate can be measured in accordance with JIS Z1707:1997, Section 7.4 (Heat Seal Strength Test). Specifically, ten 15 mm wide rectangular test pieces are cut from the laminate with the machine direction as the longitudinal direction. Next, the first and second base layers of the ten test pieces are each gripped with the gripping tools of a tensile tester, opened 180°, and pulled at a tensile speed of 50 mm/min to obtain a T-shaped peel, at which the maximum force (N) is measured. The measurement conditions are a temperature of 25°C and a relative humidity of 50%. A Tensilon STA-115 manufactured by A&D Corporation, for example, can be used as the tensile tester.

13. Uses Uses of the laminate according to the present disclosure include, for example, packaging, labels, and the like.

When the laminate of the present disclosure is used in a package, the first base material layer and heat seal layer can be peeled off from the laminate, ensuring the virginity of the package. Therefore, for example, after obtaining a package filled with contents, the first base material layer and heat seal layer can be peeled off from the laminate that makes up the package and discarded, allowing the package to be stored and used hygienically and safely.

Packaging using the laminate in this disclosure will be described later.

Furthermore, when the laminate of the present disclosure is used for a label, the label can be adhered to, for example, a plastic bottle, a plastic cup, a metal can, a glass bottle, etc.

B. Package The package of the present disclosure has the laminate described above.

Figures 9(a) and (b) are a schematic plan view and a cross-sectional view showing an example of a package according to the present disclosure, and Figure 9(b) is a cross-sectional view taken along line B-B in Figure 9(a). As shown in Figures 9(a) and (b), the package 10 has two laminates 1 arranged with their sealing layers 6 facing each other, with a seal portion 11 formed at the periphery where the sealing layers 6 of the laminates 1 are bonded together. The configuration of the laminate 1 can be similar to the configuration of the laminate 1 illustrated in Figure 1 above. Furthermore, in Figures 9(a) and (b), the package 10 is a four-sided sealed bag and can have a cutout portion 12.

The heat seal layer 3 of the laminate 1 that constitutes the package 10 is easily peelable, so the first base material layer 2 and heat seal layer 3 can be peeled from the laminate 1, as shown in Figures 10(a) and 10(b), for example. Note that Figure 10(a) is a plan view of the laminate that constitutes the package when the first base material layer and part of the heat seal layer have been peeled off, and Figure 10(b) is a cross-sectional view of the laminate that constitutes the package when the entire first base material layer and heat seal layer have been peeled off.

In the present disclosure, a laminate constituting a package has a patterned heat seal layer with easy peelability disposed between the first base material layer and the second base material layer, allowing the first base material layer and the heat seal layer to be peeled from the laminate. Therefore, by peeling the first base material layer and the heat seal layer from the laminate constituting the package and discarding them, the hygiene of the surface of the package after peeling can be ensured. This ensures the virginity of the package. Furthermore, even if the first base material layer and the heat seal layer are peeled from the laminate, the second base material layer and the seal layer remain, allowing the package to fulfill its function. Therefore, for example, after obtaining a package filled with contents, the first base material layer and the heat seal layer can be peeled from the laminate constituting the package and discarded, allowing the package to be stored and used hygienically and safely.

Furthermore, in the present disclosure, when the first and second base material layers of the laminate constituting the packaging are made of different materials, the first and second base material layers can be separated by peeling the first and heat seal layers from the laminate. This improves environmental conservation, including recyclability and ease of separate disposal.

In addition, in the present disclosure, in a laminate constituting a packaging body, for example, when the first substrate layer and the second substrate layer are different colors, or when the first substrate layer or the heat seal layer contains a colorant, the design and color can be changed by peeling the first substrate layer and the heat seal layer from the laminate. Furthermore, even when the laminate has a first printed layer disposed between the first substrate layer and the heat seal layer or on the surface of the first substrate layer opposite the heat seal layer, or a second printed layer disposed between the second substrate layer and the heat seal layer or between the second substrate layer and the seal layer, the design and color can be changed by peeling the first substrate layer and the heat seal layer from the laminate. This allows for improved design.

The configuration of the packaging body in this disclosure is described below.

The packaging may have a seal around the periphery where the sealing layers of the laminate are bonded together, or where the sealing layer of the laminate is bonded to another layer. The position of the seal can be selected appropriately depending on the shape of the packaging, the bag-making method, etc.

The form of the packaging is not particularly limited, and examples include two-sided sealed bags, three-sided sealed bags, four-sided sealed bags, pillow bags (with seams or envelopes), stick bags, gusset bags, stand-up bags, zip-top bags, laminated tubes, and lids.

Examples of bag-making methods include overlapping two laminates with their sealing layers facing each other and sealing the edges, folding one laminate with the sealing layer facing inward and sealing the edges, and sealing the laminate to create a cylindrical body, and then sealing the cylindrical body to a base made of another laminate or other material.

The sealing method is selected appropriately depending on the type of sealing layer. In the case of a heat-sealed sealing layer or a hot-melt sealing layer, examples of the sealing method include heat sealing such as hot plate sealing, band sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing. In the case of a cold-sealed sealing layer, examples of the sealing method include applying pressure at room temperature.

In the case of heat-sealable or hot-melt-type sealing layers, heat is also applied to the heat-sealable layer of the laminate during sealing, but this heating does not usually increase the adhesive strength of the heat-sealable layer.

The laminate that makes up the packaging body has been described in detail above in "A. Laminate," so further explanation will be omitted here.

As described above, the heat seal layer of the laminate needs only to be arranged in a pattern on one surface of the first base layer, and may be arranged in a pattern over the entire surface of the first base layer, or may be arranged in a localized pattern.

In particular, as mentioned above, it is preferable that the heat seal layer be arranged in a pattern over the entire surface of one side of the first base layer.

Furthermore, when the heat seal layer is locally arranged in a pattern on one surface of the first base layer, it is preferably arranged on the peripheral edge of the first base layer, as described above. In this case, when the laminate has a rectangular shape in plan view, the heat seal layer is preferably arranged on the peripheral edge of, for example, three or four sides of the first base layer, and more preferably on the peripheral edge of four sides of the first base layer.

Furthermore, when the heat seal layer is locally arranged in a pattern on one surface of the first base layer, it is preferable that the heat seal layer be arranged continuously, as described above.

Furthermore, when the heat seal layer is locally arranged in a pattern on one surface of the first base material layer, it is preferable that the heat seal layer be arranged in the sealed portion where the seal layers of the laminate are bonded together. By arranging the heat seal layer in the sealed portion and not in areas other than the sealed portion, the heat seal layer can be made less noticeable.

For example, in Figures 11(a) and (b), the heat seal layer 3 is continuously disposed around the four peripheral edges of the first base layer 2. The heat seal layer 3 is also disposed in the sealed portion 11. Note that Figure 11(b) is a cross-sectional view taken along line B-B in Figure 11(a).

The laminate constituting the package can have a tab portion on one side of the first base material layer where no heat seal layer is disposed. By having a tab portion on the package, the first base material layer and heat seal layer can be easily peeled off by grasping the tab portion when peeling them off from the laminate.

The tab portion is an area on one side of the first base material layer where no heat seal layer is located. The position of the tab portion is selected appropriately depending on the shape of the package, etc. If the tab portion is located in the seal portion, for example, the seal portion will become thicker and more rigid, making it easier to peel.

For example, if the package is a pillow bag, the tab 13 can be located in part of the seal. Specifically, as shown in Figures 12(a) and (b), the tab 13 can be located near the area where the top seal 11a and the seam seal 11c overlap, and near the area where the bottom seal 11b and the seam seal 11c overlap; as shown in Figures 13(a) and (b), the tab 13 can be located over the entire top seal 11a and the entire bottom seal 11b; or as shown in Figures 14(a) and (b), the tab 13 can be located near the center of the seam seal 11c. Note that Figures 12(a), 13(a), and 14(a) are plan views of the pillow bag from the side opposite the seam seal, while Figures 12(b), 13(b), and 14(b) are plan views of the pillow bag from the side facing the seam seal.

Furthermore, for example, if the package is a four-sided sealed bag, the tabs may be located on the periphery of the package, or if the package has a tear line at the top, they may be located near the tear line. Specifically, as shown in Figures 15(a), (b), and (c), the tabs 13 may be located at the corners of the package 10. In this case, the tabs 13 may be located only in the sealed portion 11 as shown in Figure 15(a), or may be located not only in the sealed portion 11 but also in areas other than the sealed portion 11 as shown in Figure 15(b). In this case, the tabs 13 may be located at one corner of the package 10 as shown in Figures 15(a) and (b), or at two corners of the package 10 as shown in Figure 15(c). Furthermore, if the package 10 has a tear line 15, the tabs 13 may be located near the tear line 15 as shown in Figure 15(d). In this case, the package 10 can be cut along the cut line 15 to allow the grip portion 13 to be grasped. In Figure 15(d), the package 10 has a zipper 14.

Furthermore, for example, if the package is a four-sided sealed bag and heat seal layers are arranged around the three edges of the first base material layer (not shown), the first base material layer and heat seal layer can be easily peeled off from the laminate by grasping one edge of the first base material layer where the heat seal layer is not arranged.

Furthermore, for example, if the package is a stand-up bag (stand-up pouch), the tabs can be located at the upper or side edges of the package. Specifically, the tabs 13 may be located at corners of the upper edge of the package 10 as shown in Figures 16(a) and (b), or at corners and side edges of the upper edge as shown in Figure 16(c). In this case, although not shown, the tabs may be located only in the sealed area, or may be located in areas other than the sealed area as well as the sealed area. Furthermore, in this case, the tabs 13 may be located at one corner of the upper edge of the package 10 as shown in Figure 16(a), or at two corners of the upper edge of the package 10 as shown in Figure 16(b).

Furthermore, for example, if the packaging body is a stand-up bag (stand-up pouch) and the heat seal layer 3 is arranged around the three edges of the first base material layer 2 as shown in Figure 17, the first base material layer 2 and the heat seal layer 3 can be easily peeled off from the laminate 1 by grasping one edge of the first base material layer 2 on which the heat seal layer 3 is not arranged.

The packaging may have, for example, at least one of a cutout, a tear line, a zipper, a spout, etc.

For example, if the packaging is a stand-up bag (stand-up pouch), as shown in Figure 18, part of the seal portion 11 may be a modified seal portion 11d that serves as a spout.

The contents to be filled into the package are not particularly limited, and examples include food, toiletries, cosmetics, pharmaceuticals, and quasi-drugs. The contents may be in the form of, for example, solids, liquids, pastes, powders, granules, tablets, capsules, etc.

The packaging may be filled with contents, or may be in a state before contents are filled inside.

Among these, packaging that can be stored in its original packaging for a certain period of time after receiving the package filled with the contents, or that can be used in its original packaging, is preferred.

Note that this disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical concept described in the claims of this disclosure and that provides similar effects is encompassed within the technical scope of this disclosure.

The following examples further illustrate this disclosure.

[Example 1]
The first base layer was a 15 μm thick biaxially oriented nylon film (ON, manufactured by Unitika Ltd.), the second base layer and barrier layer were a 12 μm thick aluminum-deposited PET film (1310, manufactured by Toray Advanced Film Co., Ltd.), the heat-seal type seal layer was a 100 μm thick polyethylene film (LLDPE, HR-543, manufactured by Sky Films Co., Ltd.), and the heat-sealing agent was Seikadyne BP-1910W, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

First, a first printed layer was formed on the first substrate layer. Next, a heat-sealing agent was applied in the form of dots on the first printed layer at a coating weight of 1.1 g/ ^m2 . The dots were circular, with a diameter of 5 mm and a dot pitch of 10 mm. Next, the surface to which the heat-sealing agent was applied was heat-laminated to the surface of the second substrate layer of the barrier layer-attached second substrate layer, thereby bonding the surface of the first printed layer of the first substrate layer to the surface of the second substrate layer of the barrier layer-attached second substrate layer via the heat-sealing layer. Next, a heat-sealing type seal layer was dry-laminated to the surface of the barrier layer-attached second substrate layer via an adhesive. This resulted in a laminate.

[Example 2]
A laminate was produced in the same manner as in Example 1, except that the coating amount of the heat sealing agent was 3.0 g/m ² .

[Example 3]
The first base layer was a 12 μm thick PET film (E5102, manufactured by Toyobo Co., Ltd.), the second base layer was a 12 μm thick biaxially oriented nylon film (ONBC, manufactured by Unitika Ltd.), the barrier layer was a 7 μm thick aluminum foil (8079 material, manufactured by Toyo Aluminum K.K.), the heat seal type seal layer was an 80 μm thick polyethylene film (LLDPE, TUX-MC-S, manufactured by Mitsui Chemicals Tocello Inc.), and the heat seal agent was Seikadyne BP-1910W, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

First, a first printed layer was formed on the first substrate layer. Next, a heat-sealing agent was applied in dots on the first printed layer at a coating weight of 1.1 g/ ^m2 . The dots were circular, with a diameter of 5 mm and a dot pitch of 10 mm. Next, the surface coated with the heat-sealing agent was heat-laminated to the second substrate layer, and the surface of the first substrate layer facing the first printed layer was bonded to the second substrate layer via the heat-sealing layer. Next, aluminum foil and a heat-sealing seal layer were dry-laminated onto the second substrate layer via an adhesive. This resulted in a laminate.

[Example 4]
A laminate was produced in the same manner as in Example 3, except that the coating amount of the heat sealing agent was 3.0 g/m ² .

[Example 5]
The first base layer was a 20 μm thick biaxially oriented polypropylene film (P2161, manufactured by Toyobo Co., Ltd.), the second base layer and barrier layer were a 12 μm thick aluminum-deposited PET film (1310, manufactured by Toray Advanced Film Co., Ltd.), the heat-sealable seal layer was a 30 μm thick unstretched polypropylene film (CPP, GLC, manufactured by Mitsui Chemicals Tocello Inc.), and the heat-sealing agent was Seikadyne BP-1910W, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

First, a first printed layer was formed on the first substrate layer. Next, a heat-sealing agent was applied in dots on the first printed layer at a coating weight of 1.1 g/ ^m2 to form a heat-sealing layer. The dots were circular, with a diameter of 5 mm and a dot pitch of 10 mm. Next, the surface coated with the heat-sealing agent was heat-laminated to the surface of the second substrate layer of the barrier layer-attached second substrate layer, bonding the surface of the first printed layer of the first substrate layer to the surface of the second substrate layer of the barrier layer-attached second substrate layer via the heat-sealing layer. Next, a heat-sealing type seal layer was dry-laminated to the surface of the barrier layer-attached second substrate layer via an adhesive. This resulted in a laminate.

[Example 6]
A laminate was produced in the same manner as in Example 5, except that the coating amount of the heat sealing agent was 3.0 g/ ^m2 .

[Comparative Example 1]
A laminate was produced in the same manner as in Example 1, except that a heat sealing agent was applied to the entire surface of the first printed layer at a coating amount of 4.0 g/m ² .

[Comparative Example 2]
A laminate was produced in the same manner as in Example 3, except that a heat sealing agent was applied to the entire surface of the first printed layer at a coating amount of 4.0 g/ ^m2 .

[Comparative Example 3]
A laminate was produced in the same manner as in Example 5, except that a heat sealing agent was applied to the entire surface of the first printed layer at a coating amount of 4.0 g/ ^m2 .

[evaluation]
The laminate was measured for peel strength when peeled between the first base material layer and the second base material layer in accordance with JIS Z1707:1997 7.4 (heat seal strength test). Specifically, first, 10 strip-shaped test pieces 15 mm wide were cut out from the laminate with the MD direction as the longitudinal direction. Next, the first base material layer and the second base material layer of the 10 test pieces were each gripped with the gripping tool of a tensile tester, opened 180°, and pulled at a tensile speed of 50 mm/min, and the maximum force (N) when T-peel was measured. The measurement environment was a temperature of 25 ° C and a relative humidity of 50%. A Tensilon STA-115 manufactured by A&D Corporation was used as the tensile tester.

Furthermore, in the laminate, the peelability when the first base material layer and the second base material layer were peeled off was evaluated by sensory evaluation and evaluated according to the following criteria.
A: The peeling feeling is good.
B: Peel resistance is high but peeling is possible.
C: Peel resistance is high and peeling is difficult.

REFERENCE SIGNS LIST 1 laminate 2 first base material layer 3 heat seal layer 4 second base material layer 5 adhesive layer 6 seal layer 10 package

Claims (6)

A laminate for use in packaging,
The laminate has, in this order, a first base material layer, a patterned heat seal layer having easy peelability, a second base material layer, and a seal layer;
When the first base material layer and the heat seal layer are peeled from the package, the second base material layer and the seal layer function as packaging materials ,
The laminate has a barrier layer at any position between the heat seal layer and the seal layer . The laminate of claim 1, wherein the heat seal layer contains at least one of ethylene-vinyl acetate copolymer (EVA), acrylic resin, vinyl chloride resin, polyester resin, ethylene-methacrylic acid copolymer, acid-modified polyolefin resin, chlorinated polyolefin resin, and styrene-butadiene copolymer as a heat seal agent. The laminate according to claim 1 or 2, wherein the peel strength when the first substrate layer and the second substrate layer are peeled off is 0.1 N/15 mm or more and 3.5 N/15 mm or less. The laminate described in any one of claims 1 to 3, having a first printed layer between the first base layer and the heat seal layer or on the surface of the first base layer opposite the heat seal layer. The laminate described in any one of claims 1 to 4, further comprising a second printed layer between the second base material layer and the heat seal layer, or between the second base material layer and the seal layer. A package comprising the laminate according to any one of claims 1 to 5 .