Laminate film, packaging material, packaging bag, and method for manufacturing laminate film

Abstract

To provide a laminate film which has strength to endure practical uses, and can improve recyclability.SOLUTION: A laminate film 10 includes an aluminum vapor-deposited resin film 14 having a first film 12, a first surface 14A and a second surface 14B opposite to the first surface 14A, and a second film 16 in this order, wherein the aluminum vapor-deposited resin film 14 has an aluminum vapor-deposited layer 141 on the first surface 14A, the first film 12 is laminated on the side of the first surface 14A, the second film 16 is laminated on the side of the second surface 14B, and the first film 12, the aluminum vapor-deposited resin film 14 and the second film 16 contain a polypropylene-based resin as a main component.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminated film, a packaging material, a packaging bag, and a method for producing the laminated film. [Background technology]

[0002] 2. Description of the Related Art Laminated films, as well as packaging materials and packaging bags made from such laminated films, are used for the purpose of protecting or transporting products such as food, beverages, medicines, cosmetics, industrial materials, and electronic components. As the resin constituting the laminated film, polyester resin and polyolefin resin are widely used. For example, Patent Document 1 discloses a packaging bag for heating in a microwave oven, which is formed from a laminated film having a base layer made of a polyethylene terephthalate film having a barrier layer of an oxide vapor deposition film, a first intermediate layer made of a polyethylene terephthalate film laminated on the inner side of the base layer, a second intermediate layer made of a polyethylene terephthalate film laminated on the inner side of the first intermediate layer, and a heat adhesive resin layer made of a polyolefin film laminated on the inner side of the second intermediate layer, and which is characterized in that the first intermediate layer or the second intermediate layer has straight-line tearability at least at the opening location. Furthermore, Patent Document 2 describes a barrier laminate film comprising an unstretched polyolefin resin film, a gas barrier coating film provided on the unstretched polyolefin resin film, and an aluminum vapor deposition layer provided on the gas barrier coating film, characterized in that the gas barrier coating film contains polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, and at least one or more types of alkoxide hydrolysate or alkoxide hydrolyzate condensate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-134599 A [Patent Document 2] JP 2017-052282 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, from the viewpoint of environmental conservation in recent years, there is a demand for recycling packaging materials and packaging bags. However, since packaging materials and packages are usually made of laminated films in which different types of resin films are bonded together, there is a problem that it is difficult to recycle them as mono-material packaging materials. An object of the present invention is to provide a laminated film that has a strength sufficient for practical use and can improve recyclability, a packaging material using the laminated film, a packaging bag made from the laminated film, and a method for manufacturing the laminated film. [Means for solving the problem]

[0005] [1] A laminate film comprising, in this order, a first film, an aluminum-vapor-deposited resin film having a first surface and a second surface opposite to the first surface, and a second film, wherein the aluminum-vapor-deposited resin film has an aluminum-vapor-deposited layer on the first surface, the first film being laminated on the side of the first surface and the second film being laminated on the side of the second surface, and the first film, the aluminum-vapor-deposited resin film, and the second film each containing a polypropylene-based resin as a main component.

[0006] [2] The laminated film according to [1] above, wherein the first film contains the polypropylene-based resin in an amount of 70% by mass or more relative to the entire first film, the aluminum-vapor-deposited resin film contains the polypropylene-based resin in an amount of 70% by mass or more relative to the entire aluminum-vapor-deposited resin film, and the second film contains the polypropylene-based resin in an amount of 70% by mass or more relative to the entire second film.

[0007] [3] The laminated film according to [1] or [2], wherein the first film contains the polypropylene-based resin in an amount of 90% by mass or more relative to the entire first film, the aluminum-vapor-deposited resin film contains the polypropylene-based resin in an amount of 90% by mass or more relative to the entire aluminum-vapor-deposited resin film, and the second film contains the polypropylene-based resin in an amount of 90% by mass or more relative to the entire second film.

[0008] [4] The laminate film according to any one of [1] to [3], wherein the first film contains the polypropylene-based resin in an amount of 95% by mass or more relative to the entire first film, the aluminum-vapor-deposited resin film contains the polypropylene-based resin in an amount of 95% by mass or more relative to the entire aluminum-vapor-deposited resin film, and the second film contains the polypropylene-based resin in an amount of 95% by mass or more relative to the entire second film.

[0009] [5] The laminate film according to any one of [1] to [4], wherein the aluminum vapor-deposited resin film is composed of an aluminum vapor-deposited layer having the first surface and a vapor-deposited base film having the second surface, the first film being a stretched polypropylene-based resin film, the vapor-deposited base film being a stretched polypropylene-based resin film, and the second film being a non-stretched polypropylene-based resin film.

[0010] [6] The laminate film according to any one of [1] to [5] above, having a first adhesive layer between the first film and the aluminum-vapor-deposited resin film, and having a second adhesive layer between the second film and the aluminum-vapor-deposited resin film. [7] The laminate film according to any one of [1] to [6] above, wherein a heat seal strength is 15.0 N / 15 mm or more when a peel test is conducted using a test piece obtained by placing the second films of the laminate film opposite each other and heat welding them. [8] The laminated film according to any one of [1] to [7] above, wherein the peel strength between the first film and the aluminum-vapor-deposited resin film is 0.6 N / 15 mm or more. [9] The laminated film according to any one of [1] to [8] above, wherein the peel strength between the second film and the aluminum-vapor-deposited resin film is 0.8 N / 15 mm or more.

[10] In the laminated film according to any one of [1] to [9], the second film has a zipper portion. Laminated film.

[11] The laminated film according to

[10] above, wherein the zipper portion contains a polypropylene-based resin as a main component.

[12] The laminate film according to

[10] or

[11] above, wherein when a peel test is conducted using a zippered laminate film obtained by attaching a zipper to the second film, the heat seal strength of the zippered laminate film is 15 N / 15 mm or more.

[0011]

[13] A packaging material comprising the laminate film according to any one of [1] to

[12] above.

[14] A packaging bag made by forming the laminated film described in any one of [1] to

[12] above.

[15] The packaging bag according to

[14] above, which is a self-supporting packaging bag.

[0012]

[16] A method for manufacturing a laminated film comprising, in this order, a first film, an aluminum-vapor-deposited resin film having an aluminum-vapor-deposited layer on the first side, and a second film, the method comprising the steps of: preparing the aluminum-vapor-deposited resin film having an aluminum-vapor-deposited layer on the first side; bonding the first side of the aluminum-vapor-deposited resin film to the first film, and bonding the second side of the aluminum-vapor-deposited resin film to the second film, wherein the first film, the aluminum-vapor-deposited resin film, and the second film each contain a polypropylene-based resin as a main component.

[17] In the method for producing a laminated film described in

[16] above, the aluminum vapor-deposited resin film is composed of an aluminum vapor-deposited layer having the first side and a vapor-deposited base film having the second side, the first film is a stretched polypropylene-based resin film, the vapor-deposited base film is a stretched polypropylene-based resin film, and the second film is a non-stretched polypropylene-based resin film.

[18] The method for producing a laminated film according to

[16] or

[17] above, further comprising a step of attaching a zipper portion to the second film. Effect of the Invention

[0013] According to one aspect of the present invention, it is possible to provide a laminate film that has a strength sufficient for practical use and can improve recyclability, a packaging material using the laminate film, a packaging bag made from the laminate film, and a method for manufacturing the laminate film. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic cross-sectional view of a laminated film according to a first embodiment. [Diagram 2] FIG. 4 is a schematic cross-sectional view of a laminated film according to a second embodiment. [Diagram 3] FIG. 4 is a schematic cross-sectional view of a laminated film according to a third embodiment. [Figure 4] 13 is a schematic diagram of a packaging bag according to a fifth embodiment. FIG. [Figure 5A] 13 is a schematic diagram of a packaging bag according to a sixth embodiment. FIG. [Figure 5B] 5B is a schematic diagram of the packaging bag shown in FIG. 5A as viewed from the bottom side. [Figure 6] 13A to 13C are diagrams illustrating a method for manufacturing a laminated film according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] First Embodiment [Laminated film] FIG. 1 is a schematic cross-sectional view of a laminated film according to the first embodiment. The laminated film 10 of the first embodiment includes, in this order, a first film 12, an aluminum-vapor-deposited resin film 14 having a first surface 14A and a second surface 14B opposite the first surface 14A, and a second film 16. The aluminum-deposited resin film 14 has an aluminum-deposited layer 141 on a first surface 14A, with a first film 12 laminated on the first surface 14A side and a second film 16 laminated on the second surface 14B side. The first film 12, the aluminum-deposited resin film 14, and the second film 16 each contain a polypropylene-based resin as a main component. The aluminum-deposited resin film 14 is composed of an aluminum-deposited layer 141 having a first surface 14A, and a deposited base film 142 having a second surface 14B. The first surface 14A corresponds to the surface of the aluminum-deposited layer 141 (the side facing the first film 12), and the second surface 14B corresponds to the surface of the deposited base film 142 (the side facing the second film 16). The laminated film 10 is formed to a thickness suitable for forming packaging materials, packaging bags, and containers, specifically, for example, a thickness of 0.2 mm or more and 1.4 mm or less, but is not limited to this example.

[0016] In this specification, "containing a polypropylene-based resin as a main component" means that 50% by mass or more of the components forming each film is a polypropylene-based resin. The polypropylene resin will be described later.

[0017] Typically, in a laminated film in which a surface film and a sealing layer film are laminated, the sealing layer film is made of a material that is easily heat-melted and the surface film is made of a material that is not easily heat-melted (i.e., has excellent heat resistance), which makes it easier to heat-seal the sealing layer films together when the laminated film is made into a bag, thereby improving the heat seal strength. In light of the recent increase in recyclability, the inventors have discovered a laminate film that can ensure heat seal strength and also ensure lamination strength between each film, even when each film constituting the laminate film is made of the same type, i.e., when the thermal melting properties of each film are approximately the same. Specifically, the inventors have discovered a laminated film 10 having a first film 12, an aluminum-deposited resin film 14, and a second film 16 in this order, all of which contain a polypropylene-based resin as a main component. Here, being able to ensure the heat seal strength and the lamination strength between the films means that when the laminate film 10 is used as a packaging material and when the laminate film 10 is made into a packaging bag, it has a strength that can withstand practical use. Therefore, when the laminate film 10 according to this embodiment is made into a packaging bag, a self-supporting packaging bag can be easily obtained (see Figs. 4 and 5A). Furthermore, in the laminate film 10 according to this embodiment, the first film 12, the aluminum-vapor-deposited resin film 14, and the second film 16 all contain polypropylene-based resin as the main component, making the laminate film suitable for recycling as a mono-material packaging material. As described above, the laminated film 10 according to this embodiment has a strength sufficient for practical use and can improve recyclability.

[0018] In the laminate film 10 according to this embodiment, the second surface 14B of the aluminum-deposited resin film 14 is preferably subjected to a corona treatment. When corona treatment is applied to the second surface 14B of the aluminum-vapor-deposited resin film 14, functional groups such as carbonyl groups and carboxyl groups increase on the second surface 14B, thereby ensuring better laminate strength between the aluminum-vapor-deposited resin film 14 and the second film 16.

[0019] (Characteristics of the laminated film 10) The heat seal strength and lamination strength of the laminated film 10 according to this embodiment are preferably within the following ranges: Lamination strength is also called peel strength or interlayer peel strength.

[0020] (Heat seal strength) In this embodiment, a test piece obtained by opposing the second films of the laminated film to each other and heat welding them is used, and when a peel test is performed, the heat seal strength is preferably 15 N / 15 mm or more, more preferably 17 N / 15 mm or more, and even more preferably 19 N / 15 mm or more. The heat seal strength of "15N / 15mm or more" satisfies the requirement of "general packaging bags, etc., for which the mass of the contents is large and a relatively strong heat seal strength is required" in the intended use of JIS Z0238 (1998). In other words, the heat seal strength of "15N / 15mm or more" is a seal strength that is sufficiently durable for practical use.

[0021] The heat seal strength is measured by the following method in accordance with JIS K7127 (1999) under conditions of 23° C. and 50% relative humidity. First, prepare two laminated films. The laminated films are stacked so that the second films face each other, and heat sealed at 170°C, with a sealing pressure of 0.2 MPa and a sealing time of 1.0 seconds. After leaving it for 24 hours, cut out a rectangular test piece (15 mm wide x 50 mm long) from the stacked laminated films. The test piece is placed in a tensile tester (Shimadzu Corporation, product number: EZ-L), and one laminate film is peeled off from the test piece (two laminate films stacked together) at a peeling speed of 300 mm / min so that the second film surfaces (heat seal surfaces) form an angle of 180°. The peel strength at this time is defined as the "heat seal strength of the laminate film."

[0022] (Zipper heat seal strength) In this embodiment, when a peel test is conducted using a zippered laminate film obtained by attaching a zipper to the second film, the heat seal strength of the zippered laminate film is preferably 15 N / 15 mm or more, more preferably 17 N / 15 mm or more, and even more preferably 19 N / 15 mm or more.

[0023] The heat seal strength of the zipper laminate film is measured by the following method. The zipper used is made of a pair of male and female polypropylene members. First, two laminate films (each 15 mm wide x 150 mm long) are prepared. A male member is heat-sealed to the second film surface of one of the laminate films at 170°C, a sealing pressure of 0.2 MPa, and a sealing time of 1.0 second. A female member is heat-sealed to the second film surface of the other laminate film under the same conditions. After leaving each laminate film for 24 hours, the male member and female member are engaged to overlap the two laminate films, and this is used as a test specimen. The peel strength of the test piece is measured using a tensile tester (Shimadzu Corporation, product number: EZ-L), and this is defined as the "zipper heat seal strength."

[0024] (Lamination strength between each film (peel strength)) In this embodiment, the peel strength between the first film and the aluminum-deposited resin film is preferably 0.6 N / 15 mm or more, more preferably 1.5 N / 15 mm or more, and even more preferably 2.0 N / 15 mm or more. In this embodiment, the peel strength between the second film and the aluminum-deposited resin film is preferably 0.8 N / 15 mm or more, and more preferably 1.5 N / 15 mm or more. When the peel strength between the first film and the aluminum vapor-deposited resin film, and the peel strength between the second film and the aluminum vapor-deposited resin film are within the above ranges, it becomes easier to obtain packaging materials and packaging bags that are practical (preferably packaging bags that can stand up on their own).

[0025] The peel strength is measured by the following method in accordance with JIS K7127 (1999) under conditions of 23° C. and 50% relative humidity. First, a rectangular test piece (15 mm wide x 50 mm long) is cut out from the laminated film. The test piece is placed in a tensile tester (Shimadzu Corporation, product number: EZ-L), and the first film is peeled off from the laminated film at a peeling speed of 300 mm / min so that the laminated surfaces of the first film and the aluminum-deposited resin film form an angle of 180°. The peel strength at this time is defined as the "lamination strength between the first film and the aluminum-deposited resin film." Using the same method as above, cut out a rectangular test piece (15 mm wide x 50 mm long) from the laminated film. Place the test piece in the tensile tester, and peel the second film from the laminated film at a peeling speed of 300 mm / min so that the laminated surfaces of the second film and the aluminum-deposited resin film form an angle of 180°. The peel strength at this time is defined as the "lamination strength between the second film and the aluminum-deposited resin film."

[0026] The laminate film 10 according to this embodiment has at least one of the following configurations (1) to (4) so ​​that the above-mentioned heat seal strength, zipper heat seal strength, and lamination strength between the films can be more easily obtained. (1) The first film 12 is a stretched polypropylene-based resin film, the vapor-deposited base film 142 of the aluminum-deposited resin film 14 is a stretched polypropylene-based resin film, and the second film 16 is a non-stretched polypropylene-based resin film. (2) The first film 12 contains a polypropylene-based resin in an amount of 70% by mass or more (more preferably 90% by mass, and even more preferably 95% by mass or more) relative to the entire first film 12, the aluminum-vapor-deposited resin film 14 contains a polypropylene-based resin in an amount of 70% by mass or more (more preferably 90% by mass, and even more preferably 95% by mass or more) relative to the entire aluminum-vapor-deposited resin film, and the second film 16 contains a polypropylene-based resin in an amount of 70% by mass or more (more preferably 90% by mass, and even more preferably 95% by mass or more) relative to the entire second film. (3) A first adhesive layer is provided between the first film 12 and the aluminum-deposited resin film 14, and a second adhesive layer is provided between the second film 16 and the aluminum-deposited resin film 14 (second embodiment). (4) The second surface 14B of the aluminum-deposited resin film 14 is subjected to a corona treatment.

[0027] Next, there will be described the polypropylene-based resin contained in each of the first film 12, the aluminum-deposited resin film 14, and the second film 16. In the following description, the first film 12, the aluminum-deposited resin film 14, and the second film 16 may be collectively referred to as "each polypropylene-based film."

[0028] (Polypropylene resin) Examples of polypropylene-based resins include homopolypropylene (HPP), random polypropylene (RPP), and block polypropylene. A part of the polypropylene-based resin may be bioplastic (biopolypropylene). Biopolypropylene is obtained, for example, by fermenting the molasses of sorgo, a non-edible plant, with microorganisms to produce an intermediate material, and then dehydrating the intermediate material. Each polypropylene-based film may contain one kind of polypropylene-based resin alone, or may contain two or more kinds of polypropylene-based resins. From the viewpoint of improving rigidity, the polypropylene resin contained in each polypropylene film is preferably at least one of homopolypropylene and block polypropylene, and more preferably homopolypropylene.

[0029] The polypropylene resin contained in each polypropylene film preferably has an isotactic pentad fraction of 90 mol% or more, more preferably 92 mol% or more, and even more preferably 95 mol% or more. If the isotactic pentad fraction is 90 mol% or more, the rigidity of each polypropylene film is improved. The upper limit of the isotactic pentad fraction of the polypropylene resin contained in each polypropylene film is not particularly limited, but is usually 99.9 mol %. The isotactic pentad fraction is the fraction of pentad units (units in which five consecutive propylene monomers are isotactically bonded) in the molecular chain of the resin composition. The method for measuring this fraction is described, for example, in Macromolecules, Vol. 8 (1975), p. 687, 13 It can be measured by C-NMR.

[0030] From the viewpoint of improving moldability, the polypropylene resin contained in each polypropylene film preferably has a melt flow rate of 5 g / 10 min or less. The upper limit of the melt flow rate of the polypropylene resin is preferably 4 g / 10 min or less, more preferably 3 g / 10 min or less, and even more preferably 1 g / 10 min or less. The lower limit of the melt flow rate of the polypropylene resin is more preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, and even more preferably 0.4 g / 10 min or more. The melt flow rate of the polypropylene resin in this specification can be measured in accordance with ASTM D1238-89 at a measurement temperature of 230° C. and a load of 2.16 kg.

[0031] The configuration of the laminated film 10 according to this embodiment will be described in detail.

[0032] (First Film 12) The first film 12 functions as a surface film of the laminated film 10 . The first film 12 contains a polypropylene-based resin as a main component, and is preferably a stretched polypropylene-based resin film. Examples of the stretching include uniaxial stretching and biaxial stretching.

[0033] From the viewpoint of further improving recyclability, the first film 12 preferably contains 60% by mass or more of polypropylene-based resin relative to the entire first film 12, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more. The upper limit of the polypropylene resin content in the first film 12 is 100% by mass.

[0034] The thickness T1 of the first film 12 is preferably 10 μm or more and 80 μm or less, more preferably 15 μm or more and 60 μm or less, and even more preferably 20 μm or more and 50 μm or less. The first film 12 may be a single layer or multiple layers.

[0035] (Aluminum-deposited resin film 14) The aluminum vapor-deposited resin film 14 contains polypropylene resin as a main component. The aluminum-vapor-deposited resin film 14 is composed of an aluminum-vapor-deposited layer 141 having a first surface 14A and a vapor-deposited base film 142 having a second surface 14B, and the vapor-deposited base film 142 is preferably a stretched polypropylene-based resin film.

[0036] From the viewpoint of further improving recyclability, the aluminum vapor-deposited resin film 14 preferably contains 60% by mass or more of polypropylene-based resin, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the entire aluminum vapor-deposited resin film 14. The upper limit of the polypropylene resin content in the aluminum-deposited resin film 14 is preferably 98% by mass or less.

[0037] In order to ensure a high lamination strength with the second film 16, it is preferable that the second surface 14B of the aluminum-deposited resin film 14 be subjected to a corona treatment.

[0038] Thickness T of the aluminum vapor deposition layer 141 A2 The thickness is preferably 25 nm or more and 80 nm or less. The aluminum deposition layer 141 may be a single layer or multiple layers.

[0039] Thickness T of aluminum vapor deposition resin film 14 A1 is preferably 10 μm or more and 80 μm or less, more preferably 15 μm or more and 60 μm or less, and even more preferably 20 μm or more and 50 μm or less.

[0040] (2nd film 16) The second film 16 is a film having heat sealability. For example, when the laminated film 10 is made into a bag, it forms the inner surface of the packaging bag. The second film 16 contains a polypropylene resin as a main component. The second film 16 is preferably a non-oriented polypropylene resin film. "Unoriented" means that the film is produced without stretching during the film production process, although slight orientation in the extrusion direction is permitted when using an extrusion process under commonly used conditions.

[0041] From the viewpoint of further improving recyclability, the second film 16 preferably contains 60% by mass or more of polypropylene-based resin relative to the entire second film 16, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more. The upper limit of the polypropylene resin content in the second film 16 is 100% by mass.

[0042] The thickness T2 of the second film 16 is preferably 10 μm or more and 60 μm or less, more preferably 18 μm or more and 50 μm or less, and even more preferably 20 μm or more and 40 μm or less. The thickness T2 of the second film 16 is preferably greater than the thickness T1 of the first film 12. The second film 16 may be a single layer or multiple layers.

[0043] In the laminated film 10 of this embodiment, it is preferable that the first film 12 is a stretched polypropylene-based resin film, the vapor-deposited base film 142 of the aluminum-deposited resin film 14 is a stretched polypropylene-based resin film, and the second film 16 is a non-stretched polypropylene-based resin film.

[0044] In the laminated film 10 of this embodiment, the first film 12, the vapor-deposited base film 142 (the film before the aluminum vapor-deposited layer 141 is formed), and the second film 16 may have the same composition or may be different. In other words, the polypropylene-based resin and its content in the first film 12, the polypropylene-based resin and its content in the vapor-deposited base film 142, and the polypropylene-based resin and its content in the second film 16 may be the same as or different from each other. For example, in the case of a polypropylene-based resin, if the first film 12 contains 80% by mass of homopolypropylene, the second film 16 may contain 80% by mass or another amount of homopolypropylene, or may contain 80% by mass or another amount of a polypropylene-based resin other than homopolypropylene. The same applies to the deposited base film 142.

[0045] (Other Ingredients) In the laminate film 10 according to this embodiment, each polypropylene-based film may contain resins other than polypropylene-based resins and known additives, etc., within a range that does not impair the effects of this embodiment. Examples of additives include nucleating agents, stabilizers, antioxidants, lubricants, antistatic agents, antiblocking agents, and colorants. Examples of resins other than polypropylene-based resins include petroleum resins and polyethylene.

[0046] Second Embodiment The laminated film 10A according to the second embodiment is different from the laminated film 10 of the first embodiment in that it further has a first adhesive layer 18A between the first film 12 and the aluminum-vapor-deposited resin film 14, and further has a second adhesive layer 18B between the second film 16 and the aluminum-vapor-deposited resin film 14. Other than this, the configuration is the same as that of the first embodiment. Therefore, in the following explanation, explanations that overlap with the configuration of the first embodiment will be omitted. FIG. 2 is a schematic cross-sectional view of a laminated film 10A according to the second embodiment. The laminated film 10A according to the second embodiment includes, in this order, a first film 12, a first adhesive layer 18A, an aluminum-vapor-deposited resin film 14, a second adhesive layer 18B, and a second film 16. The first film 12 and the aluminum-vapor-deposited resin film 14 are bonded together via the first adhesive layer 18A. The second film 16 and the aluminum-vapor-deposited resin film 14 are bonded together via the second adhesive layer 18B.

[0047] The adhesive used to form the first adhesive layer 18A and the second adhesive layer 18B is not particularly limited, but for example, an ester-based adhesive or an ether-based adhesive is preferably used. The first adhesive layer 18A and the second adhesive layer 18B may have the same composition or may be different. The thickness T of the first adhesive layer 18A S1 and the thickness T of the second adhesive layer 18B S2 are each preferably independently 0.5 μm or more and 3.0 μm or less.

[0048] In the laminate film 10A according to the second embodiment, in order to ensure a higher laminate strength between the aluminum-vapor-deposited resin film 14 and the second film 16, it is preferable that the second surface 14B of the aluminum-vapor-deposited resin film 14 is subjected to a corona treatment.

[0049] (Effects of the Second Embodiment) In addition to the effects of the first embodiment, the following effects are achieved. In the laminated film 10A according to the second embodiment, a first adhesive layer is disposed on the first surface 14A of the aluminum-deposited resin film 14, and a second adhesive layer is disposed on the second surface 14B of the aluminum-deposited resin film 14, thereby ensuring the lamination strength between the films. Therefore, for example, when the laminated film 10A according to the second embodiment is made into a stand-up bag (self-supporting packaging bag), the self-supporting property of the packaging bag is more easily ensured.

[0050] Third Embodiment The laminated film according to the third embodiment is different from the laminated film 10A according to the second embodiment in that the second film 16 has a zipper portion. Other than this, the laminated film according to the third embodiment has the same configuration as the second embodiment. Therefore, in the following description, the description that overlaps with the second embodiment will be omitted. FIG. 3 is a schematic cross-sectional view of a laminated film 10B according to a third embodiment. In the laminated film 10B shown in FIG. The zipper section 19 is preferably formed on the heat-sealable second film 16. The zipper section 19 is usually formed on the surface of the second film 16 opposite to the second adhesive layer 18B. A zipper is, for example, a combination of a pair of engaging male and female members. The zipper does not have to have an engaging portion and may be, for example, a hook-and-loop fastener. The zipper is sometimes called a chuck. Although the material of the zipper portion 19 is not particularly limited, from the viewpoint of further improving recyclability, it is preferable that the zipper portion 19 contains a polypropylene-based resin as a main component. The zipper portion 19 preferably contains 70% by mass or more of polypropylene-based resin relative to the entire zipper portion, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more. The upper limit of the polypropylene-based resin content in the zipper portion is 100% by mass. A preformed zipper portion is usually used as the zipper portion 19. One embodiment of the zipper portion 19 is a male member or a female member. The size, shape and attachment position of the zipper portion 19 are not particularly limited and may be appropriately selected depending on the size and use of the packaging bag.

[0051] (Effects of the Third Embodiment) In addition to the effects of the second embodiment, the following effects are achieved. The laminated film 10B according to the third embodiment has a zipper portion attached to the second film 16, so that it can be easily made into a packaging bag with a zipper. A known method can be used to make the laminated film 10B into a packaging bag with a zipper. For example, when the zipper portion 19 in Fig. 3 is a male member, a female member is attached to an arbitrary location of the second film 16, and then the laminated film 10B is made so that the male member and the female member are engaged with each other, thereby obtaining a packaging bag with a zipper.

[0052] Furthermore, in the laminate film 10B according to the third embodiment, when the zipper portion 19 contains a polypropylene-based resin as a main component, the laminate film becomes more suitable for recycling as a mono-material packaging material.

[0053] Fourth Embodiment (packaging material) The packaging material according to the fourth embodiment is a packaging material formed using the laminate film according to any one of the above-described embodiments. Packaging materials are used for packaging, for example, food products, seasonings, food ingredients, medicines, cosmetics, detergents, nutrients, chemicals, adhesives, pressure sensitive adhesives, paints, agricultural chemicals, fertilizers, and the like.

[0054] (Effects of the Fourth Embodiment) According to the fourth embodiment, since the laminate film according to any one of the above-mentioned embodiments is used, a packaging material having sufficient strength for practical use and capable of improving recyclability is realized.

[0055] Fifth Embodiment (packaging bag) The packaging bag according to the fifth embodiment is obtained by making a bag from the laminate film according to any of the above-described embodiments. The packaging bag according to the fifth embodiment is preferably a self-supporting packaging bag. In the fifth embodiment, a packaging bag produced by making the laminated film 10A according to the second embodiment will be described.

[0056] FIG. 4 is a schematic diagram of a packaging bag 20 according to a fifth embodiment. The packaging bag 20 is used for filling, for example, food products, seasonings, food ingredients, beverages, medicines, blood, cosmetics, detergents, nutrients, chemicals, adhesives, pressure sensitive adhesives, paints, agricultural chemicals, fertilizers, etc. The same applies to the packaging bag 30 described later. The packaging bag 20 shown in FIG. 4 is a self-supporting packaging bag. In the packaging bag 20, the first film 12 of the laminated film 10A is disposed on the outer surface of the packaging bag 30 (the side opposite to the contents), and the second film 16 is disposed on the inner surface of the packaging bag 20 that comes into contact with the contents (for example, the innermost surface). The packaging bag 20 is obtained by heat-sealing predetermined locations of the laminated film 10A. The packaging bag 20 has a bag body 22, which has both side seal portions 26, an upper seal portion 27, and a bottom portion 24. A cut opening 28 is formed in the bag body 22. The contents can be removed from the packaging bag 20 by cutting the bag body 22 from the cut opening 28.

[0057] (Effects of the Fifth Embodiment) The packaging bag 20 of the fifth embodiment is obtained by manufacturing a laminated film according to any of the above-mentioned embodiments, thereby realizing a packaging bag (preferably a self-supporting packaging bag) that has sufficient strength for practical use and can be improved in recyclability.

[0058] Sixth Embodiment (zipper bag) The packaging bag according to the sixth embodiment has a zipper part, that is, the packaging bag according to the sixth embodiment is a packaging bag with a zipper. The packaging bag according to the sixth embodiment is obtained by making a bag from the laminate film according to any one of the above-described embodiments. The packaging bag according to the sixth embodiment is preferably a self-supporting packaging bag. In the sixth embodiment, a packaging bag produced by manufacturing the laminated film 10B according to the third embodiment will be described.

[0059] FIG. 5A is a schematic diagram of a packaging bag 30 according to a sixth embodiment. FIG. 5B is a schematic diagram of the packaging bag 30 shown in FIG. 5A as viewed from the bottom side. The packaging bag 30 is a self-supporting packaging bag. In the packaging bag 30 made from the laminated film 10B, the first film 12 is placed on the outer surface of the packaging bag 30 (the side opposite the contents), and the second film 16 is placed on the inner surface of the packaging bag 30 that comes into contact with the contents (e.g., the innermost surface). When the zipper portion 19 in FIG. 3 is a male member, the male member and a female member (for example, a female member attached to any location of the second film 16) are positioned at the top of the packaging bag 30 so as to face each other at the engagement portion 39A of the zipper 39.

[0060] The zipper 39 is made up of an engagement portion 39A where the male and female members are engaged, and a base portion 39B connected to the engagement portion 39A. The zipper 39 is fixed by the seal portions 36 on both sides. The packaging bag 30 is obtained by heat-sealing predetermined locations of the laminated film 10B. The packaging bag 30 has a bag body 32, and the bag body 32 has a first bottom surface portion 31 that is connected to the bag body 32 at a lower portion. The first bottom surface portion 31 is heat-sealed in a state where it is folded inward (toward the zipper 39) at approximately the center. The bag body 32 also has two side sealed portions 36, a bottom sealed portion 35, a top sealed portion 37 having a hanging portion 37A, and a second bottom portion 34. The lower seal portion 35 is heat-sealed so that the second bottom surface portion 34 has a boat bottom shape. The lower seal portion 35 helps the packaging bag 30 to stand on its own. A cut opening 38 is formed in the bag body 32. The contents can be removed from the packaging bag 30 by cutting the opening 33 from the cut opening 38 and opening the engaging portion 39A of the zipper 39.

[0061] (Effects of the Sixth Embodiment) In addition to the effects of the fifth embodiment, the following effects are achieved. In the packaging bag 30 according to the sixth embodiment, when the male and female components constituting the zipper 39 contain polypropylene-based resin as the main component, a packaging bag (preferably a self-supporting packaging bag) that can further improve recyclability is realized.

[0062] Seventh Embodiment The method for producing a laminated film according to the seventh embodiment is a method for producing a laminated film according to any of the previous embodiments.

[0063] (Laminated Film Manufacturing Method) The method for producing a laminated film according to a seventh embodiment (hereinafter also referred to as the production method of the seventh embodiment) is a method for producing a laminated film according to any of the above-mentioned embodiments. The manufacturing method of the seventh embodiment includes a step of preparing an aluminum vapor-deposited resin film having an aluminum vapor-deposited layer on the first surface (hereinafter also referred to as an aluminum vapor-deposited resin film preparation step), and a step of bonding the first surface side of the aluminum vapor-deposited resin film to a first film and bonding the second surface side of the aluminum vapor-deposited resin film to a second film. The first film, the aluminum-deposited resin film, and the second film each contain a polypropylene resin as a main component. The configurations of the first film, the aluminum-deposited resin film, and the second film are the same as those in the first embodiment, and the preferred ranges are also the same.

[0064] (Aluminum vapor deposition resin film preparation process) The aluminum vapor-deposited resin film preparation step is a step for convenience, in which an aluminum vapor-deposited resin film having an aluminum vapor-deposited layer on its first surface (the surface on which the first film is laminated) is prepared. The aluminum-vapor-deposited resin film preparing step may be a step of simply preparing a previously manufactured aluminum-vapor-deposited resin film, or may be a step of manufacturing an aluminum-vapor-deposited resin film. The method for forming the aluminum vapor deposition layer is not particularly limited, and examples thereof include gas phase film formation methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD). Examples of physical vapor deposition (PVD) include vacuum deposition, sputtering, and ion plating. Examples of chemical vapor deposition include thermal CVD and plasma CVD. The film formation conditions can be general conditions. The film formation time is appropriately selected so as to obtain the desired thickness. The thickness T of the aluminum vapor deposition layer is A2 The preferred range is as described in the first embodiment.

[0065] The aluminum-deposited resin film may further be subjected to a corona treatment on a second surface of the aluminum-deposited resin film. That is, the aluminum vapor-deposited resin film preparing step may be a step of preparing an aluminum vapor-deposited resin film having an aluminum vapor-deposited layer on a first surface and having a corona treatment applied to a second surface. As the corona treatment conditions, general conditions can be applied. The irradiation energy in corona treatment is, for example, 6kW·min / m 2 More than 150kW min / m 2 The following is the result.

[0066] (Laminating process) The lamination step is a step of laminating the first surface of the aluminum-deposited resin film to the first film, and laminating the second surface of the aluminum-deposited resin film to the second film.

[0067] As the first film 12, a first film 12 that has been manufactured in advance may be used, or a first film 12 that has been manufactured may be used. There is no particular limitation on the manufacturing method of the first film 12. Examples of the manufacturing method of the first film 12 include a method of preparing a composition (first film-forming composition) containing a polypropylene resin and, if desired, other resins or resin compositions, and additives, and then extruding or inflation molding the first film-forming composition. Alternatively, the first film 12 may be formed by preparing a coating liquid by dissolving or dispersing the first film-forming composition in an appropriate solvent, and using this coating liquid. The second film 16 is manufactured in a similar manner.

[0068] The bonding method is not particularly limited, but for example, when producing the laminated film 10 according to the first embodiment, the first film 12, the aluminum-deposited resin film 14, and the second film 16 may be laminated so that the first surface of the aluminum-deposited resin film faces the first film 12, and the second surface of the aluminum-deposited resin film faces the second film 16. The order of lamination is not particularly limited.

[0069] (The zipper attachment process) The manufacturing method of the seventh embodiment preferably further includes a step of attaching a zipper portion to the second film 16. The method of attaching zipper portion 19 is not particularly limited, and examples thereof include a method of thermally welding the zipper portion to second film 16, and a method of bonding the zipper portion to second film 16 using a known adhesive. The timing of attaching zipper portion 19 is not particularly limited.

[0070] When the zipper portion contains a polypropylene-based resin as a main component, it is preferable to reinforce the zipper portion by ultrasonic sealing in order to improve the adhesion of the zipper portion to the second film during bag production.

[0071] FIG. 6 is a diagram for explaining the production method according to the seventh embodiment, showing a schematic diagram of an example of a laminated film production apparatus. An example of a method for producing the laminated film 10A according to the second embodiment will be described with reference to FIG. A pre-manufactured film is used as the aluminum-deposited resin film 14 (aluminum-deposited resin film preparation step). Similarly, pre-manufactured films are used for the first film 12 and the second film 16. The manufacturing apparatus 50 includes a first roll R1 around which the first film 12 is wound, a second roll R2 around which the aluminum-deposited resin film 14 is wound, a third roll R3, and a plurality of guide rolls GR. The manufacturing apparatus 50 also includes an adhesive application means 52 that applies a first adhesive onto the first film 12, a drying means 54 that dries the first adhesive, and a laminating means 56. The adhesive application means 52 includes a first application roll 52B and an opposing roll 52A disposed opposite the first application roll 52B. The laminating means 56 includes a pair of pressing rolls 56A, 56B. When the first film 12 unwound from the first roll R1 passes between the first application roll 52B, which applies the first adhesive, and the opposing roll 52A, the first adhesive is applied to one surface of the first film 12. When the first film 12 to which the first adhesive has been applied passes through drying means 54, a first adhesive layer (first film with a first adhesive layer) is formed on the first film 12. The aluminum-deposited resin film 14 unwound from the second roll R2 passes through a pair of pressing rolls 56A, 56B in the laminating means 56 so that the first surface 14A of the aluminum-deposited resin film 14 faces the first adhesive layer 18A of the first film with the first adhesive layer, thereby producing a laminate in which the first film with the first adhesive layer and the aluminum-deposited resin film 14 are bonded together (bonding step). The laminate 100 is taken up by the third roll R3. Using a method similar to that described above, a second adhesive is applied to one surface of the second film 16 and dried to form a second adhesive layer (second film with the second adhesive layer) on the second film 16. The second surface 14B of the aluminum-deposited resin film 14 of the laminate 100 and the second film with the second adhesive layer are bonded together to obtain the laminate film 10A of the second embodiment (bonding step).

[0072] (Effects of the Seventh Embodiment) According to the manufacturing method of the seventh embodiment, a laminated film having sufficient strength for practical use and improved recyclability is manufactured. EXAMPLES

[0073] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0074] <Manufacturing of laminated film> Example 1 As the first film, a stretched polypropylene film (thickness: 20 μm) was prepared. As the second film, a non-stretched polypropylene film (thickness: 40 μm) was prepared. An aluminum-deposited resin film (thickness: 25 μm) was prepared, which had an aluminum-deposited layer on one side (first side) and was corona-treated on the other side (second side). The substrate (deposited substrate film) of the aluminum-deposited resin film was made of a stretched polypropylene film. First, an ether-based adhesive was applied to one side of a first film and dried to form a first adhesive layer on the first film. Similarly, an ether-based adhesive was applied to one side of a second film and dried to form a second adhesive layer on the second film. The first surface of the aluminum-deposited resin film was bonded to the first adhesive layer of the first film, and then the second surface of the aluminum-deposited resin film was bonded to the second adhesive layer of the second film. In this manner, the laminated film of Example 1 was obtained.

[0075] [Reference example 1] A laminated film was prepared by extrusion laminating a polyethylene terephthalate (PET) film (thickness 12 μm), an aluminum-vapor-deposited PET film (thickness 12 μm) with an aluminum vapor-deposited layer on one side, and a linear low-density polyethylene (LLDPE) film (thickness 40 μm). The PET film and the aluminum-deposited PET film, and the LLDPE film and the aluminum-deposited PET film are bonded together with molten polyethylene resin (adhesive layer). The structure of the laminated film of Reference Example 1 is as follows. PET film / adhesive layer / aluminum-deposited PET film / adhesive layer / LLDPE film The aluminum vapor deposition layer side of the aluminum vapor deposition PET film is placed on the PET film side.

[0076] 〔evaluation〕 The following measurements were carried out, and the results are shown in Table 1.

[0077] (Laminate strength) Test pieces were prepared from the laminated film of Example 1 by the method described above, and the "peel strength between the first film and the aluminum-deposited resin film" and the "peel strength between the second film and the aluminum-deposited resin film" were measured. The peel strength was measured in the MD (Machine Direction). The unit is [N / 15mm]. Test pieces were also prepared for the laminated film of Reference Example 1 in the same manner, and the "peel strength between the PET film and the aluminum-vapor-deposited PET film" and the "peel strength between the LLPE film and the aluminum-vapor-deposited PET film" were measured.

[0078] (Heat seal strength) Two sheets of the laminated film of Example 1 were prepared. The laminated films were overlapped so that the second films faced each other, and the bottom and both sides were heat-sealed under conditions of 170°C, sealing pressure of 0.2 MPa, and sealing time of 1.0 seconds to obtain a packaging bag of length 10 cm x width 10 cm. After leaving it to stand for 24 hours, a test piece for measuring the bottom (width 15 mm x length 50 mm) and a test piece for measuring the side (width 15 mm x length 50 mm) were cut out from the bottom and side of the packaging bag, respectively, and the heat seal strength was measured by the method described above. The unit is [N / 15 mm]. For the laminated film of Reference Example 1, packaging bags, test pieces for measuring the bottom portion, and test pieces for measuring the side portion were prepared in the same manner, and the heat seal strength was measured for each.

[0079] (zipper laminated film) A test piece was prepared from the laminated film of Example 1 by the method described above, and the heat seal strength of the zippered laminated film was measured, with the unit being [N / 15 mm].

[0080] [Table 1]

[0081] As shown in Table 1, the laminate film of Example 1 had lamination strength between the films, heat seal strength, and zipper heat seal strength sufficient for practical use. In particular, the heat seal strength is "15N / 15mm or more," which is confirmed to meet the requirement of JIS Z0238 (1998) that states "for general packaging bags, etc., where the mass of the contents is large and a relatively strong heat seal strength is required." [Explanation of symbols]

[0082] 10, 10A, 10B...Laminated film, 12...First film, 14...Aluminum vapor-deposited resin film, 14A...First surface, 14B...Second surface, 16...Second film, 18A...First adhesive layer, 18B...Second adhesive layer, 19...Zipper portion, 20, 30...Packaging bag, 22, 32...Bag body, 24...Bottom portion, 26, 36...Both side seal portions, 27...Upper seal portion, 28, 38...Slit, 31 ...first bottom portion, 33...opening portion, 34...second bottom portion, 35...lower seal portion, 37...upper seal portion, 37A...hanging portion, 39...zipper, 39A...engagement portion, 39B...base, 50...manufacturing apparatus, 52...adhesive application means, 52A...opposing roll, 54...drying means, 56...laminating means, 56A, 56B...pressing roll, 141...aluminum vapor-deposited layer, 142...vapor-deposited base film.

Claims

1. The first film and An aluminum vapor-deposited resin film having a first surface and a second surface opposite to the first surface, The second film and the following are included in this order: The aluminum vapor-deposited resin film has an aluminum vapor-deposited layer on the first surface, The first film is laminated on the side of the first surface, The second film is laminated on the side of the second surface. The first film, the aluminum-deposited resin film, and the second film each contain a polypropylene resin as their main component. Laminated film.

2. In the laminated film according to claim 1, The first film contains 70% by mass or more of the polypropylene resin relative to the entire first film. The aluminum vapor-deposited resin film contains 70% by mass or more of the polypropylene resin relative to the entire aluminum vapor-deposited resin film. The second film contains 70% by mass or more of the polypropylene resin relative to the entire second film. Laminated film.

3. In the laminated film according to claim 1 or claim 2, The first film contains 90% by mass or more of the polypropylene resin relative to the entire first film. The aluminum vapor-deposited resin film contains 90% by mass or more of the polypropylene resin relative to the entire aluminum vapor-deposited resin film. The second film contains 90% by mass or more of the polypropylene resin relative to the entire second film. Laminated film.

4. In the laminated film according to claim 1 or claim 2, The first film contains 95% by mass or more of the polypropylene resin relative to the entire first film. The aluminum vapor-deposited resin film contains 95% by mass or more of the polypropylene resin relative to the entire aluminum vapor-deposited resin film. The second film contains 95% by mass or more of the polypropylene resin relative to the entire second film. Laminated film.

5. In the laminated film according to claim 1 or claim 2, The aluminum vapor-deposited resin film is composed of an aluminum vapor-deposited layer having the first surface and a vapor-deposited substrate film having the second surface. The first film is a stretched polypropylene resin film, The aforementioned vapor-deposited substrate film is a stretched polypropylene resin film. The second film is an unoriented polypropylene resin film. Laminated film.

6. In the laminated film according to claim 1 or claim 2, A first adhesive layer is provided between the first film and the aluminum vapor-deposited resin film. A second adhesive layer is provided between the second film and the aluminum vapor-deposited resin film. Laminated film.

7. In the laminated film according to claim 1 or claim 2, The heat seal strength obtained when a peel test is performed using a test piece obtained by heat-welding the second films of the laminated film facing each other is 15.0 N / 15 mm or more. Laminated film.

8. In the laminated film according to claim 1 or claim 2, The peel strength between the first film and the aluminum vapor-deposited resin film is 0.6 N / 15 mm or more. Laminated film.

9. In the laminated film according to claim 1 or claim 2, The peel strength between the second film and the aluminum vapor-deposited resin film is 0.8 N / 15 mm or more. Laminated film.

10. In the laminated film according to claim 1 or claim 2, The second film has a zipper portion, Laminated film.

11. In the laminated film according to claim 10, The zipper portion mainly contains polypropylene resin, Laminated film.

12. In the laminated film according to claim 10, When a peel test is performed using a zippered laminated film obtained by attaching a zipper to the second film, the heat seal strength of the zippered laminated film is 15 N / 15 mm or more. Laminated film.

13. A packaging material comprising a laminated film according to claim 1 or claim 2.

14. A packaging bag made by forming a bag from the laminated film described in claim 1 or claim 2.

15. In the packaging bag according to claim 14, A self-standing packaging bag.

16. A method for manufacturing a laminated film comprising, in this order, a first film, an aluminum vapor-deposited resin film having a first surface and a second surface opposite to the first surface, and a second film, A step of preparing the aluminum vapor-deposited resin film having an aluminum vapor-deposited layer on the first surface, The process includes the steps of laminating the first side of the aluminum vapor-deposited resin film with the first film, and laminating the second side of the aluminum vapor-deposited resin film with the second film, The first film, the aluminum-deposited resin film, and the second film each contain a polypropylene resin as their main component. A method for manufacturing laminated films.

17. In the method for manufacturing a laminated film according to claim 16, The aluminum vapor-deposited resin film is composed of an aluminum vapor-deposited layer having the first surface and a vapor-deposited substrate film having the second surface. The first film is a stretched polypropylene resin film, The aforementioned vapor-deposited substrate film is a stretched polypropylene resin film. The second film is an unoriented polypropylene resin film. A method for manufacturing laminated films.

18. In the method for manufacturing a laminated film according to claim 16 or claim 17, The process further includes attaching a zipper portion to the second film. A method for manufacturing laminated films.

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