Method for manufacturing a laminate, the laminate, and the packaging bag

Abstract

To provide a method for manufacturing laminates that can increase manufacturing efficiency while reducing environmental impact. [Solution] A method for manufacturing a laminate is a method for manufacturing a laminate in which a base layer, a first adhesive layer, a first intermediate layer, a second adhesive layer, and a sealant layer are laminated in this order, and the method includes: a first adhesive coating step of coating a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin onto the base layer to form an uncured first adhesive layer; a second adhesive coating step of coating a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin onto the first intermediate layer to form an uncured second adhesive layer; and an electron beam irradiation step of irradiating the laminate, in which the base layer, the uncured first adhesive layer, the first intermediate layer, the uncured second adhesive layer, and the sealant layer are laminated, with an electron beam having an acceleration voltage of 50kV or more and 300kV or less from the base layer side.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminate, a laminate, and a packaging bag.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a laminate in which a solution obtained by mixing a polyester resin, an isocyanate component, and an organic solvent is applied to an inorganic barrier layer, the solution is dried to form a first urethane adhesive layer, and a sealant layer is laminated on the first urethane adhesive layer via a second urethane adhesive layer.

[0003] Further, Patent Document 2 discloses a method for manufacturing a laminate, which includes a step of applying an adhesive containing an acid group-containing resin and an epoxy compound to a first substrate, a step of bonding the first substrate and a second substrate via the adhesive, and a step of aging at 25°C or higher and 100°C or lower for 12 hours or more.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the conventional technology, when an adhesive containing a solvent is used for the adhesive layer of a laminate, a drying process that consumes a large amount of energy is required when evaporating the solvent after applying the adhesive, resulting in a large amount of CO2 emissions and a large environmental load. Further, when a two-component adhesive is used for the adhesive layer of a laminate, a long aging process is required when curing the adhesive, resulting in a long manufacturing lead time for the laminate and a decrease in manufacturing efficiency.

[0006] The objective of this invention is to provide a method for manufacturing laminates that can increase manufacturing efficiency while reducing environmental impact. [Means for solving the problem]

[0007] The present disclosure is a method for manufacturing a laminate in which a base layer, a first adhesive layer, a first intermediate layer, a second adhesive layer, and a sealant layer are laminated in this order, comprising: a first adhesive coating step of coating the base layer with a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to form an uncured first adhesive layer; a second adhesive coating step of coating the first intermediate layer with a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to form an uncured second adhesive layer; and an electron beam irradiation step of irradiating the laminate, which comprises the base layer, the uncured first adhesive layer, the first intermediate layer, the uncured second adhesive layer, and the sealant layer, with an electron beam having an acceleration voltage of 50kV to 300kV from the base layer side. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a method for manufacturing laminates that can increase manufacturing efficiency while reducing environmental impact. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing an example of a laminate. [Figure 2] This is a flowchart showing a method for manufacturing a laminate according to the first embodiment. [Figure 3] This is a schematic diagram showing an example of an apparatus for carrying out the manufacturing method of a laminate according to the first embodiment. [Figure 4] This figure shows the laminated material after being irradiated with an electron beam. [Figure 5] This is a flowchart showing a method for manufacturing a laminate according to the second embodiment. [Figure 6] This is a flowchart showing the method for manufacturing a laminate according to the third embodiment. [Figure 7]It is a schematic diagram showing a modified example of an apparatus for manufacturing a laminate according to the first embodiment. [Figure 8] It is a cross-sectional view showing an example of a laminate having three adhesive layers and two intermediate layers. [Figure 9] It is a flowchart showing a method for manufacturing a laminate according to the fourth embodiment. [Figure 10] It is a schematic diagram showing an example of an apparatus for implementing a method for manufacturing a laminate according to the fourth embodiment. [Figure 11] It is a cross-sectional view showing an example of a laminate having a printed layer. [Figure 12] It is a flowchart showing a method for manufacturing a laminate according to the fifth embodiment. [Figure 13] It is a schematic diagram showing an example of an apparatus for implementing a method for manufacturing a laminate according to the fifth embodiment. [Figure 14] It is a diagram showing an example of a packaging bag manufactured using a laminate.

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present disclosure will be described in detail with reference to the drawings. In each figure, for common parts, the same reference numerals may be given and the description may be omitted. Also, in each figure, the scales of each member may be different from the actual ones.

[0011] <Laminate> The laminate of the present disclosure is a laminate in which a base material layer, a first adhesive layer, a first intermediate layer, a second adhesive layer, and a sealant layer are laminated in this order.

[0012] FIG. 1 is a cross-sectional view showing an example of the laminate of the present disclosure. In FIG. 1, the laminate 1 has a base material layer 10, an adhesive layer 20, an intermediate layer 30, an adhesive layer 40, and a sealant layer 80 laminated in this order. The base material layer 10 is an example of a base material layer, the adhesive layer 20 is an example of a first adhesive layer, the intermediate layer 30 is an example of a first intermediate layer, the adhesive layer 40 is an example of a second adhesive layer, and the sealant layer 80 is an example of a sealant layer.

[0013] The base material layer 10 is a layer that holds each layer other than the base material layer in the laminate. The form of the base material layer 10 is not particularly limited, and for example, it may be formed of a sheet or a film.

[0014] The components of the base material layer 10 are not particularly limited as long as they have sufficient mechanical strength. Examples of the components of the base material layer 10 include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyamide resins such as nylon (Ny); polyolefin resins such as polyethylene (PE) and oriented polypropylene (OPP); and synthetic resins composed of polyether ether ketone (PEEK), polyphenylene sulfide (PPS), etc. A plurality of resins can also be selected from these according to the purpose.

[0015] The thickness of the base material layer 10 is preferably 35 μm or less, more preferably 33 μm or less, still more preferably 30 μm or less, and particularly preferably 15 μm or less. The lower limit of the thickness of the base material layer 10 is not particularly limited, but from the viewpoint of maintaining the original function of the base material layer, it is preferably 1 μm or more, more preferably 5 μm or more, and still more preferably 10 μm or more.

[0016] The base material layer may have a single-layer structure or a multilayer structure. Also, when the base material layer has a multilayer structure, each layer may be composed of the same type of component or different types of components.

[0017] The adhesive layer 20 and the adhesive layer 40 are disposed between the base material layer 10 and the sealant layer 80, and are layers that bond each layer other than the adhesive layer in the laminate. The adhesive layer 20 and the adhesive layer 40 are formed of a solvent-free adhesive containing an electron beam curable (meth)acrylate resin.

[0018] In this specification, (meth)acrylate means either or both acrylate and methacrylate. (Meth)acrylate resins are resins obtained by polymerizing (meth)acrylate monomers having two or more acryloyl groups (CH2=CH-CO-) or methacryloyl groups (CH2=C(CH3)-CO-) in one molecule.

[0019] Furthermore, electron beam curable resins refer to resins that have functional groups that undergo a curing reaction when irradiated with an electron beam. Here, an electron beam (EB) refers to a stream of electrons obtained by applying an acceleration voltage to electrons. An electron beam (EB) is a type of electrically charged particle beam and has higher energy than electromagnetic waves such as ultraviolet (UV) rays. Also, solvent-free adhesives refer to adhesives that do not contain solvents.

[0020] The electron beam curable (meth)acrylate resin is not particularly limited, but examples include resins obtained by polymerizing (meth)acrylate monomers such as polyester (meth)acrylate, polyether (meth)acrylate, polyol methacrylate, melamine methacrylate, epoxy (meth)acrylate, and urethane (meth)acrylate. These electron beam curable (meth)acrylate resins may be used individually or in combination of two or more.

[0021] The molecular weight of the electron beam-curable (meth)acrylate resin is not particularly limited, but is preferably 500 to 100,000 in weight-average molecular weight (MW), more preferably 1,000 to 80,000, and even more preferably 2,000 to 50,000. When the molecular weight of the electron beam-curable (meth)acrylate resin is 500 to 100,000, it is possible to prevent a significant increase in the viscosity of the solvent-free adhesive, which would otherwise reduce the applicability of the adhesive.

[0022] The adhesive layer 20 and the adhesive layer 40 may be composed of the same type of electron beam curable (meth)acrylate resin, or they may be composed of different types of electron beam curable (meth)acrylate resins.

[0023] The thicknesses of adhesive layers 20 and 40 are not particularly limited, but are, for example, 0.1 μm or more and 5 μm or less, preferably 0.5 μm or more and 4 μm or less, and more preferably 1 μm or more and 3 μm or less. The thicknesses of adhesive layer 20 and adhesive layer 40 may be the same or different.

[0024] The intermediate layer 30 is positioned between the base layer 10 and the sealant layer 80 to improve the strength and / or barrier properties of the laminate. The form of the intermediate layer 30 is not particularly limited and may be formed, for example, as a sheet or a film.

[0025] The components of the intermediate layer 30 are not particularly limited, and for example, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyamide resins such as nylon (Ny); polyolefin resins such as polyethylene (PE) and stretched polypropylene (OPP); and synthetic resins such as polyether ether ketone (PEEK) and polyphenylene sulfide (PPS) can be used. In terms of improving the barrier properties of the laminate, metal foils such as aluminum foil, metal vapor-deposited layers such as aluminum, inorganic vapor-deposited layers such as alumina or silica, ethylene vinyl alcohol copolymer resin (EVOH), polyvinyl alcohol resin (PVA), etc. can be used.

[0026] The thickness of the intermediate layer 30 is preferably 35 μm or less, more preferably 30 μm or less, and even more preferably 25 μm or less. The lower limit of the thickness of the intermediate layer 30 is not particularly limited, but from the viewpoint of maintaining the original function of the intermediate layer, it is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more.

[0027] The sealant layer 80 is a layer for fusing together with heat. The form of the sealant layer is not particularly limited and may be formed, for example, as a sheet or a film.

[0028] The sealant layer contains a resin that fuses with itself upon heat. Examples of resin materials that can fuse with each other upon heat include polyolefins, specifically polyethylene such as low-density polyethylene, linear low-density polyethylene and medium-density polyethylene, polypropylene, polybutene, polymethylpentene, and cyclic olefin copolymers.

[0029] Furthermore, as the polyolefin, a polyolefin resin derived from biomass or a mixture of a polyolefin resin derived from biomass and a polyolefin resin derived from petroleum can be used.

[0030] In addition to polyolefins, other resin materials that can fuse together with heat include, for example, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, polyvinyl acetate, polyvinyl chloride, and polyethylene terephthalate.

[0031] Among these, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or very low-density polyethylene (VLDPE) are preferred as the sealant layer, with linear low-density polyethylene being more preferred.

[0032] The thickness of the sealant layer 80 is not particularly limited, but can be, for example, 10 μm or more and 250 μm or less, preferably 20 μm or more and 200 μm or less, and more preferably 30 μm or more and 150 μm or less.

[0033] The sealant layer may be a single layer or a multilayer structure. Furthermore, if the sealant layer is a multilayer structure, each layer may be composed of the same type of component, or it may be composed of different types of components.

[0034] In the example shown in Figure 1, the adhesive layer consists of two layers, adhesive layer 20 and adhesive layer 40, but the adhesive layer may consist of three or more layers. Also, in the example shown in Figure 1, the intermediate layer consists of one layer, intermediate layer 30, but the intermediate layer may consist of two or more layers.

[0035] Figure 8 is a cross-sectional view showing an example of a laminate having three adhesive layers and two intermediate layers. In the laminate shown in Figure 8, parts common to the laminate shown in Figure 1 may be denoted by the same or corresponding reference numerals and their description may be omitted. In Figure 8, the laminate 2 is constructed by laminating a base layer 10, an adhesive layer 20, an intermediate layer 30, an adhesive layer 40, an intermediate layer 50, an adhesive layer 60, and a sealant layer 80 in this order. Intermediate layer 50 is an example of a second intermediate layer, adhesive layer 60 is an example of a third adhesive layer, and sealant layer 80 is an example of a sealant layer.

[0036] In the laminate 2 shown in Figure 8, an intermediate layer 50 and an adhesive layer 60 are further laminated between the adhesive layer 40 and the sealant layer 80 in that order. That is, in laminate 2, the adhesive layer consists of three layers: adhesive layer 20, adhesive layer 40, and adhesive layer 60, and the intermediate layer consists of two layers: intermediate layer 30 and intermediate layer 50.

[0037] The thicknesses of adhesive layers 20, 40, and 60 are not particularly limited, but are, for example, 0.1 μm or more and 5 μm or less, preferably 0.5 μm or more and 4 μm or less, and more preferably 1 μm or more and 3 μm or less. The thicknesses of adhesive layer 20, adhesive layer 40, and adhesive layer 60 may be all or partly the same, or all or partly different.

[0038] Furthermore, if there are two or more intermediate layers, each intermediate layer may be composed of the same type of component, or it may be composed of different types of components.

[0039] If there are two or more intermediate layers, and each intermediate layer is composed of a different type of component, for example, intermediate layer 30 may be Ny and intermediate layer 50 may be aluminum foil. When intermediate layer 50 is aluminum foil, the thickness of the aluminum foil is preferably 1 μm to 15 μm, more preferably 2 μm to 12 μm, and even more preferably 3 μm to 10 μm.

[0040] The laminates of this disclosure may further include a printed layer. Figure 11 is a cross-sectional view showing an example of a laminate having a printed layer. In the laminate shown in Figure 11, parts common to the laminates shown in Figure 1 and / or Figure 8 may be denoted by the same or corresponding reference numerals and their descriptions may be omitted.

[0041] In Figure 11, the laminate 3 is constructed by laminating a base layer 10, a printed layer 70, an adhesive layer 20, an intermediate layer 30, an adhesive layer 40, an intermediate layer 50, an adhesive layer 60, and a sealant layer 80 in that order. The printed layer 70 is an example of a printed layer, and the sealant layer 80 is an example of a sealant layer.

[0042] The printing layer 70 is a layer containing ink. The ink constituting the printing layer contains a coloring agent such as a dye and / or pigment, and a binder such as an aqueous and / or solvent-based resin. Examples of resins contained in the ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, etc. These resins may be used individually or in mixtures of two or more types.

[0043] The resin contained in the ink of the printing layer may be an electron beam curable resin. Examples of electron beam curable resins include the electron beam curable (meth)acrylate resin mentioned above.

[0044] Furthermore, the printed layer 70 may optionally contain plasticizers, stabilizers, antioxidants, light stabilizers, UV absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, defoamers, and the like.

[0045] The printed layer 70 can be formed using an ink prepared by thoroughly mixing the ink with a solvent, diluent, etc. Furthermore, in forming the printed layer 70, a desired printed pattern consisting of characters, figures, symbols, patterns, etc., can be formed using such an ink and a printing method such as gravure printing, offset printing, letterpress printing, screen printing, transfer printing, or flexographic printing.

[0046] The printed layer 70 may be formed at any position between the substrate layer 10 and the sealant layer 80, but it is preferable that it is not adjacent to the sealant layer. Furthermore, multiple printed layers may be laminated. If multiple printed layers are laminated, one layer may be laminated between each layer of the laminate. Additionally, the printed layer may be formed on the outermost layer of the laminate 3 on the substrate layer 10 side.

[0047] The laminate 1 is not limited to packaging laminates such as pouches, bags, containers, and packaging films, but can be used for a variety of applications.

[0048] <Method for manufacturing laminates> <<First Embodiment>> The method for manufacturing a laminate according to the present disclosure is a method for manufacturing the laminate described above. The method for manufacturing a laminate according to the present disclosure includes a first adhesive coating step, a second adhesive coating step, and an electron beam irradiation step.

[0049] Figure 2 is a flowchart showing a method for manufacturing a laminate according to the first embodiment of this disclosure. In Figure 2, the method for manufacturing a laminate according to the first embodiment includes a first adhesive coating step S11, a second adhesive coating step S12, and an electron beam irradiation step S13. Figure 3 is a schematic diagram of an apparatus for manufacturing a laminate according to the first embodiment.

[0050] In the first adhesive coating step S11, a solvent-free adhesive containing the electron beam-curable (meth)acrylate resin described above is applied to the substrate layer 10 to form an uncured adhesive layer 20.

[0051] The method of applying the adhesive is not particularly limited, and known coating devices can be used. Examples of coating devices include gravure coaters, knife coaters, reverse coaters, bar coaters, spray coaters, spin coaters, die coaters, slit coaters, roll coaters, dip coaters, and the like.

[0052] In this specification, the uncured adhesive layer is the adhesive layer containing the coated electron beam-curable resin before it is cured by an electron beam.

[0053] An intermediate layer 30 is further laminated on the side of the uncured adhesive layer 20 opposite to the side on which the base layer 10 is laminated. As a result, the uncured adhesive layer 20 is laminated between the base layer 10 and the intermediate layer 30.

[0054] In the second adhesive coating step S12, a solvent-free adhesive containing the electron beam-curable (meth)acrylate resin described above is applied to the intermediate layer 30 to form an uncured adhesive layer 40.

[0055] A sealant layer 80 is further laminated on the side of the uncured adhesive layer 40 opposite to the side where the intermediate layer 30 is laminated. As a result, the uncured adhesive layer 40 is laminated between the intermediate layer 30 and the sealant layer 80.

[0056] As a result, as shown in Figure 4, a laminate 1' is obtained in which the base layer 10, the uncured adhesive layer 20, the intermediate layer 30, the uncured adhesive layer 40, and the sealant layer 80 are laminated in this order.

[0057] In the electron beam irradiation step S13, as shown in Figure 4, the uncured laminate 1' is irradiated with an electron beam EB.

[0058] The acceleration voltage of the irradiated electron beam is 50kV to 300kV, preferably 70kV to 250kV, and more preferably 90kV to 200kV. The mode of electron beam irradiation is not particularly limited, and known electron beam irradiation devices can be used. Examples of electron beam irradiation devices include scanning electron beam irradiation devices, curtain type electron beam irradiation devices, plasma discharge type electron beam irradiation devices, and the like.

[0059] As shown in Figure 4, the electron beam EB is irradiated from the substrate layer 10 side. In the uncured laminate 1', the substrate layer 10 is relatively thinner than the sealant layer 80, so irradiating from the substrate layer 10 side with the electron beam EB makes it easier to reach the uncured adhesive layers 20 and 40 within the laminate 1' than irradiating from the sealant layer 80.

[0060] In this case, the thickness of the laminate 1' excluding the sealant layer 80 is preferably 80 μm or less, more preferably 65 μm or less, and even more preferably 50 μm or less. The lower limit of the thickness of the laminate 1' excluding the sealant layer 80 is not particularly limited, but from the viewpoint of maintaining the function of the laminate, it is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more.

[0061] <<Second Embodiment>> The method for manufacturing the laminate according to this disclosure preferably further includes an adhesive heating step.

[0062] Figure 5 is a flowchart illustrating a method for manufacturing a laminate according to the second embodiment of this disclosure. In the second embodiment shown in Figure 5, parts common to the first embodiment shown in Figure 2 may be denoted by corresponding reference numerals and their descriptions may be omitted.

[0063] In Figure 5, the method for manufacturing the laminate according to the second embodiment includes an adhesive heating step S21, a first adhesive coating step S22, a second adhesive coating step S23, and an electron beam irradiation step S24.

[0064] In the adhesive heating step S21, the solvent-free adhesive described above is heated before application. In the second embodiment, the adhesive heating step S21 is performed before the first adhesive application step S22 and the second adhesive application step S23.

[0065] The method of heating the solvent-free adhesive is not particularly limited, and examples include installing a heating device in the storage tank or piping that supplies the solvent-free adhesive.

[0066] The temperature at which the solvent-free adhesive is heated is not particularly limited, but it is preferable to heat it to a temperature at which the viscosity of the solvent-free adhesive decreases to an extent that improves the coating properties of the solvent-free adhesive, depending on the type of solvent-free adhesive.

[0067] <<Third Embodiment>> The method for manufacturing a laminate according to this disclosure preferably further includes an adhesive heat retention step.

[0068] Figure 6 is a flowchart illustrating a method for manufacturing a laminate according to the third embodiment of this disclosure. In the third embodiment shown in Figure 6, parts common to the first embodiment in Figure 2 and / or the second embodiment in Figure 5 may be denoted by corresponding reference numerals and their descriptions may be omitted.

[0069] In Figure 5, the manufacturing method of the laminate according to the third embodiment includes an adhesive heating step S31, an adhesive heat retention step S32, a first adhesive coating step S33, a second adhesive coating step S34, and an electron beam irradiation step S35.

[0070] In the adhesive heat retention process S32, the heated solvent-free adhesive is kept at a constant temperature. In the third embodiment, the adhesive heat retention process S21 is performed after the adhesive heating process S31 and before the first adhesive coating process S22 and the second adhesive coating process S23.

[0071] The method for maintaining the heat of solvent-free adhesives is not particularly limited, and examples include installing a heating device in the storage tank or piping that supplies the solvent-free adhesive.

[0072] The temperature at which the solvent-free adhesive is kept warm is not particularly limited, but it is preferable to set the temperature at which the viscosity of the solvent-free adhesive is reduced to a degree that improves its coatability.

[0073] <<Fourth Embodiment>> The method for manufacturing a laminate according to this disclosure may further include a third adhesive coating step. Figure 9 is a flowchart illustrating the method for manufacturing a laminate according to the fourth embodiment. In the fourth embodiment shown in Figure 9, parts common to the first embodiment in Figure 2 may be denoted by corresponding reference numerals and their descriptions may be omitted.

[0074] In Figure 9, the manufacturing method of the laminate according to the fourth embodiment involves a first adhesive coating step S41, a second adhesive coating step S42, a third adhesive coating step S43, and an electron beam irradiation step S44.

[0075] In the third adhesive coating step S43, a solvent-free adhesive containing the electron beam-curable (meth)acrylate resin described above is applied to the intermediate layer 50 to form an uncured adhesive layer 60.

[0076] A sealant layer 80 is further laminated on the side of the uncured adhesive layer 60 opposite to the side on which the intermediate layer 50 is laminated. As a result, the uncured adhesive layer 60 is laminated between the intermediate layer 50 and the sealant layer 80. Consequently, a laminate is obtained in which the base layer 10, uncured adhesive layer 20, intermediate layer 30, uncured adhesive layer 40, intermediate layer 50, uncured adhesive layer 60, and sealant layer 80 are laminated in this order.

[0077] In the electron beam irradiation step S44, the uncured laminate (a laminate consisting of a base layer 10, an uncured adhesive layer 20, an intermediate layer 30, an uncured adhesive layer 40, an intermediate layer 50, an uncured third adhesive layer 60, and a sealant layer 80) is irradiated with an electron beam EB from the base layer 10 side.

[0078] In this case, the thickness of the uncured laminate excluding the sealant layer 80 is preferably 80 μm or less, more preferably 65 μm or less, and even more preferably 50 μm or less. The lower limit of the thickness of the uncured laminate excluding the sealant layer 80 is not particularly limited, but from the viewpoint of maintaining the function of the laminate, it is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more.

[0079] <<Fifth Embodiment>> The method for manufacturing a laminate according to this disclosure may further include a printing step. Figure 12 is a flowchart showing the method for manufacturing a laminate according to the fifth embodiment. In the fifth embodiment shown in Figure 12, parts common to the first embodiment in Figure 2 and / or the fourth embodiment in Figure 9 may be denoted by corresponding reference numerals and their descriptions may be omitted.

[0080] In Figure 12, the manufacturing method of the laminate according to the fifth embodiment involves a first adhesive coating step S51, a second adhesive coating step S52, a third adhesive coating step S53, a printing step S54, and an electron beam irradiation step S55.

[0081] In the printing process S54, the ink containing the electron beam-curable (meth)acrylate resin described above is printed on the opposite side of the substrate layer 10 from the side facing the intermediate layer 30 to form an uncured printed layer 70.

[0082] The manner in which the uncured print layer 70 is formed is not particularly limited, but a desired print pattern consisting of characters, figures, symbols, patterns, etc. is formed using such ink and a printing method such as gravure printing, offset printing, letterpress printing, screen printing, transfer printing, or flexographic printing.

[0083] This results in a laminate in which an uncured printing layer 70, a substrate layer 10, an uncured adhesive layer 20, an intermediate layer 30, an uncured adhesive layer 40, an intermediate layer 50, an uncured adhesive layer 60, and a sealant layer 80 are laminated in this order.

[0084] In the electron beam irradiation step S55, the uncured laminate (a laminate consisting of an uncured printed layer 70, a substrate layer 10, an uncured adhesive layer 20, an intermediate layer 30, an uncured adhesive layer 40, an intermediate layer 50, an uncured third adhesive layer 60, and a sealant layer 80) is irradiated with an electron beam EB from the substrate layer 10 side.

[0085] In this case, the thickness of the uncured laminate excluding the sealant layer 80 is preferably 80 μm or less, more preferably 65 μm or less, and even more preferably 50 μm or less. The lower limit of the thickness of the uncured laminate excluding the sealant layer 80 is not particularly limited, but from the viewpoint of maintaining the function of the laminate, it is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more.

[0086] In the method for manufacturing a laminate according to this disclosure, as described above, an electron beam (EB) with an acceleration voltage of 50kV to 300kV is irradiated from the substrate layer side onto a laminate in which multiple uncured adhesive layers using a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin are laminated. As a result, the EB can penetrate to the region in the laminate where the uncured adhesive layers are present, thereby simultaneously curing two adhesive layers in the uncured laminate.

[0087] Furthermore, even if the uncured laminate has a second intermediate layer and an uncured third adhesive layer laminated on top of it, the three adhesive layers in the uncured laminate can be cured simultaneously by irradiating it with an EB (electromagnetic beam) with an acceleration voltage of 50kV to 300kV from the substrate layer side.

[0088] In other words, even with a multilayer laminate formed by bonding multiple films together with an adhesive that hardens upon EB irradiation, a laminate with hardened adhesive can be obtained by simply irradiating the substrate layer with EB irradiation once. Therefore, the manufacturing method for laminates according to this disclosure can shorten the manufacturing lead time of the laminate without reducing the adhesive strength of each layer of the laminate, thereby increasing the manufacturing efficiency of the laminate.

[0089] Furthermore, the method for manufacturing a laminate according to this disclosure uses a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to form multiple adhesive layers. This allows multiple adhesive layers in an uncured laminate to be cured simply by EB irradiation, without requiring drying or aging steps. Therefore, the method for manufacturing a laminate according to this disclosure can increase the manufacturing efficiency of laminates while reducing environmental impact.

[0090] Furthermore, as mentioned above, if the thickness of the laminate excluding the sealant layer is 80 μm or less, EB can be sufficiently transmitted to areas within the laminate where uncured adhesive layers exist. Also, if the thickness of the laminate excluding the sealant layer is 80 μm or less, EB can be sufficiently transmitted into the laminate even if an aluminum foil intermediate layer or printed layer is present. Multiple adhesive layers within the uncured laminate can be reliably cured.

[0091] Furthermore, as mentioned above, if the thickness of the substrate layer is 35 μm or less, EB can easily penetrate each layer of the laminate containing multiple uncured adhesive layers, thus ensuring that the uncured adhesive layers are reliably cured.

[0092] Furthermore, as mentioned above, even when the thickness of the first intermediate layer is 35 μm or less, EB can easily penetrate each layer of the laminate containing multiple uncured adhesive layers, thus ensuring that the uncured adhesive layers are reliably cured.

[0093] Furthermore, as mentioned above, if the second intermediate layer is aluminum foil, barrier properties can be imparted to the laminate. Also, if the aluminum foil constituting the second intermediate layer is between 1 μm and 15 μm in thickness, the EB rays can sufficiently penetrate the aluminum foil. Therefore, even when the second intermediate layer is composed of aluminum foil, the uncured adhesive layer between the second intermediate layer and the sealant layer can be cured.

[0094] Furthermore, in the method for manufacturing a laminate according to this disclosure, the solvent-free adhesive can be melted by heating it before coating. As a result, even if the adhesive to be coated is solvent-free, the adhesive can be applied at a low viscosity, making it less likely for uneven coating of the adhesive to occur. Therefore, even when multiple adhesive layers constituting the laminate are formed using solvent-free adhesives, it is possible to prevent a decrease in the adhesive strength of each layer of the laminate.

[0095] Furthermore, as mentioned above, by maintaining the heat of the heated solvent-free adhesive, the temperature of the adhesive after heating can be maintained until immediately before coating. Therefore, the heated and melted adhesive can be coated while it is still at a low viscosity, further reducing the likelihood of uneven coating. As a result, even when multiple adhesive layers constituting the laminate are formed using solvent-free adhesives, a decrease in the adhesive strength of each layer of the laminate can be reliably prevented.

[0096] Furthermore, in the method for manufacturing a laminate according to this disclosure, as described above, an electron beam is irradiated from the substrate layer side onto a laminate in which an uncured printed layer printed with an ink containing an electron beam-curable (meth)acrylate resin is further laminated. Since the ink in the printed layer contains an electron beam-curable (meth)acrylate resin, even if a printed layer is laminated onto the laminate, the printed layer can be cured simultaneously with multiple adhesive layers.

[0097] This eliminates the need for drying and aging processes, thereby reducing environmental impact and increasing the manufacturing efficiency of laminates with printed layers.

[0098] <Equipment for manufacturing laminates> The laminate manufacturing apparatus of this disclosure is an apparatus for carrying out the laminate manufacturing method described above. Figure 3 is a schematic diagram of an apparatus for carrying out the laminate manufacturing method according to the first embodiment. The apparatus 100 shown in Figure 3 comprises a base material layer supply unit 101, a laminate winding unit 102, a transport unit 103, an adhesive storage unit 104, an adhesive supply unit 105, an adhesive coating unit 106, an intermediate layer supply unit 107, a sealant layer supply unit 108, and an electron beam irradiation unit 109.

[0099] The base material supply unit 101 supplies the base material layer 10 to the conveying unit 103. As shown in Figure 3, the base material supply unit 101 is configured as a supply roll. A long base material layer 10 is wound onto the supply roll. The base material supply unit 101 continuously supplies the wound base material layer 10 to the conveying unit 103.

[0100] The laminate winding unit 102 recovers the laminate 1 from the conveying unit 103. As shown in Figure 3, the laminate winding unit 102 is configured as a recovery roll. The recovered laminate 1 is wound onto this recovery roll in a roll shape. The laminate winding unit 102 continuously recovers the laminate 1 from the conveying unit 103.

[0101] The conveying unit 103 constitutes the manufacturing line for the laminate 1 and conveys the base material layer 10. The conveying unit 103 has a plurality of conveying rolls 103A, 103B, and 103C. Each conveying roll 103A to 103C rotates freely. The base material layer 10 is conveyed in the conveying direction D1 by the conveying rolls 103A and 103B that constitute the bonding roll, and by the rotation of 103A to 103C driven by the laminate winding unit 102.

[0102] The transport speed is arbitrary, but for example, it is 50 m / min or more, preferably 100 m / min to 300 m / min, and more preferably 150 m / min to 250 m / min.

[0103] The adhesive storage unit 104 stores solvent-free adhesives that serve as raw materials for the adhesive layers 20, 40, and 60. The adhesive storage unit 104 is, for example, a container, which is provided with a replenishment port (not shown) for replenishing the solvent-free adhesive and a supply port (not shown) for supplying the solvent-free adhesive to the adhesive supply unit 105. Multiple adhesive storage units 104 may be provided for each adhesive layer, in which case different adhesives can be supplied to each adhesive layer.

[0104] The adhesive storage section 104 is further provided with a heater (not shown). This heater has the function of heating the solvent-free adhesive stored in the adhesive storage section 104 to a predetermined temperature. The heater provided in the adhesive storage section 104 allows the solvent-free adhesive to be heated before coating. That is, in the adhesive storage section 104 equipped with the heater, the adhesive heating steps S21 and S31 in the second and third embodiments of the method for manufacturing a laminate of this disclosure are performed (see Figures 5 and 6).

[0105] The adhesive supply unit 105 supplies solvent-free adhesive to the transport unit 103. The adhesive supply unit 105 is, for example, a pipe. The pipe 105 is further composed of a main pipe 105A and branch pipes 105B and 105C. The main pipe 105A is connected to the supply port of the adhesive storage unit 104 and distributes the solvent-free adhesive supplied from the adhesive storage unit 104 to the branch pipes 105B and 105C. The branch pipes 105B and 105C each supply solvent-free adhesive to the adhesive coating unit 106. The pipe 105 can also be provided for each adhesive coating unit 106 without having a main pipe and branch pipes.

[0106] The adhesive supply unit 105 is further equipped with a heater (not shown). This heater has the function of heating the solvent-free adhesive supplied to the adhesive storage unit 105 to a predetermined temperature. The heater provided in the adhesive storage unit 105 allows the solvent-free adhesive to be heated before application, and also allows the heat of the solvent-free adhesive heated in the adhesive storage unit 104 to be maintained.

[0107] In other words, in the adhesive supply unit 105 equipped with a heater, the adhesive heating steps S21, S31 and / or adhesive heat retention step S32 in the second and third embodiments of the method for manufacturing the laminate of the present disclosure are performed (see Figures 5 and 6).

[0108] The adhesive coating unit 106 applies a solvent-free adhesive. The adhesive coating unit 106 is, for example, a nozzle. The nozzle 106 consists of nozzle heads 106A and 106B. Nozzle head 106A is connected to the branch pipe 105B and applies the solvent-free adhesive to the substrate layer 10 which is transported to the transport unit 103. Nozzle head 106B is connected to the branch pipe 106B and applies the solvent-free adhesive to the intermediate layer 30 which is laminated on the substrate layer 10 which is transported to the transport unit 103.

[0109] As a result, in nozzle head 106A, the solvent-free adhesive is applied to the base layer 10, forming an uncured adhesive layer 20, which is then laminated onto the base layer 10. In nozzle head 106B, the solvent-free adhesive is applied to the intermediate layer 30, forming an uncured adhesive layer 40, which is then laminated onto the intermediate layer 30.

[0110] In other words, in the adhesive coating section 106, the first adhesive coating steps S11, S22, S33 and / or the second adhesive coating steps S12, S23, S34 in the first, second, and third embodiments of the method for manufacturing the laminate of the present disclosure are performed (see Figures 2, 5, and 6).

[0111] The intermediate layer supply unit 107 supplies the intermediate layer 30 to the conveying unit 103. As shown in Figure 3, the intermediate layer supply unit 107 is configured as a supply roll. A long intermediate layer 30 is wound into a roll on this supply roll. As shown in Figure 3, the intermediate layer supply unit 107 supplies the long intermediate layer 30 to the conveying unit 103, and as it passes through the conveying roll 103A, it is laminated onto the uncured adhesive layer 20.

[0112] The sealant layer supply unit 108 supplies the sealant layer 80 to the conveying unit 103. As shown in Figure 3, the sealant layer supply unit 108 is configured as a supply roll. A long piece of sealant layer 80 is wound onto this supply roll. As shown in Figure 3, the long piece of sealant layer 80 is supplied to the conveying unit 103 from the sealant layer supply unit 108. After passing through the conveying roll 103B, it is laminated onto the uncured adhesive layer 40, resulting in an uncured laminate 1'.

[0113] The electron beam irradiation unit 109 irradiates the uncured laminate 1' (a laminate consisting of a base layer 10, an uncured adhesive layer 20, an intermediate layer 30, an uncured adhesive layer 40, and a sealant layer 80) with an electron beam EB. As shown in Figure 3, the electron beam irradiation unit 109 is located on the base layer 10 side of the laminate 1', near the laminate winding unit 102. In the electron beam irradiation unit 109, the acceleration voltage of the irradiated electron beam is controlled to be between 50kV and 300kV.

[0114] As a result, the electron beam irradiation unit 109 irradiates the uncured laminate 1' from the substrate layer 10 side with an electron beam EB having an acceleration voltage of 50kV to 300kV, as shown in Figures 3 and 4. That is, the electron beam irradiation unit 109 performs the electron beam irradiation steps S13, S24, and S35 in the first, second, and third embodiments of the method for manufacturing the laminate of this disclosure (see Figures 2, 5, and 6).

[0115] As a result, in the apparatus 100, the uncured layer of the laminate 1' hardens, and a laminate 1 (a laminate in which a base layer 10, an adhesive layer 20, an intermediate layer 30, an adhesive layer 40, and a sealant layer 80 are laminated) is obtained.

[0116] In the example of the apparatus shown in Figure 3, the nozzle head 106A of the adhesive coating section 106 is arranged to coat the substrate layer 10 with solvent-free adhesive, and the nozzle head 106B is arranged to coat the intermediate layer 30 with solvent-free adhesive. However, the manner in which the solvent-free adhesive is applied is not limited to this, and may also be as shown in Figure 7 below.

[0117] Figure 7 is a schematic diagram showing a modified example of an apparatus for manufacturing a laminate according to the first embodiment. In Figure 7, parts common to Figure 3 are denoted by the same or corresponding reference numerals and their descriptions are omitted. In the apparatus 200 shown in Figure 7, the nozzle head 206A of the adhesive coating section 206 is arranged to coat the intermediate layer 30 with solvent-free adhesive, and the nozzle head 206B is arranged to coat the sealant layer 80 with solvent-free adhesive.

[0118] In the case of applying a solvent-free adhesive, as shown in the apparatus 200 in Figure 7, the solvent-free adhesive is applied to the intermediate layer 30 by nozzle head 206A, forming an uncured adhesive layer 20. The solvent-free adhesive is also applied to the sealant layer 80 by nozzle head 206B, forming an uncured adhesive layer 40.

[0119] Figure 10 is a schematic diagram of an apparatus for carrying out the manufacturing method of the laminate according to the fourth embodiment. In Figure 10, parts common to Figure 3 are denoted by the same or corresponding reference numerals and their descriptions are omitted.

[0120] In the apparatus 300 shown in Figure 10, the piping constituting the adhesive supply section 305 further comprises a branch pipe 305D, the nozzle constituting the adhesive coating section 306 further comprises a nozzle head 306C, and the intermediate layer supply section 307 is composed of two supply rolls 307A and 307B.

[0121] A long intermediate layer 50 is wound into a roll on the supply roll 307B. In the intermediate layer supply section 307B, as shown in Figure 10, the long intermediate layer 50 is supplied to the conveying section 303, and after passing through the conveying roll 303B, it is laminated onto the uncured adhesive layer 40.

[0122] The nozzle head 306C of the adhesive coating unit 306 is connected to the branch pipe 305D of the adhesive supply unit 305 and applies a solvent-free adhesive to the intermediate layer 50 laminated on the base material layer 10 which is transported to the transport unit 303.

[0123] As a result, in the nozzle head 306C, a solvent-free adhesive is applied to the intermediate layer 50 to form an uncured adhesive layer 60, and the uncured adhesive layer 60 is laminated onto the intermediate layer 50. That is, in the adhesive coating section 306, in the fourth embodiment of the method for manufacturing the laminate of this disclosure, a third adhesive coating step S43 is further performed between the second adhesive coating step S42 and the electron beam irradiation step S44 (see Figure 9).

[0124] In the apparatus 300, the electron beam irradiation unit 309 further irradiates the uncured laminate 1' (a laminate in which a base layer 10, an uncured adhesive layer 20, an intermediate layer 30, an uncured adhesive layer 40, an intermediate layer 50, an uncured adhesive layer 60, and a sealant layer 80 are laminated) with an electron beam EB having an acceleration voltage of 50kV to 300kV from the base layer 10 side. That is, the electron beam irradiation unit 309 performs the electron beam irradiation step S44 in the fourth embodiment of the method for manufacturing a laminate of this disclosure (see Figure 9).

[0125] As a result, in the apparatus 300, the uncured layer of the laminate 1' hardens, and a laminate 1 (a laminate in which a base layer 10, an adhesive layer 20, an intermediate layer 30, an adhesive layer 40, an intermediate layer 50, an adhesive layer 60, and a sealant layer 80 are laminated) is obtained.

[0126] Figure 13 is a schematic diagram of an apparatus for manufacturing a laminate according to the fifth embodiment. In Figure 13, parts common to Figures 3 and / or 10 are denoted by the same or corresponding reference numerals and their descriptions are omitted.

[0127] In the apparatus 400 shown in Figure 13, a printing unit 410 is further provided between the sealant layer supply unit 408 and the electron beam irradiation unit 409. The configuration of the printing unit 410 is not particularly limited, and for example, the printing unit 410 may include a nozzle for dispensing ink, an ink tank (not shown) for storing ink, and the like.

[0128] The printing unit 410 prints an ink containing an electron beam-curable resin onto the outside (lower side in the figure) of the substrate layer 10. As a result, the ink containing the electron beam-curable resin is printed on the opposite side of the substrate layer 10 from the sealant layer 80 side, forming an uncured printed layer 70. In other words, the printing unit 410 performs the printing step S54 in the fifth embodiment of the method for manufacturing the laminate of this disclosure (see Figure 12).

[0129] In the apparatus 400, the electron beam irradiation unit 409 further irradiates the uncured laminate 1' (a laminate consisting of an uncured printed layer 70, a substrate layer 10, an uncured adhesive layer 20, an intermediate layer 30, an uncured adhesive layer 40, an intermediate layer 50, an uncured adhesive layer 60, and a sealant layer 80) with an electron beam EB having an acceleration voltage of 50kV to 300kV, starting from the uncured printed layer 70.

[0130] As a result, in the apparatus 400, the uncured layer of the laminate 1' hardens, and a laminate 1 (a laminate in which a printed layer 70, a base layer 10, an adhesive layer 20, an intermediate layer 30, an adhesive layer 40, an intermediate layer 50, an adhesive layer 60, and a sealant layer 80 are laminated) is obtained.

[0131] As described above, the manufacturing apparatus for the laminate of the present disclosure, when laminated using the manufacturing method for the laminate of the present disclosure, can obtain the same effects as those obtained in the manufacturing method for the laminate of the present disclosure. In other words, it is possible to obtain a laminate with improved manufacturing efficiency while reducing environmental impact without reducing the adhesive strength of each layer of the laminate.

[0132] <Packaging bag> The laminate 1 can be used to manufacture a packaging bag. The packaging bag only needs to have at least some of its components made from the laminate 1. The use of the packaging bag is not particularly limited, but it is suitable for use in applications where the contents are refilled once or multiple times into a main container used when the contents are consumed, such as for disposable use, refilling, storage, or storing goods.

[0133] The laminate 1 may have a portion for opening or cutting the packaging bag. The portion for opening or cutting may have a structure processed in the thickness direction of the film, such as a perforation, notch, or half-cut groove, or it may have a shape that suggests opening or cutting within the surface of the film, such as a thinly protruding spout, or it may be an indication such as an arrow, line, or dot printed on it. Cutting the packaging bag is not limited to cutting the opening portion, but may also be used to cut between or around packaging bags in areas where two or more packaging bags are formed in a continuous manner, or in areas where tags or display portions are continuous around the packaging bag.

[0134] Specific examples of packaging bags are not limited to pillow bags, flat bags, gusset bags, and standing pouches. Figure 14 shows an example of a packaging bag manufactured using a laminate. In Figure 14, the packaging bag 500 is a standing pouch formed from a pair of body members 501 and a bottom member 502 that is folded in half along a fold line 503.

[0135] The packaging bag 500 has two body members 501, one at the front and one at the back. The planar shapes of the front and back body members 501 may be the same. The bottom member 502 is folded in along a fold line 503 so that its outer surfaces face each other. Above the fold line 503, body seal portions 504 are formed on the left and right sides, and the inner surfaces of the front and back body members 501 are joined together. The inner surfaces of the body members 501 correspond to the sealant layer 80 of the laminate 1.

[0136] The bottom member 502 is sandwiched between the front and rear body members 501 with the fold line 503 facing upwards. Below the fold line 503, a bottom seal portion 505 is formed where the inner surface of the bottom member 502 is joined to the inner surface of the body member 501. The bottom seal portion 505 joins the area of ​​the bottom member 502 demarcated by the fold line 503 to the body member 501 on the same side in the front-to-back direction. By spreading the bottom member 502 relative to the fold line 503, the packaging bag 500 can be made to stand on its own.

[0137] If the packaging bag 500 has a body member 501 and a bottom member 502, the laminate 1 of the embodiment may be used for either the body member 501 or the bottom member 502, or for both. From the viewpoint of improving tearability, it is preferable to use the laminate 1 for the body member 501. Such a packaging bag 500 is suitable for packaging applications that enclose liquids.

[0138] The dimensions of the 500 packaging bag are not particularly limited, but for example, when used as a refillable container, the height in the vertical direction is approximately 80-500 mm, the width in the horizontal direction is approximately 70-300 mm, and the filling volume is approximately 80-3000 cm³. 3The degree can be mentioned. The state of the contents can be fluids such as liquids, powders, or granules, or solids such as articles. The type of contents is not particularly limited, but can be detergents, chemicals, cosmetics, pharmaceuticals, beverages, seasonings, inks, paints, fuels, etc.

[0139] The packaging bag 500 may have a filling opening, a spout, etc. For example, the top of the packaging bag 500 may be open between the front and rear body members 501, allowing it to be used for filling or dispensing contents. After filling with contents, the body members 501 may be joined together to seal the packaging bag 500. When opening the packaging bag 500, the area where the body members 501 were joined can be easily torn. Although not specifically shown, the spout may be formed in a shape that protrudes thinly from the top or corner of the packaging bag 500. The spout may be made of film or of the spout type. When a spout is installed diagonally in the corner, biaxial stretching is advantageous in terms of drop strength, etc.

[0140] The packaging bag 500 may be formed solely from the laminate 1, or it may be combined with accessories such as labels, tags, straws, and outer boxes.

[0141] Since the packaging bag of this disclosure uses the laminate of this disclosure, the same effects as those of the laminate can be obtained. In other words, it is possible to obtain a packaging bag that improves manufacturing efficiency while reducing environmental impact without reducing the adhesive strength of each layer of the laminate that constitutes the packaging bag. [Examples]

[0142] The present invention will be described in more detail below using examples. The examples and comparative examples were evaluated by the following tests.

[0143] [Laminate (test specimen)] Referring to Figures 1-6 and 8-10, laminates were prepared in the following order: a base layer, adhesive layer 1 (corresponding to the first adhesive layer), intermediate layer 1 (corresponding to the first intermediate layer), adhesive layer 2 (corresponding to the second adhesive layer), and sealant layer (Examples 1, 3-4, Comparative Examples 1-2), and a laminate in the following order: a base layer, adhesive layer 1, intermediate layer 1, adhesive layer 2, intermediate layer 2 (corresponding to the second intermediate layer), adhesive layer 3 (corresponding to the third adhesive layer), and sealant layer (Example 2).

[0144] [Adhesive strength] The adhesive strength of the laminate (test specimen) was measured. The adhesive strength was measured using a Tensilon tensile tester under the conditions of T-type peel, sample width 15 mm, gripping distance 10 mm, and tensile speed 300 mm / min in an atmosphere of 24°C and 65% RH. The adhesive strength was evaluated according to the following criteria. An evaluation of A to C was considered good, and a D was considered poor.

[0145] [Evaluation Criteria] A: No delamination occurred, but cohesive failure occurred in one of the layers of the laminate. B: Delamination occurred in a very small area, but delamination itself was hardly observed. C: Delamination was observed in several places. D: There were uncured areas, which caused cohesive failure of the adhesive, resulting in significantly weaker strength.

[0146] Furthermore, delamination refers to the separation of each layer—the base layer, intermediate layer, and sealant layer—from the adhesive layer within the laminate. Additionally, cohesive failure of any layer within the laminate refers to cohesive failure of the base layer, intermediate layer, and / or sealant layer within the laminate.

[0147] The following are examples of embodiments and comparative examples.

[0148] [Example 1] A laminate was prepared by layering PET resin (12 μm) as the base layer, EB-curable acrylic adhesive (2 μm) as adhesive layer 1, polyamide resin (Ny) (15 μm) as the intermediate layer, EB-curable acrylic adhesive (2 μm) as adhesive layer 2, and polyethylene (100 μm) as the sealant layer in this order. This laminate was irradiated with an electron beam (EB) with an acceleration voltage of 125 kV from the base layer side. The thickness from the irradiated surface (base layer) to adhesive layer 2 of the laminate was 31 μm. For Example 1, the conditions of the laminate and the evaluation results of the adhesive strength between the base layer and intermediate layer 1 and the adhesive strength between intermediate layer 1 and the sealant layer are shown in Table 1.

[0149] [Example 2] A laminate was prepared by further laminating a 7 μm aluminum foil as an intermediate layer 2 and a 2 μm EB-curable acrylic adhesive as an adhesive layer 3 between the adhesive layer 2 and the sealant layer, in that order. The thickness of the laminate from the irradiation surface (substrate layer) to adhesive layer 3 was 40 μm. The laminate was prepared and evaluated in the same manner as in Example 1. The conditions and evaluation results for Example 2 are shown in Table 1.

[0150] [Example 3] A laminate was prepared with adhesive layer 1 consisting of an EB-curing acrylic adhesive with a thickness of 1.5 μm, and adhesive layer 2 consisting of an EB-curing acrylic adhesive with a thickness of 2.5 μm. The laminate was prepared and evaluated in the same manner as in Example 1. The conditions and evaluation results for Example 3 are shown in Table 1.

[0151] [Example 4] A laminate was prepared with a PET resin base layer with a thickness of 30 μm. The thickness from the irradiation surface (base layer) to adhesive layer 2 of the laminate was 49 μm. Otherwise, the laminate was prepared and evaluated in the same manner as in Example 1. The conditions and evaluation results for Example 4 are shown in Table 1.

[0152] [Comparative Example 1] The laminate was irradiated with an electron beam (EB) from the sealant layer side. The thickness from the irradiated surface (sealant layer) to the substrate layer of the laminate was 119 μm. Otherwise, the laminate was prepared and evaluated in the same manner as in Example 1. The conditions and evaluation results for Comparative Example 1 are shown in Table 1.

[0153] [Comparative Example 2] The acceleration voltage of the EB used for irradiation was set to 40kV. Otherwise, the laminate was fabricated and evaluated in the same manner as in Example 1. The conditions and evaluation results for Comparative Example 2 are shown in Table 1.

[0154] [Table 1]

[0155] Table 1 shows that in Examples 1 to 4, laminates obtained by irradiating a laminate, which consisted of two or more uncured adhesive layers using a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin, with an electron beam (EB) at an accelerating voltage of 125 kV from the substrate layer side, exhibited good adhesive strength in each layer.

[0156] On the other hand, as in Comparative Example 1, the laminate obtained by irradiating the sealant layer with an electron beam (EB) from the sealant layer side had poor adhesion strength in each layer. Also, as in Comparative Example 2, the laminate in which the electron beam (EB) acceleration voltage was less than 50kV had poor adhesion strength between the intermediate layer and the sealant layer.

[0157] The embodiments disclosed above include, for example, the following aspects:

[0158] <1> A method for manufacturing a laminate in which a base layer, a first adhesive layer, a first intermediate layer, a second adhesive layer, and a sealant layer are laminated in this order, A first adhesive coating step involves applying a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to the substrate layer to form an uncured first adhesive layer, A second adhesive coating step involves coating the first intermediate layer with a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to form an uncured second adhesive layer, A method for manufacturing a laminate, comprising: an electron beam irradiation step of irradiating a laminate, in which the substrate layer, the uncured first adhesive layer, the first intermediate layer, the uncured second adhesive layer, and the sealant layer are laminated, with an electron beam having an acceleration voltage of 50 kV or more and 300 kV or less from the substrate layer side.

[0159] <2> A second intermediate layer and a third adhesive layer are further laminated between the second adhesive layer and the sealant layer in this order. The process includes a third adhesive coating step of applying a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to the second intermediate layer to form an uncured third adhesive layer, In the electron beam irradiation step, the electron beam is irradiated onto the laminate, which is formed by laminating the substrate layer, the uncured first adhesive layer, the first intermediate layer, the uncured second adhesive layer, the second intermediate layer, the uncured third adhesive layer, and the sealant layer. <1> A method for manufacturing the laminate described above.

[0160] <3> The thickness of the laminate excluding the sealant layer is 80 μm or less. <1> or <2> A method for manufacturing the laminate described above.

[0161] <4> The thickness of the substrate layer is 35 μm or less. <1> ~ <3> A method for manufacturing a laminate according to any one of the items.

[0162] <5> The thickness of the first intermediate layer is 25 μm or less. <1> ~ <4> A method for manufacturing a laminate according to any one of the items.

[0163] <6> The above-mentioned second intermediate layer is an aluminum foil with a thickness of 1 μm or more and 15 μm or less. <2> ~ <5> A method for manufacturing a laminate according to any one of the items.

[0164] <7> The above includes an adhesive heating step of heating the solvent-free adhesive before coating. <1> ~ <6> A method for manufacturing a laminate according to any one of the items.

[0165] <8> The above includes an adhesive heat retention step for maintaining the heat of the heated solvent-free adhesive. <7> A method for manufacturing the laminate described above.

[0166] <9> Furthermore, additional printing layers are added. The printing process includes printing an ink containing an electron beam-curable (meth)acrylate resin onto the opposite side of the substrate layer and the sealant layer to form an uncured printed layer, In the electron beam irradiation step, the electron beam is irradiated onto the laminate in which the printed layer is further stacked. <1> ~ <8> A method for manufacturing a laminate according to any one of the items.

[0167] <10> the above <1> ~ <9> A laminate manufactured by any one of the manufacturing methods described in item 1.

[0168] <11> the above <10> A packaging bag formed using the laminate described above.

[0169] Although embodiments of this disclosure have been described above, the present invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope of the invention as described in the claims. [Explanation of Symbols]

[0170] 1, 2, 3 laminates 1' Uncured adhesive layer 10 Base material layer 20 Adhesive layer 30 Middle Class 40 Adhesive layer 50 Middle Class 60 Adhesive layer 70 printing layer 80 sealant layer 100, 200, 300, 400 devices 101, 201, 301, 401 Base material layer supply section 102, 202, 302, 402 Laminate winding section 103, 203, 303, 403 Conveyor Unit 103A, 203A, 303A, 403A, 103B, 203B, 303B, 403B, 103C, 203C, 303C, 403C, 303D, 403D Conveyor Rolls D1, D2, D3, D4 Conveying direction 104, 204, 304, 404 Adhesive storage section 105, 205, 305, 405 Adhesive supply unit 105A, 205A, 305A, 405A, 105B, 205B, 305B, 405B, 105C, 205C, 305C, 405C, 305D, 405D Branch pipe 106, 206, 306, 406 Adhesive coating section 106A, 206A, 306A, 406A, 106B, 206B, 306B, 406B, 306C, 406C Nozzle Head 107, 207, 307, 407 Middle layer supply section 108, 208, 308, 408 Sealant layer supply section 109, 209, 309, 409 Electron beam irradiation section 109 410 Printing Department EB electron beam 500 packaging bags 501 Body parts 502 Bottom member 503 Fold line 504 Body seal section 505 Bottom seal section

Claims

1. A method for manufacturing a laminate in which a base layer, a first adhesive layer, a first intermediate layer, a second adhesive layer, and a sealant layer are laminated in this order, A first adhesive coating step involves applying a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to the substrate layer to form an uncured first adhesive layer, A second adhesive coating step involves coating the first intermediate layer with a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to form an uncured second adhesive layer, A method for manufacturing a laminate, comprising: an electron beam irradiation step of irradiating a laminate, in which the substrate layer, the uncured first adhesive layer, the first intermediate layer, the uncured second adhesive layer, and the sealant layer are laminated, with an electron beam having an acceleration voltage of 50 kV or more and 300 kV or less from the substrate layer side.

2. A second intermediate layer and a third adhesive layer are further laminated between the second adhesive layer and the sealant layer in this order. The process includes a third adhesive coating step of applying a solvent-free adhesive containing an electron beam-curable (meth)acrylate resin to the second intermediate layer to form an uncured third adhesive layer, The method for manufacturing a laminate according to claim 1, wherein in the electron beam irradiation step, the electron beam is irradiated onto a laminate comprising the substrate layer, the uncured first adhesive layer, the first intermediate layer, the uncured second adhesive layer, the second intermediate layer, the uncured third adhesive layer, and the sealant layer.

3. The method for manufacturing a laminate according to claim 1, wherein the thickness of the laminate excluding the sealant layer is 80 μm or less.

4. The method for manufacturing a laminate according to claim 1, wherein the thickness of the base material layer is 35 μm or less.

5. The method for manufacturing a laminate according to claim 1, wherein the thickness of the first intermediate layer is 25 μm or less.

6. The method for manufacturing a laminate according to claim 2, wherein the second intermediate layer is an aluminum foil with a thickness of 1 μm or more and 15 μm or less.

7. A method for manufacturing a laminate according to claim 1, comprising an adhesive heating step of heating the solvent-free adhesive before coating.

8. A method for manufacturing a laminate according to claim 7, comprising an adhesive heat retention step for maintaining the heat of the heated solvent-free adhesive.

9. Furthermore, additional printing layers are added. The printing process includes printing an ink containing an electron beam-curable (meth)acrylate resin onto the opposite side of the substrate layer from the side facing the sealant layer to form an uncured printed layer, The method for manufacturing a laminate according to claim 1, wherein the electron beam irradiation step involves irradiating the laminate, in which the printed layers are further stacked, with the electron beam.

10. A laminate manufactured by the manufacturing method described in any one of claims 1 to 9.

11. A packaging bag formed using the laminate described in claim 10.

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