Laminate and packaging bag

Abstract

To provide a laminate and a packaging bag that can prevent a component of an adhesive resin layer from dissolving into content and can prevent delamination from occurring between layers of the laminate.SOLUTION: A laminate 20 includes a substrate layer 21, a barrier layer 22, an adhesive layer 25, and a multilayer sealant layer 30 arranged sequentially from an outer surface 201 side toward an inner surface 202 side. The multilayer sealant layer 30 has a penetration blocking layer 31, an adhesive resin layer 32, and a liquid contact layer 33 arranged sequentially from the outer surface 201 side toward the inner surface 202 side. The adhesive resin layer 32 has heat resistance. The liquid contact layer 33 contains a polyolefin having heat resistance.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present disclosure relates to a laminate and a packaging bag. [Background technology]

[0002] 2. Description of the Related Art In recent years, packaging bags for enclosing ink containing a solvent have become known (for example, Patent Documents 1 and 2).

[0003] Patent Document 1 discloses a packaging material in which a sealant resin layer is laminated on both sides of a resin layer that serves as a core material of a coextrusion layer, with an adhesive resin layer being interposed between the sealant resin layer and the barrier layer, the resin being made by modifying a polyolefin resin such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, or ethylene-vinyl alcohol copolymer with a carbonyl group, and a reinforced resin layer made of polyethylene terephthalate, polyester, polyamide, or polypropylene is formed between the coextrusion layer and the barrier layer.

[0004] Patent Document 2 discloses a laminated sheet including a base layer disposed on the outside, a barrier layer containing a metal element disposed on the inside of the base layer, an intermediate layer containing polyamide disposed on the inside of the barrier layer, and an innermost layer containing polyethylene disposed on the inside of the barrier layer. In this laminated sheet, the innermost layer is made of a single polyethylene having a melting point of 120°C or higher and 129°C or lower, with one melting point peak. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5918462 [Patent Document 2] Patent Publication No. 2022-46080 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the contents contain a highly soluble solvent, the solvent is likely to penetrate into the sealant layer (innermost layer). When the solvent penetrates into the sealant layer in this way, the solvent may reach the adhesive resin layer that bonds the layers together. In this case, the components of the adhesive resin layer may dissolve into the solvent. When the components of the adhesive resin layer dissolve into the solvent in this way, the components of the adhesive resin layer may clog the filter of the inkjet printer. In addition, when the solvent reaches the adhesive layer that bonds the layers together, delamination (interlayer peeling) may occur between the layers that are bonded together by the adhesive layer.

[0007] The present disclosure has been made in consideration of these points, and aims to provide a laminate and a packaging bag that can prevent the components of the adhesive resin layer from dissolving into the contents and can prevent delamination from occurring between the layers of the laminate. [Means for solving the problem]

[0008] The embodiments of the present disclosure relate to the following [1] to [7].

[0009] [1] A laminate used for a packaging bag for enclosing ink, The laminated ... The multi-layer sealant layer has a permeation barrier layer, an adhesive resin layer, and a liquid-contacting layer, which are arranged in this order from the outer surface side to the inner surface side, The adhesive resin layer has heat resistance, The liquid-contacting layer comprises a heat-resistant polyolefin.

[0010] [2] The laminate according to [1], wherein the liquid-contacting layer has a peak melting temperature observed in the range of 110°C or higher and 140°C or lower.

[0011] [3] The liquid contact layer contains heat-resistant polypropylene, and the melting point of the polypropylene is 85°C or higher and 170°C or lower. The laminate according to [1] or [2].

[0012] [4] The liquid contact layer contains heat-resistant polyethylene, and the melting point of the polyethylene is 105°C or higher and 130°C or lower. The laminate according to any one of [1] to [3].

[0013] [5] The penetration barrier layer contains nylon. The laminate according to any one of [1] to [4].

[0014] [6] The adhesive resin layer contains an acid-modified polyolefin resin. The laminate according to any one of [1] to [5].

[0015] [7] A packaging bag comprising the laminate according to any one of [1] to [6].

Advantages of the Invention

[0016] According to the present disclosure, it is possible to suppress the component of the adhesive resin layer from dissolving into the contents and to suppress the occurrence of delamination between the layers of the laminate.

Brief Description of the Drawings

[0017] [Figure 1] Figure 1 is a front view showing an example of a packaging bag according to an embodiment of the present disclosure. [Figure 2A] Figure 2A is a cross-sectional view showing an example of a laminate according to an embodiment of the present disclosure. [Figure 2B] Figure 2B is a cross-sectional view showing another example of a laminate according to an embodiment of the present disclosure. [Diagram 3] Figure 3 is a graph for explaining the melting peak temperature of the laminate according to an embodiment of the present disclosure. [Figure 4]4(a)-(c) are cross-sectional views illustrating a method for manufacturing a laminate according to an embodiment of the present disclosure. [Diagram 5] FIG. 5 is a cross-sectional view illustrating the function of the packaging bag according to the embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view illustrating the operation of the packaging bag according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] An embodiment will be described below with reference to the drawings. FIGS. 1 to 6 are diagrams showing an embodiment. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, the present invention can be modified appropriately within the scope of the technical concept. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values ​​such as the dimensions of each member and the material names described in this specification are examples of an embodiment, and are not limited to these, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are interpreted to include substantially the same state in addition to their strict meanings.

[0019] (Packaging bag composition) First, an overview of a packaging bag 10 according to one embodiment of the present disclosure will be described with reference to FIG.

[0020] The packaging bag 10 shown in Fig. 1 is a packaging bag for enclosing ink. The packaging bag 10 is a bag formed by partially joining inner surfaces 202 (see Figs. 2A and 2B) of a film-like laminate 20 described below. The packaging bag 10 has a first surface 11 and a second surface 12 formed by the laminate 20.

[0021] As shown in FIG. 1, the packaging bag 10 includes a first end 13, a second end 14 facing the first end 13 in a first direction D1, and a pair of side end portions 15 extending from the first end 13 to the second end 14 along the first direction D1. The first direction D1 is the conveying direction of the laminate 20 when the packaging bag 10 is produced from the film-like laminate 20, and is the so-called MD (Machine Direction). In the example shown in FIG. 1, the first end 13 and the second end 14 extend in a second direction D2 perpendicular to the first direction D1, and the packaging bag 10 has a rectangular outer shape. Although not shown, the first end 13 and the second end 14 may extend in a direction inclined with respect to the second direction D2.

[0022] In the packaging bag 10, the first surface 11 and the second surface 12 are bonded at a seal portion that joins the inner surfaces 202 of the film-like laminate 20 together. The seal portion has a first end seal portion 131 located at the first end 13, a second end seal portion 141 located at the second end 14, and a side end seal portion 151 located at a pair of side ends 15. As long as the inner surfaces 202 of the laminate 20 can be joined together to seal the packaging bag 10, the method for forming the seal portion is not particularly limited. For example, the seal portion may be formed by melting a part of the laminate 20 by heating or the like to weld the inner surfaces 202 of the laminate 20 together. In this case, the heat sealing method may be a known method such as bar sealing, rotating roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, etc. The width of the first end seal portion 131 and the second end seal portion 141 along the first direction D1 may be, for example, 5 mm or more and 20 mm or less. The width of the side end seal portion 151 in the second direction D2 can be set to, for example, not less than 5 mm and not more than 20 mm.

[0023] In addition, a spout 16 for pouring out the contents accommodated in the packaging bag 10 is provided at the first end seal portion 131. This spout 16 is formed in a cylindrical shape, and the laminate 20 constituting the first surface 11 and the laminate 20 constituting the second surface 12 are welded to the outer periphery of the spout 16.

[0024] The packaging bag 10 shown in Fig. 1 can be suitably used, for example, when sealing ink for an inkjet printer. In this embodiment, as described below, it is possible to prevent the solvent components contained in the contents from penetrating between the layers of the laminate 20 (described below) that constitutes the packaging bag 10. Therefore, it is possible to prevent delamination from occurring between the layers of the laminate 20.

[0025] The ink to be filled in the packaging bag 10 may be a solvent-based ink, a UV-based ink, an LED-based ink, or a water-based ink. Among these, the solvent-based ink may contain diethylene glycol diethyl ether (DEDE), dipropylene glycol monomethyl ether (MEDG), or γ-butyrolactone (GBL) as a solvent. In this embodiment, as described below, even if a solvent component contained in the contents penetrates into the multi-layer sealant layer 30 described below, the solvent component can be prevented from reaching the adhesive layer 25 (the second adhesive layer 25b in FIG. 2A or the third adhesive layer 25c in FIG. 2B) described below. Therefore, even if the solvent-based ink contains diethylene glycol diethyl ether (DEDE), dipropylene glycol monomethyl ether (MEDG), or γ-butyrolactone (GBL) as a solvent, the solvent can be prevented from reaching the adhesive layer 25. Of the above three solvents, dipropylene glycol monomethyl ether (MEDG) is most likely to permeate into the multi-layer sealant layer 30, followed by diethylene glycol diethyl ether (DEDE), and γ-butyrolactone (GBL) is least likely to permeate into the multi-layer sealant layer 30. The UV ink or LED ink may contain ethylene glycol monoethyl ether acetate as a solvent. The water-based ink may contain propylene glycol or the like as a solvent.

[0026] (Structure of Laminate) Next, a description will be given of the laminate 20 used in the above-mentioned packaging bag 10. The laminate 20 constituting the packaging bag 10 according to the present disclosure includes a base layer 21, a barrier layer 22, an adhesive layer 25, and a multi-layer sealant layer 30, which are arranged in this order from the outer surface 201 side toward the inner surface 202 side. The laminate 20 may further include other layers, such as a printed layer.

[0027] Specifically, as shown in FIG. 2A, the laminate 20 includes a base layer 21, a first adhesive layer 25a, a barrier layer 22, a second adhesive layer 25b (adhesive layer 25), and a multi-layer sealant layer 30, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. The multi-layer sealant layer 30 also includes a permeation blocking layer 31, an adhesive resin layer 32, and a liquid-contacting layer 33, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. In this case, the base layer 21 constitutes the outer surface 201 of the laminate 20, and the liquid-contacting layer 33 of the multi-layer sealant layer 30 constitutes the inner surface 202 of the laminate 20. The outer surface 201 is the surface of the packaging bag 10 facing the opposite side to the contents, and the inner surface 202 is the surface facing the contents side. The thickness of the laminate 20 as shown in FIG. 2A can be, for example, 64 μm or more and 230 μm or less.

[0028] 2A, when the laminate 20 is composed of a base layer 21, a barrier layer 22, and a multilayer sealant layer 30, for example, a step of bonding layers other than the multilayer sealant layer 30 to the base layer 21 and the barrier layer 22 can be omitted when producing the laminate 20. Therefore, the number of steps required to produce the laminate 20 can be reduced.

[0029] As shown in FIG. 2B, the laminate 20 includes a base layer 21, a first adhesive layer 25a, a barrier layer 22, a second adhesive layer 25b, an intermediate layer 26, a third adhesive layer 25c (adhesive layer 25), and a multi-layer sealant layer 30, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. The multi-layer sealant layer 30 also includes a permeation blocking layer 31, an adhesive resin layer 32, and a liquid-contacting layer 33, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. In this case as well, the base layer 21 constitutes the outer surface 201 of the laminate 20, and the liquid-contacting layer 33 of the multi-layer sealant layer 30 constitutes the inner surface 202 of the laminate 20. The thickness of the laminate 20 as shown in FIG. 2B can be, for example, 64 μm or more and 230 μm or less.

[0030] 2B, when the laminate 20 is composed of a base layer 21, a barrier layer 22, an intermediate layer 26, and a multilayer sealant layer 30, the intermediate layer 26 can improve the puncture resistance and the like of the packaging bag 10. Therefore, the strength of the packaging bag 10 can be increased.

[0031] Each layer constituting the laminate will now be described.

[0032] <Base material layer> The base layer 21 is, for example, a layer that supports the multilayer sealant layer 30 and the like and enhances the strength of the entire laminate 20. Examples of materials that can be used to form the base layer 21 include films or sheets of polyamide resins such as nylon, or polyester resins such as polyethylene terephthalate or polybutylene terephthalate, and others.

[0033] As the above-mentioned resin film or sheet, an unstretched film may be used, or a stretched film that has been stretched uniaxially or biaxially may be used.

[0034] The thickness of such a base layer 21 may be, for example, not less than 5 μm and not more than 50 μm.

[0035] <Barrier layer> The barrier layer 22 is The barrier layer 22 is a layer for suppressing the transmission of oxygen gas and water vapor. For example, a material having a gas barrier property against oxygen gas or water vapor, or a light shielding property against sunlight, may be used as the barrier layer 22. Specifically, for example, aluminum foil, tin, lead, copper, iron, nickel, or an alloy thereof, or a thin metal vapor deposition layer of aluminum or the like may be used as the barrier layer 22. When aluminum foil is used as the barrier layer 22, the thickness of the barrier layer 22 may be 5 μm or more and 15 μm or less. By using aluminum foil as the barrier layer 22, the laminate 20 can be easily produced. When the content is a UV-based ink, it is preferable to use aluminum foil, a thin metal vapor deposition layer of aluminum or the like, or a transparent vapor deposition layer described later as the barrier layer 22.

[0036] When a metal vapor-deposited aluminum layer is used as the barrier layer 22, the thickness of the barrier layer 22 may be generally from 50 Å to 500 Å, and particularly from 100 Å to 300 Å. The surface of a support layer (not shown) supporting the above-mentioned vapor-deposited thin aluminum film may be coated in advance with, for example, a vapor deposition primer in order to enhance adhesion of the vapor-deposited film, or other required pretreatment may be optionally performed.

[0037] The barrier layer 22 may be a transparent vapor deposition layer that can be formed by a conventionally known method. In this case, the barrier layer 22 may be a transparent vapor deposition layer made of a vapor deposition layer of an inorganic oxide. In this way, the barrier layer 22 is a transparent vapor deposition layer, so that it is possible to impart or improve gas barrier properties that prevent the permeation of oxygen gas, water vapor, and the like while maintaining the permeability of the contents.

[0038] The transparent vapor deposition layer may be, for example, a vapor deposition layer of an oxide of silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc. In particular, for packaging bags, it is preferable to use a vapor deposition layer of aluminum oxide or silicon oxide.

[0039] Inorganic oxides are expressed as, for example, SiO X , AlO X MO X (wherein, M represents an inorganic element, and the range of the value of X varies depending on the inorganic element). The range of the value of X may be 0-2 for silicon (Si), 0-1.5 for aluminum (Al), 0-1 for magnesium (Mg), 0-1 for calcium (Ca), 0-0.5 for potassium (K), 0-2 for tin (Sn), 0-0.5 for sodium (Na), 0-1.5 for boron (B), 0-1.5 for titanium (Ti), 0-2 for lead (Pb), 0-2 for zirconium (Zr), and 0-1.5 for yttrium (Y). In the above, when X=0, it is a completely inorganic element (pure substance) and is not transparent, and the upper limit of the range of X is the value when it is completely oxidized. Silicon (Si) and aluminum (Al) are preferably used for the packaging material, and the value of x may range from 1.0 to 2.0 for silicon (Si) and from 0.5 to 1.5 for aluminum (Al).

[0040] The thickness of the transparent vapor deposition layer varies depending on the type of inorganic oxide used, but can be selected from the range of, for example, 50 Å to 2000 Å, preferably 100 Å to 1000 Å. For example, in the case of a vapor deposition layer of aluminum oxide or silicon oxide, the thickness may be 50 Å to 500 Å, more preferably 100 Å to 300 Å.

[0041] The deposition layer can be formed on a support layer (not shown). Examples of the deposition layer formation method include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. Specifically, for example, a deposition layer can be formed on a forming roller using a roller-type deposition layer formation device. In this case, the material constituting the support layer may be a plastic such as polyester, for example, polyethylene terephthalate or polybutylene terephthalate, or polyamide, for example, nylon. It is preferable that the plastic film constituting the support layer is stretched in a uniaxial or biaxial direction.

[0042] If necessary, a gas barrier coating film may be formed on the deposition layer. The gas barrier coating film is a film that functions as a layer that suppresses the permeation of oxygen gas, water vapor, etc. The gas barrier coating film is a film represented by the general formula R 1 n M(OR 2 ) m (In the formula, R 1 , R 2 represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the atomic valence of M. The gas barrier composition contains at least one alkoxide represented by the formula (I) and a polyvinyl alcohol resin and / or an ethylene-vinyl alcohol copolymer, and is further polycondensed by a sol-gel method in the presence of a sol-gel catalyst, an acid, water, and an organic solvent. The gas barrier coating film is preferably transparent.

[0043] The above general formula R 1 n M(OR 2 ) mAs the alkoxide represented by the formula (I), at least one of the following may be used: a partial hydrolyzate of an alkoxide, or a condensate of the hydrolysis of an alkoxide. In addition, the partial hydrolyzate of the alkoxide does not need to have all of the alkoxy groups hydrolyzed, and may be one in which one or more are hydrolyzed, or a mixture thereof. As the condensate of the hydrolysis of an alkoxide, a dimer or more of the partially hydrolyzed alkoxide, specifically, a dimer to hexamer, is used.

[0044] The above general formula R 1 n M(OR 2 ) m In the alkoxide represented by the formula (I), the metal atom represented by M can be silicon, zirconium, titanium, aluminum, or the like. Preferred metals include, for example, silicon and titanium. In the present disclosure, the alkoxide can be used alone or in the form of a mixture of two or more different metal atoms in the same solution.

[0045] In addition, the above general formula R 1 n M(OR 2 ) m In the alkoxide represented by the formula: 1 Specific examples of the organic group represented by the general formula R include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-hexyl, n-octyl, and the like. 1 n M(OR 2 ) m In the alkoxide represented by the formula: 2 Specific examples of the organic group represented by the formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, etc. In addition, these alkyl groups may be the same or different in the same molecule.

[0046] When preparing the gas barrier composition, for example, a silane coupling agent may be added. As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group may be used. In this embodiment, in particular, an organoalkoxysilane having an epoxy group is preferably used, and specifically, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. may be used. The above-mentioned silane coupling agents may be used alone or in combination of two or more.

[0047] <Middle Class> The intermediate layer 26 is a layer that improves the puncture resistance of the packaging bag 10 and increases the strength of the packaging bag 10. The material constituting the intermediate layer 26 may be, for example, a polyamide such as nylon, a polyester such as polyethylene terephthalate or polybutylene terephthalate, or a plastic such as linear low-density polyethylene (LLDPE). The plastic film constituting the intermediate layer 26 is preferably stretched in a uniaxial or biaxial direction. The intermediate layer 26 may be composed of a single layer or a plurality of layers. In this way, by providing the intermediate layer 26 in the laminate 20, the puncture resistance of the packaging bag 10 can be improved. The thickness of the intermediate layer 26 may be, for example, 12 μm or more and 50 μm or less.

[0048] <Multi-layer sealant layer> The multilayer sealant layer 30 is a layer for bonding the laminates 20 together, and is the innermost layer when the laminate is made into a packaging bag 10. As described above, the multilayer sealant layer 30 has the permeation blocking layer 31, the adhesive resin layer 32, and the liquid-contacting layer 33, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. The multilayer sealant layer 30 may be composed of a multilayer co-extruded film.

[0049] The permeation barrier layer 31 of the multilayer sealant layer 30 is a layer for preventing delamination between the multilayer sealant layer 30 and the barrier layer 22 or the intermediate layer 26 by blocking the permeation of the contents. The permeation barrier layer 31 may contain a polyamide such as nylon. The plastic film constituting the permeation barrier layer 31 may be an unstretched nylon film or a stretched nylon film stretched uniaxially or biaxially. When the plastic film constituting the permeation barrier layer 31 is an unstretched nylon film, the puncture resistance of the packaging bag 10 is improved, and the strength of the packaging bag 10 can be effectively increased.

[0050] The adhesive resin layer 32 of the multi-layer sealant layer 30 is a layer that bonds the permeation blocking layer 31 and the liquid contact layer 33 together. In this embodiment, the adhesive resin layer 32 has heat resistance.

[0051] The adhesive resin layer 32 can be formed by a conventionally known method, such as a melt extrusion lamination method or a sand lamination method. A heat-resistant resin is used as the thermoplastic resin that can be used for the adhesive resin layer 32. In this case, the adhesive resin layer 32 may contain an acid-modified polyolefin resin.

[0052] The liquid-contacting layer 33 of the multilayer sealant layer 30 is a layer for preventing the components of the adhesive resin layer 32 from dissolving into the contents. In this embodiment, the liquid-contacting layer 33 contains a heat-resistant polyolefin.

[0053] The liquid contact layer 33 may contain a heat-resistant polypropylene. In this specification, the term "heat-resistant polypropylene" refers to a block copolymer obtained by blending ethylene and propylene copolymer rubber (EPR) or the like in the polymerization process of polypropylene, and a polypropylene having a heat-resistant temperature of at least 85°C or more, which is a boiling sterilization level. The melting point of the heat-resistant polypropylene may be 85°C or more and 170°C or less, or 125°C or more and 170°C or less. In addition, the heat-resistant polypropylene is preferably a polypropylene having a heat resistance of 105°C or more, which is a semi-retort level. This can effectively prevent the components of the adhesive resin layer 32 from eluting into the contents. In this case, the melting point of the heat-resistant polypropylene may be 105°C or more and 160°C or less, or 130°C or more and 160°C or less. In addition, the density of the heat-resistant polypropylene is 9.0 kg / m 3 More than 9.1kg / m 3 It may be the following.

[0054] The liquid contact layer 33 may contain heat-resistant polyethylene. In this specification, "heat-resistant polyethylene" means polyethylene having a heat resistance of 105°C or more, which is a semi-retort level. In this case, the melting point of the heat-resistant polyethylene may be 105°C or more and 130°C or less. This makes it possible to effectively prevent the components of the adhesive resin layer 32 from eluting into the contents. In this case, the density of the polyethylene is 9.28 kg / m 3 More than 9.45kg / m 3 It may be the following.

[0055] The liquid contact layer 33 may have a melting peak temperature observed in the range of 110° C. or more and 140° C. or less, as shown in Fig. 3. Here, by observing the melting peak temperature in the liquid contact layer 33 in the range of 110° C. or more and 140° C. or less, for example, even when the packaging bag 10 is subjected to semi-retort sterilization, it is possible to effectively prevent the components of the adhesive resin layer 32 from eluting into the contents.

[0056] Such a melting peak temperature can be measured by differential scanning calorimetry (DSC).

[0057] <Differential Scanning Calorimetry (DSC)> In differential scanning calorimetry (DSC), the melting peak temperature is measured using a differential scanning calorimeter (manufactured by Hitachi High-Tech Science Corporation, product name: DSC7000X). Specifically, in accordance with JIS K7121:2012 (Method for measuring transition temperature of plastics), the liquid contact layer 33 is held at 20°C for 1 minute, and then heated from 20°C to 200°C at a heating rate of 10°C / min, to measure the melting peak temperature (°C). At this time, the flow rate of nitrogen gas is 20 ml / min.

[0058] The method for producing the multilayer co-extruded film constituting the multilayer sealant layer 30 is not particularly limited, and it can be produced by a conventionally known method. The multilayer co-extruded film is an extrusion-molded film, and the extrusion is preferably performed by a T-die method, an inflation method, or the like.

[0059] The thickness of the multi-layer sealant layer 30 may be, for example, not less than 50 μm and not more than 200 μm.

[0060] <Adhesive layer> Adhesive layers such as the first adhesive layer 25a, the second adhesive layer 25b and the third adhesive layer 25c are layers that are provided when bonding any two layers together, for example, between the base material layer 21 and the intermediate layer 26, or between the intermediate layer 26 and the multi-layer sealant layer 30, etc.

[0061] The adhesive layer can be formed by a conventional method, for example, a dry lamination method. When two layers are bonded by the dry lamination method, the adhesive layer is formed by applying an adhesive to the surface of the layer to be laminated and drying it. The adhesive to be applied can be, for example, a one-component or two-component cured or non-cured type vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, or other solvent-based, water-based, or emulsion-based adhesive. A two-component cured adhesive can be a cured product of a polyol and an isocyanate compound. The above-mentioned lamination adhesive can be applied by, for example, a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fountain method, a transfer roll coating method, or other methods.

[0062] <Print layer> The printing layer is a layer that forms any desired printed pattern such as letters, numbers, pictures, figures, symbols, patterns, etc., for decoration, display of contents, display of expiration date, display of manufacturer, seller, etc., and for imparting aesthetics. The printing layer can be provided as necessary, for example, between the base layer 21 and the intermediate layer 26, or between the intermediate layer 26 and the multi-layer sealant layer 30. The printing layer may be provided on the entire surface of the base layer 21, etc., or may be provided on a part of it. The printing layer can be formed using a conventionally known pigment or dye, and the method of forming it is not particularly limited, but when imparting light-shielding properties to the packaging bag 10, it is preferable that the printing layer contains a black pigment. The thickness of the printing layer can be, for example, 0.5 μm or more and 5 μm or less.

[0063] Next, the operation of the packaging bag 10 according to the present embodiment having such a configuration will be described. First, a method for producing the laminate 20 shown in Fig. 2A will be described with reference to Figs. 4(a)-(c), and then a method for producing the packaging bag 10 shown in Fig. 1 will be described.

[0064] 4(a), a first laminate film 20a is produced. In this case, for example, a resin film as the base layer 21 and an aluminum foil as the barrier layer 22 are first prepared.

[0065] Next, the resin film as the base material layer 21 and the aluminum foil as the barrier layer 22 are bonded together by a dry lamination method. As a result, the base material layer 21 and the barrier layer 22 are bonded together via the first adhesive layer 25a. In this manner, a first laminated film 20a is obtained, as shown in FIG. 4(a).

[0066] Also, as shown in FIG. 4(b), a second laminated film 20b is produced as a multi-layer sealant layer 30. At this time, resin materials constituting the permeation blocking layer 31, the adhesive resin layer 32, and the liquid-contacting layer 33 are co-extruded. At this time, for example, nylon may be used as the material constituting the permeation blocking layer 31. Furthermore, a material having heat resistance is used as the material constituting the adhesive resin layer 32. For example, an acid-modified polyolefin resin may be used as the material constituting the adhesive resin layer 32. Furthermore, a polyolefin having heat resistance is used as the material constituting the liquid-contacting layer 33. In this way, as shown in FIG. 4(b), a second laminated film 20b is obtained.

[0067] Next, the first laminate film 20a and the second laminate film 20b are bonded to each other by a dry lamination method. As a result, the first laminate film 20a and the second laminate film 20b are bonded to each other via the second adhesive layer 25b. In this manner, the laminate 20 is obtained as shown in FIG. 4(c). Although not shown, such a laminate 20 is wound up in a roll and stored.

[0068] Next, the packaging bag 10 is produced using the laminate 20. In this case, for example, a strip-shaped laminate 20 is continuously unwound from the laminate 20 wound in a roll shape, and this is overlapped with another strip-shaped laminate 20. Next, a position corresponding to the vicinity of a pair of side ends 15 of the packaging bag 10 is heat-sealed to form a pair of side end seal parts 151. Next, the two sheets of the laminate 20 heat-sealed at the pair of side end seal parts 151 are cut into the shape of the packaging bag 10 and separated into individual pieces. Next, the spout 16 is inserted into the part corresponding to the first end 13, and a position corresponding to the vicinity of the first end 13 is heat-sealed to form the first end seal part 131. In this manner, a packaging bag 10 with an open second end 14 is obtained.

[0069] Next, ink is filled as the content into the packaging bag 10 with the second end 14 open. At this time, the content is filled into the packaging bag 10 from the open second end 14.

[0070] Next, the vicinity of second end 14 of packaging bag 10 is heat-sealed to form second end seal portion 141, and second end 14 of packaging bag 10 is closed. In this manner, the contents are sealed in packaging bag 10. Packaging bag 10 with the contents sealed therein is shipped and stored in a store, warehouse, or the like.

[0071] During such storage, the solvent component SC contained in the contents may permeate into the multilayer sealant layer 30, and the solvent component SC may reach the adhesive resin layer 32 of the multilayer sealant layer 30. In this case, the component AC of the adhesive resin layer 32 may dissolve into the contents via the solvent component SC. If the component AC of the adhesive resin layer 32 dissolves into the contents in this way, the component AC of the adhesive resin layer 32 may clog the filter of the inkjet printer.

[0072] In contrast, in this embodiment, the adhesive resin layer 32 of the multi-layer sealant layer 30 has heat resistance. Therefore, even if the solvent component SC contained in the contents reaches the adhesive resin layer 32 of the multi-layer sealant layer 30, the component AC of the adhesive resin layer 32 can be prevented from being dissolved by the solvent component SC. In addition, the liquid-contact layer 33 of the multi-layer sealant layer 30 contains a polyolefin having heat resistance. As a result, even if the component AC of the adhesive resin layer 32 has dissolved as shown in FIG. 5, the liquid-contact layer 33 can prevent the component AC of the adhesive resin layer 32 from dissolving into the contents. Therefore, the component AC of the adhesive resin layer 32 can be prevented from dissolving into the contents. The fact that the component AC of the adhesive resin layer 32 can be prevented from dissolving into the contents will be described in the following examples.

[0073] During such storage, the solvent component SC contained in the contents may permeate between the layers of the laminate 20 constituting the packaging bag 10. If the solvent component SC contained in the contents permeates between the layers of the laminate 20, delamination may occur in the laminate 20 constituting the packaging bag 10. In this case, there is a risk that the contents sealed in the packaging bag 10 may leak out of the packaging bag 10.

[0074] In contrast, in this embodiment, the multi-layer sealant layer 30 has a permeation blocking layer 31, an adhesive resin layer 32, and a liquid-contacting layer 33, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. As a result, even if the solvent component SC contained in the contents permeates into the multi-layer sealant layer 30 as shown in FIG. 6, the permeation blocking layer 31 can suppress the permeation of the solvent component SC. Therefore, the solvent component SC can be suppressed from reaching the adhesive layer 25 (the second adhesive layer 25b in FIG. 2A or the third adhesive layer 25c in FIG. 2B) that bonds the multi-layer sealant layer 30 and the barrier layer 22 or the intermediate layer 26 to each other. As a result, the occurrence of delamination can be suppressed between the layers of the laminate 20, and the defect of the contents sealed in the packaging bag 10 leaking out of the packaging bag 10 can be suppressed. The fact that the defect of the contents sealed in the packaging bag 10 leaking out of the packaging bag 10 can be suppressed in this way will be explained by examples described later.

[0075] In addition, in this embodiment, the adhesive resin layer 32 of the multi-layer sealant layer 30 has heat resistance. Therefore, even if the solvent component SC contained in the contents permeates into the adhesive resin layer 32 of the multi-layer sealant layer 30, delamination between the permeation blocking layer 31 and the adhesive resin layer 32 can be suppressed. Particularly, in this embodiment, the multi-layer sealant layer 30 is composed of a multi-layer co-extrusion film. In this case, the interface between each layer of the multi-layer sealant layer 30 becomes unclear. That is, in the vicinity of the boundary between each layer, the resin constituting each layer is mixed. In this case, even in the vicinity of the boundary between the permeation blocking layer 31 and the adhesive resin layer 32, the resin constituting the permeation blocking layer 31 and the resin constituting the adhesive resin layer 32 are mixed. Therefore, even if the solvent component SC contained in the contents permeates into the adhesive resin layer 32 of the multi-layer sealant layer 30, delamination between the permeation blocking layer 31 and the adhesive resin layer 32 can be suppressed.

[0076] As described above, according to this embodiment, the laminate 20 includes the base layer 21, the barrier layer 22, the adhesive layer 25, and the multilayer sealant layer 30, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. The multilayer sealant layer 30 includes the permeation blocking layer 31, the adhesive resin layer 32, and the liquid-contacting layer 33, which are arranged in this order from the outer surface 201 side to the inner surface 202 side. The adhesive resin layer 32 has heat resistance. This makes it possible to prevent the component AC of the adhesive resin layer 32 from being dissolved by the solvent component SC, even if the solvent component SC contained in the contents reaches the adhesive resin layer 32 of the multilayer sealant layer 30. The liquid-contacting layer 33 of the multilayer sealant layer 30 contains a polyolefin having heat resistance. This makes it possible to prevent the component AC of the adhesive resin layer 32 from being dissolved into the contents, even if the component AC of the adhesive resin layer 32 is dissolved out, by the liquid-contacting layer 33. This makes it possible to prevent the component AC of the adhesive resin layer 32 from dissolving into the contents.

[0077] In addition, since the multi-layer sealant layer 30 has the permeation blocking layer 31, the adhesive resin layer 32, and the liquid-contacting layer 33 arranged in this order from the outer surface 201 side to the inner surface 202 side, the permeation blocking layer 31 can suppress the permeation of the solvent component SC. Therefore, the solvent component SC can be suppressed from reaching the adhesive layer 25 that bonds the multi-layer sealant layer 30 to the barrier layer 22 or the intermediate layer 26. As a result, the occurrence of delamination between each layer of the laminate 20 can be suppressed, and the defect that the contents enclosed in the packaging bag 10 leak out of the packaging bag 10 can be suppressed. In addition, since the solvent component SC contained in the contents can be suppressed from permeating between each layer of the laminate 20, the laminate strength between each layer of the laminate 20 can be stabilized. In addition, the seal strength between each laminate 20 in the packaging bag 10 can be stabilized.

[0078] According to the present embodiment, the permeation blocking layer 31 contains nylon. This effectively prevents the solvent component SC contained in the contents from permeating. This effectively prevents the solvent component SC from reaching the adhesive layer 25.

[0079] Furthermore, according to this embodiment, the adhesive resin layer 32 contains an acid-modified polyolefin resin. This effectively prevents the component AC of the adhesive resin layer 32 from dissolving into the content via the solvent component SC, even if the solvent component SC contained in the content reaches the adhesive resin layer 32 of the multilayer sealant layer 30.

[0080] In the above-described embodiment, an example has been described in which packaging bag 10 is a four-side sealed bag (flat pouch) sealed by first end seal portion 131, second end seal portion 141, and side end seal portion 151, but the present invention is not limited to this. For example, packaging bag 10 may be a stand-up bag, a gusset bag, or a pillow bag. EXAMPLES

[0081] Next, the operation of the above-described embodiment will be specifically described.

[0082] (Example) First, a biaxially stretched nylon film (EMBLEM ON-RT, 15 μm thick, manufactured by Unitika Ltd.) was prepared as a substrate layer, and an aluminum layer (Toyo Aluminum Co., Ltd., 9 μm thick) was prepared as a barrier layer.

[0083] Next, a nylon film and an aluminum foil were bonded together using a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base agent: RU-004, curing agent: H-1) to produce a first laminated film. The layer structure of the obtained first laminated film is expressed as follows. ONY / DL / ALM The " / " indicates the boundary between layers. "ONY" means biaxially oriented nylon film (hereinafter the same). "DL" means adhesive layer containing adhesive (hereinafter the same). "ALM" means aluminum foil (hereinafter the same).

[0084] In addition, a second laminated film (manufactured by Kurilon Chemical Co., Ltd., grade name: Laminar Ace, thickness 80 μm) was prepared as a multi-layer sealant layer by co-extruding unstretched nylon, which functions as a permeation blocking layer, and polypropylene, which functions as a liquid-contacting layer, with an adhesive resin (acid-modified polyolefin resin).

[0085] Next, the first laminate film and the second laminate film were bonded together using a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base: RU-004, curing agent: H-1) to produce a laminate. The layer structure of the obtained laminate is expressed as follows. ONY / DL / ALM / DL / CNY / PO / PP "CNY" means unstretched nylon (hereinafter the same). "PO" means an adhesive resin layer using an acid-modified polyolefin resin (hereinafter the same). "PP" means polypropylene (hereinafter the same).

[0086] Next, the obtained laminate was cut into two pieces having a size of 100 mm x 200 mm, and three sides were heat-sealed. In this way, a packaging bag having an opening formed on one side was produced. Next, diethylene glycol diethyl ether was filled into the obtained packaging bag from the opening as the content. Next, the vicinity of the opening of the packaging bag was heat-sealed to close the opening of the packaging bag, and a packaging bag containing the content was obtained.

[0087] <Dissolution test> The prepared package was stored in a 60°C environment for one week. Thereafter, the package was returned to room temperature, and the contents were removed from the package at room temperature. At this time, the opening was cut out, and the contents were removed using a screw tube. Then, it was confirmed whether the components of the adhesive resin layer had dissolved into the removed contents. In this case, it was confirmed by gas analysis using gas chromatography whether the components of the adhesive resin layer had dissolved.

[0088] Comparative Example 1 A laminate was produced in the same manner as in the examples, except that a co-extruded laminated film (thickness: 100 μm) having the following layer structure was used as the multi-layer sealant layer. Then, an elution test was conducted in the same manner as in the examples. (Layer structure of the laminated film used in Comparative Example 1) CNY / AD / EVOH / AD / LLDPE "AD" means an adhesive resin layer using an acid-modified polyolefin resin modified with an unsaturated carboxylic acid. "EVOH" means an ethylene-vinyl alcohol copolymer. "LLDPE" means linear low-density polyethylene. (Layer structure of the laminate according to Comparative Example 1) ONY / DL / ALM / DL / CNY / AD / EVOH / AD / LLDPE

[0089] (Comparative Example 2) A laminate was produced in the same manner as in the examples, except that a co-extruded laminated film (thickness: 100 μm) having the following layer structure was used as the multi-layer sealant layer. Then, an elution test was conducted in the same manner as in the examples. (Layer structure of the laminated film used in Comparative Example 2) LLDPE / AD / CNY / AD / LLDPE (Layer structure of the laminate according to Comparative Example 2) ONY / DL / ALM / DL / LLDPE / AD / CNY / AD / LLDPE

[0090] The above results are shown in Table 1.

[0091]

Table 1

[0092] As a result, as shown in Table 1, elution of the components of the adhesive resin layer was confirmed in the packaging bag according to Comparative Example 1 and the packaging bag according to Comparative Example 2. In contrast, elution of the components of the adhesive resin layer was not confirmed in the packaging bag according to the example. Thus, it was found that this embodiment can prevent the components AC of the adhesive resin layer 32 from eluting into the contents.

[0093] It is also possible to combine the multiple components disclosed in each of the above embodiments as necessary, or to delete some of the components disclosed in each of the above embodiments. [Explanation of symbols]

[0094] 10 packaging bags 20 Laminate 21 Base material layer 22 Barrier Layer 25 Adhesive layer 30 Multi-layer sealant layer 31 Permeation barrier layer 32 Adhesive resin layer 33 Wetted layer

Claims

1. A laminate used for a packaging bag for enclosing ink, The laminated ... The multi-layer sealant layer has a permeation barrier layer, an adhesive resin layer, and a liquid-contacting layer, which are arranged in this order from the outer surface side to the inner surface side, The adhesive resin layer has heat resistance, The liquid-contacting layer comprises a heat-resistant polyolefin.

2. The laminate according to claim 1 , wherein the liquid contact layer has a peak melting temperature observed in the range of 110° C. or higher and 140° C. or lower.

3. The laminate according to claim 1 , wherein the liquid contact layer contains a heat-resistant polypropylene, and the melting point of the polypropylene is 85° C. or higher and 170° C. or lower.

4. 2. The laminate according to claim 1, wherein the liquid contact layer contains heat-resistant polyethylene, and the melting point of the polyethylene is 105°C or higher and 130°C or lower.

5. The laminate of claim 1 , wherein the permeation barrier layer comprises nylon.

6. The laminate according to claim 1 , wherein the adhesive resin layer comprises an acid-modified polyolefin resin.

7. A packaging bag comprising the laminate according to any one of claims 1 to 6.

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