JP7104896B2 - Laminates and packaging bags - Google Patents

Description

The present disclosure relates to laminates and packaging bags.

2. Description of the Related Art In recent years, packaging bags for enclosing solvent-containing ink or the like have been known. Such a packaging bag is constructed by heat-sealing a surface film and a back film facing each other to form a seal portion. In addition, the packaging material (laminate) used for such packaging bags generally has a structure consisting of multiple layers using an aluminum film having water vapor barrier properties and light blocking properties ( For example, Patent Document 1).

Japanese Patent No. 5918462

However, in the packaging bag disclosed in Patent Document 1, even if the packaging material contains an aluminum film, the solvent component contained in the ink or the like penetrates to the layer located inside the aluminum film, Delamination can occur between layers of material. In addition, since the solvent component penetrates to the layers located inside the aluminum film, the lamination strength between the layers of the packaging material may decrease, and the sealing strength of the sealing portion of the packaging bag may decrease. As a result, the contents enclosed in the packaging bag may leak out of the packaging bag.

The present disclosure has been made in consideration of such points, suppressing the occurrence of delamination between the layers of the laminate, reducing the laminate strength between the layers of the laminate, and preventing the sealing in the packaging bag. An object of the present invention is to provide a laminate and a packaging bag capable of suppressing a decrease in strength.

The present disclosure is a laminate used in a packaging bag for enclosing contents containing a solvent, comprising a protective substrate layer and a multilayer sealant layer in this order, wherein the protective substrate layer is a substrate layer and a transparent layer provided on one surface of the base material layer, wherein the multilayer sealant layer has a core material, and the core material of the multilayer sealant layer contains an ethylene-vinyl alcohol copolymer. It is a laminate containing.

The present disclosure is a laminate in which the protective base layer further includes a gas barrier layer provided on a surface of the transparent layer opposite to the base layer.

The present disclosure is a laminate used in a packaging bag for enclosing contents containing a solvent, comprising a protective base layer, a reinforcing layer, and a multilayer sealant layer in this order, wherein the protective base layer is , a substrate layer, and a transparent layer provided on one surface of the substrate layer, the multilayer sealant layer comprising at least a first resin layer, a first adhesive resin layer, a core material, and a second It has two adhesive resin layers and a second resin layer in this order, the first resin layer of the multilayer sealant layer contains a polyamide, and the core material of the multilayer sealant layer is an ethylene-vinyl alcohol copolymer. A laminate comprising

The present disclosure is a laminate in which the protective base layer further includes a gas barrier layer provided on a surface of the transparent layer opposite to the base layer.

The present disclosure is a laminate in which the reinforcing layer includes polyamide, polyester or linear low density polyethylene.

The present disclosure is a laminate used in a packaging bag for enclosing contents containing a solvent, comprising a substrate layer, a barrier layer, and a multilayer sealant layer in this order, wherein the multilayer sealant layer includes a core material, and the core material of the multilayer sealant layer includes an ethylene-vinyl alcohol copolymer.

The present disclosure is a laminate used in a packaging bag for enclosing contents containing a solvent, comprising a substrate layer, a barrier layer, a reinforcing layer, and a multilayer sealant layer in this order, wherein the multilayer sealant The layer is a laminate having a core material, and the core material of the multilayer sealant layer contains an ethylene-vinyl alcohol copolymer.

The present disclosure is a laminate in which the reinforcing layer includes polyamide, polyester or linear low density polyethylene.

The present disclosure is a laminate in which the barrier layer includes an aluminum layer.

In the present disclosure, the multilayer sealant layer has at least a first resin layer, a first adhesive resin layer, the core material, a second adhesive resin layer, and a second resin layer in this order, and the One resin layer is a laminate containing polyamide, low density polyethylene or linear low density polyethylene.

The present disclosure is a laminate in which the multilayer sealant layer is composed of a multilayer co-extruded film.

The present disclosure is a packaging bag comprising a laminate according to the present disclosure.

According to the present disclosure, it is possible to suppress the occurrence of delamination between the layers of the laminate, and suppress the deterioration of the lamination strength between the layers of the laminate and the deterioration of the sealing strength of the packaging bag.

1 is a schematic front view showing an example of a packaging bag according to a first embodiment of the present disclosure; FIG. FIG. 2 is a cross-sectional view (cross-sectional view taken along lines II, III-II, and III in FIG. 1) showing the packaging bag according to the first embodiment of the present disclosure, showing the laminated bag according to the first embodiment of the present disclosure. It is a schematic cross section showing an example of a body. FIG. 3 is a cross-sectional view (cross-sectional view taken along lines II, III-II, and III in FIG. 1) showing the packaging bag according to the first embodiment of the present disclosure, showing the laminated bag according to the first embodiment of the present disclosure. FIG. 10 is a schematic cross-sectional view showing another example of the body; FIG. 4 is a schematic cross-sectional view showing an example of a laminate according to the second embodiment of the present disclosure. FIG. 5 is a schematic cross-sectional view showing another example of the laminate according to the second embodiment of the present disclosure. FIG. 6 is a diagram showing an example of a method for measuring lamination strength. FIG. 7 is a diagram showing an example of a method for measuring lamination strength. FIG. 8 is a diagram showing changes in tensile stress with respect to the distance between a pair of grippers. FIG. 9 is a diagram showing an example of a method for measuring seal strength. FIG. 10 is a diagram showing an example of a method for measuring seal strength.

(First embodiment)
A first embodiment of the present disclosure will be described below with reference to the drawings. 1 to 3 are diagrams showing the first embodiment of the present disclosure. The configurations shown in FIGS. 1 to 3 may include portions whose sizes, scales, etc. are changed from those of the actual ones for the sake of ease of illustration and understanding.

(Structure of packaging bag)
First, an outline of a packaging bag according to a first embodiment of the present disclosure will be described with reference to FIG.

The packaging bag 10 shown in FIG. 1 is formed by partially joining the inner surfaces 202 (see FIGS. 2 and 3) of the film-like laminate 20 to be described later. The packaging bag 10 has a first surface 11 and a second surface 12 configured by the laminate 20 .

As shown in FIG. 1, the packaging bag 10 includes a first end 13, a second end 14 facing the first end 13 in the first direction D1, and a second end 14 from the first end 13 to the second end 14. and a pair of side ends 15 extending along the first direction D1. The first direction D1 is the direction in which the laminate 20 is transported when the packaging bag 10 is produced from the film 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 orthogonal to the first direction D1, and the packaging bag 10 has a rectangular outer shape. Although not shown, the first end portion 13 and the second end portion 14 may extend in a direction inclined with respect to the second direction D2.

In the packaging bag 10 , the first surface 11 and the second surface 12 are adhered to each other at the sealing portion that joins the inner surfaces 202 of the film-like laminate 20 . The seal portions include a first end seal portion 131 located at the first end portion 13 , a second end seal portion 141 located at the second end portion 14 , and side end portions located at the pair of side end portions 15 . and a seal portion 151 . In addition, as long as the inner surfaces 202 of the laminate 20 can be joined to seal the packaging bag 10, the method for forming the seal portion is not particularly limited. For example, the sealing portion may be formed by melting a part of the laminate 20 by heating and welding the inner surfaces 202 of the laminate 20 together. At this time, as a method of heat sealing, for example, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing and ultrasonic sealing can be used. The widths of the first end seal portion 131 and the second end seal portion 141 along the first direction D1 can be, for example, 5 mm or more and 20 mm or less. Also, the width of the side end seal portion 151 along the second direction D2 can be, for example, 5 mm or more and 20 mm or less.

Also, the first end sealing portion 131 is provided with a pouring port 16 for pouring out the contents accommodated in the packaging bag 10 . The spout 16 is formed in a cylindrical shape, and the laminate 20 forming the first surface 11 and the laminate 20 forming the second surface 12 are welded to the outer periphery of the spout 16 .

The packaging bag 10 shown in FIG. 1 can be suitably used to enclose contents containing a solvent, such as inkjet inks, liquid preparations for medical use, and fluid contents such as industrial solvents. can. In this case, as will be described later, it is possible to suppress the penetration of the solvent component contained in the contents between the layers of the layered body 20, which constitutes the packaging bag 10, and thus between the layers of the layered body 20. , the occurrence of delamination can be suppressed.

(Structure of laminate)
Next, the laminate used for the packaging bag 10 described above will be described. A laminate constituting a packaging bag according to the present disclosure includes at least a protective base layer and a multilayer sealant layer in this order. The laminate may further comprise printed layers, other layers, and the like. 2 and 3 show examples of schematic cross-sectional views of laminates that constitute the packaging bag according to the present disclosure.

A laminate 20 shown in FIG. 2 includes a protective substrate layer 21 and a multilayer sealant layer 23 in this order. That is, the laminate 20 includes a protective substrate layer 21 positioned on the outer surface 201 side and a multilayer sealant layer 23 positioned on the inner surface 202 side. In the example shown in FIG. 2 , protective substrate layer 21 forms outer surface 201 of laminate 20 and multilayer sealant layer 23 forms inner surface 202 of laminate 20 . In addition, the outer surface 201 is the surface facing the opposite side of the contents in the packaging bag 10, and the inner surface 202 is the surface facing the contents side. The laminate 20 also includes an adhesive layer 25 positioned between the protective substrate layer 21 and the multi-layer sealant layer 23 . Note that the laminate 20 may further include other layers. The thickness of the laminate 20 as shown in FIG. 2 can be, for example, 64 μm or more and 230 μm or less.

As in the laminate 20 shown in FIG. 2 , when the laminate 20 is composed of a protective substrate layer 21 and a multilayer sealant layer 23 , when producing the laminate 20 , for example, the protective substrate layer 21 In contrast, the step of adhering layers other than the multilayer sealant layer 23 can be omitted. Therefore, the number of man-hours for manufacturing the laminate 20 can be reduced.

A laminate 20 shown in FIG. 3 includes a protective substrate layer 21, a reinforcing layer 22, and a multilayer sealant layer 23 in this order. That is, the laminate 20 includes a protective base layer 21 positioned on the outer surface 201 side, a multilayer sealant layer 23 positioned on the inner surface 202 side, and a reinforcing layer positioned between the protective base layer 21 and the multilayer sealant layer 23. 22. In the example shown in FIG. 3 , protective substrate layer 21 forms outer surface 201 of laminate 20 and multilayer sealant layer 23 forms inner surface 202 of laminate 20 . The laminate 20 also includes an adhesive layer 25 positioned between the protective base layer 21 and the reinforcing layer 22, and an adhesive layer 27 positioned between the reinforcing layer 22 and the multilayer sealant layer 23. there is Note that the laminate 20 may further include other layers. The thickness of the laminate 20 as shown in FIG. 3 can be, for example, 64 μm or more and 230 μm or less.

When the laminate 20 is composed of a protective substrate layer 21, a reinforcing layer 22, and a multilayer sealant layer 23, as in the laminate 20 shown in FIG. The piercing property can be improved. Therefore, the strength of the packaging bag 10 can be increased.

Each layer constituting the laminate will be described below.

Protective Base Material Layer The protective base material layer 21 is a layer for protecting the laminate 20 from external impacts and the like. As shown in FIGS. 2 and 3, the protective base layer 21 includes a base layer 211 and a transparent layer provided on one surface of the base layer 211 (the surface on the inner surface 202 side of the base layer 211). 212 , and a gas barrier layer 213 provided on the surface of the transparent layer 212 opposite to the substrate layer 211 . Among them, the base material layer 211 is a layer for supporting the reinforcement layer 22 and the multilayer sealant layer 23 and increasing the strength of the laminate 20 as a whole, for example. As a material constituting the base material layer 211, for example, plastic such as polyester such as polyethylene terephthalate or polybutylene terephthalate, or polyamide such as nylon can be used. The plastic film forming the base layer 211 is preferably uniaxially or biaxially stretched.

The transparent layer 212 of the protective base material layer 21 is a layer for imparting or improving gas barrier properties that prevent permeation of oxygen gas, water vapor, and the like. In addition, the protective base material layer 21 may include two or more transparent layers 212 . When two or more transparent layers 212 are provided, they may have the same composition or may have different compositions.

The transparent layer 212 may be a transparent deposited layer that can be formed by a conventionally known method. In this case, the transparent layer 212 may be a transparent deposition layer made of an inorganic oxide deposition layer. As described above, since the transparent layer 212 is a transparent vapor deposition layer, it is possible to impart or improve gas barrier properties that prevent permeation of oxygen gas, water vapor, etc., while maintaining the permeability of the contents.

Examples of transparent deposited layers include 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. can be used. In particular, for packaging bags, it is preferable to have a deposited layer of aluminum oxide or silicon oxide.

Inorganic oxides are represented by MO _X such as SiO _X and AlO _X (wherein M represents an inorganic element, and the value of X varies depending on the inorganic element). expressed. The range of values of X is 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), 0 to 1 for calcium (Ca), Potassium (K) is 0 to 0.5, Tin (Sn) is 0 to 2, Sodium (Na) is 0 to 0.5, Boron (B) is 0 to 1.5, Titanium (Ti) can range from 0 to 2, lead (Pb) from 0 to 2, zirconium (Zr) from 0 to 2, and yttrium (Y) from 0 to 1.5. In the above, when X=0, it is a completely inorganic substance (pure substance) and not transparent, and the upper limit of the range of X is the fully oxidized value. Silicon (Si) and aluminum (Al) are preferably used for packaging materials, with silicon (Si) in the range of 1.0 to 2.0 and aluminum (Al) in the range of 0.5 to 1.5. values can be used.

Although the thickness of the transparent deposition layer varies depending on the type of inorganic oxide used, it is desirable to form the layer by selecting it arbitrarily within the range of, for example, 50 Å or more and 2000 Å or less, preferably 100 Å or more and 1000 Å or less. For example, in the case of a deposited layer of aluminum oxide or silicon oxide, the thickness is desirably 50 Å or more and 500 Å or less, more preferably 100 Å or more and 300 Å or less.

The vapor deposition layer can be formed on the substrate layer or the like using the following formation method. Examples of methods for forming the vapor deposition layer include physical vapor deposition methods such as vacuum deposition, sputtering, and ion plating (Physical Vapor Deposition, PVD), plasma chemical vapor deposition, and thermochemical vapor deposition. A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a chemical vapor deposition method and a photochemical vapor deposition method can be used. Specifically, a vapor deposition layer can be formed on a forming roller using a roller vapor deposition layer forming apparatus.

The gas barrier layer 213 of the protective base material layer 21 is a layer that functions as a layer that suppresses permeation of oxygen gas and water vapor. The gas barrier layer 213 has the general formula R ¹ _n M (OR ² ) _m (wherein R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n is , represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) and at least one or more alkoxides represented by ), polyvinyl alcohol-based resin and / or ethylene • A gas barrier composition containing a vinyl alcohol copolymer and polycondensed by the sol-gel method in the presence of a sol-gel catalyst, acid, water and an organic solvent. Note that the gas barrier layer 213 is preferably transparent.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , at least one of partial hydrolyzate of alkoxide and condensate of hydrolysis of alkoxide can be used. The partial hydrolyzate of the above alkoxide does not need to have all of the alkoxy groups hydrolyzed, and may be those in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. As the condensate obtained by hydrolysis of alkoxide, a partially hydrolyzed alkoxide dimer or higher, specifically a dimer to hexamer, is used.

In the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , the metal atom represented by M can be silicon, zirconium, titanium, aluminum, or the like. Preferred metals include, for example, silicon and titanium. In addition, in the present disclosure, alkoxides can be used singly or as a mixture of alkoxides of two or more different metal atoms in the same solution.

Further, in the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ¹ include a methyl group, an ethyl group, an n-propyl group, i -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group, and the like. Further, in the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ² include a methyl group, an ethyl group, an n-propyl group, i -propyl group, n-butyl group, sec-butyl group, and the like. These alkyl groups may be the same or different in the same molecule.

For example, a silane coupling agent may be added when preparing the gas barrier composition. Known organic reactive group-containing organoalkoxysilanes can be used as the silane coupling agent. In this embodiment, organoalkoxysilanes having an epoxy group are particularly preferably used, and specific examples include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β -(3,4-Epoxycyclohexyl)ethyltrimethoxysilane and the like can be used. The above silane coupling agents may be used singly or in combination of two or more.

The thickness of such a protective base material layer 21 can be, for example, 5 μm or more and 50 μm or less.

Reinforcing Layer The reinforcing layer 22 is a layer that improves the puncture resistance of the packaging bag 10 and enhances the strength of the packaging bag 10 . As a material constituting the reinforcing layer 22, for example, polyamide such as nylon, polyester such as polyethylene terephthalate or polybutylene terephthalate, or plastic such as linear low density polyethylene (LLDPE) can be used. The plastic film forming the reinforcing layer 22 is preferably uniaxially or biaxially stretched. Further, the reinforcing layer 22 may be composed of a single layer, or may be composed of a plurality of layers. By providing the reinforcing layer 22 in the laminate 20 in this way, the puncture resistance of the packaging bag 10 can be improved. Also, the thickness of the reinforcing layer 22 can be set to, for example, 12 μm or more and 50 μm or less.

Multi-Layer Sealant Layer The multi-layer sealant layer 23 is a layer for bonding the laminates 20 together, and is the innermost layer side when the packaging bag 10 is formed. This multilayer sealant layer 23 has at least a core material 233 . The multilayer sealant layer 23 is preferably made of a multilayer co-extruded film. As shown in FIGS. 2 and 3, in the present embodiment, the multilayer sealant layer 23 includes a first resin layer 231, a first adhesive resin layer 232, a core material 233, a second adhesive resin layer 234, and a second resin layer 235 in this order. Among these, the first resin layer 231 may contain, for example, polyamide such as nylon, low density polyethylene (LDPE), or linear low density polyethylene (LLDPE). These may be used alone or as a mixture of two or more. In addition, when the first resin layer 231 contains nylon, the plastic film forming the first resin layer 231 is preferably an unstretched nylon film. In this case, the puncture resistance of the packaging bag 10 can be improved, and the strength of the packaging bag 10 can be effectively increased. The second resin layer 235 may also contain, for example, low density polyethylene (LDPE) or linear low density polyethylene (LLDPE). These may also be used singly or as a mixture of two or more.

The core material 233 is a layer for imparting barrier properties such as water vapor barrier properties and gas barrier properties to the multilayer sealant layer 23 . This core material 233 contains ethylene-vinyl alcohol copolymer (EVOH). By including the ethylene-vinyl alcohol copolymer in the core material 233, the barrier properties of the multilayer sealant layer 23 can be enhanced. In this way, by increasing the barrier properties of the multilayer sealant layer 23, which is the innermost layer in the packaging bag 10, the solvent component contained in the contents is suppressed from permeating between the layers of the laminate 20. be able to. Therefore, it is possible to suppress the problem of delamination occurring between the layers of the laminate 20 . The thickness of the core material 233 can be, for example, 5 μm or more and 20 μm or less.

The first adhesive resin layer 232 and the second adhesive resin layer 234 of the multilayer sealant layer 23 are layers provided for bonding the first resin layer 231 and the core material 233, and the core material 233 and the second resin layer 235. .

The first adhesive resin layer 232 and the second adhesive resin layer 234 can be formed by a conventionally known method such as a melt extrusion lamination method or a sand lamination method. Thermoplastic resins that can be used for the adhesive resin layer include polyethylene-based resins, polypropylene-based resins, cyclic polyolefin-based resins, or copolymer resins, modified resins, or mixtures (including alloys) containing these resins as main components. ) can be used. Polyolefin resins include, for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), metallocene catalyst Ethylene-α-olefin copolymer polymerized using , ethylene-polypropylene random or block copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene- Ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-maleic acid copolymer, ionomer resin, adhesion between layers In order to improve the above-described polyolefin resin, it is possible to use an acid-modified polyolefin resin obtained by modifying the above polyolefin resin with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, or itaconic acid. can. In addition, a resin obtained by graft polymerization or copolymerization of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or an ester monomer can be used as the polyolefin resin. These materials can be used singly or in combination of two or more. Cyclic polyolefins such as ethylene-propylene copolymers, polymethylpentene, polybutene, and polynorbonene can be used as cyclic polyolefin resins. These resins can be used singly or in combination. When the adhesive resin layer is laminated by the melt extrusion lamination method, an anchor coat layer formed by applying an anchor coat agent and drying it may be provided on the surface of the layer to be laminated. Moreover, the plastic film constituting the multilayer sealant layer 23 is preferably uniaxially or biaxially stretched. The thickness of the multilayer sealant layer 23 can be, for example, 50 μm or more and 200 μm or less. Furthermore, the number of layers of the multilayer sealant layer 23 may be, for example, seven or five.

In addition, the multilayer sealant layer 23 described above may be formed by a dry lamination method. In this case, the first resin layer 231 and the core material 233, and the core material 233 and the second resin layer 235 are bonded to each other via an adhesive. Examples of adhesives include one-component or two-component curing or non-curing vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, etc. A solvent-type, water-based, or emulsion-type adhesive can be used. A cured product of a polyol and an isocyanate compound can be used as the two-liquid curing adhesive. Examples of coating methods for the lamination adhesive include a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, a transfer roll coating method, and other methods. .

Printed layer The printed layer contains letters, numbers, patterns, figures, symbols, and patterns for decoration, display of contents, display of expiration date, display of manufacturer, seller, etc., and other displays and aesthetics. It is a layer that forms any desired printed pattern such as The printed layer can be provided as necessary, for example, between the protective base layer 21 and the reinforcing layer 22, or between the reinforcing layer 22 and the multilayer sealant layer 23, or the like. The printed layer may be provided on the entire surface of the protective base material layer 21 or the like, or may be provided on a part thereof. The printed layer can be formed using conventionally known pigments and dyes, and the formation method is not particularly limited. However, when imparting a light-shielding property to the packaging bag 10, it preferably contains a black pigment. . The thickness of the printed layer can be, for example, 0.5 μm or more and 5 μm or less.

Adhesive layers The adhesive layers 25 and 27 are layers provided when any two layers are adhered, and are, for example, between the protective base layer 21 and the reinforcing layer 22, or between the reinforcing layer 22 and the multilayer sealant layer 23. can be set between

The adhesive layers 25 and 27 can be formed by a conventionally known method such as a dry lamination method. When two layers are adhered by a dry lamination method, the adhesive layers 25 and 27 are formed by applying an adhesive to the surfaces of the layers to be laminated and drying the adhesive. Examples of adhesives to be applied include one-component or two-component curing or non-curing vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber Adhesives such as solvent-based, water-based, or emulsion-based, such as systems, etc., can be used. A cured product of a polyol and an isocyanate compound can be used as the two-liquid curing adhesive. Examples of coating methods for the lamination adhesive include a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, a transfer roll coating method, and other methods. .

Next, the operation of the packaging bag 10 according to this embodiment having such a configuration will be described. Here, a method for producing the laminate 20 shown in FIG. 2 will be described, and then a method for producing the packaging bag 10 shown in FIG. 1 will be described.

First, the laminated body 20 is produced. In this case, for example, first, the protective base layer 21 is prepared. At this time, first, the base material layer 211 of the protective base material layer 21 is prepared. Next, the transparent layer 212 is formed on the surface of the base material layer 211 that is positioned on the inner surface 202 side when the packaging bag 10 is constructed. Then, the gas barrier layer 213 is formed on the surface of the transparent layer 212 opposite to the substrate layer 211 .

Also, a multilayer sealant layer 23 is provided. At this time, resin materials forming the first resin layer 231, the first adhesive resin layer 232, the core material 233, the second adhesive resin layer 234, and the second resin layer 235 are co-extruded. Thereby, the multilayer sealant layer 23 is produced.

Next, an adhesive is applied to the surface of the protective substrate layer 21 opposite to the transparent layer 212 among the surfaces of the gas barrier layer 213 to bond the multilayer sealant layer 23 to the protective substrate layer 21 . Thus, the laminate 20 shown in FIG. 2 is obtained. Although not shown, such a laminate 20 is wound into a roll and stored.

Next, the laminate 20 is used to produce the packaging bag 10 . In this case, for example, a belt-shaped laminate 20 is continuously unwound from a roll-wound laminate 20, and overlapped with another belt-shaped laminate 20. As shown in FIG. Next, positions corresponding to the vicinity of the pair of side ends 15 of the packaging bag 10 are heat-sealed to form a pair of side end seal portions 151 . Subsequently, the two laminates 20 heat-sealed by the pair of side end sealing portions 151 are cut into the shape of the packaging bag 10 to separate them. Next, the spout 16 is inserted into the portion corresponding to the first end 13 , and the position corresponding to the vicinity of the first end 13 is heat-sealed to form the first end seal portion 131 . Thus, the packaging bag 10 with the second end 14 open is obtained.

Next, the packaging bag 10 with the second end 14 open is filled with contents such as ink. At this time, the contents are filled into the packaging bag 10 from the opened second end 14 .

Next, the vicinity of the second end 14 of the packaging bag 10 is heat-sealed to form a second end seal portion 141 to close the second end 14 of the packaging bag 10 . In this way, the contents are enclosed in the packaging bag 10. FIG. The packaging bag 10 containing the contents is shipped and stored in a store, a warehouse, or the like.

During storage in this way, the solvent component contained in the contents may permeate between the layers of the laminate 20 forming the packaging bag 10 . When the solvent component contained in the contents permeates between the layers of the laminate 20 , delamination may occur in the laminate 20 forming the packaging bag 10 . In this case, the contents enclosed in the packaging bag 10 may leak out of the packaging bag 10 .

In contrast, in the present embodiment, core material 233 of multilayer sealant layer 23 contains ethylene-vinyl alcohol copolymer. Thereby, the barrier property of the multilayer sealant layer 23 can be improved. In this way, by increasing the barrier properties of the multilayer sealant layer 23, which is the innermost layer in the packaging bag 10, the solvent component contained in the contents is separated between the layers of the laminate 20 constituting the packaging bag 10. Permeation can be suppressed. Therefore, it is possible to suppress the occurrence of delamination between the layers of the laminate 20 , and it is possible to suppress the problem that the contents enclosed in the packaging bag 10 leak out of the packaging bag 10 . It should be noted that it is possible to suppress the problem of leakage of the contents enclosed in the packaging bag 10 to the outside of the packaging bag 10 in this way, which will be described in the examples described later.

Thus, according to the present embodiment, core material 233 of multilayer sealant layer 23 contains ethylene-vinyl alcohol copolymer. As a result, the barrier property of the multilayer sealant layer 23, which is the innermost layer in the packaging bag 10, can be improved, and the solvent component contained in the contents is separated between the layers of the laminate 20 constituting the packaging bag 10. Permeation can be suppressed. Therefore, it is possible to suppress the occurrence of delamination between the layers of the laminate 20 and suppress the problem of the contents leaking out of the packaging bag 10 .

In addition, since the solvent component contained in the content can be suppressed from permeating between the layers of the laminate 20, the lamination strength between the layers of the laminate 20 can be stabilized. In addition, the sealing strength between the laminates 20 in the packaging bag 10 can be stabilized.

Also, by enhancing the barrier properties of the multilayer sealant layer 23, the laminate 20 does not need to include an aluminum layer. Therefore, when manufacturing the laminate 20, for example, a step of adhering an aluminum layer to the protective base material layer 21 can be omitted. Therefore, the number of man-hours for manufacturing the laminate 20 can be reduced.

Furthermore, the protective base layer 21 has a base layer 211 and a transparent layer 212 provided on one surface of the base layer 211 . Thus, the protective base material layer 21 having the transparent layer 212 can also make the packaging bag 10 transparent. Therefore, it is possible to manufacture the packaging bag 10 in which the contents can be visually recognized, and for example, it is possible to easily check the remaining amount of the contents in the packaging bag 10 .

Moreover, according to the present embodiment, the protective base layer 21 further has the gas barrier layer 213 provided on the surface of the transparent layer 212 opposite to the base layer 211 . Thereby, the gas barrier property of the protective base material layer 21 can be improved.

Moreover, according to the present embodiment, the laminate 20 includes the protective substrate layer 21, the reinforcing layer 22, and the multilayer sealant layer 23. As shown in FIG. Thereby, the reinforcing layer 22 can improve the puncture resistance of the packaging bag 10 . Therefore, the strength of the packaging bag 10 can be increased.

Further, according to this embodiment, the reinforcing layer 22 contains polyamide, polyester or linear low density polyethylene. Thereby, the puncture resistance of the packaging bag 10 can be improved more effectively.

In the present embodiment described above, the packaging bag 10 is a four-sided seal bag (flat pouch) sealed by the first end seal portion 131, the second end seal portion 141 and the side end seal portions 151. Although one example has been described, it is not limited to this. For example, the packaging bag 10 may be a stand bag, a gusset bag, or a pillow bag.

(Second embodiment)
Next, a second embodiment of the present disclosure will be described with reference to FIGS. 4 and 5. FIG. 4 and 5 are schematic cross-sectional views showing examples of laminates according to the second embodiment of the present disclosure. The second embodiment shown in FIGS. 4 and 5 has a different layer structure of the laminate, and other structures are substantially the same as those of the above-described first embodiment. In FIGS. 4 and 5, the same reference numerals are given to the same parts as in the first embodiment, and detailed description thereof will be omitted. Also, the configurations shown in FIGS. 4 and 5 may include portions whose size, scale, etc. are changed from those of the real thing for convenience of illustration and ease of understanding.

As shown in FIG. 4, the laminate 20A according to the present embodiment includes a base material layer 211, a barrier layer 29, and a multilayer sealant layer 23 in this order. That is, the laminate 20A includes a base layer 211 positioned on the outer surface 201 side, a multilayer sealant layer 23 positioned on the inner surface 202 side, and a barrier layer 29 positioned between the base layer 211 and the multilayer sealant layer 23. It has In the example shown in FIG. 4, the substrate layer 211 constitutes the outer surface 201 of the laminate 20A, and the multilayer sealant layer 23 constitutes the inner surface 202 of the laminate 20A. The laminate 20A also includes an adhesive layer 25 positioned between the base layer 211 and the barrier layer 29, and an adhesive layer 27 positioned between the barrier layer 29 and the multilayer sealant layer 23. . Note that the laminate 20A may further include other layers. The thickness of the laminate 20A as shown in FIG. 4 can be, for example, 64 μm or more and 230 μm or less.

When the laminate 20A is composed of a substrate layer 211, a barrier layer 29, and a multilayer sealant layer 23, as in the laminate 20A shown in FIG. can be improved.

FIG. 5 is a cross-sectional view showing a modification of this embodiment. A laminate 20A shown in FIG. 5 includes a substrate layer 211, a barrier layer 29, a reinforcing layer 22, and a multilayer sealant layer 23 in this order. That is, the laminate 20A includes a base layer 211 positioned on the outer surface 201 side, a multilayer sealant layer 23 positioned on the inner surface 202 side, a barrier layer 29 positioned between the base layer 211 and the multilayer sealant layer 23, and and a reinforcing layer 22 . In the example shown in FIG. 5, the substrate layer 211 constitutes the outer surface 201 of the laminate 20A, and the multilayer sealant layer 23 constitutes the inner surface 202 of the laminate 20A. The laminate 20A includes an adhesive layer 25 positioned between the base layer 211 and the barrier layer 29, an adhesive layer 26 positioned between the barrier layer 29 and the reinforcing layer 22, and the reinforcing layer 22. and an adhesive layer 27 positioned between the multi-layer sealant layer 23 . Of these layers, the adhesive layer 26 is substantially the same as the adhesive layers 25 and 27 described above, so a detailed description thereof is omitted here. Note that the laminate 20A may further include other layers. The thickness of the laminate 20A as shown in FIG. 5 can be, for example, 64 μm or more and 230 μm or less.

Like the laminate 20A shown in FIG. The barrier property of the body 20A can be improved, and the piercing resistance of the packaging bag 10 can be improved by the reinforcing layer 22.

The barrier layer 29 constituting the laminate 20A described above is a layer for imparting barrier properties such as water vapor barrier properties and gas barrier properties to the packaging bag 10 . This barrier layer 29 includes a metal layer. In this case, a conventionally known metal layer can be used as the metal layer. The metal layer is preferably an aluminum layer from the viewpoint of gas barrier properties that prevent permeation of oxygen gas and water vapor, and light shielding properties that prevent permeation of visible light, ultraviolet rays, and the like. In this case, the thickness of the metal layer can be, for example, 6 μm or more and 40 μm or less.

Also in the present embodiment, since the core material 233 of the multilayer sealant layer 23 contains an ethylene-vinyl alcohol copolymer, the barrier property of the multilayer sealant layer 23, which is the innermost layer in the packaging bag 10, is improved. can be enhanced. As a result, it is possible to suppress the penetration of the solvent component contained in the contents between the layers of the laminate 20A constituting the packaging bag 10, and suppress the occurrence of delamination between the layers of the laminate 20A. , the problem that the contents leak out of the packaging bag 10 can be suppressed.

Moreover, according to the present embodiment, the laminate 20A includes the base material layer 211, the barrier layer 29, and the multilayer sealant layer 23. As shown in FIG. Thereby, the barrier properties of the laminate 20A can be improved.

Moreover, according to the present embodiment, the laminate 20A includes the base material layer 211, the barrier layer 29, the reinforcing layer 22, and the multilayer sealant layer 23. As shown in FIG. Thereby, the barrier properties of the laminate 20A can be improved, and the piercing resistance of the packaging bag 10 can be improved by the reinforcing layer 22 .

Next, the operation of the present embodiment described above will be specifically described.

(Example)
As the base material layer 211, a biaxially stretched PET film (E5012 manufactured by Toyobo Co., Ltd., thickness 12 μm) was prepared.

As the barrier layer 29, an aluminum layer (manufactured by Toyo Aluminum Co., Ltd., thickness 7 μm) was prepared.

As the reinforcing layer 22, a biaxially oriented nylon film (Bonyl W, manufactured by Koujin Film & Chemicals Co., Ltd., thickness 15 μm) was prepared.

Furthermore, as the multilayer sealant layer 23, an unstretched nylon functioning as the first resin layer 231, an acid-modified polyolefin resin modified with an unsaturated carboxylic acid functioning as the first adhesive resin layer 232, and a core material 233 functioning. an ethylene-vinyl alcohol copolymer (EVOH), an acid-modified polyolefin resin modified with an unsaturated carboxylic acid that functions as the second adhesive resin layer 234, and a linear low-density resin that functions as the second resin layer 235 A multilayer coextruded film was prepared comprising polyethylene and made by coextrusion. The thickness of the entire multilayer co-extruded film was 100 μm.
The layer structure of this multilayer co-extruded film is expressed as follows.
CNY/Contact/EVOH/Contact/LLDPE
"/" represents the boundary between layers.
"CNY" means unoriented nylon. "Contact" means an adhesive resin layer. "LLDPE" means linear low density polyethylene (and so on).

Subsequently, a biaxially stretched PET film, an aluminum layer, a biaxially stretched nylon film, and a multilayer co-extruded film were laminated in this order by a dry lamination method to produce a laminate 20A shown in FIG. The layer structure of this laminate 20A is expressed as follows.
PET/DL/ALM/DL/ONY/DL/CNY/contact/EVOH/contact/LLDPE
"/" represents the boundary between layers. The layer on the left end is the layer that forms the outer surface 201 of the laminate 20A, and the layer on the right end is the layer that forms the inner surface 202 of the laminate 20A.
"PET" means biaxially oriented polyethylene terephthalate film. "DL" means adhesive layer containing adhesive. "ALM" means aluminum layer. "ONY" means biaxially oriented nylon film (same below).

The adhesive layer between the biaxially oriented polyethylene terephthalate film and the aluminum layer contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., main agent: RU-004, curing agent: H-1). The adhesive layer between the aluminum layer and the biaxially oriented nylon film contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., main agent: RU-004, curing agent: H-1). The adhesive layer between the biaxially oriented nylon film and the multi-layer co-extruded film contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., main agent: RU-004, curing agent: H-1).

Next, the multi-layered sealant layers 23 of the obtained laminate 20A were heat-sealed to produce five packaging bags 10 shown in FIG. At this time, first, an empty packaging bag 10 having an open second end portion 14 was prepared, and the packaging bag 10 was filled with diethylene glycol diethyl ether as a content. Next, the vicinity of the second end 14 of the packaging bag 10 was heat-sealed to close the second end 14 of the packaging bag 10, thereby obtaining the packaging bag 10 containing the contents.

<Laminate strength measurement test>
Subsequently, the laminate strength between the reinforcing layer 22 and the multilayer sealant layer 23 was measured. As a measuring instrument, a Tensilon universal material testing machine RTC-1310 manufactured by A&D was used. Specifically, first, the packaging bag 10 immediately after enclosing the contents, and after enclosing the contents in the packaging bag 10, the packaging bag 10 stored for one month in a constant temperature bath whose storage temperature was set to 60 ° C. 20A was cut out, and as shown in FIG. 6, a rectangular test piece 50 was prepared by separating the reinforcement layer 22 and the multilayer sealant layer 23 by 15 mm in the long side direction. The width (length of the short side) of the test piece 50 was 15 mm. After that, as shown in FIG. 7, the already peeled portions of the reinforcement layer 22 and the multilayer sealant layer 23 were gripped by grips 51 and 52 of the measuring instrument, respectively. In addition, the clamps 51 and 52 were pulled in opposite directions in directions orthogonal to the surface direction of the portion where the reinforcing layer 22 and the multilayer sealant layer 23 were still laminated at a speed of 300 mm/min, and were stabilized. The average value of the tensile stress in the area (see Figure 8) was measured. The interval S1 between the grippers 51 and 52 when starting to pull was set to 30 mm, and the interval S1 between the grippers 51 and 52 when completing the pulling was set to 60 mm. FIG. 8 is a diagram showing changes in tensile stress with respect to the distance S1 between the grips 51 and 52. As shown in FIG. As shown in FIG. 8, the change in tensile stress with respect to the interval S1 passes through the first region and enters the second region (stable region) where the rate of change is smaller than that of the first region.

The average value of the tensile stress in the stable region was measured for the five test pieces 50, and the average value was taken as the lamination strength between the reinforcing layer 22 and the multilayer sealant layer 23. The environment during the measurement was a temperature of 23° C. and a relative humidity of 50%.

<Seal strength measurement test>
Next, the seal strength between the heat-sealed multilayer sealant layers 23 was measured. As a measuring instrument, Tensilon universal material testing machine RTC-1310 manufactured by A&D was used. Specifically, first, the packaging bag 10 immediately after enclosing the contents, and the packaging bag 10 stored for one month in a constant temperature bath with the storage temperature set to 60 ° C. after enclosing the contents in the packaging bag 10 are cut out. As shown in FIG. 9, a rectangular test piece 60 was prepared by separating the multilayer sealant layers 23 from each other by 15 mm in the long side direction. The width (short side length) of the test piece 60 was 15 mm. After that, as shown in FIG. 10, the portions of the multilayer sealant layer 23 that had already been peeled off were gripped by grippers 51 and 52 of the measuring device, respectively. In addition, the grips 51 and 52 were pulled at a speed of 300 mm/min in opposite directions to each other in the direction orthogonal to the surface direction of the portion where the multilayer sealant layers 23 were still laminated, and the tensile stress in the stable region was was measured. The interval S2 between the grippers 51 and 52 when starting to pull was set to 30 mm, and the interval S2 between the grippers 51 and 52 when completing the pulling was set to 60 mm.

For the five test pieces 50, the average value of the tensile stress in the stable region was measured in the same manner as in the laminate strength measurement test described above, and the average value was taken as the seal strength between the multilayer sealant layers 23. The environment during the measurement was a temperature of 23° C. and a relative humidity of 50%.

<Tensile strength measurement test>
Next, the tensile strength of the laminate 20A was measured according to JIS K7127. As a measuring instrument, a Tensilon universal material testing machine RTC-1310 manufactured by A&D was used. Specifically, first, the packaging bag 10 that has been stored for one month in a constant temperature bath whose storage temperature is set to 60° C. is cut out, and the first direction D1 shown in FIG. 1 is 80 mm in length and 15 mm in width. A first test piece and a second test piece having a length of 80 mm and a width of 15 mm along the second direction shown in FIG. 1 were prepared. After that, each test piece was pulled in its length direction at a rate of 300 mm/min, and the tensile strength (N/15 mm) and the elongation (%) of the test piece in this case were measured.

<Content leakage inspection>
The five packaging bags 10 were stored for one month in a constant temperature bath set at a storage temperature of 60° C., and then stored for one day at room temperature to check whether the contents had leaked out of the packaging bags 10.

(Comparative example)
A laminate was produced in the same manner as in Example except that a single-layer unstretched linear low-density polyethylene film (manufactured by Mitsui Chemicals Tohcello, TUX-HZR2, thickness 120 μm) was used as the sealant layer. Then, the lamination strength measurement test, the seal strength measurement test, and the content leakage test were performed in the same manner as in the Examples.

The layer structure of this laminate is expressed as follows.
PET/DL/ALM/DL/ONY/DL/LLDPE

Tables 1 and 2 show the above results.

評価基準
○：全ての包装袋において、内容物が漏れ出していなかった。

Evaluation Criteria ◯: The contents did not leak out from any of the packaging bags.

As a result, as shown in Table 1, in the comparative example, the laminate strength between the reinforcing layer and the multilayer sealant layer when the packaging bag was stored for one month in a constant temperature bath set at a storage temperature of 60 ° C. , from 8.2 N/15 mm to 1.4 N/15 mm. On the other hand, in the example, the laminate strength between the reinforcing layer and the multilayer sealant layer was changed from 8.0 N/15 mm to 7.8 N/15 mm. As described above, in the laminate 20A of the embodiment, it is possible to suppress a decrease in lamination strength and stabilize the lamination strength.

Further, as shown in Table 1, in the comparative example, the seal strength between the multilayer sealant layers when the packaging bag was stored for one month in a constant temperature bath set at a storage temperature of 60° C. ranged from 80 N/15 mm to 35 N/ It was down to 15mm. On the other hand, in the example, the seal strength between the multilayer sealant layers was changed from 100 N/15 mm to 106 N/15 mm. Thus, in the laminate 20A of the embodiment, it is possible to suppress a decrease in seal strength and stabilize the seal strength.

Moreover, as shown in Table 2, in the comparative example, the tensile strength of the first test piece was 120 N/15 mm, and the elongation of the first test piece was 148%. In the comparative example, the second test piece had a tensile strength of 120 N/15 mm and an elongation of 129%. On the other hand, in the example, the tensile strength of the first test piece was 113 N/15 mm, and the elongation of the first test piece was 177%. Moreover, in the example, the tensile strength of the second test piece was 109 N/15 mm, and the elongation of the second test piece was 142%. Thus, the laminate 20A of the example had a property of being more easily stretched than the laminate of the comparative example. Here, since the laminate has the property of being easily stretched, it is possible to impart a high piercing property to the packaging bag using the laminate. That is, for example, when the laminate is pierced by a needle-like member, the needle-like member is less likely to pierce the laminate due to the elongation of the laminate having the property of being easily stretched. Therefore, the packaging bag 10 using the laminate 20A of the embodiment can have high puncture resistance.

Furthermore, in the examples, the contents did not leak out from any of the packaging bags. As described above, according to the present embodiment, it is possible to suppress the occurrence of delamination between the layers of the laminate 20A, and to suppress the problem of the contents leaking out of the packaging bag 10. FIG.

It is also possible to appropriately combine a plurality of constituent elements disclosed in the above embodiments as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiments.

REFERENCE SIGNS LIST 10 packaging bag 20 laminate 20A laminate 21 protective substrate layer 211 substrate layer 212 transparent layer 213 gas barrier layer 22 reinforcing layer 23 multilayer sealant layer 231 first resin layer 232 first adhesive resin layer 233 core material 234 second adhesive resin Layer 235 Second resin layer 29 Barrier layer

Claims (9)

A laminate used in a packaging bag for enclosing contents containing a solvent,
A protective base layer, a reinforcing layer, and a multilayer sealant layer are provided in this order,
The protective base layer includes a base layer and a transparent layer provided on one surface of the base layer,
The multilayer sealant layer has at least a first resin layer, a first adhesive resin layer, a core material, a second adhesive resin layer, and a second resin layer in this order,
The first resin layer of the multilayer sealant layer contains a polyamide,
The laminate, wherein the core material of the multilayer sealant layer includes an ethylene-vinyl alcohol copolymer. 2. The laminate according to claim 1 , wherein the protective substrate layer further includes a gas barrier layer provided on a surface of the transparent layer opposite to the substrate layer. 3. Laminate according to claim 1 or 2 , wherein the reinforcing layer comprises polyamide, polyester or linear low density polyethylene. A laminate used in a packaging bag for enclosing contents containing a solvent,
comprising a substrate layer, a barrier layer, and a multilayer sealant layer in this order,
The multilayer sealant layer comprises:At least a first resin layer, a first adhesive resin layer,Core material, a second adhesive resin layer, and a second resin layerofin this orderhave
The first resin layer of the multilayer sealant layer contains a polyamide,
The laminate, wherein the core material of the multilayer sealant layer includes an ethylene-vinyl alcohol copolymer. further comprising a reinforcing layer provided between the barrier layer and the multi-layer sealant layer;
The laminate according to claim 4. 6. The laminate of claim 5 , wherein said reinforcing layer comprises polyamide, polyester or linear low density polyethylene. 7. Laminate according to any one of claims 4 to 6 , wherein the barrier layer comprises an aluminum layer. 8. Laminate according to any one of claims 1 to 7 , wherein the multilayer sealant layer comprises a multilayer co-extruded film. A packaging bag comprising the laminate according to any one of claims 1 to 8 .

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