Packaging laminate, packaging bag, and packaging bag containing contents

Abstract

To provide a novel laminate for packaging capable of suppressing the occurrence of a pinhole.SOLUTION: There is provided a laminate for packaging which comprises a base material layer, a first adhesive layer and a sealant layer in this order, wherein a protective layer is laminated via a second adhesive layer on the outside of the base material layer and the first adhesive layer and the second adhesive layer are composed of a reaction curable adhesive containing a plasticizer. Specifically, as shown in Fig. 1, a laminate for packaging 10 has a first base material layer 12, a first adhesive layer 13, a second base material layer 14, a second adhesive layer 15 and a sealant layer 16 and the first adhesive layer 13 and the second adhesive layer 15 are composed of a reaction curable adhesive containing a plasticizer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging laminate, a packaging bag, and a packaging bag containing a content. [Background technology]

[0002] In recent years, in the field of packaging, in line with the increasing speed of filling contents and packaging machines, a sealant layer of laminated packaging materials has been used that has excellent low-temperature sealing properties, sealing strength, and bending resistance, and has a density of 0.925 g / m. 3 The following linear low density polyethylene (LLDPE) is widely used. However, when linear low density polyethylene (LLDPE) is used as a sealant layer, the physical properties such as puncture strength, slipperiness, and abrasion resistance are sometimes insufficient.

[0003] To improve slipperiness and abrasion resistance, sealant layers made of linear low-density polyethylene (LLDPE) with various slip agents added are used. However, slip agents tend to precipitate on the surface of the sealant layer over time, which can have a negative effect on the contents, such as medicines.

[0004] In addition, to improve puncture strength, slipperiness, and abrasion resistance, the density is 0.925 g / m 3 However, this linear medium density polyethylene resin has drawbacks such as being stiff and having low bending resistance, and being poor in pinhole resistance.

[0005] Regarding the improvement of pinhole resistance, Patent Document 1 proposes an improvement of pinhole resistance in a bag using nylon as a base material. Specifically, it is proposed to laminate a protective layer made of a polyolefin-based film on the outside of a stretched nylon film in a film in which a heat-sealable layer (sealant layer) is provided on the inner layer of the stretched nylon film. The laminate described in Patent Document 1 improves pinhole resistance by laminating a polyolefin-based film layer as the outer layer of the stretched nylon film.

[0006] Patent Document 2 describes the addition of a plasticizer as an additive to the vinylidene chloride resin composition that is the material for vinylidene chloride resin wrap films in order to obtain good processability and good physical properties. Examples of plasticizers include acetyl tributyl citrate (ATBC) and dibutyl sebacate (DBS). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 8-323937 [Patent Document 2] JP 2014-15590 A Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above background, and has an object to provide a novel packaging laminate capable of suppressing the occurrence of pinholes. [Means for solving the problem]

[0009] The present inventors conducted extensive research to solve the above problems. They found that the above problems could be solved by forming the first adhesive layer and the second adhesive layer from a reactive curing adhesive containing a plasticizer in a packaging laminate including a first base layer, a first adhesive layer, a second base layer, a second adhesive layer, and a sealant layer in this order, and thus completed the present invention. That is, the present invention is as follows:

[0010] Aspect 1 The laminate includes, in order, a first substrate layer, a first adhesive layer, a second substrate layer, a second adhesive layer, and a sealant layer; the first base material layer and the second base material layer are bonded to each other by the first adhesive layer, the second base layer and the sealant layer are bonded to each other by the second adhesive layer; The first adhesive layer and the second adhesive layer are made of a reactive curing adhesive containing a plasticizer. Packaging laminates. Aspect 2 2. The packaging laminate of claim 1, wherein the plasticizer is an aliphatic dibasic acid ester. Aspect 3 2. The packaging laminate of claim 1, wherein the plasticizer is a benzoic acid-based resin. Aspect 4 The packaging laminate according to any one of Aspects 1 to 3, wherein the reaction curing adhesive is a two-component curing adhesive made of a urethane resin. Aspect 5 The packaging laminate according to any one of Aspects 1 to 4, wherein the first base layer is made of a polyolefin-based resin. Aspect 6 The packaging laminate according to any one of Aspects 1 to 5, wherein the sealant layer is made of linear low-density polyethylene. Aspect 7 The packaging laminate according to any one of aspects 1 to 6, wherein the second base layer has a polyamide layer. Aspect 8 A packaging bag formed using one or more sheets of the packaging laminate according to any one of aspects 1 to 7, The sealant layer has a joint formed by heat sealing to another part of the packaging laminate or a film other than the packaging laminate. packaging bag. Aspect 9: The packaging bag according to embodiment 8, and The contents contained in the packaging bag A packaging bag containing an item. Effect of the Invention

[0011] According to the present invention, it is possible to provide a novel packaging laminate capable of suppressing the occurrence of pinholes. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view of a packaging laminate according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <<Packaging laminate>> The packaging laminate of the present invention comprises at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, and a sealant layer laminated in this order, the first base material layer and the second base material layer being bonded to each other by the first adhesive layer, and the second base material layer and the sealant layer being bonded to each other by the second adhesive layer, and the first adhesive layer and the second adhesive layer are made of a specific material.

[0014] The configuration of the packaging laminate of the present invention will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of the packaging laminate according to one embodiment of the present invention.

[0015] 1 includes a first base material layer 12, a first adhesive layer 13, a second base material layer 14, a second adhesive layer 15, and a sealant layer 16, with the first base material layer 12 and the second base material layer 14 being bonded to each other by the first adhesive layer 13, and the second base material layer 14 and the sealant layer 16 being bonded to each other by the second adhesive layer 15. The first adhesive layer 13 and the second adhesive layer 15 are made of a specific material, which will be described later.

[0016] In a packaging laminate 10 according to one embodiment of the present invention shown in Fig. 1, the first base material layer 12 and the second base material layer 14 are laminates each consisting of a single layer. In the present invention, each of the first base material layer and the second base material layer is not limited to a single layer, and may consist of two or more layers.

[0017] Furthermore, so long as the packaging laminate of the present invention includes a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, and a sealant layer as essential components, it may optionally include layers other than these.

[0018] The thickness and other properties of each layer constituting the packaging laminate of the present invention can be appropriately determined depending on the application and other factors of the packaging laminate.

[0019] <First Base Layer> The first base material layer is an essential constituent layer in the packaging laminate of the present invention. The first base material layer is adjacent to the first adhesive layer and is bonded to the second base material layer by the first adhesive layer. In the packaging laminate of the present invention, the first base material layer may be a single layer or a laminate consisting of multiple layers.

[0020] In the packaging laminate of the present invention, the first base layer, the first adhesive layer, the second base layer, the second adhesive layer, and the sealant layer are laminated in this order, so that the first base layer may become the outer layer of a structure, such as a package, when the structure is formed. In this case, the first base layer can be a protective layer when the sealant layer, which is the innermost layer, is heat-sealed to form a structure. It can also be a printing layer for applying printing to display the contents, etc.

[0021] (Resin layer) When the first base layer is a single layer, the first base layer may be a resin layer made of a resin, particularly a resin that serves as a protective layer and is printable. The material for forming the resin layer that serves as the first base layer may be a thermoplastic resin that is excellent in impact resistance, abrasion resistance, etc., such as a polyolefin resin, a vinyl polymer, a polyester, or a polyamide.

[0022] Among these, polyolefin-based resins are preferred because they have high pinhole resistance against bending, and polypropylene-based resins are more preferred because they have high pinhole resistance against bending and friction.

[0023] When the first base layer is a laminate of two or more layers, other layers may be provided in addition to the resin layer, or two or more resin layers, or two or more layers of the same type may be provided. Examples of other layers include a barrier layer for imparting barrier properties, a reinforcing layer for reinforcing strength, and a base adhesive layer for bonding between layers.

[0024] When the first base layer is a laminate, it may be a laminate in which a resin layer and a barrier layer are laminated in this order from the side opposite to the side adjacent to the first adhesive layer, or a laminate in which a first resin layer, a barrier layer, and a second resin layer are laminated in this order from the side opposite to the side adjacent to the first adhesive layer.

[0025] Examples of polyolefin resins that form the resin layer that becomes the first base layer include polyethylene resins and polypropylene resins.

[0026] In this specification, a polyethylene resin is a resin that contains more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of ethylene group repeating units in the main chain of the polymer, and is, for example, low-density polyethylene (LDPE, density 0.925 g / m 3 0.925g / m or less), linear low-density polyethylene (LLDPE, density 0.925g / m 3 less), medium density polyethylene (MDPE, density 0.925g / m 3 Super 0.942g / m 3 less), high density polyethylene (HDPE, density 0.942g / m 3 Examples of the polyolefin polymer include ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-vinyl acetate copolymer (EVA), carboxylic acid modified polyethylene, carboxylic acid modified ethylene-vinyl acetate copolymer, ionomers, and derivatives thereof.

[0027] In this specification, a polypropylene-based resin is a resin containing more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of repeating units of propylene groups in the main chain of the polymer, and examples thereof include polypropylene (PP) homopolymer, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, acid-modified polypropylene, and derivatives thereof. As described above, the first base layer constituting the packaging laminate of the present invention is preferably composed of a polypropylene-based resin because it has high pinhole resistance against bending and friction.

[0028] Examples of vinyl polymers forming the resin layer that becomes the first base layer include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polychlorotrifluoroethylene, polytetrafluoroethylene, and polyacrylonitrile (PAN).

[0029] Examples of polyesters that form the resin layer that becomes the first base layer include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT).

[0030] Examples of polyamide (PA) that forms the resin layer that becomes the first base material layer include nylons such as Nylon (registered trademark)-6, Nylon-66, and Nylon MXD6.

[0031] The above resins may be used alone or in a blend of two or more kinds, and additives for imparting functionality, etc. may be added as necessary.

[0032] In addition, when the first base layer is a resin layer, a resin film formed in advance may be used. The resin film to be the first base layer may be a film formed from the above-mentioned resin, etc., and may be unstretched or uniaxially or biaxially stretched. Among them, a biaxially stretched film is preferable.

[0033] Furthermore, the resin film that becomes the first base layer may be subjected to a roughening treatment to roughen its surface. By roughening the surface, an anchor effect with the adjacent first adhesive layer is generated, and adhesion can be improved.

[0034] The thickness of the resin layer that becomes the first base material layer is preferably 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of providing good protection when a barrier layer or the like is provided, and is preferably 55 μm or less, 50 μm or less, or 45 μm or less from the viewpoint of improving handleability when the packaging laminate is made into a packaging bag or the like.

[0035] (Barrier layer) The barrier layer constituting the first base material layer is a layer for imparting barrier properties to the packaging laminate. When the first base material layer includes the above-mentioned resin layer and barrier layer, the resin layer may be present on one or both sides of the barrier layer.

[0036] Examples of the barrier layer include a resin layer made of ethylene-vinyl alcohol copolymer (EVOH), nylon (NY), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN), or the like, which exhibits the function of blocking gases such as oxygen and water vapor.

[0037] The above resins may be used alone or in a blend of two or more kinds, and additives for imparting functionality, etc. may be added as necessary.

[0038] Alternatively, for example, it may be an inorganic vapor deposition film layer, a metal foil layer, an organic coating layer, or the like.

[0039] Examples of inorganic vapor-deposited film layers that serve as barrier layers include silica vapor-deposited films, aluminum vapor-deposited films, alumina vapor-deposited films, and silica-alumina vapor-deposited films.

[0040] Examples of the metal foil that can be used as the barrier layer include metal foils such as aluminum foil, copper foil, and titanium foil, and alloy foils such as aluminum alloy foil and stainless steel foil.

[0041] The organic coating layer serving as a barrier layer may be a barrier coating layer such as a vinylidene chloride coating layer or a polyvinylidene fluoride coating layer.

[0042] When an inorganic vapor deposition film layer or an organic coating layer is present as the barrier layer, the thickness of the barrier layer is preferably 100 nm or more, 200 nm or more, 300 nm or more, 500 nm or more, 700 nm or more, or 1 μm or more, from the viewpoint of ensuring strength and barrier properties, and is preferably 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less, from the viewpoint of improving handleability when the packaging laminate is used as a packaging bag or the like.

[0043] When a metal foil is used as the barrier layer, the thickness of the barrier layer is preferably 5 μm or more, 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of ensuring strength and barrier properties, and is preferably 100 μm or less, 80 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, or 35 μm or less from the viewpoint of improving handleability when the packaging laminate is used as a packaging bag or the like.

[0044] (Reinforcing layer) The reinforcing layer constituting the first base layer is a layer for reinforcing the strength of the packaging laminate. Examples of materials for the reinforcing layer include paper such as coated paper and art paper, synthetic paper, nonwoven fabric, etc. When the paper or the like that becomes the reinforcing layer faces the outside of the base layer, the surface may be printed by gravure printing, flexographic printing, etc.

[0045] (Base adhesive layer) The substrate adhesive layer constituting the first substrate layer is present between the layers constituting the first substrate layer, and serves to bond the layers together. The substrate adhesive layer is not particularly limited, and examples thereof include a layer made of ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), and an ionomer.

[0046] The substrate adhesive layer may also be a layer made of an adhesive, such as a dry lamination adhesive, a hot melt adhesive, a water-soluble adhesive, an emulsion adhesive, a non-solvent lamination adhesive, or a thermoplastic resin for extrusion lamination.

[0047] As described above, the substrate adhesive layer constituting the first substrate layer is not particularly limited, but from the viewpoint of pinhole resistance, it is preferable that the substrate adhesive layer be made of a reactive curing adhesive containing a plasticizer, i.e., a layer made of the material constituting the first adhesive layer and second adhesive layer described below.

[0048] <First adhesive layer and second adhesive layer> The first adhesive layer is an essential component layer in the packaging laminate of the present invention, and is disposed between the adjacent first base material layer and second base material layer to bond them to each other. The second adhesive layer is an essential component layer in the packaging laminate of the present invention, and is disposed between the adjacent second base material layer and sealant layer to bond them to each other.

[0049] The first adhesive layer and the second adhesive layer may be layers of the same structure made of the same material, or layers of different structures. If they are made of the same material and have the same structure, this can contribute to improving productivity in terms of not complicating the manufacturing process.

[0050] The first adhesive layer and the second adhesive layer of the present invention are composed of a reaction curing adhesive containing a plasticizer.

[0051] The present inventors have found that the adhesive layer having the above-mentioned structure can suppress the occurrence of pinholes. Without being bound by theory, this is believed to be due to the presence of a plasticizer, which enhances the shear resistance of the adhesive layer.

[0052] In general, adhesives used for packaging materials, especially dry lamination adhesives, are used in thin thicknesses, so the elasticity of the adhesive layer formed by the adhesive does not pose a problem. Also, it was thought that the adhesive strength would be weakened if a plasticizer was added to the adhesive. Therefore, the above-mentioned effect was unexpected.

[0053] In addition, the first adhesive layer and the second adhesive layer in the packaging laminate of the present invention may contain, in addition to the plasticizer, which is an essential component, other resins, additives, etc., for imparting functionality, etc., as necessary.

[0054] (Plasticizer) The plasticizer contained in the first adhesive layer and the second adhesive layer is not particularly limited, but may be, for example, an aliphatic dibasic acid ester or a benzoic acid resin. As described above, the plasticizers contained in the first adhesive layer and the second adhesive layer may be the same or different.

[0055] An aliphatic dibasic acid ester is formed by esterifying two aliphatic alcohols to the two carboxyl groups of an aliphatic dicarboxylic acid.

[0056] Examples of the aliphatic dicarboxylic acid include unsaturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, and saturated aliphatic carboxylic acids such as fumaric acid and maleic acid.

[0057] Examples of aliphatic alcohols include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butyl alcohol, 1-pentanol, isoamyl alcohol, sec-amyl alcohol, 3-pentanol, tert-amyl alcohol, n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-octanol, 2-ethylhexanol, 3,5,5-trimethylhexanol, nonanol, n-decanol, undecanol, n-decanol, trimethylnonyl alcohol, tetradecanol, heptadecanol, cyclohexanol, and 2-methylcyclohexanol.

[0058] Examples of such aliphatic dibasic acid esters include dibutyl sebacate (DBS), bis(2-ethylhexyl) adipate (DOA), and bis(2-ethylhexyl) sebacate (DOS).

[0059] As the benzoic acid resin, a resin commercially available as a "benzoic acid resin" can be used. For example, as a benzoic acid ester plasticizer, Monocizer (registered trademark) PB-3A, PB-10 (DIC Corporation), etc. can be mentioned.

[0060] From the viewpoint of effectively suppressing pinholes, it is preferable that the plasticizer content is 1 mass% or more, 3 mass% or more, 5 mass% or more, 7 mass% or more, 9 mass% or more, 10 mass% or more, 12 mass% or more, or 15 mass% or more, and 27 mass% or less, or 25 mass% or less, based on the total mass of the solid contents of the adhesive layer.

[0061] The plasticizer contents in the first adhesive layer and the second adhesive layer may be the same or different.

[0062] (Reaction curing adhesive) A reaction-curing adhesive is an adhesive that provides adhesion by curing through a reaction. For example, it may be a heat-curing adhesive, an ultraviolet-curing adhesive, or the like. These adhesives may be one-component curing adhesives or two-component curing adhesives. Whether an adhesive is a one-component curing adhesive or a two-component curing adhesive can be determined by referring to the product labeling, such as a catalog for each adhesive.

[0063] The reaction curing adhesives constituting the first adhesive layer and the second adhesive layer may be the same or different.

[0064] The thermosetting adhesive may be any adhesive that cures with heat to provide adhesion, and may be, for example, an adhesive made of a thermosetting resin such as a urethane resin, an epoxy resin, an acrylic resin, a phenolic resin, a polyimide resin, or a bismaleimide resin, particularly an adhesive commercially available as a "dry lamination adhesive." Among these, a two-component curing adhesive made of a urethane resin is preferred from the viewpoints of food hygiene, heat resistance, and durability.

[0065] The ultraviolet-curable adhesive may be any adhesive that cures with ultraviolet light to provide adhesion, and may be, for example, a mixture containing an ultraviolet-curable component and a photopolymerization initiator.

[0066] Examples of the ultraviolet-curable component include (meth)acrylates such as polyester acrylate, polyurethane acrylate, and epoxy acrylate, and monomers or oligomers such as vinyl ether.

[0067] The photopolymerization initiator is not particularly limited, but examples thereof include aromatic photopolymerization initiators such as benzoin, acetophenone, benzophenone, anthraquinone, and thioxanthone, aliphatic photopolymerization initiators such as phosphine oxide and acetal, and derivatives thereof.

[0068] <Second Base Layer> The second substrate layer is an essential constituent layer of the packaging laminate of the present invention. The second substrate layer is adjacent to the second adhesive layer and is bonded to the sealant layer by the second adhesive layer.

[0069] In the packaging laminate of the present invention, the second base layer may be a single layer or a laminate consisting of multiple layers. The material constituting the second base layer is the same as that of the first base layer. The first base layer and the second base layer may be layers of the same composition made of the same material, or layers of different compositions.

[0070] In particular, when considering heavy bags, liquid packaging, and the like, it is preferable that the second base layer has a polyamide layer made of polyamide (PA) having high impact resistance.

[0071] <Sealant layer> The sealant layer is an essential constituent layer in the packaging laminate of the present invention, and is adhered to the second base material layer via the adjacent second adhesive layer.

[0072] The sealant layer is a layer used for thermal bonding to itself or to other materials when forming a structure such as a packaging bag or a package from the packaging laminate of the present invention. For this reason, the sealant layer is disposed so as to be the innermost layer of the packaging laminate.

[0073] The material constituting the sealant layer is not particularly limited as long as it is heat-adhesive and can impart sufficient sealing strength to the molded structure. Known materials can be used, such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), polypropylene (PP), ethylene-propylene copolymer (EP), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ionomer resin, ethylene-vinyl acetate copolymer (EVA), etc.

[0074] For example, when forming a structure such as a packaging bag filled with contents, the sealant layer constituting the composite film of the present invention is a layer that forms a space for filling the contents, and therefore is a layer that comes into direct contact with the contents. For this reason, when it is desired to impart resistance to contents, it is preferable to use, for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), etc.

[0075] In particular, the sealant layer in the packaging laminate of the present invention is preferably composed of linear low density polyethylene (LLDPE). By being composed of linear low density polyethylene (LLDPE), it is possible to impart sufficient seal strength to the molded structure and to impart resistance to contents. In addition, linear low density polyethylene (LLDPE) has a molecular chain with few branches and a structure close to a straight line, and therefore can further improve pinhole resistance in a synergistic manner with a reaction-curing adhesive containing a plasticizer.

[0076] In the packaging laminate of the present invention, the sealant layer may be formed using a film preformed from the above-mentioned material, or may be formed by melting and extruding a material for forming the sealant layer onto the surface of a laminate having a first base layer, a first adhesive layer, a second base layer, a second adhesive layer, and other layers, and then cooling and solidifying the material.

[0077] The material constituting the sealant layer may contain other resins or additives for imparting functionality, etc., as necessary.

[0078] Furthermore, the sealant layer may be a single layer or may be a multi-layer structure.

[0079] 《Packaging bag》 The packaging bag of the present invention is formed using one or more sheets of the above-mentioned packaging laminate, and has a joint formed by heat sealing the sealant layer to another part of the packaging laminate or to a film other than the packaging laminate.

[0080] The packaging bag of the present invention may be a content-containing packaging bag having the above-mentioned packaging bag and the content stored in the packaging bag.

[0081] The packaging bag of the present invention may be in the form of, for example, a three-side sealed bag, a four-side sealed bag, a pillow bag, a gusset bag, a standing pouch, or the like.

[0082] <Contents> The contents to be stored in the packaging bag to form the content-containing packaging bag are not particularly limited. For example, the contents may be things that can deteriorate when exposed to the outside air, and examples of such things include medicines, food, cosmetics, medical instruments, medical equipment, electronic parts, precision machinery, recording materials, etc. Furthermore, examples of medicines include pharmaceutical preparations, cleaning agents, agricultural chemicals, etc.

[0083] In particular, in the case of low-temperature preserved foods such as frozen foods and refrigerated foods, the packaging laminate of the present invention is beneficial since films generally tend to become brittle. EXAMPLES

[0084] The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these.

[0085] <Material> In the examples and comparative examples, the following materials were prepared as materials constituting layers.

[0086] (1) First base layer OPP: Biaxially oriented PP film (Pylen (registered trademark) P2161, Toyobo Co., Ltd., thickness: 20 μm) Multi-layer PP film: [PP / LLDPE / LLDPE] (Diffaren® R3360T, DIC Corporation, thickness: 30 μm) Multi-layer LLDPE film: [LLDPE / LLDPE / LLDPE] (Diffaren® L3300T, DIC Corporation, thickness: 50 μm) HDPE film (Hibron (registered trademark) 191, Tokyo Ink Co., Ltd., thickness: 25 μm)

[0087] (2) A first adhesive layer and a second adhesive layer Two-component urethane adhesive (Rock Paint Co., Ltd.) (base agent:hardener = 10:1 (mass ratio)) Main agent: RU-50 Hardener: H-4 Aliphatic dibasic acid ester plasticizer Dibutyl sebacate (DBS) (Daihachi Chemical Industry)

[0088] (3) Second base layer Biaxially oriented nylon (Ny) film (Bonyl (registered trademark) W, Kohjin Film & Chemicals Co., Ltd., thickness: 15 μm)

[0089] (4) Sealant layer Linear low-density polyethylene (LLDPE) film: SK615P (Tamapoly Corporation, thickness: 70 μm)

[0090] Example 1 A biaxially oriented polypropylene (PP) film (Pylen (registered trademark) P2161, Toyobo Co., Ltd., thickness: 20 μm) serving as the first base layer and a nylon film (Bonyl (registered trademark) W, Kohjin & Film Chemicals Co., Ltd., thickness: 15 μm) serving as the second base layer were dry laminated with an adhesive to serve as the first adhesive layer.

[0091] Next, the nylon film (Bonyl (registered trademark) W, Kohjin & Film Chemicals Co., Ltd., thickness: 15 μm) side that would become the second base material layer of the prepared laminate and a linear low-density polyethylene (LLDPE) film (SK615P, Tamapoly Co., Ltd., thickness: 70 μm) were dry laminated with an adhesive that would become the second adhesive layer to produce a packaging laminate.

[0092] A two-liquid urethane adhesive (Rock Paint Co., Ltd.) was used as the adhesive for forming the first adhesive layer and the second adhesive layer. Specifically, 10 parts by weight of RU-50 as the base agent and 1 part by weight of H-4 as the hardener were mixed, to which dibutyl sebacate (DBS) (Daihachi Chemical Industry Co., Ltd.) as a plasticizer was added at a concentration of 9% by mass relative to the solid content of the adhesive, and this was diluted with ethyl acetate before use.

[0093] Examples 2 to 4 and Comparative Examples 1 to 6 A packaging laminate was prepared in the same manner as in Example 1, except that the type of film serving as the first base layer and the presence or absence of a plasticizer in the first adhesive layer and the second adhesive layer were changed as shown in Table 1.

[0094] "evaluation" <Pinhole resistance> The produced packaging laminate was cut into a rectangle of 286 mm × 210 mm with the longitudinal direction being the vertical (TD) direction. Next, this packaging laminate was shaped into a cylinder with the sealant layer side on the inside and the MD direction being the height direction, and placed on the fixed head and movable head of a bending tester (Gelbo Flex Tester, Tester Sangyo Co., Ltd.) so that the axial direction of the cylinder was horizontal.

[0095] In accordance with the US military specification MIL-B-131D, the packaging laminate was bent 3000 times in a 5°C environment under the following test conditions, and the number of pinholes was visually confirmed. The evaluation results are shown in Table 1. (Test conditions) The movable head of the tester was rotated 440° while moving 88.9 mm toward the fixed head, then moved another 63.5 mm toward the fixed head without rotating, and then these movements were reversed and returned to the original position, forming one cycle, and the bending test was performed a specified number of times at a speed of 40 cycles / min. This bending test was performed on three packaging laminates for each example, and the minimum number of pinholes was regarded as the evaluation result.

[0096] <Adhesive strength> The packaging laminate produced in each example was cut into a width of 15 mm, and the Ny layer and the LLDPE layer were separated and placed on one and the other grips of a tensile tester conforming to JIS K 6854-3. Next, in accordance with JIS K 6854-3, the adhesive strength was measured by T-peel at a tensile speed of 300 mm / min using the tensile tester, and evaluated according to the following criteria. 〇: Adhesive strength is 7N / 15mm or more ×: Adhesive strength is less than 7N / 15mm

[0097] [Table 1]

[0098] From Table 1, it can be seen that the packaging laminates of Examples 1 to 4, in which the adhesive layer is composed of a reactive curing adhesive containing a plasticizer and the sealant layer is composed of linear low-density polyethylene, were able to significantly reduce the number of pinholes compared to the packaging laminate of the comparative example, in which the adhesive layer does not contain a plasticizer and / or does not have a first base layer.

[0099] Moreover, all of the packaging laminates of Examples 1 to 4 and Comparative Examples 1 to 6 had sufficient adhesive strength (7 N / 15 mm or more). [Explanation of symbols]

[0100] 10 Packaging laminate 12 First base layer 13 First adhesive layer 14 Second base layer 15 Second adhesive layer 16 Sealant layer

Claims

1. The laminate includes, in this order, a first substrate layer, a first adhesive layer, a second substrate layer, a second adhesive layer, and a sealant layer; the first base material layer and the second base material layer are bonded to each other by the first adhesive layer, the second base layer and the sealant layer are bonded to each other by the second adhesive layer, the first adhesive layer and the second adhesive layer are made of a reaction-curing adhesive containing a plasticizer, the plasticizer is dibutyl sebacate (DBS), bis(2-ethylhexyl) adipate (DOA), or bis(2-ethylhexyl) sebacate (DOS); and the first base layer is a laminate consisting of a polypropylene layer, a linear low density polyethylene layer, and a linear low density polyethylene layer, or a laminate consisting of a linear low density polyethylene layer, a linear low density polyethylene layer, and a linear low density polyethylene layer; Packaging laminates.

2. 2. The packaging laminate of claim 1, wherein the plasticizer is dibutyl sebacate (DBS).

3. 3. The packaging laminate according to claim 1, wherein the reaction curing adhesive is a two-component curing adhesive made of a urethane resin.

4. The packaging laminate according to any one of claims 1 to 3, wherein the sealant layer is composed of linear low density polyethylene.

5. The packaging laminate according to any one of claims 1 to 4, wherein the second base material layer has a polyamide layer.

6. A packaging bag formed using one or more sheets of the packaging laminate according to any one of claims 1 to 5, The sealant layer has a joint formed by heat sealing to another part of the packaging laminate or a film other than the packaging laminate. packaging bag.

7. The packaging bag according to claim 6, and The contents contained in the packaging bag A packaging bag containing an item.

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