Gas barrier laminate, packaging bag, self-supporting packaging bag, and self-supporting package

Abstract

To provide a gas barrier laminate excellent in content resistance and hard to lower in lamination strength even under a high temperature.SOLUTION: A gas barrier laminate having a laminated structure comprising a substrate layer, a gas barrier layer, an adhesive resin layer and a sealant layer in this order, wherein the adhesive resin layer contains a base resin and an elastomer, the elastomer has an average particle diameter of 0.15 μm or less, and the elastomer has a melting peak temperature of 80 °C. or lower as observed when the temperature is raised from 0 °C. to 200 °C. at a temperature rise rate of 10 °C. / min in differential scanning calorimetry.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gas barrier laminate, a packaging bag, a self-standing packaging bag, and a self-standing package. [Background technology]

[0002] BACKGROUND ART Conventionally, packaging bags used for packaging food, medicines, etc. generally use laminates having gas barrier properties that block the intrusion of water vapor, oxygen, and other gases that can deteriorate the contents, in order to prevent deterioration and spoilage of the contents and to maintain their functions and properties.

[0003] As such a laminate, for example, Patent Document 1 discloses a highly resistant laminate for packaging material characterized by a specific lamination, which is a melt-coextruded layer in which a base layer, an aluminum layer, an adhesive layer, and a thermoplastic resin layer are laminated in this order from the surface layer side, the adhesive layer containing at least acid-modified polyethylene and low-density polyethylene, and the acid-modified polyethylene layer is disposed on the aluminum layer side and the low-density polyethylene layer is disposed on the thermoplastic resin layer side.

[0004] Furthermore, Patent Document 2 discloses a laminate of at least three layers including a structure in which a cyclic olefin resin layer, an adhesive layer, and a polypropylene resin layer are laminated in this order, wherein the resin components contained in the adhesive layer are composed of three specific components, and the ratios of the three specific components are within specific ranges. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7404752 [Patent Document 2] Patent No. 7240435 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, packaging bags may contain highly chemically reactive contents such as highly acidic and basic ingredients, hair coloring agents, alcoholic ingredients, and pharmaceuticals. When packages containing such contents are transported or stored, the contents may erode or penetrate the gas barrier laminate, causing delamination of the gas barrier laminate. In other words, gas barrier laminates are required to have excellent resistance to the contents.

[0007] There is a known gas barrier laminate in which a gas barrier layer and a sealant layer are bonded together by dry lamination. When highly chemically reactive contents are placed in such a gas barrier laminate, the strength of the laminate between the gas barrier layer and the sealant layer decreases over time, resulting in delamination.

[0008] The present inventors have investigated gas barrier laminates that include an adhesive resin layer between a gas barrier layer and a sealant layer in order to realize a laminate with excellent resistance to contents. The inventors' investigations have revealed that such laminates suffer from a significant decrease in laminate strength at high temperatures.

[0009] The present disclosure provides a gas barrier laminate that has excellent resistance to contents and is resistant to deterioration in laminate strength even at high temperatures. The present disclosure also provides a packaging bag, a self-standing packaging bag, and a self-standing package that use such a gas barrier laminate. [Means for solving the problem]

[0010] In order to solve the above problems, the present disclosure provides the following gas barrier laminate, packaging bag, self-standing packaging bag, and self-standing packaging body. [1] a substrate layer; a gas barrier layer; an adhesive resin layer; a sealant layer; in this order, the adhesive resin layer includes a base resin and an elastomer; The average particle size of the elastomer is 0.15 μm or less, A gas barrier laminate in which the peak melting temperature of the elastomer observed in differential scanning calorimetry when heated from 0°C to 200°C at a heating rate of 10°C / min is 80°C or less. [2] The gas barrier laminate according to [1], wherein the base resin comprises a polyolefin resin. [3] The gas barrier laminate according to [1], wherein the base resin comprises linear low-density polyethylene modified with an unsaturated carboxylic acid. [4] The gas barrier laminate according to any one of [1] to [3], wherein the adhesive resin layer has a laminate structure of two layers. [5] A packaging bag comprising the gas barrier laminate according to any one of [1] to [4]. [6] A pair of main bodies; a bottom tape having a mountain fold; A self-standing packaging bag formed by heat sealing the A self-standing packaging bag, wherein a pair of main bodies are each made of the laminate according to any one of [1] to [4]. [7] [6] The self-standing packaging bag according to [6], The contents and A self-standing package comprising: [8] The self-standing package described in [7], wherein the contents include an alcoholic component. [Effects of the Invention]

[0011] According to the present disclosure, there is provided a gas barrier laminate that has excellent resistance to contents and is resistant to deterioration in laminate strength even at high temperatures. The present disclosure also provides a packaging bag, a self-standing packaging bag, and a self-standing package that use such a gas barrier laminate. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a gas barrier laminate according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a front view schematically showing a self-standing packaging bag according to one embodiment of the present disclosure. [Figure 3]FIG. 3 is a cross-sectional view schematically showing the configuration of the self-standing packaging bag shown in FIG. [Figure 4] FIG. 4 is a perspective view schematically showing a pair of main body portions and a bottom tape that constitute the self-standing packaging pouch shown in FIG. [Figure 5] Fig. 5(a) is a melting curve obtained for the material of the first adhesive resin layer in Example 1. Fig. 5(b) is a melting curve obtained for the material of the first adhesive resin layer in Example 2. Fig. 5(c) is a melting curve obtained for the material of the first adhesive resin layer in Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described. Note that the same components are denoted by the same reference numerals, and duplicate explanations will be omitted. Furthermore, the dimensional ratios in the drawings are not limited to those shown in the drawings.

[0014] <Gas barrier laminate> A gas barrier laminate according to one embodiment will now be described. FIG. 1 is a schematic cross-sectional view showing the laminate according to this embodiment. The laminate 1 has a laminate structure including, in this order, a base layer 10, a printing ink layer 11, an adhesive layer 12, a gas barrier layer 13, an adhesive resin layer 14, and a sealant layer 15. The adhesive resin layer 14 includes a first adhesive resin layer 14a and a second adhesive resin layer 14b. The first adhesive resin layer 14a is located on the gas barrier layer 13 side, and the second adhesive resin layer 14b is located on the sealant layer 15 side. The average particle size of the elastomer contained in the adhesive resin layer is 0.15 μm or less. In differential scanning calorimetry (DSC) of the elastomer, the melting peak temperature observed when the temperature is increased from 0°C to 200°C at a heating rate of 10°C / min is 80°C or less.

[0015] The laminate 1 has excellent resistance to contents and is resistant to deterioration of laminate strength even at high temperatures. The inventors speculate that the reason for this effect is as follows. The adhesive resin layer is located between the gas barrier layer and the sealant layer, improving the laminate 1's resistance to contents compared to when the gas barrier layer and the sealant layer are bonded together by dry lamination. Furthermore, the average particle size of the elastomer contained in the adhesive resin layer of the laminate 1 is 0.15 μm or less, which reduces the likelihood of peeling across the interface between the elastomer and the base resin at high temperatures, improving heat resistance. As a result, the laminate 1 has excellent resistance to contents and is resistant to deterioration of laminate strength even at high temperatures.

[0016] Furthermore, laminate 1 has improved processability when forming the adhesive resin layer because the peak melting temperature of the elastomer is 80°C or less. Improved processability enables laminate 1 to suppress the occurrence of foreign matter such as gels and fish eyes, and poor appearance such as wrinkles due to uneven thickness (non-uniform thickness).

[0017] The following describes each layer of the laminate 1. The components contained in each layer may be used alone or in combination of two or more.

[0018] [Base material layer 10] The base layer 10 is a plastic member that functions as the outermost layer in the laminate 1. There are no particular limitations on the thickness of the base layer 10. Depending on the application, the thickness can be set to 6 to 200 μm, but from the viewpoint of reducing materials to reduce the environmental impact and from the viewpoint of obtaining excellent heat resistance, impact resistance, and excellent gas barrier properties, the thickness may be 9 to 50 μm, 12 to 38 μm, 18 to 30 μm, or 15 to 30 μm.

[0019] The base layer 10 contains a resin. Examples of such resins include polyester-based resins, polyamide-based resins, and polyolefin-based resins. Examples of polyester-based resins include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene-2,6-naphthalate, and polybutylene terephthalate, as well as copolymers thereof. Examples of polyamide resins include nylon 6 and nylon 66. Examples of polyolefin-based resins include polyethylene and polypropylene.

[0020] The content of the resin contained in the base material layer 10 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass based on the total amount of the base material layer 10.

[0021] The base layer 10 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent.

[0022] The base layer 10 may be a stretched film or a non-stretched film. From the viewpoints of impact resistance, heat resistance, water resistance, dimensional stability, etc., the base layer 10 is preferably a stretched film. This can prevent the base layer 10 from thermally fusing during the heat sealing step during bag production. Furthermore, the laminate 1 can be more suitably used for applications that require heat treatment such as retort treatment or boiling treatment. The stretching method is not particularly limited, and any method may be used, such as inflation stretching, uniaxial stretching, or biaxial stretching, as long as it can provide a dimensionally stable film.

[0023] The lamination surface of the base material layer 10 may be subjected to various pretreatments such as corona treatment, plasma treatment, and flame treatment, or may be provided with a coating layer such as an easy-adhesion layer.

[0024] [Printing ink layer] The printing ink layer 11 is a layer formed of one or more inks. Examples of inks that can be used include general gravure ink, flexographic ink, offset ink, and digital printing ink. When the ink is an oil-based gravure ink, the ink may contain a binder resin such as a mixture of urethane resin and vinyl chloride-vinyl acetate copolymer resin. The ink contains a pigment and a binder resin, and may further contain various additives and a solvent (e.g., a volatile organic solvent). The ink may be a colored ink containing a colored pigment, or a colorless ink containing no colored pigment. Examples of inks that can be used include vegetable oil ink and biomass ink. The ink may also be a water-based ink.

[0025] [Adhesive layer] The adhesive layer 12 is a layered member located between the base material layer 10 and the gas barrier layer 13 and bonds them together. Examples of adhesive materials that can be used in the adhesive layer 12 include polyester-isocyanate resins, urethane resins, and polyether resins. From an environmental perspective, the adhesive does not need to contain 3-glycidyloxypropyltrimethoxysilane (GPTMS). The adhesive layer 12 does not need to contain chlorine. In this case, the adhesive layer 12 can suppress discoloration of recycled resins and odors caused by heat treatment after recycling. From an environmental perspective, the adhesive layer 12 may be made of biomass materials and may not contain solvents.

[0026] The urethane adhesive contains a polyol and a polyisocyanate. When a urethane adhesive is used, the adhesive layer 12 may contain polyurethane obtained by curing these, or may contain an uncured urethane adhesive.

[0027] Polyols have two or more hydroxyl groups in one molecule. Polyisocyanates have two or more isocyanate groups in one molecule. Polyols and polyisocyanates may react as a base resin and a curing agent, respectively, to produce polyurethane.

[0028] The polyol may contain at least one selected from the group consisting of polyester polyols and polyether polyols.

[0029] The polyisocyanate may be used alone or in combination of two or more thereof. Examples of the polyisocyanate include aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, and aromatic polyisocyanate compounds.

[0030] Examples of aliphatic polyisocyanate compounds include hexamethylene diisocyanate (HDI) and xylylene diisocyanate (XDI). Examples of alicyclic polyisocyanate compounds include isophorone diisocyanate (IPDI). Examples of aromatic polyisocyanate compounds include tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI). As the polyisocyanate compound, multimers (e.g., trimers) of these compounds can also be used, and specifically, adducts, biurets, isocyanurates, etc. can be used. As the polyisocyanate, a polymer of hexamethylene diisocyanate is preferred because the resulting packaging bag tends to have even better oxygen barrier properties after retort treatment.

[0031] The mass ratio of polyol to polyisocyanate (polyol:polyisocyanate) is preferably 5:1 to 15:1, and more preferably 6:1 to 8:1.

[0032] The temperature at which the urethane adhesive is cured is preferably 40 to 60°C, and more preferably 40 to 50°C.

[0033] The time for curing the urethane adhesive is preferably 72 to 168 hours, and more preferably 72 to 120 hours.

[0034] The thickness of the adhesive layer 12 is, for example, 0.5 μm or more and 10 μm or less. When the thickness of the adhesive layer 12 is 0.5 μm or more, peeling between the base layer 10 and the gas barrier layer 13 can be effectively suppressed. The thickness of the adhesive layer 12 may be 1 μm or more, 2 μm or more, 8 μm or less, 6 μm or less, or 5 μm or less.

[0035] [Gas barrier layer] The gas barrier layer 13 exhibits gas barrier properties against gases such as water vapor and oxygen. The laminate 1 may include, for example, a vapor-deposited layer of an inorganic oxide. By using a vapor-deposited layer of an inorganic oxide, high barrier properties can be achieved with a very thin layer that does not affect the recyclability of the laminate. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoints of transparency and barrier properties, the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. The thickness of the vapor-deposited layer of the inorganic oxide may be, for example, 5 to 100 nm or 10 to 50 nm. By having a thickness of 5 nm or more, excellent barrier properties can be easily obtained, and by having a thickness of 100 nm or less, the flexibility of the laminate can be easily maintained. The vapor-deposited layer can be formed, for example, by physical vapor deposition, chemical vapor deposition, or the like.

[0036] The laminate may include a metal layer (metal foil) instead of or in addition to the inorganic oxide vapor-deposited layer. Various metal foils made of aluminum, stainless steel, etc. can be used as the metal layer, and aluminum foil may be used from the viewpoints of moisture resistance, processability such as ductility, and cost. Soft aluminum foil can be used as the aluminum foil. The aluminum foil may contain iron from the viewpoints of excellent pinhole resistance and ductility during molding. The thickness of the metal layer may be 7 to 50 μm or 9 to 15 μm from the viewpoints of barrier properties, pinhole resistance, processability, etc.

[0037] [Adhesive resin layer] The adhesive resin layer 14 has a first adhesive resin layer 14a and a second adhesive resin layer 14b. That is, the adhesive resin layer 14 has a two-layer laminate structure. This makes it easier to control the physical properties and tends to stabilize the adhesiveness. The adhesive resin layer 14 may be an extruded resin layer.

[0038] The ratio (T1 / (T1+T2)) of the thickness (T1) of the first adhesive resin layer 14a to the sum of the thickness (T1) of the first adhesive resin layer 14a and the thickness (T2) of the second adhesive resin layer 14b is preferably 0.25 to 0.75. When the ratio (T1 / (T1+T2)) is 0.25 or more, the adhesion between the gas barrier layer and the adhesive resin layer tends to be more stable. When the ratio (T1 / (T1+T2)) is 0.75 or less, the adhesion between the adhesive resin layer and the sealant layer tends to be more stable.

[0039] The first adhesive resin layer 14a and the second adhesive resin layer 14b will be described below.

[0040] (First adhesive resin layer) The first adhesive resin layer 14a contains a base resin and an elastomer. The first adhesive resin layer 14a is formed from a first adhesive resin layer-forming composition containing a base resin and an elastomer.

[0041] The base resin is a heat-sealable adhesive thermoplastic resin that can be melted and fused to each other by heat, and examples of the base resin include acid-modified polyolefin resins obtained by modifying polyolefin resins with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, and the like.

[0042] Examples of polyolefin resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, and methylpentene polymer.

[0043] The base resin is preferably maleic anhydride graft-modified polyethylene, and is preferably maleic anhydride graft-modified linear low-density polyethylene (density: 0.870 g / cm 3 More than 0.940g / cm 3 This, combined with the effect of the average particle size of the elastomer of the laminate 1 being 0.15 μm or less, makes it possible to suppress defects in appearance such as wrinkles while further preventing the laminate strength from decreasing at high temperatures.

[0044] In the maleic anhydride graft-modified polyethylene, the graft ratio of maleic anhydride is preferably 0.1% by mass or more and 1.0% by mass or less. When the graft ratio of maleic anhydride is 0.1% by mass or more, the adhesiveness of the first adhesive resin layer is further improved. When the graft ratio of maleic anhydride is 1.0% by mass or less, moisture adsorption is suppressed and foaming is suppressed.

[0045] The content of the base resin may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more, based on the total amount of the first adhesive resin layer. The content of the base resin may be 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, or 2% by mass or less, based on the total amount of the first adhesive resin layer.

[0046] The elastomer is not particularly limited, and examples thereof include olefin-based elastomers and styrene-based elastomers. The elastomer may also be an acid-modified product obtained by modifying an olefin-based elastomer or the like with an unsaturated carboxylic acid.

[0047] The average particle size of the elastomer is 0.15 μm or less, preferably 0.12 μm or less, more preferably 0.10 μm or less, even more preferably 0.07 μm or less, and particularly preferably 0.04 μm or less. When the average particle size of the elastomer is 0.10 μm or less, the laminate strength tends to be less likely to decrease even at high temperatures. The average particle size of the elastomer may be, for example, 0.01 μm or more.

[0048] The average particle size of the elastomer may be a value measured by the following method. Specifically, a cross section of the laminate 1 is cut using an ultramicrotome. The cross section is stained with Ru using ruthenium oxide at room temperature (25°C) and 80°C. Then, a thin section is cut from the stained cross section using the ultramicrotome. The cross section of the thin section is observed at a magnification of 5,000 to 100,000 times using a scanning electron microscope equipped with a STEM detector to confirm the presence or absence of elastomer. If elastomer is confirmed, the particle sizes of 50 elastomer particles are measured and the average value is taken as the average particle size of the elastomer. If the elastomer is not a perfect circle, the minor axis of the elastomer is used as the particle size. If the elastomer is not clearly confirmed, the average particle size of the elastomer is taken as 0.02 μm or less.

[0049] In differential scanning calorimetry of the elastomer, the melting peak temperature observed when the temperature is raised from 0°C to 200°C at a heating rate of 10°C / min is 80°C or lower, preferably 70°C or lower, and more preferably 60°C or lower. A melting peak temperature of 70°C or lower further improves processability during adhesive resin layer formation. This improved processability tends to further reduce the occurrence of foreign matter such as gels and fish eyes, and appearance defects such as wrinkles due to uneven thickness (uneven thickness). The melting peak temperature of the elastomer may be lower than the melting point of the base resin. The melting peak temperature may be 40°C or higher.

[0050] The sample for differential scanning calorimetry of the elastomer may be a portion of the first adhesive resin layer of the gas barrier laminate, or may be a composition for forming the first adhesive resin layer.

[0051] The content of the elastomer may be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 1% by mass or more, 5% by mass or more, or 10% by mass or more, based on the total amount of the first adhesive resin layer. The content of the elastomer may be 50% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less, based on the total amount of the first adhesive resin layer.

[0052] The base resin and the elastomer may be compatible or incompatible. The base resin and the elastomer are preferably compatible, since this tends to further reduce the decrease in laminate strength even at high temperatures. The term "compatible" means that the cross-section of the laminate 1 is observed in the same manner as in the measurement of the average particle diameter of the elastomer described above, and the elastomer is not clearly visible (the average particle diameter of the elastomer is 0.02 μm or less). The term "incompatible" means that the cross-section of the laminate 1 is observed in the same manner as in the measurement of the average particle diameter of the elastomer described above, and the elastomer is clearly visible (the average particle diameter of the elastomer is greater than 0.02 μm).

[0053] The thickness (T1) of the first adhesive resin layer 14a may be 1 μm or more, 2 μm or more, or 5 μm or more, and may be 50 μm or less, 30 μm or less, or 20 μm or less.

[0054] (Second adhesive resin layer) The second adhesive resin layer 14b contains a base resin. Examples of the base resin include polyolefin resins and acid-modified polyolefin resins obtained by modifying polyolefin resins with acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, or other unsaturated carboxylic acids. From the viewpoint of adhesion to the sealant layer, the base resin is preferably polyethylene or polypropylene.

[0055] The content of the base resin may be 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass based on the total amount of the second adhesive resin layer.

[0056] The thickness (T2) of the second adhesive resin layer 14b may be 1 μm or more, 2 μm or more, or 5 μm or more, and may be 50 μm or less, 30 μm or less, or 20 μm or less.

[0057] [Sealant layer] The sealant layer 15 is a layer that provides heat-sealing properties to the laminate 1. The sealant layer 15 contains a resin. Examples of such resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, epoxy resin (EP), ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and metal-crosslinked products thereof. Of these, linear low-density polyethylene is preferred.

[0058] The sealant layer 15 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent.

[0059] The thickness of the sealant layer 15 is determined depending on the weight of the contents, the shape of the packaging bag, etc., but may be approximately 30 to 150 μm, or may be 50 to 80 μm.

[0060] Although the gas barrier laminate according to one embodiment has been described above, the gas barrier laminate according to the present disclosure is not limited to the above embodiment. For example, the gas barrier laminate according to the present disclosure does not have to include a printed ink layer.

[0061] In addition, in the gas barrier laminate of the present disclosure, the adhesive resin layer does not have to have a second adhesive resin layer. That is, the adhesive resin layer may consist of only a first adhesive resin layer. In addition, in the gas barrier laminate of the present disclosure, the adhesive resin layer may be composed of three or more layers.

[0062] The gas barrier laminate of the present disclosure may further include a second substrate layer. The second substrate layer may be located, for example, between the substrate layer and the gas barrier layer. That is, the gas barrier laminate may have a layered structure including, in this order, a substrate layer, a printing ink layer, an adhesive layer, a second substrate layer, an adhesive layer, a gas barrier layer, an adhesive resin layer, and a sealant layer.

[0063] (2nd base layer) The thickness of the second base material layer may be the same as that of the base material layer 10 according to the above embodiment. The type and content of the resin contained in the second base material layer may be the same as that of the base material layer 10 according to the above embodiment. The second base material layer may contain various additives similar to those of the base material layer 10 according to the above embodiment.

[0064] In the gas barrier laminate of the present disclosure, the gas barrier layer may have at least one of an anchor coat layer and an overcoat layer.

[0065] <Packaging bag> Hereinafter, a self-standing packaging bag (standing pouch) will be described as a packaging bag according to one embodiment. FIG. 2 is a front view schematically illustrating a standing pouch (self-standing packaging bag) according to this embodiment. FIG. 3 is a cross-sectional view schematically illustrating the configuration of the standing pouch. The standing pouch 20 shown in these figures is formed by heat-sealing a pair of main body portions 21, 22 and a bottom tape 23. In this embodiment, the pair of main body portions 21, 22 and the bottom tape 23 are all composed of the laminate 1 according to the above embodiment (the printing ink layer 11, adhesive layer 12, gas barrier layer 13, and adhesive resin layer 14 are not shown). Self-standing packaging bags have a complex structure, particularly due to folded portions, and therefore require improved pressure resistance. By configuring the pair of main body portions 21, 22 and the bottom tape 23 as the laminate 1 according to the above embodiment, the self-standing packaging bag 20 tends to have excellent content resistance and even better pressure resistance even at high temperatures.

[0066] Formation of a standing pouch by heat sealing can be carried out in the same manner as in conventional methods.

[0067] The bottom tape 23 has one mountain fold 23a. That is, when the self-standing packaging pouch 20 is in a self-standing state, the bottom tape 23 is arranged in an inverted V shape (see FIGS. 2 and 3).

[0068] As shown in Fig. 2, the bottom of the self-standing packaging bag 20 is composed of heat-sealed portions 25 and 26. Heat-sealed portion 25 is a portion where the bottom portion 21a of main body portion 21 is heat-sealed to one bottom portion 23b of bottom tape 23. Heat-sealed portion 26 is a portion where the bottom portion 22a of main body portion 22 is heat-sealed to the other bottom portion 23c of bottom tape 23. As shown in Fig. 2, main body portions 21, 22 and bottom tape 23 are heat-sealed so that the bottom of the area for accommodating the contents is curved and the upper side is arc-shaped.

[0069] The distance L from the bottom side 20a of the standing pouch 20 to the mountain fold 23a depends on the type and amount of the contents, but may be, for example, 30 to 60 mm, or may be 35 to 50 mm, or 40 to 50 mm. When the distance L is 30 mm or more, the drop resistance of the self-standing packaging pouch 20 tends to be improved. On the other hand, when the distance L is 60 mm or less, it tends to be easier to ensure a sufficient content capacity of the standing pouch 20. The width W of the standing pouch 20 also depends on the type and amount of the contents, but may be, for example, 100 to 300 mm, or may be 105 to 295 mm, or 110 to 290 mm.

[0070] The sides of the standing pouch 20 are configured with heat-sealed portions 27. The width of the heat-sealed portions 27 is, for example, 3 to 18 mm, and may be 7 to 15 mm. When the width of the heat-sealed portions 27 is 3 mm or more, the self-standing packaging bag 20 tends to be able to stand up sufficiently, while when the width is 18 mm or less, the self-standing packaging bag 20 tends to be able to easily secure a sufficient internal capacity.

[0071] As shown in Fig. 2, the stand-up pouch 20 has local joints 29 on both sides of the bottom 20b. The local joints 29 join the main body 21 and the main body 22. That is, the local joints 29 are locations where the sealant layers 15 of the main body 21 and the main body 22 are locally bonded to each other through cutouts 28 provided in the bottom tape 23. As shown in Fig. 4, the cutouts 28 of the bottom tape 23 are provided in the region between the mountain fold 23a and the bottom edges 23d, 23d, on the sides of the bottom tape 23. By providing the local joints 29 on both sides of the bottom 20b, the self-supporting ability and drop-bag resistance of the stand-up pouch 20 can be further improved.

[0072] The internal volume of the self-standing packaging bag may be 50 mL or more, 100 mL or more, or 300 mL or more, and may be 5000 mL or less, 3000 mL or less, or 1000 mL or less.

[0073] Although an example of a self-standing packaging bag has been described above, the self-standing packaging bag of the present disclosure is not limited to the above example. For example, a laminate different from the laminate according to the above embodiment may be used as the bottom tape.

[0074] Furthermore, the packaging bag of the present disclosure is not limited to a self-standing packaging bag. For example, the packaging bag may be a two-sided bag, a three-sided bag, a four-sided bag, a palm-shaped bag, or a gusset bag.

[0075] <Package> A package according to one embodiment will be described below. The package is obtained by placing contents in a packaging bag. That is, the package includes a packaging bag and the contents placed in the packaging bag. The package may be a self-standing package. The self-standing package includes a self-standing packaging bag 20 and the contents placed in the self-standing packaging bag 20.

[0076] The contents include, for example, acid components, base components, alcohol components, hair coloring agents, fragrances, and pesticides. The self-standing packaging body can suitably store highly chemically reactive contents because the self-standing packaging bag 20 is made of the laminate 1.

[0077] When the contents contain an alcohol component, the concentration of the alcohol component may be 50% by volume or more, 60% by volume or more, 70% by volume or more, 80% by volume or more, 90% by volume or more, 95% by volume or more, or 100% by volume based on the total volume of the contents. Examples of alcohol components include ethanol and isopropanol. [Example]

[0078] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0079] <Material> The following materials were prepared: (base material layer) Biaxially oriented nylon film (product name: Bonyl RX, manufactured by Kohjin Film & Chemicals Co., Ltd., thickness: 15 μm) (gas barrier layer) Aluminum foil (8021 material, manufactured by Toyo Aluminum, thickness: 9 μm) (First adhesive resin layer) M545 (trade name, composition containing a base resin and an elastomer, base resin: linear low-density polyethylene grafted with maleic anhydride, manufactured by Mitsubishi Chemical Corporation, melting point 103°C, density 0.90 g / cm 3 , MFR 6g / cm 3 ) M555 (trade name, composition containing a base resin and an elastomer, base resin: maleic anhydride grafted linear low-density polyethylene, manufactured by Mitsubishi Chemical Corporation, melting point 122°C, density 0.91 g / cm 3 , MFR6.5g / cm 3 ) M605 (trade name, composition containing a base resin and an elastomer, base resin: maleic anhydride grafted linear low-density polyethylene, manufactured by Mitsubishi Chemical Corporation, melting point 98°C, density 0.88 g / cm 3 , MFR10g / cm 3 ) (Second adhesive resin layer) Low-density polyethylene (LC600A, manufactured by Japan Polyethylene Co., Ltd., melting point 106°C, density 0.918 g / cm 3 , MFR7.0g / cm 3 ) (sealant layer) Polyethylene film (linear low-density polyethylene, product name: SE620A, manufactured by Tamapoly Co., Ltd., thickness: 80 μm) (ink layer) Gravure ink (product name: Riogran, manufactured by Toyo Ink Co., Ltd.) (adhesive layer) Two-component curing urethane adhesive (product name: base agent A525 / curing agent A52, manufactured by Mitsui Chemicals, Inc.)

[0080] <Preparation of gas barrier laminate> Example 1 A printing ink layer was formed on one main surface of a biaxially oriented nylon film (substrate layer) using gravure ink. The printing ink layer and aluminum foil (gas barrier layer) were then bonded together by dry lamination using a two-component curing urethane adhesive (adhesive layer) to obtain a first laminate. The first laminate, M545 (first adhesive resin layer, thickness: 10 μm), LC600A (second adhesive resin layer, thickness: 10 μm), and a polyethylene film (sealant layer) were laminated in this order using a sandwich lamination method using an extrusion laminator. The first laminate was laminated so that the gas barrier layer side of the first laminate faced the first adhesive resin layer. This resulted in a gas barrier laminate (layer configuration: substrate layer / printing ink layer / adhesive layer / gas barrier layer / first adhesive resin layer / second adhesive resin layer / sealant layer).

[0081] Example 2 A gas barrier laminate was obtained in the same manner as in Example 1, except that M555 was used in place of M545 for the first adhesive resin layer.

[0082] (Comparative Example 1) A gas barrier laminate was obtained in the same manner as in Example 1, except that M605 was used instead of M545 for the first adhesive resin layer.

[0083] (Comparative Example 2) A printing ink layer was formed on one main surface of a biaxially oriented nylon film (substrate layer) using gravure ink. The printing ink layer and aluminum foil (gas barrier layer) were bonded together by dry lamination using a two-component curing urethane adhesive (adhesive layer) to obtain a first laminate. The first laminate was then bonded to a polyethylene film (sealant layer) by dry lamination using a two-component curing urethane adhesive (adhesive layer). The first laminate was laminated so that the gas barrier layer side faced the sealant layer. This resulted in a gas barrier laminate (layer configuration: substrate layer / printing ink layer / adhesive layer / gas barrier layer / adhesive layer / sealant layer).

[0084] <Production of self-standing packaging bags> The gas barrier laminates of each of the Examples and Comparative Examples were used as a main body and a bottom tape to produce self-standing packaging bags using a bag making machine. ·Content capacity: 400mL Height: 230mm ·Width: 140mm

[0085] <Lamination strength> The laminate strength of the gas barrier laminate of each Example and Comparative Example was measured in accordance with JIS Z 1707. Specifically, the gas barrier laminate was cut into a 15 mm width to obtain a measurement sample. In Examples 1 and 2 and Comparative Example 1, the gas barrier layer and the adhesive resin layer were peeled off at the edge of the measurement sample, followed by T-peel at a rate of 300 mm / min using a tensile tester at room temperature (25°C) or 80°C to measure the laminate strength. In Comparative Example 2, the gas barrier layer and the sealant layer were peeled off at the edge of the measurement sample, followed by T-peel at a rate of 300 mm / min using a tensile tester at room temperature (25°C) or 80°C to measure the laminate strength. The laminate strength was measured for three measurement samples, and the average value was used as the laminate strength of the gas barrier laminate. The results are shown in Table 1.

[0086] <Content resistance> The self-standing packaging bags of each Example and Comparative Example were filled with an aqueous ethanol solution (ethanol concentration: 80% by volume) to obtain self-standing packages. The self-standing packages were stored in a thermostatic chamber (temperature: 50°C, humidity: uncontrolled) for 6 months. After storage, the main body of the self-standing package was cut into a 15 mm width to obtain a measurement sample, and the laminate strength was measured in the same manner as in the <Lamination strength> section described above. The presence or absence of delamination was also visually confirmed. The laminate strength and the presence or absence of delamination were evaluated according to the following criteria. The results are shown in Table 1.

[0087] (standard) A: Laminate strength is 5N / 15mm or more and no delamination is observed B: The average laminate strength is less than 5N / 15mm or delamination is observed.

[0088] <80℃ pressure resistance test> The self-standing packaging bags of each Example and Comparative Example were filled with water at 80°C to obtain self-standing packages. The self-standing packages were placed on a horizontal board so that the main surface of the body of the self-standing packaging bag was horizontal. A load of 80 kg was then applied to the self-standing packages for 3 minutes. The presence or absence of bag breakage and water leakage during the load application was visually confirmed and evaluated according to the following criteria. The results are shown in Table 1.

[0089] (standard) A: No breakage or water leakage was observed B: Bag breakage or water leakage confirmed

[0090] <Overall rating> The gas barrier laminates of each Example and Comparative Example were comprehensively evaluated for long-term storage stability according to the following criteria. The results are shown in Table 1. (standard) A: The evaluation of both the contents resistance and pressure resistance test is "A". B: At least one of the evaluations of the contents resistance and pressure resistance test is "B"

[0091] <Differential scanning calorimetry> Differential scanning calorimetry was performed on the elastomer contained in the first adhesive resin layer of the gas barrier laminates of Examples 1 and 2 and Comparative Example 1. Specifically, a melting curve was obtained for the material of the first adhesive resin layer of each example, and the peak below 100°C was taken as the melting peak temperature of the elastomer. The measurement equipment and heating conditions were as follows. The results are shown in Table 1. Figure 5(a) shows the melting curve obtained for the material of the first adhesive resin layer of Example 1. Figure 5(b) shows the melting curve obtained for the material of the first adhesive resin layer of Example 2. Figure 5(c) shows the melting curve obtained for the material of the first adhesive resin layer of Comparative Example 1. (Measurement equipment and heating conditions) Measurement equipment: Differential scanning calorimeter (PerkinElmer DSC8000) Heating conditions: Heat from 0°C to 200°C at a rate of 10°C / min.

[0092] <Cross-section observation> Measurement samples were obtained from the gas barrier laminates of each Example and Comparative Example. The measurement samples were embedded in a photocurable resin, and then cross sections of the gas barrier laminates were cut using an ultramicrotome (EMUC7, manufactured by Leica Microsystems). The cross sections were stained with ruthenium oxide at room temperature and 80°C. Thin sections were then cut from the stained surface using the ultramicrotome. The cross sections of the thin sections were observed at magnifications of 5,000 to 100,000 times using a STEM detector attached to a scanning electron microscope (Regulus 8220, manufactured by Hitachi High-Technologies) to confirm the presence or absence of elastomer. If elastomer was detected, the particle sizes of 50 elastomer particles were measured, and the average value was used as the average particle size of the elastomer. If elastomer was not clearly detected, the average particle size of the elastomer was 0.02 μm or less. The results are shown in Table 1.

[0093] [Table 1] [Explanation of symbols]

[0094] 1... laminate, 10... base material layer, 13... gas barrier layer, 14... adhesive resin layer, 15... sealant layer, 20... self-standing packaging bag, 21, 22... main body portion, 23... bottom tape, 23a... mountain fold portion.

Claims

1. a substrate layer; a gas barrier layer; an adhesive resin layer; a sealant layer; in this order, the adhesive resin layer contains a base resin and an elastomer, The average particle size of the elastomer is 0.15 μm or less, A gas barrier laminate, wherein the peak melting temperature of the elastomer observed in differential scanning calorimetry when heated from 0°C to 200°C at a heating rate of 10°C / min is 80°C or less.

2. The gas barrier laminate according to claim 1 , wherein the base resin comprises a polyolefin resin.

3. 2. The gas barrier laminate according to claim 1, wherein the base resin comprises a linear low-density polyethylene modified with an unsaturated carboxylic acid.

4. The gas barrier laminate according to claim 1 , wherein the adhesive resin layer has a laminate structure of two layers.

5. A packaging bag comprising the gas barrier laminate according to any one of claims 1 to 4.

6. A pair of main bodies; a bottom tape having a mountain fold; A self-standing packaging bag formed by heat sealing the A self-standing packaging bag, wherein the pair of main body portions are each made of the laminate according to any one of claims 1 to 4.

7. The self-standing packaging bag according to claim 6; The contents and A self-standing package comprising:

8. The self-standing package according to claim 7, wherein the contents include an alcoholic component.

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