packaging bags

Abstract

To provide a packaging bag which has a more excellent CO2 reduction effect than a laminate comprising non-recycled polyethylene terephthalate, and which has a laminate having excellent hygiene.SOLUTION: A packaging bag for packaging a content includes a laminate. The laminate includes at least an adhesive layer, a barrier layer, and a sealant layer in this order. A base material layer includes polyethylene terephthalate in which ethylene glycol is a diol unit and terephthalic acid and isophthalic acid are a dicarboxylic acid unit. The thickness of the base material layer is 5 μm or more and 25 μm or less. The barrier layer includes a vapor deposition layer provided at the sealant layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a packaging bag having a laminate, and more particularly to a packaging bag having a laminate made from recycled polyester resin as a raw material, which is recovered from packaging materials and can be reused. [Background technology]

[0002] In the production of packaging materials for filling products such as pharmaceuticals, cosmetics, and food, plastics, which are materials derived from fossil fuels, are mainly used from the viewpoints of ease of molding, cost, etc. Plastic materials commonly used as materials for packaging containers include polyester-based resins, polyolefin-based resins, polyamide-based resins, etc. Among these, polyester-based resins are widely used in various industrial applications such as films, sheets, and packaging containers because of their excellent mechanical properties, chemical stability, heat resistance, transparency, etc., and their low cost.

[0003] Polyesters are obtained by polycondensation of diol units and dicarboxylic acid units. For example, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is produced by esterifying ethylene glycol and terephthalic acid as raw materials, followed by polycondensation. These raw materials are produced from petroleum, a fossil resource; for example, ethylene glycol is produced industrially from ethylene, and terephthalic acid is produced industrially from xylene.

[0004] In recent years, there has been a growing trend toward reducing the use of fossil fuels in various applications and reducing CO2 emissions in consideration of the environment, particularly with regard to such fossil fuel-derived materials. One attempt to reduce the use of fossil fuels has been to propose a method of recycling polyester, which is recovered from used packaging materials such as PET bottles and made reusable, and then recycled into molding packaging materials (see, for example, Patent Documents 1 and 2). Patent Documents 1 and 2 propose a reduction in CO2 emissions by recovering used products formed using fossil fuel-derived polyester and making the recycled polyester reusable and using it as part of a packaging material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-256328 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-41463 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is an impression that packaging materials made from recycled PET, which is recycled through mechanical recycling—in which collected polyester resin products such as PET bottles are crushed, washed, and reused—may be contaminated due to foreign matter adhering to the recycled PET. For this reason, packaging materials made from laminates made from recycled PET, particularly packaging materials for filling food and other products, are finding it difficult to gain consumer trust.

[0007] An object of the present invention is to provide a packaging bag including a laminate that can effectively solve such problems. [Means for solving the problem]

[0008] The present invention provides a packaging bag for packaging contents, comprising a laminate, the laminate comprising at least a base layer, an adhesive layer, a barrier layer, and a sealant layer, in this order, the base layer containing polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units, the base layer having a thickness of 5 μm or more and 25 μm or less, and the barrier layer including a vapor deposition layer provided on the sealant layer.

[0009] In the packaging bag according to the present invention, the vapor-deposited layer may be a metal vapor-deposited layer.

[0010] The present invention provides a packaging bag for packaging contents, the packaging bag comprising a laminate, the laminate comprising at least a base material layer, a barrier layer, an adhesive layer, and a sealant layer in this order, the base material layer comprising polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units, the thickness of the base material layer being 5 μm or more and 25 μm or less, and the barrier layer including a vapor deposition layer provided on the base material layer.

[0011] In the packaging bag according to the present invention, the vapor deposition layer may be a transparent vapor deposition layer.

[0012] In the packaging bag according to the present invention, the barrier layer may further include a gas barrier coating film provided on the surface of the transparent vapor deposition layer.

[0013] In the packaging bag according to the present invention, the adhesive layer may include a cured product of a polyester polyol and an aliphatic isocyanate compound.

[0014] In the packaging bag according to the present invention, the polyester polyol has two or more hydroxyl groups as functional groups in one molecule, the isocyanate compound has two or more isocyanate groups as functional groups in one molecule, and the polyester polyol may be a polycondensate of an ortho-oriented polycarboxylic acid or an anhydride thereof and a polyhydric alcohol.

[0015] In the packaging bag according to the present invention, the polyester polyol has two or more hydroxyl groups as functional groups in one molecule, the isocyanate compound has two or more isocyanate groups as functional groups in one molecule, and the polyester polyol is a compound represented by the following general formula (1): [ka] In general formula (1), R1, R2, and R3 each independently represent H (hydrogen atom) or a compound represented by the following general formula (2): [ka] In formula (2), n represents an integer of 1 to 5; X represents an arylene group selected from the group consisting of 1,2-phenylene groups, 1,2-naphthylene groups, 2,3-naphthylene groups, 2,3-anthraquinonediyl groups, and 2,3-anthracenediyl groups, which may have a substituent; and Y represents an alkylene group having 2 to 6 carbon atoms), provided that at least one of R1, R2, and R3 may represent a group represented by general formula (2).

[0016] In the packaging bag according to the present invention, the polyester polyol may have two or more hydroxyl groups as functional groups in one molecule, the isocyanate compound may have two or more isocyanate groups as functional groups in one molecule, and the polyester polyol may have an isocyanuric ring.

[0017] In the packaging bag according to the present invention, the content of the isophthalic acid may be 0.5 mol % or more and 5.0 mol % or less with respect to all dicarboxylic acid units constituting the polyethylene terephthalate.

[0018] In the packaging bag according to the present invention, the polyethylene terephthalate may have an intrinsic viscosity of 0.58 dL / g or more and 0.80 dL / g or less.

[0019] In the packaging bag according to the present invention, the sealant layer may have a thickness of 30 μm or more and 130 μm or less.

[0020] In the packaging bag according to the present invention, the adhesive layer may have a thickness of 1.0 μm or more and 4.5 μm or less. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a packaging bag including a laminate that is more effective in reducing CO2 emissions than a laminate made of non-recycled polyethylene terephthalate and that is also highly hygienic. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present embodiment. [Figure 2] FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present embodiment. [Figure 3] FIG. 2 is a schematic cross-sectional view showing an example of a base material layer. DETAILED DESCRIPTION OF THE INVENTION

[0023] <Laminate> The laminate according to this embodiment includes at least a base layer, a barrier layer, and a sealant layer in this order. The laminate may further include an adhesive layer, a printed layer, or other layers.

[0024] The laminate according to the present embodiment will be described with reference to the drawings. Examples of schematic cross-sectional views of the laminate according to the present embodiment are shown in FIGS.

[0025] The laminate 10 shown in Fig. 1 includes, in this order, a base material layer 11, an adhesive layer 14, a barrier layer 12, and a sealant layer 13. As shown in Fig. 1, the barrier layer 12 includes a vapor deposition layer 121 provided on the sealant layer 13. Although not shown, the laminate 10 may further include a printed layer provided on the base material layer 11. In a packaging bag including the laminate 10 shown in Fig. 1, the sealant layer 13 forms the inner surface of the packaging bag.

[0026] The laminate 10 shown in Fig. 2 includes, in this order, a base layer 11, a barrier layer 12, an adhesive layer 14, and a sealant layer 13. As shown in Fig. 2, the barrier layer 12 includes at least a vapor deposition layer 121 provided on the base layer 11. The barrier layer 12 may further include a gas barrier coating film 122 provided on the surface of the vapor deposition layer 121. Although not shown, the laminate 10 may further include a printed layer located between the barrier layer 12 and the adhesive layer 14. In a packaging bag including the laminate 10 shown in Fig. 2, the sealant layer 13 also forms the inner surface of the packaging bag.

[0027] Each layer constituting the laminate will now be described.

[0028] [Base material layer] The substrate layer contains polyethylene terephthalate (hereinafter, polyethylene terephthalate will also be referred to as PET) recycled by mechanical recycling. Specifically, the substrate layer contains PET mechanically recycled from PET bottles, where the diol unit is ethylene glycol and the dicarboxylic acid units are terephthalic acid and isophthalic acid. Mechanical recycling generally refers to a process in which collected polyethylene terephthalate resin products, such as PET bottles, are crushed and washed with alkali to remove surface contamination and foreign matter from the PET resin product, and then dried at high temperature and reduced pressure for a certain period of time to diffuse contaminants remaining inside the PET resin, thereby decontaminating the PET resin product and returning it to PET resin. Hereinafter, in this specification, polyethylene terephthalate recycled from PET bottles will be referred to as "recycled polyethylene terephthalate (hereinafter, also referred to as recycled PET)," and unrecycled polyethylene terephthalate will be referred to as "virgin polyethylene terephthalate (hereinafter, also referred to as virgin PET)."

[0029] The content of isophthalic acid in the PET contained in the base layer is preferably 0.5 mol% to 5 mol% and more preferably 1.0 mol% to 2.5 mol% relative to the total dicarboxylic acid units constituting the PET. If the content of isophthalic acid is less than 0.5 mol%, flexibility may not be improved, while if it exceeds 5 mol%, the melting point of the PET may decrease, resulting in insufficient heat resistance. The PET may be a conventional PET derived from fossil fuels or a biomass PET. "Biomass PET" refers to a PET containing biomass-derived ethylene glycol as the diol unit and a fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit. This biomass PET may be formed solely from PET containing biomass-derived ethylene glycol as the diol unit and fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit, or it may be formed from PET containing biomass-derived ethylene glycol and fossil fuel-derived diol as the diol unit and a fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit.

[0030] The PET used for PET bottles can be obtained by a conventionally known method of polycondensing the above-mentioned diol units and dicarboxylic acid units. Specifically, it can be produced by a general melt polymerization method in which the above-mentioned diol units and dicarboxylic acid units are subjected to an esterification reaction and / or transesterification reaction, followed by a polycondensation reaction under reduced pressure, or by a known solution heating dehydration condensation method using an organic solvent.

[0031] The amount of diol units used in producing the above-mentioned PET is substantially equimolar to 100 moles of dicarboxylic acid or its derivative, but is generally used in an excess of 0.1 mol % to 20 mol % because distillates are generated during the esterification and / or transesterification reaction and / or polycondensation reaction.

[0032] The polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and the catalyst may be added when the raw materials are charged or when pressure reduction is initiated.

[0033] After the PET recycled from PET bottles has been polymerized and solidified as described above, it may be subjected to solid-state polymerization as necessary to further increase the degree of polymerization or to remove oligomers such as cyclic trimers. Specifically, the solid-state polymerization is carried out by cutting the PET into chips, drying it, heating it at a temperature of 100°C to 180°C for about 1 to 8 hours to pre-crystallize the PET, and then heating it at a temperature of 190°C to 230°C in an inert gas atmosphere or under reduced pressure for 1 hour to several tens of hours.

[0034] The intrinsic viscosity of the PET contained in the substrate layer is preferably 0.58 dL / g or more and 0.80 dL / g or less. If the intrinsic viscosity is less than 0.58 dL / g, the mechanical properties required for the PET film as a substrate may be insufficient. On the other hand, if the intrinsic viscosity exceeds 0.80 dL / g, productivity in the film formation process may be impaired. The intrinsic viscosity is measured in an orthochlorophenol solution at 35°C.

[0035] The substrate layer preferably contains recycled PET in a proportion of 50% by weight to 95% by weight, and may contain virgin PET in addition to recycled PET. Virgin PET may be PET containing ethylene glycol as the diol unit and terephthalic acid and isophthalic acid as the dicarboxylic acid unit, as described above, or PET containing no isophthalic acid as the dicarboxylic acid unit. The substrate layer may also contain polyester other than PET. For example, the dicarboxylic acid unit may contain aliphatic dicarboxylic acids in addition to aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid.

[0036] Specific examples of aliphatic dicarboxylic acids include linear or alicyclic dicarboxylic acids typically having 2 to 40 carbon atoms, such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid. Derivatives of aliphatic dicarboxylic acids include lower alkyl esters of the above aliphatic dicarboxylic acids, such as methyl esters, ethyl esters, propyl esters, and butyl esters, and cyclic acid anhydrides of the above aliphatic dicarboxylic acids, such as succinic anhydride. Among these, preferred aliphatic dicarboxylic acids are adipic acid, succinic acid, dimer acid, or mixtures thereof, with those primarily composed of succinic acid being particularly preferred. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

[0037] Such a substrate layer made of PET may be a single layer or multiple layers. As shown in FIG. 3, when the recycled PET described above is used for the substrate layer, the substrate layer may include three layers: a first layer 31, a second layer 32, and a third layer 33. In this case, the third layer 33 of the substrate layer is located on the sealant layer side of the laminate. In this case, it is preferable that the second layer 32 be a layer made solely of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 31 and the third layer 33 be layers made solely of virgin PET. Using only virgin PET for the first layer 31 and the third layer 33 in this way prevents the recycled PET from appearing on the front or back surface of the substrate layer. This ensures the hygienic properties of the laminate. Alternatively, the substrate layer may include two layers: a second layer 32 and a third layer 33, without the first layer 31 shown in FIG. 3. Furthermore, the substrate layer may be a substrate layer having two layers, a first layer 31 and a second layer 32, without providing the third layer 33 shown in Fig. 3. Even in these cases, it is preferable that the second layer 32 be a layer made only of recycled PET or a mixed layer of recycled PET and virgin PET, and that the first layer 31 and the third layer 33 be layers made only of virgin PET.

[0038] When recycled PET and virgin PET are mixed to form a single layer, they may be fed separately to a molding machine, or they may be mixed by dry blending or the like and then fed. Of these, the dry blending method is preferred from the viewpoint of ease of operation.

[0039] Various additives can be added to the PET constituting the base layer during or after its production, provided that the properties of the PET are not impaired. Examples of additives include plasticizers, UV stabilizers, color inhibitors, matting agents, deodorizers, flame retardants, weather resistance agents, antistatic agents, thread friction reducers, mold release agents, antioxidants, ion exchange agents, and color pigments. The additives are preferably added in an amount of 5% by mass to 50% by mass, and more preferably 5% by mass to 20% by mass, based on the total mass of the resin composition containing PET.

[0040] The substrate layer can be formed by forming the above-mentioned PET into a film by, for example, a T-die method. Specifically, after drying the above-mentioned PET, the resin composition is supplied to a melt extruder heated to a temperature above the melting point of PET (Tm) to Tm+70°C, melted, and extruded into a sheet form through a die such as a T-die. The extruded sheet can be rapidly cooled and solidified using a rotating cooling drum or the like to form a film. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

[0041] The film obtained as described above is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to form a longitudinally stretched film. This stretching is preferably performed by utilizing the difference in peripheral speed between two or more rolls. The longitudinal stretching is usually performed at a temperature range of 50°C or higher and 100°C or lower. The longitudinal stretching ratio is preferably 2.5 times or higher and 4.2 times or lower, depending on the required properties of the film application. If the stretching ratio is less than 2.5 times, the thickness unevenness of the PET film becomes large, making it difficult to obtain a good film.

[0042] The longitudinally stretched film is then subjected to the sequential processes of transverse stretching, heat setting, and heat relaxation to become a biaxially stretched film. Transverse stretching is usually carried out at a temperature ranging from 50°C to 100°C. The transverse stretching ratio is preferably 2.5 times to 5.0 times, depending on the required properties of the application. If the ratio is less than 2.5 times, the film thickness will become uneven, making it difficult to obtain a good film, and if the ratio is more than 5.0 times, breakage will occur during film formation.

[0043] After transverse stretching, heat setting is carried out. The preferred temperature range for heat setting is Tg+70 to Tm-10°C of PET. The heat setting time is preferably 1 second or more and 60 seconds or less. For applications requiring a reduction in heat shrinkage, heat relaxation treatment may be carried out as necessary.

[0044] The thickness of the PET film obtained as described above is optional depending on its application, but is usually about 5 μm to 100 μm, preferably 5 μm to 25 μm. The breaking strength of the PET film is 5 kg / mm ​​in the MD direction. 2 More than 40kg / mm 2 Below, 5 kg / mm ​​in the TD direction 2 More than 35kg / mm 2 The elongation at break is 50% to 350% in the MD direction and 50% to 300% in the TD direction. The shrinkage when left in a 150°C temperature environment for 30 minutes is 0.1% to 5%.

[0045] Virgin PET may be fossil fuel polyethylene terephthalate (hereinafter also referred to as fossil fuel PET) or biomass PET. Here, "fossil fuel PET" refers to PET in which a diol derived from a fossil fuel is used as a diol unit and a dicarboxylic acid derived from a fossil fuel is used as a dicarboxylic acid unit. Recycled PET may be obtained by recycling a PET resin product formed using fossil fuel PET, or may be obtained by recycling a PET resin product formed using biomass PET.

[0046] [Barrier layer] Next, the barrier layer will be described. The barrier layer is a layer for preventing foreign matter from adhering to the recycled PET used in the base layer, which may cause the foreign matter to be exposed to the sealant layer side of the barrier layer. This prevents foreign matter from being exposed to the inner side of the barrier layer in a packaging bag made using the laminate, thereby ensuring the hygiene of the contents.

[0047] (deposited layer) Next, the vapor-deposited layer of the barrier layer will be described. The vapor-deposited layer is a layer made of a vapor-deposited film that can be formed by a conventionally known method. By providing a vapor-deposited layer, it is possible to impart or improve gas barrier properties that prevent the permeation of oxygen gas, water vapor, etc. The vapor-deposited film that constitutes the barrier layer may have two or more vapor-deposited layers. When two or more vapor-deposited layers are provided, they may have the same composition or different compositions.

[0048] The vapor-deposited film may be a metal vapor-deposited layer made of a vapor-deposited metal film, or may be a transparent vapor-deposited layer made of a vapor-deposited inorganic oxide film.

[0049] When the barrier layer includes a metal vapor deposition layer, in addition to the gas barrier property described above, it is possible to impart or improve light blocking properties that prevent the transmission of visible light, ultraviolet light, etc. Furthermore, it is possible to impart metallic luster to the packaging bag, thereby improving the design properties. When the barrier layer includes a transparent vapor-deposited layer, it is possible to impart or improve gas barrier properties that prevent the permeation of oxygen gas, water vapor, etc. while maintaining permeability to the contents.

[0050] In the laminate 10 shown in Fig. 1, the printed layer can be provided on the base material layer 11 located on the outer surface side of the barrier layer 12. Therefore, the barrier layer 12 may have light-blocking properties. Therefore, in the laminate 10 shown in Fig. 1, the vapor-deposited layer 121 is preferably a metal vapor-deposited layer.

[0051] The metal vapor deposition layer may be, for example, a metal vapor deposition layer of aluminum (Al), magnesium (Mg), tin (Sn), sodium (Na), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), gold (Au), chromium (Cr), etc. In particular, for packaging bags, it is preferable to have an aluminum vapor deposition layer.

[0052] The thickness of the metal vapor deposition layer varies depending on the type of metal used, but is desirably selected from the range of, for example, 50 to 2000 Å, preferably 100 to 1000 Å. More specifically, in the case of an aluminum vapor deposition layer, the thickness is desirably 50 to 600 Å, more preferably 100 to 450 Å.

[0053] When the vapor-deposited layer of the barrier layer is a transparent vapor-deposited layer, the printed layer can be seen from the outer surface even if the printed layer is located closer to the sealant layer than the barrier layer. Therefore, as shown in Figure 2, when the barrier layer 12 is provided on the base layer 11, it is preferable that the vapor-deposited layer 121 of the barrier layer 12 is a transparent vapor-deposited layer.

[0054] The transparent vapor-deposited layer may be, for example, a vapor-deposited layer of an oxide of silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc. In particular, for packaging bags, it is preferable to have a vapor-deposited layer of aluminum oxide or silicon oxide.

[0055] Inorganic oxides are expressed as, for example, SiO X , AlO X MO etc. X(wherein, M represents an inorganic element, and the value of X varies depending on the inorganic element.) The value of X can range from 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1.5 for magnesium (Mg), 0 to 1 for calcium (Ca), 0 to 1 for potassium (K), 0 to 0.5 for tin (Sn), 0 to 2 for sodium (Na), 0 to 0.5 for boron (B), 0 to 1.5 for titanium (Ti), 0 to 2 for lead (Pb), 0 to 2 for zirconium (Zr), and 0 to 1.5 for yttrium (Y). In the above, when X=0, it is a completely inorganic element (pure substance) and is not transparent, and the upper limit of the range of X is the value when it is completely oxidized. Silicon (Si) and aluminum (Al) are preferably used for packaging materials, with silicon (Si) having a value in the range of 1.0 to 2.0 and aluminum (Al) having a value in the range of 0.5 to 1.5.

[0056] The thickness of the transparent vapor-deposited layer varies depending on the type of inorganic oxide used, but is desirably selected from the range of, for example, 50 to 2000 Å, preferably 100 to 1000 Å. For example, in the case of a vapor-deposited layer of aluminum oxide or silicon oxide, the thickness is desirably 50 to 500 Å, more preferably 100 to 300 Å.

[0057] The vapor deposition layer can be formed on the base layer or the sealant layer by the following methods: Examples of methods for forming the vapor deposition layer include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

[0058] (Gas barrier coating film) A gas barrier coating film is provided on the surface of the above-mentioned vapor deposition layer as needed. In particular, when the vapor deposition layer is a transparent vapor deposition layer, it is preferred that the gas barrier coating film be provided on the surface of the transparent vapor deposition layer.

[0059] The gas barrier coating film is a coating film that functions as a layer that suppresses the permeation of oxygen gas, water vapor, etc. The gas barrier coating film is a coating film that functions as a layer that suppresses the permeation of oxygen gas, water vapor, etc. 1 n M(OR 2 ) m (wherein, R 1 , R 2 represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M. The gas barrier composition contains at least one alkoxide represented by the formula (I) above, and a polyvinyl alcohol resin and / or an ethylene-vinyl alcohol copolymer, and is further obtained by polycondensation by a sol-gel method in the presence of a sol-gel catalyst, an acid, water, and an organic solvent.

[0060] The general formula R 1 n M(OR 2 ) m As the alkoxide represented by the formula (I), at least one of a partial hydrolyzate of an alkoxide and a condensate of the hydrolysis of an alkoxide can be used. In addition, the partial hydrolyzate of the alkoxide does not necessarily have to have all of the alkoxy groups hydrolyzed, and may be one in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. As the condensate of the hydrolysis of an alkoxide, a dimer or higher of the partially hydrolyzed alkoxide, specifically a dimer to hexamer, is used.

[0061] The general formula R 1 n M(OR 2 ) mIn the alkoxide represented by the formula (I), silicon, zirconium, titanium, aluminum, and the like can be used as the metal atom represented by M. In this embodiment, preferred metals include silicon and titanium. In addition, in this embodiment, the alkoxide can be used alone or by mixing two or more alkoxides of different metal atoms in the same solution.

[0062] In addition, the above general formula R 1 n M(OR 2 ) m In the alkoxide represented by the formula 1 Specific examples of the organic group represented by the general formula R include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-hexyl, n-octyl, and the like. 1 n M(OR 2 ) m In the alkoxide represented by the formula 2 Specific examples of the organic group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, etc. These alkyl groups may be the same or different in the same molecule.

[0063] When preparing the gas barrier composition, for example, a silane coupling agent may be added. A known organoalkoxysilane containing an organic reactive group can be used as the silane coupling agent. In this embodiment, an organoalkoxysilane having an epoxy group is particularly preferably used. Specific examples that can be used include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The above-mentioned silane coupling agents may be used alone or in combination of two or more.

[0064] [Sealant layer] The sealant layer is the innermost layer when the package is made. is a layer formed of a thermoplastic resin that can be fused to each other by heat. The sealant layer may contain a resin material derived from fossil fuels or a resin material derived from biomass.

[0065] The resin material for forming the sealant layer is not particularly limited as long as it is a resin that can be fused to each other by heat, and specific examples thereof include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), ethylene-α-olefin copolymers polymerized using a metallocene catalyst, random or block copolymers of ethylene and polypropylene, polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methacrylic acid copolymer (EMAA). Examples of suitable resins include ethylene-methyl methacrylate copolymers (EMMA), ionomer resins, heat-sealable ethylene-vinyl alcohol resins, polyolefin resins such as methylpentene resins, ethylene-propylene copolymers, methylpentene polymers, polybutene polymers, polyethylene, polypropylene, and cyclic olefin copolymers, 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, and itaconic acid, polyvinyl acetate resins, poly(meth)acrylic resins, polyvinyl chloride resins, and other resins. These may be used alone or as a mixture of two or more. The sealant layer can be a film or sheet of the above resins, or a coating film thereof.

[0066] When polyethylene is used as the resin material forming the sealant layer, in addition to ethylene obtained from fossil fuels, polymerized ethylene derived from biomass may also be used as the raw material. Specific examples of biomass-derived ethylene include those described in JP 2012-251006 A. By using polyethylene obtained by polymerizing biomass-derived ethylene as the material constituting the sealant layer, a layer made of a carbon-neutral material can be formed. Therefore, by using it in combination with the base layer, the amount of fossil fuel used can be further reduced, thereby reducing the environmental impact.

[0067] As the biomass-derived ethylene, commercially available products may be used, such as "C4LL-LL118 (d=0.916, MFR=1.0 g / 10 min)" sugarcane-derived linear low-density polyethylene resin and "SBC118 (d=0.918, MFR=8.1 g / 10 min)" sugarcane-derived low-density polyethylene resin, both manufactured by Braskem.

[0068] In this embodiment, the sealant layer is one layer, but two or more sealant layers may be provided. When two or more sealant layers are provided, each may have the same composition or different compositions. For example, the sealant layer may be configured as three layers, with a first layer, a second layer, and a third layer laminated in this order, and the first and third layers may be made of a resin material derived from fossil fuels, and the second layer may be made of a resin material containing a biomass-derived resin material. When the sealant layer is configured as two or more layers, they may be laminated using a co-extrusion method.

[0069] The thickness of the sealant layer is preferably 20 μm or more and 200 μm or less, and more preferably 30 μm or more and 130 μm or less.

[0070] [Adhesive layer] The adhesive layer is a layer formed by applying an adhesive to the surface of the film including the base layer 11 and the film including the sealant layer 13, whichever is to be laminated, and then drying the adhesive. Examples of adhesives that can be used include one-component or two-component curing or non-curing vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, and other solvent-based, water-based, or emulsion-based adhesives. Examples of two-component curing adhesives that can be used include cured products of polyols and isocyanate compounds. Examples of coating methods for the above-mentioned laminating adhesives include direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fountain coating, transfer roll coating, and other methods.

[0071] The adhesive layer may be configured to reinforce the barrier properties of the barrier layer. In the following description, among adhesive layers containing a cured product of a polyol and an isocyanate compound, an adhesive layer configured to reinforce the barrier properties of the barrier layer is particularly referred to as a barrier adhesive layer. The barrier adhesive layer will be described below.

[0072] (Barrier adhesive layer) The barrier adhesive layer has gas barrier properties, particularly oxygen and water vapor barrier properties. The thickness of the barrier adhesive layer is, for example, 0.5 μm to 6.0 μm, preferably 0.8 μm to 5.0 μm, and more preferably 1.0 μm to 4.5 μm. If the thickness is thinner than the above range, the gas barrier properties are likely to be insufficient, and if the thickness is thicker than the above range, the bending resistance is likely to be poor, which is likely to lead to a decrease in the gas barrier properties after bending.

[0073] The barrier adhesive layer contains a cured product of a polyester polyol and an isocyanate compound. The polyester polyol has two or more hydroxyl groups as functional groups in one molecule. The isocyanate compound has two or more isocyanate groups as functional groups in one molecule. The polyester polyol has, for example, a polyester structure or a polyester polyurethane structure as a main skeleton.

[0074] The resin composition for forming the cured product of the polyester polyol and the isocyanate compound may further contain a plate-like inorganic compound, a phosphoric acid-modified compound, a coupling agent, cyclodextrin and / or a derivative thereof, and the like.

[0075] The glass transition temperature of the cured coating film of the adhesive resin composition is preferably in the range of -30°C to 80°C. More preferably, it is 0°C to 70°C. Even more preferably, it is 25°C to 70°C. If the glass transition temperature is higher than 80°C, the flexibility of the cured coating film at around room temperature may decrease, resulting in poor adhesion to films and therefore reduced adhesive strength. On the other hand, if the glass transition temperature is lower than -30°C, the molecular motion of the cured coating film at around room temperature may be so intense that sufficient oxygen barrier properties may not be achieved, or the adhesive strength may be reduced due to insufficient cohesive strength.

[0076] Specific examples of resin compositions containing polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound include the oxygen barrier adhesive PASLIM series sold by DIC Corporation, and particularly preferred are PASLIM VM001 / VM102CP, which have a polyester main skeleton and a curing agent containing two or more isocyanate groups.

[0077] (polyester polyol) As polyester polyols having two or more hydroxyl groups in one molecule as functional groups, for example, the following [Example 1] to [Example 3] can be used. [Example 1] Polyester polyol obtained by polycondensation of ortho-oriented polycarboxylic acid or its anhydride with polyhydric alcohol [Example 2] Polyester polyol with a glycerol skeleton [Example 3] Polyester polyol with isocyanuric ring Each polyester polyol will be described below.

[0078] [Example 1] Polyester polyol obtained by polycondensation of ortho-oriented polycarboxylic acid or its anhydride with polyhydric alcohol The polyester polyol according to the first example may be a polycondensate obtained by polycondensing a polycarboxylic acid component containing at least one of orthophthalic acid and its anhydride with a polyhydric alcohol component containing at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. In particular, a polyester polyol in which the content of orthophthalic acid and its anhydride relative to the total amount of the polycarboxylic acid components is 70 to 100 mass% is preferred.

[0079] The polyester polyol according to the first example essentially contains the above-mentioned orthophthalic acid and its anhydride as polycarboxylic acid components, but other polycarboxylic acid components may be copolymerized within a range that does not impair the effects of this embodiment. Specifically, examples of aliphatic polycarboxylic acids that can be used include succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; examples of unsaturated bond-containing polycarboxylic acids include maleic anhydride, maleic acid, and fumaric acid; examples of alicyclic polycarboxylic acids include 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; and examples of aromatic polycarboxylic acids include terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, and anhydrides or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, which can be used alone or in mixtures of two or more. Of these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferred.

[0080] Examples of the polyhydric alcohol component and other components include those described above.

[0081] [Example 2] Polyester polyol with a glycerol skeleton As a polyester polyol according to a second example, a polyester polyol having a glycerol skeleton represented by general formula (1) can be mentioned. [ka] In general formula (1), R1, R2, and R3 are each independently H (hydrogen atom) or a compound represented by the following general formula (2). [ka]

[0082] In formula (2), n represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of 1,2-phenylene groups, 1,2-naphthylene groups, 2,3-naphthylene groups, 2,3-anthraquinonediyl groups, and 2,3-anthracenediyl groups, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms, provided that at least one of R1, R2, and R3 represents a group represented by general formula (2).

[0083] In the general formula (1), at least one of R1, R2, and R3 must be a group represented by the general formula (2). In particular, it is preferable that all of R1, R2, and R3 are groups represented by the general formula (2).

[0084] In addition, the compound may be a mixture of two or more of the following compounds: a compound in which any one of R1, R2, and R3 is a group represented by general formula (2); a compound in which any two of R1, R2, and R3 are groups represented by general formula (2); and a compound in which all of R1, R2, and R3 are groups represented by general formula (2).

[0085] X represents an arylene group selected from the group consisting of 1,2-phenylene, 1,2-naphthylene, 2,3-naphthylene, 2,3-anthraquinonediyl, and 2,3-anthracenediyl, which may have a substituent. When X is substituted with a substituent, it may be substituted with one or more substituents, and the substituents are bonded to any carbon atom on X that is different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0086] In the general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, a dimethylbutylene group, etc. Among these, Y is preferably a propylene group or an ethylene group, and most preferably an ethylene group.

[0087] The polyester resin compound having a glycerol skeleton represented by the general formula (1) is obtained by reacting glycerol with an aromatic polycarboxylic acid or an anhydride thereof in which a carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component as essential components.

[0088] Examples of aromatic polycarboxylic acids or anhydrides thereof in which a carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride, naphthalene 2,3-dicarboxylic acid or anhydride, naphthalene 1,2-dicarboxylic acid or anhydride, anthraquinone 2,3-dicarboxylic acid or anhydride, and 2,3-anthracene carboxylic acid or anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0089] Examples of polyhydric alcohol components include alkylene diols having 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol.

[0090] [Example 3] Polyester polyol with isocyanuric ring The polyester polyol according to the third example is a polyester polyol having an isocyanuric ring represented by the following general formula (3). [ka] In the general formula (3), R1, R2, and R3 each independently represent "-(CH2)n1-OH (wherein n1 represents an integer of 2 to 4)" or a structure of the general formula (4). [ka]

[0091] In general formula (4), n2 represents an integer of 2 to 4, n3 represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms, provided that at least one of R1, R2, and R3 is a group represented by general formula (4).

[0092] In the general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. Among these, n1 is preferably 2 or 3, and most preferably 2.

[0093] In the general formula (4), n2 represents an integer of 2 to 4, and n3 represents an integer of 1 to 5. X represents an optionally substituted arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group.

[0094] When X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0095] The substituent for X is preferably a hydroxyl group, a cyano group, a nitro group, an amino group, a phthalimido group, a carbamoyl group, an N-ethylcarbamoyl group, or a phenyl group, and most preferably a hydroxyl group, a phenoxy group, a cyano group, a nitro group, a phthalimido group, or a phenyl group.

[0096] In the general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, a dimethylbutylene group, etc. Among these, Y is preferably a propylene group or an ethylene group, and most preferably an ethylene group.

[0097] In the general formula (3), at least one of R1, R2, and R3 is a group represented by the general formula (4). In particular, it is preferable that all of R1, R2, and R3 are groups represented by the general formula (4).

[0098] In addition, the compound may be a mixture of two or more of the following compounds: a compound in which any one of R1, R2, and R3 is a group represented by general formula (4); a compound in which any two of R1, R2, and R3 are groups represented by general formula (4); and a compound in which all of R1, R2, and R3 are groups represented by general formula (4).

[0099] The polyester polyol having an isocyanuric ring represented by the general formula (3) is obtained by reacting a triol having an isocyanuric ring, an aromatic polycarboxylic acid or anhydride thereof in which a carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component as essential components.

[0100] Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.

[0101] Examples of aromatic polycarboxylic acids or anhydrides in which a carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride, naphthalene 2,3-dicarboxylic acid or anhydride, naphthalene 1,2-dicarboxylic acid or anhydride, anthraquinone 2,3-dicarboxylic acid or anhydride, and 2,3-anthracene carboxylic acid or anhydride, etc. These compounds may have a substituent on any carbon atom of the aromatic ring.

[0102] Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0103] Examples of polyhydric alcohol components include alkylene diols having 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol.

[0104] Among these, polyester polyol compounds having an isocyanuric ring, which use 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid as the triol compound having an isocyanuric ring, orthophthalic anhydride as the aromatic polycarboxylic acid or its anhydride in which the carboxylic acid is substituted at the ortho position, and ethylene glycol as the polyhydric alcohol, are particularly preferred because of their excellent oxygen barrier properties and adhesiveness.

[0105] Isocyanuric rings are highly polar and trifunctional. Therefore, the entire system can be made highly polar and the crosslink density can be increased. From this perspective, it is preferable that the adhesive resin contains 5% by mass or more of isocyanuric rings based on the total solid content.

[0106] The reason why adhesives having an isocyanuric ring can ensure oxygen barrier properties and dry lamination adhesiveness is presumed to be as follows.

[0107] Isocyanuric rings are highly polar and do not form hydrogen bonds. A commonly known method for improving adhesiveness is to incorporate highly polar functional groups such as hydroxyl groups, urethane bonds, ureido bonds, and amide bonds. However, resins containing these bonds tend to form intermolecular hydrogen bonds, which can impair solubility in ethyl acetate and 2-butanone solvents commonly used in dry lamination adhesives. However, polyester resins containing isocyanuric rings do not impair this solubility and can be easily diluted.

[0108] Furthermore, because the isocyanuric ring is trifunctional, polyester polyol compounds that have an isocyanuric ring at the center of the resin skeleton and a polyester skeleton with a specific structure in its branched chain can achieve a high crosslink density. It is believed that increasing the crosslink density can reduce gaps through which gases such as oxygen can pass. Because the isocyanuric ring is highly polar and can achieve a high crosslink density without forming intermolecular hydrogen bonds, it is believed that this can ensure oxygen barrier properties and dry laminate adhesion.

[0109] (Isocyanate compounds) The isocyanate compound has two or more isocyanate groups in the molecule, and may be either aromatic or aliphatic, and may be either a low-molecular-weight compound or a high-molecular-weight compound, and known compounds such as diisocyanate compounds with two isocyanate groups or polyisocyanate compounds with three or more isocyanate groups can be used. The isocyanate compound (K) may also be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by an appropriate known and commonly used method.

[0110] Among these, polyisocyanate compounds are preferred from the viewpoint of adhesiveness and retort resistance, and those having aromatic rings are preferred in terms of imparting oxygen barrier properties. Isocyanate compounds containing a meta-xylene skeleton are particularly preferred because they can improve oxygen barrier properties not only through hydrogen bonding of urethane groups but also through π-π stacking between aromatic rings.

[0111] Specific examples of the isocyanate compound include adducts, biuret compounds, and allophanate compounds obtained by reacting an excess amount of these isocyanate compounds with low-molecular-weight active hydrogen compounds such as ethylene glycol, propylene glycol, meta-xylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and meta-xylylenediamine, alkylene oxide adducts thereof, various polyester resins, polyether polyols, and high-molecular-weight active hydrogen compounds such as polyamides.

[0112] (plate-like inorganic compound) The plate-like inorganic compound has the effect of improving the laminate strength and gas barrier properties of the barrier adhesive layer obtained by curing the adhesive resin composition. Specific examples of the plate-like inorganic compounds include kaolinite-serpentine group clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, talc, keroli, etc.), etc., and one or more of these can be used.

[0113] (Phosphate-modified compounds) The phosphoric acid-modified compound is, for example, a compound represented by the following general formula (5) or (6).

[0114] [ka] In general formula (5), R1, R2, and R3 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms which has a (meth)acryloyloxy group, at least one of which is a hydrogen atom, and n is an integer of 1 to 4.

[0115] [ka] In the formula, R4 and R5 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms and having a (meth)acryloyloxy group, n is an integer of 1 to 4, x is an integer of 0 to 30, and y is an integer of 0 to 30, except when both x and y are 0.

[0116] The phosphoric acid-modified compound has the effect of improving the laminate strength with respect to the inorganic member of this embodiment, and any known and commonly used compound can be used.

[0117] More specific examples include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, polyoxyethylene alkyl ether phosphate, and the like, and one or more of these can be used.

[0118] The content of the phosphate-modified compound in the adhesive resin composition of this embodiment is preferably 0.005% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less. If it is less than 0.005% by mass, good adhesion cannot be obtained. If it is more than 10% by mass or less, the barrier property may deteriorate.

[0119] (coupling agent) The coupling agent is a silane-based coupling agent, a titanium-based coupling agent, or an aluminum-based coupling agent represented by the following general formula (7): These coupling agents may be used alone or in combination of two or more. [ka]

[0120] Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N- Examples of suitable silanes include β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene).

[0121] Examples of the titanium-based coupling agent include isopropyl triisostearoyl titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(didodecyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, and bis(dioctyl pyrophosphate). )oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctane nor titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, diisostearoyl ethylene titanate, isopropyl tri(dioctylphosphate) titanate, isopropyl tricumylphenyl titanate, dicumyl phenyloxyacetate titanate, and the like.

[0122] Specific examples of the aluminum-based coupling agent include acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethyl acetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkyl acetoacetate mono(dioctyl phosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkyl acetoacetate aluminum oxide trimer.

[0123] (Cyclodextrin and / or its derivatives) The cyclodextrin and / or its derivatives are preferred components for achieving 1) excellent adhesion to films having inorganic layers and 2) excellent oxygen barrier properties. Specifically, in addition to cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, hydroxyalkylated cyclodextrin, and other cyclodextrins in which the hydrogen atoms of the hydroxyl groups of the glucose units of cyclodextrin are substituted with other functional groups can be used. Branched cyclic dextrins can also be used. Furthermore, the cyclodextrin skeleton of cyclodextrin and cyclodextrin derivatives can be any of α-cyclodextrin consisting of six glucose units, β-cyclodextrin consisting of seven glucose units, and γ-cyclodextrin consisting of eight glucose units. These compounds can be used alone or in combination. Hereinafter, these cyclodextrins and / or their derivatives may be collectively referred to as dextrin compounds.

[0124] From the viewpoint of compatibility and dispersibility in the adhesive resin composition, it is preferable to use a cyclodextrin derivative as the cyclodextrin compound. From the viewpoint of the polarity of the above-mentioned various resins, the degree of substitution is preferably in the range of 0.1 to 14 per glucose, more preferably in the range of 0.3 to 8 per glucose.

[0125] Examples of the alkylated cyclodextrin that can be used include methyl-α-cyclodextrin, methyl-β-cyclodextrin, methyl-γ-cyclodextrin, etc. These compounds may be used alone or in combination of two or more.

[0126] Examples of the acetylated cyclodextrin that can be used include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, monoacetyl-γ-cyclodextrin, etc. These compounds may be used alone or in combination of two or more.

[0127] Examples of the hydroxyalkylated cyclodextrin that can be used include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroxypropyl-γ-cyclodextrin, etc. These compounds may be used alone or in combination of two or more.

[0128] There are no particular restrictions on the content of the cyclodextrin and / or derivative thereof, but from the viewpoints of compatibility with resins, solvents, and isocyanate compounds, improving adhesive strength, and improving barrier properties, the content is preferably in the range of 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.05 parts by mass or more and 10 parts by mass or less, and even more preferably 0.1 parts by mass or more and 5 parts by mass or less, in the barrier adhesive layer.

[0129] When the adhesive resin composition contains cyclodextrin and / or its derivatives, the cyclic and regularly arranged hydroxyl groups and ether groups of the cyclodextrin and / or its derivatives have multiple interaction points with the inorganic surface through coordination bonds and hydrogen bonds, which is thought to result in an adhesive with strong adhesive strength when laminated with films having inorganic layers, particularly various films such as metal foils, metal-deposited films, and transparent-deposited films. It is also thought that the numerous hydroxyl groups of the cyclodextrin and / or its derivatives interact with each other intermolecularly, narrowing the free volume pores through which gases pass, thereby improving the barrier function.

[0130] (solvent) There are no particular restrictions on the solvent, as long as it can dissolve the polyester polyol and the isocyanate compound, can uniformly disperse the phosphoric acid-modified compound and the plate-like inorganic compound, and has an appropriate boiling point and volatility from the perspective of the barrier adhesive layer formation process.

[0131] [Print layer] The printed layer is a layer on which any desired printed pattern such as letters, numbers, pictures, figures, symbols, designs, etc. is formed for the purpose of decoration, indication of contents, indication of expiration date, indication of manufacturer, seller, etc., or for the purpose of imparting aesthetic appeal. The printed layer can be provided as needed, and can be provided, for example, between the substrate layer and the barrier layer, or between the barrier layer and the sealant layer. The printed layer may be provided on the entire surface of the substrate layer, or on a part of it. The printed layer can be formed using conventionally known pigments or dyes, and the method of forming the printed layer is not particularly limited.

[0132] The printing layer preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and even more preferably 1 μm or more and 3 μm or less.

[0133] Examples of layer structures of laminates formed by combining the above-mentioned layers are listed below. Configuration example 1: Base layer / adhesive layer / metal vapor deposition layer / sealant layer Configuration example 2: Base layer / barrier adhesive layer / metal vapor deposition layer / sealant layer Configuration example 3: Base layer / transparent vapor deposition layer / adhesive layer / sealant layer Configuration example 4: Base layer / transparent vapor deposition layer / barrier adhesive layer / sealant layer Configuration example 5: Base layer / transparent vapor deposition layer / gas barrier coating film / adhesive layer / sealant layer Configuration Example 6: Base layer / transparent vapor deposition layer / gas barrier coating film / barrier adhesive layer / sealant layer The " / " indicates the boundary between layers.

[0134] As described above, the base layer contains recycled PET in a proportion of, for example, 50% by weight or more and 95% by weight or less. According to this embodiment, since the base layer contains recycled PET, a laminate having a superior CO2 reduction effect than a laminate not containing recycled PET can be provided. Furthermore, according to this embodiment, since the laminate contains the above-mentioned barrier layer, a laminate having excellent hygiene can be provided.

[0135] <Method of manufacturing laminate> The method for producing the laminate according to the present embodiment is not particularly limited, and it can be produced using a conventionally known method such as a dry lamination method.

[0136] The laminate according to this embodiment can also be subjected to secondary processing in order to impart surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubrication functions, optical functions, thermal functions, and biocompatibility. Examples of secondary processing include embossing, painting, bonding, printing, metallizing (plating, etc.), machining, and surface treatments (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Furthermore, the laminate according to this embodiment can also be subjected to lamination (dry lamination or extrusion lamination), bag making, and other post-processing to manufacture molded products.

[0137] The laminate can be used for packaging bags to be filled with products such as food, etc. For example, packaging bags of various shapes can be produced by using the laminate and folding it in half, or by preparing two sheets of the laminate and overlapping them with their sealant surfaces facing each other, and then heat-sealing the peripheral edges using a heat seal method such as a side seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope seal type, palm seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, or gusset type.

[0138] In the above, the heat sealing method can be any known method such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, etc.

[0139] The packaging bag has excellent hygienic properties while reducing the environmental impact, and therefore can be suitably used particularly as a packaging bag for sealing and packaging food and the like.

[0140] (Other aspects) In another aspect of the present invention, there is provided a laminate comprising at least a substrate layer, an adhesive layer, a barrier layer, and a sealant layer, in this order, wherein the substrate layer contains polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units, and the barrier layer includes a vapor-deposited layer provided on the sealant layer.

[0141] In the laminate according to another aspect of the present invention, the vapor-deposited layer may be a vapor-deposited metal layer.

[0142] Another aspect of the present invention is a laminate comprising at least a substrate layer, a barrier layer, an adhesive layer, and a sealant layer in this order, wherein the substrate layer contains polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units, and the barrier layer includes a vapor-deposited layer provided on the substrate layer.

[0143] In the laminate according to another aspect of the present invention, the vapor deposition layer may be a transparent vapor deposition layer.

[0144] In the laminate according to another aspect of the present invention, the barrier layer may further include a gas barrier coating film provided on the surface of the transparent vapor deposition layer.

[0145] In the laminate according to another aspect of the present invention, the adhesive layer may include a cured product of a polyester polyol and an aliphatic isocyanate compound.

[0146] In another aspect of the laminate of the present invention, the polyester polyol has two or more hydroxyl groups as functional groups in one molecule, the isocyanate compound has two or more isocyanate groups as functional groups in one molecule, and the polyester polyol may be a polycondensate of an ortho-oriented polycarboxylic acid or an anhydride thereof and a polyhydric alcohol.

[0147] In another aspect of the laminate of the present invention, the polyester polyol has two or more hydroxyl groups as functional groups in one molecule, the isocyanate compound has two or more isocyanate groups as functional groups in one molecule, and the polyester polyol is a compound represented by the following general formula (1): [ka] In general formula (1), R1, R2, and R3 may each independently be H (hydrogen atom) or a compound represented by the following general formula (2). [ka]

[0148] In another aspect of the laminate of the present invention, the polyester polyol may have two or more hydroxyl groups as functional groups in one molecule, the isocyanate compound may have two or more isocyanate groups as functional groups in one molecule, and the polyester polyol may have an isocyanuric ring.

[0149] In the laminate according to another aspect of the present invention, the content of the isophthalic acid may be 0.5 mol % or more and 5.0 mol % or less based on all dicarboxylic acid units constituting the polyethylene terephthalate.

[0150] In the laminate according to another aspect of the present invention, the polyethylene terephthalate may have an intrinsic viscosity of 0.58 dL / g or more and 0.80 dL / g or less. [Explanation of symbols]

[0151] 10 Laminate 11 Base material layer 12 Barrier Layer 121 Deposited layer 122 Gas barrier coating film 13 Sealant layer 14 Adhesive layer

Claims

1. A packaging bag for packaging contents, A laminate is provided, the laminate includes at least a base layer, a barrier layer, an adhesive layer, and a sealant layer in this order; the base layer is a biaxially stretched film having a first layer, a second layer, and a third layer in this order; the first layer and the third layer are layers composed only of virgin polyethylene terephthalate, The virgin polyethylene terephthalate is fossil fuel polyethylene terephthalate; the second layer is a layer made of only recycled polyethylene terephthalate or a mixed layer of recycled polyethylene terephthalate and virgin polyethylene terephthalate, The recycled polyethylene terephthalate contains polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as dicarboxylic acid units, The thickness of the base layer is 5 μm or more and 25 μm or less, the barrier layer includes a transparent vapor deposition layer provided on the base layer and a gas barrier coating film provided on a surface of the transparent vapor deposition layer, the transparent vapor deposition layer is made of aluminum oxide; The gas barrier coating film is a compound represented by the general formula R １ ｎ M (OR ２ ) ｍ (wherein, R １ , R ２ represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) and a polyvinyl alcohol resin and / or an ethylene-vinyl alcohol copolymer.

2. The packaging bag according to claim 1 , wherein the adhesive layer comprises a cured product of a polyester polyol and an isocyanate compound.

3. 3. The packaging bag according to claim 1, wherein the content of the isophthalic acid is 0.5 mol % or more and 5.0 mol % or less based on all dicarboxylic acid units constituting the polyethylene terephthalate.

4. The packaging bag according to claim 1 , wherein the sealant layer has a thickness of 30 μm or more and 130 μm or less.

5. The packaging bag according to claim 1 , wherein the sealant layer comprises low-density polyethylene, linear low-density polyethylene, a random or block copolymer of ethylene and polypropylene, or polypropylene.

6. The packaging bag according to claim 1 , wherein the adhesive layer has a thickness of 1.0 μm or more and 4.5 μm or less.

7. The packaging bag according to claim 1 , further comprising a printed layer between the base material layer and the barrier layer.

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