Standing Pouch

Abstract

To provide a standing pouch that contains polyethylene and has excellent film heat resistance.SOLUTION: A standing pouch 110 comprises a body film 111A and a bottom film. Each of the body film and the bottom film includes a base material layer containing polyethylene, a sealant layer provided on the base material layer and containing polyethylene, and an adhesive layer interposed between the base material layer and the sealant layer. In each of the body film and the bottom film, the base material layer has a crystallinity of 35% or more, which is the ratio of the crystalline peak area to the total peak area as measured by the parallel beam method of X-ray diffraction in the diffraction angle range from 10° to 30°.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stand-up pouch. [Background technology]

[0002] A packaged article obtained by filling a content into a standing pouch can stand on its own. Therefore, such a packaged article can be stored in a box in a self-supporting state, for example, and can be easily packed. Furthermore, such a packaged article can be easily arranged on a shelf in a store in an attractive manner (for example, see Patent Document 1).

[0003] Packaging materials used in packaging bags such as standing pouches are required to have various properties depending on the application. Required properties include, for example, heat resistance, transparency, heat sealability, strength, gas barrier properties, puncture resistance, visibility, bag-making suitability, printability, and transport suitability, which are necessary for packaging materials. In order to achieve these performance properties, it has been common practice to use a combination of multiple types of synthetic resin films with different properties (see, for example, Patent Document 2).

[0004] In recent years, with the growing demand for the creation of a recycling-based society, packaging materials with high recyclability are in demand. In general, packaging materials are considered to have high recyclability when the ratio of the main resin contained therein is 90% by mass or more. However, as described above, conventional packaging materials are composed of different types of resins, and it is difficult to separate the resins by type after use. Therefore, it is not possible to recycle the resin from the packaging materials after use. Therefore, the packaging bodies formed using conventional packaging materials have no utility value after use other than burning them and recovering the heat.

[0005] From the viewpoint of recyclability, techniques have been proposed for making packaging materials with a high polyethylene content into as simple a layer structure as possible (see, for example, Patent Documents 3 and 4). However, the applications of such packaging materials are limited due to, for example, aspects such as heat resistance.

[0006] In recent years, with the change in consumer behavior, toiletry packaging products in which contents such as detergents are filled in stand-up pouches are mainly used for refills. Such stand-up pouches are required to have a large capacity and a form equipped with a spout with a cap that allows multiple refills.

[0007] Conventional standing pouches (multi-material configuration) with low recyclability can meet the demand for larger capacity. However, the demand for high recyclability has brought new technical challenges to the surface.

[0008] One of such technical issues is resistance to falling objects. As the contents become heavier with increasing capacity, problems arise in that the packaged goods may fall during transportation, display in store, or when used by consumers, causing the stand-up pouch to break. In particular, breakage at the overlapping area (intersection seal area, point seal area) of the body of the stand-up pouch and the bottom film is a problem.

[0009] Another technical challenge is that when attempting to impart high recyclability to a spouted standing pouch, it is difficult to attach the spout with high productivity. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2001-206384 A [Patent Document 2] JP 2009-241359 A [Patent Document 3] JP 2020-196791 A [Patent Document 4] JP 2020-55157 A Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention aims to provide a standing pouch containing polyethylene and having an excellent heat resistance of the film. It is also an object of the present invention to provide a technology that can contribute to improving the drop resistance and spout welding property. [Means for solving the problem]

[0012] According to one aspect of the present invention, there is provided a standing pouch comprising a pair of main films and a bottom film, each of the pair of main films and the bottom film comprising a base layer containing polyethylene, a sealant layer containing polyethylene provided on the base layer, and an adhesive layer interposed between the base layer and the sealant layer, and in each of the pair of main films and the bottom film, the base layer has a crystallinity of 35% or more, which is the ratio of the crystalline peak area to the total peak area, measured by a parallel beam method of X-ray diffraction at diffraction angles in the range of 10° to 30°.

[0013] According to another aspect of the present invention, there is provided a standing pouch according to the above aspect, wherein each of the pair of main films and the bottom film further comprises an intermediate layer interposed between the base layer and the sealant layer and containing polyethylene, and the intermediate layer has a crystallinity of 35% or more, which is the ratio of the crystalline peak area to the total peak area, measured by a parallel beam method of X-ray diffraction at a diffraction angle range of 10° to 30°.

[0014] Alternatively, according to another aspect of the present invention, there is provided a standing pouch according to the above aspect, wherein one or more of the pair of main films and the bottom film are interposed between the base layer and the sealant layer, and further include an intermediate layer containing polyethylene.

[0015] According to yet another aspect of the present invention, there is provided a standing pouch relating to any of the above aspects, wherein the intermediate layer has a crystallinity, which is the ratio of the crystalline peak area to the total peak area, measured by a parallel beam method of X-ray diffraction in the diffraction angle range of 10° to 30°, of 35% or more.

[0016] Alternatively, according to yet another aspect of the present invention, there is provided a standing pouch according to the above aspect, wherein the intermediate layer has a crystallinity, which is the ratio of the crystalline peak area to the total peak area, measured by a parallel beam method of X-ray diffraction in the diffraction angle range of 10° to 30°, of less than 35%.

[0017] According to yet another aspect of the present invention, there is provided a standing pouch relating to any of the above aspects, wherein one or more of the pair of main films and the bottom film further comprises a protective layer as an outermost layer facing the sealant layer with the base layer sandwiched therebetween.

[0018] According to yet another aspect of the present invention, there is provided the standing pouch according to the above aspect, wherein the protective layer contains a thermosetting resin.

[0019] According to yet another aspect of the present invention, there is provided a standing pouch according to any one of the above aspects, wherein the base layer of at least one of the pair of main films and the bottom film is a biaxially stretched film.

[0020] According to yet another aspect of the present invention, there is provided a standing pouch according to any one of the above aspects, wherein the base layer of at least one of the pair of main films and the bottom film is a uniaxially stretched film.

[0021] According to yet another aspect of the present invention, there is provided a standing pouch according to any of the above aspects, wherein at least one of the pair of main films and the bottom film further comprises a gas barrier layer interposed between the base layer and the sealant layer.

[0022] According to yet another aspect of the present invention, there is provided a standing pouch according to any one of the above aspects, wherein the adhesive layer in at least one of the pair of main films and the bottom film has gas barrier properties.

[0023] According to yet another aspect of the present invention, there is provided a standing pouch according to any one of the above aspects, wherein the sealant layer in at least one of the pair of main films and the bottom film is white.

[0024] According to yet another aspect of the present invention, there is provided a standing pouch according to any of the above aspects, wherein at least one of the pair of main films and the bottom film has a polyethylene content of 90% by mass or more.

[0025] According to yet another aspect of the present invention, there is provided a standing pouch relating to any of the above aspects, wherein at least one of the pair of main films and the bottom film further comprises an intermediate layer containing polyethylene and interposed between the base layer and the sealant layer, and the adhesive layers include a first adhesive layer and a second adhesive layer, the first adhesive layer being interposed between the base layer and the intermediate layer, and the second adhesive layer being interposed between the intermediate layer and the sealant layer.

[0026] According to yet another aspect of the present invention, there is provided a standing pouch according to any one of the above aspects, further comprising a spout welded to the pair of main body films.

[0027] According to yet another aspect of the present invention, there is provided a packaging article comprising the stand-up pouch according to any one of the above aspects and contents accommodated in the stand-up pouch.

[0028] According to yet another aspect of the present invention, there is provided a packaging article relating to the above aspect, wherein the standing pouch further comprises a spout welded to the pair of main body films and a cap fitted or screwed onto the mouth of the spout. Effect of the Invention

[0029] According to the present invention, there is provided a standing pouch containing polyethylene and having an excellent heat resistance of the film. Also, according to the present invention, there is provided a technology that can contribute to improving the drop resistance and the spout welding property. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a front view of a packaged article according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a portion of the package shown in FIG. [Diagram 3] FIG. 3 is an enlarged cross-sectional view showing a part of a standing pouch used in producing the packaged article of FIG. [Figure 4] FIG. 4 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a first embodiment of the present invention. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates a schematic diagram of a modified example of the laminate shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a third embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a fourth embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a fifth embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a sixth embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a seventh embodiment of the present invention. [Figure 12]FIG. 12 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to an eighth embodiment of the present invention. [Figure 13] FIG. 13 is a front view of a packaged article according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects alone or in combination.

[0032] The embodiments described below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited by the materials, shapes, structures, etc. of the components described below. Various modifications can be made to the technical idea of ​​the present invention within the technical scope defined by the claims.

[0033] In addition, elements having the same or similar functions are given the same reference numerals in the drawings referred to below, and duplicated explanations are omitted. In addition, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual ones.

[0034] <1> First embodiment <1.1> Standing pouches and packaging articles Fig. 1 is a front view of a packaging article according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view showing an enlarged portion of the packaging article shown in Fig. 1. Fig. 3 is a cross-sectional view showing an enlarged portion of a standing pouch used in manufacturing the packaging article of Fig. 1.

[0035] Here, the cross section in Fig. 2 is a portion near the bottom of a cross section perpendicular to the width direction of the packaged article 100 shown in Fig. 1 and passing through the center of the width. The cross section in Fig. 3 corresponds to the portion of the cross section of the standing pouch 110 depicted in Fig. 2. Note that the standing pouch 110 has a folded, flat bottom immediately after production, but in Fig. 3, the bottom is slightly expanded to make it easier to understand.

[0036] The packaged article 100 shown in Figs. 1 and 2 includes a standing pouch 110 which is a package, and a content 120 contained therein.

[0037] The standing pouch 110 includes a pair of main body films 111A and 111B and a bottom film 112, as shown in FIGS.

[0038] Each of the main films 111A and 111B and the bottom film 112 is a laminate including a base layer and a sealant layer provided thereon, as described below.

[0039] In the standing pouch 110 before being filled with the content 120, the main films 111A and 111B are arranged so that their sealant layers face each other, as shown in Fig. 3. The bottom film 112 is folded in half so as to form a mountain fold when viewed from the sealant layer side, and is sandwiched between the main films 111A and 111B at one end thereof so that the mountain fold MF faces the other end of the main films 111A and 111B.

[0040] The edges of the main body films 111A and 111B are heat-sealed to each other from the position of the mountain fold MF of the bottom film 112 to the other ends of the main body films 111A and 111B. As a result, the main body films 111A and 111B form heat-sealed parts HS1 shown in FIG. 1 on both sides thereof.

[0041] The bottom film 112 is heat-sealed to the main film 111A and 111B except for its central portion. Specifically, one of the two portions of the bottom film 112 defined by the mountain fold MF is heat-sealed to the main film 111A at a position other than the central portion of the bottom film 112, forming the heat-sealed portion HS2A shown in Figs. 1 to 3. The other of the two portions of the bottom film 112 defined by the mountain fold MF is heat-sealed to the main film 111B at a position other than the central portion of the bottom film 112, forming the heat-sealed portion HS2B shown in Figs. 2 and 3. The outer surfaces of these two portions of the bottom film 112 are bonded to each other at both sides of the bottom of the standing pouch 110.

[0042] The heat-sealed portions HS1 and HS4 shown in Fig. 1 are portions heat-sealed by a side seal and a point seal, respectively, which will be described later. The heat-sealed portion HS2A shown in Figs. 1 to 3 and the heat-sealed portion HS2B shown in Figs. 2 and 3 are portions heat-sealed by a bottom seal, which will be described later. In the heat-sealed portion HS4, the main body films 111A and 111B overlap with the bottom film 112. A typical standing pouch is prone to bursting at the overlapping portions (intersection seal portion, point seal portion) when a packaged article containing the pouch is dropped.

[0043] In the packaged article 100 in which the content 120 is accommodated in the standing pouch 110, the main body films 111A and 111B are further heat-sealed at the other ends thereof, so that the main body films 111A and 111B form the heat-sealed portion HS3 shown in FIG.

[0044] The standing pouch 110 is formed so that its upper corner can be used as a mouth after opening. An easy-to-open structure can be provided at the position of this corner. The easy-to-open structure is, for example, a notch.

[0045] The standing pouch 110 may be formed so that a portion other than the upper corners can be used as a mouth portion after opening. For example, the standing pouch 110 may be formed so that an upper central portion can be used as a mouth portion after opening. The standing pouch 110 may further include a mouth member and a lid body at its upper portion. For example, as in the standing pouch 110 of the packaged article 100A shown in FIG. 13, a spout 113 which is a member for extracting the contents may be interposed between the main body films 111A and 111B at the upper position of the standing pouch 110 and may be welded thereto, and a cap 114 which is a member for sealing the spout 113 may be fitted or screwed to the mouth portion of the spout 113.

[0046] The contents 120 may be, for example, a liquid or a mixture of a liquid and a solid, such as food or medicine.

[0047] Although there is no limit to the volume of the contents 120, the technology described herein is particularly useful when the volume of the contents 120 is large. In this respect, the volume of the contents 120 is preferably within the range of 0.2 to 4.0 L. The volume of the contents 120 is more preferably 0.8 L or more. Moreover, the volume of the contents 120 is more preferably 3.0 L or less.

[0048] The standing pouch 110 can be manufactured, for example, by using a bag-making machine that performs a heat-sealing step and a cutting step in this order. In this bag-making machine, two rolls each made of a laminate for the main film and a roll made of a laminate for the bottom film are installed. In the heat-sealing step, the bottom film laminate, which is folded in half so as to form a mountain fold when viewed from the sealant layer during the conveying process, is sandwiched between a pair of main film laminates that are conveyed so that the sealant layers face each other, and these are heat-sealed with a heat seal bar. Specifically, bottom sealing, point sealing, and side sealing are performed, thereby forming heat-sealed parts HS1, HS2A, and HS2B. The length direction of the heat-sealed part HS1 is perpendicular to the conveying direction. In the cutting step, the composite obtained by heat sealing is cut into individual standing pouches 110.

[0049] The packaged article 100 can be manufactured, for example, by using a filling machine that performs a filling step and a heat sealing step in this order. In the filling step, the content 120 is filled into the standing pouch 110. In the heat sealing step, the opening of the standing pouch 110 is heat sealed with a heat seal bar to form a heat sealed portion HS3. In this manner, the packaged article 100 is obtained.

[0050] <1.2> Laminate FIG. 4 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a first embodiment of the present invention. The laminate 10A1 shown in FIG. 4 includes a base layer 1, a printed layer 4, an adhesive layer 3, and a sealant layer 2 in this order.

[0051] The laminate 10A1 is used as the main films 111A and 111B and the bottom film 112 in the standing pouch 110 described above.

[0052] The base layer 1 and the sealant layer 2 contain polyethylene. The laminate 10A1 preferably has a polyethylene ratio of 90% by mass or more. Here, the ratio of polyethylene in the laminate means the ratio of the total amount of polyethylene to the total amount of resin material in each layer constituting the laminate. By making the ratio of polyethylene 90% by mass or more, high recyclability can be achieved.

[0053] <1.3> Base material layer The substrate layer 1 contains polyethylene. Preferably, the substrate layer 1 is made of polyethylene. The substrate layer 1 has a crystallinity of 35% or more, which is the ratio of the crystalline peak area to the total peak area, measured by a parallel beam method of X-ray diffraction in the diffraction angle range of 10° to 30°. Here, the crystallinity of the substrate layer 1 is a value obtained by the measurement method described below.

[0054] In the laminate 10A1 according to the present invention, the crystallinity of the base material layer 1 is 35% or more, which improves the heat resistance of the base material layer 1. As a result, even when the laminate 10A1 is used as a packaging material and processed into bags in a bag making machine, there is no need to reduce the bag making speed, and the laminate has excellent processability.

[0055] Furthermore, when the crystallinity of the base layer 1 is 35% or more, the base layer 1 is less prone to elongation, and the printability is improved.

[0056] The polyethylene contained in the base layer 1 may be a homopolymer of ethylene or a copolymer of ethylene and another monomer. When the polyethylene is a copolymer of ethylene and another monomer, the proportion of ethylene in the copolymer is, for example, 80 mol % or more.

[0057] The other monomer is, for example, an α-olefin. According to one example, the α-olefin has a carbon number in the range of 3 to 20. Such an α-olefin is, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, or 6-methyl-1-heptene.

[0058] The polyethylene may be a copolymer of ethylene and one of vinyl acetate and acrylic esters.

[0059] The substrate layer 1 is, for example, high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or very low density polyethylene (VLDPE).

[0060] Here, high density polyethylene has a density of 0.942 g / cm 3 and medium density polyethylene has a density of 0.930 g / cm 3 More than 0.942g / cm 3 and low density polyethylene has a density of 0.910 g / cm 3 More than 0.930g / cm 3 Linear low density polyethylene has a density of 0.910 g / cm 3 More than 0.930cm 3 and ultra-low density polyethylene has a density of 0.910 g / cm 3 is less than. The density is a value obtained by a method in accordance with JIS K7112:1999.

[0061] The polyethylene contained in the base layer 1 may be polyethylene derived from biomass. As the polyethylene derived from biomass, for example, Green Polyethylene (manufactured by Braskem) can be used.

[0062] Alternatively, the polyethylene contained in the base layer 1 may be polyethylene recycled by mechanical recycling. Here, mechanical recycling refers to decontaminating the polyethylene film by crushing collected polyethylene films and the like, cleaning the crushed films with an alkali to remove dirt and foreign matter on the film surface, and then drying the films at high temperature and reduced pressure to diffuse contaminants remaining inside the films.

[0063] Alternatively, the polyethylene contained in the base layer 1 may be polyethylene recycled by chemical recycling. The melting point of the base layer 1 is preferably within a range of 100° C. to 140° C., and more preferably within a range of 120° C. to 140° C. The melting point is a value obtained by a method in accordance with JIS K7121-1987.

[0064] The base layer 1 may be a non-stretched film or a stretched film. The base layer 1 is preferably a stretched film. When the base layer 1 is a stretched film in addition to having a crystallinity of 35% or more, the following effects are obtained. That is, the heat resistance and strength are particularly excellent. In addition, the elongation of the base layer 1 is reduced, improving the printability. In this specification, the term "film" does not include the concept of thickness.

[0065] When the base layer 1 is a stretched film, the base layer 1 may be a uniaxially stretched film or a biaxially stretched film. When a uniaxially stretched film is used as the base layer 1, the heat resistance during bag making, that is, the sealability described below, is further improved. When a biaxially stretched film is used as the base layer 1, the drop strength of a packaged article using the laminate 10A1 as a packaging material is improved.

[0066] Whether a stretched film is uniaxially or biaxially stretched can be determined by in-plane measurement using wide-angle X-ray diffraction, as described below. The X-ray diffraction pattern obtained by this measurement contains information about the degree of orientation of molecular chains present on the film surface.

[0067] When a polymer film is uniaxially stretched, a higher-order structure called a shish-kebab structure appears. The shish-kebab structure consists of a shish structure, which is an extended chain crystal, and a kebab structure, which is a lamellar crystal. In a uniaxially stretched film, this higher-order structure is arranged with a high degree of order, and therefore the X-ray diffraction pattern obtained by the above measurement of the uniaxially stretched film contains a sharp diffraction peak. That is, when the above measurement is performed on a uniaxially stretched film, a clear diffraction peak appears. Note that a "clear diffraction peak" means a diffraction peak with a half-width of less than 10°.

[0068] In contrast, in the manufacture of biaxially stretched films, the film is stretched in a specific direction, and then stretched in a direction perpendicular to the first direction. Therefore, although the first stretching produces the above-mentioned high-order structure, this high-order structure is disturbed by the second stretching. Therefore, when the above-mentioned measurements are performed on a biaxially stretched film, the diffraction peaks in the resulting X-ray diffraction pattern are broad. In other words, when the above-mentioned measurements are performed on a biaxially stretched film, no clear diffraction peaks appear.

[0069] As described above, the X-ray diffraction patterns obtained by the above-mentioned measurements are different between uniaxially stretched films and biaxially stretched films, and therefore it is possible to determine whether a stretched film is a uniaxially stretched film or a biaxially stretched film based on the X-ray diffraction patterns.

[0070] The film can be produced by a known production method such as a casting method or an inflation method. A multilayer polyethylene film obtained by co-extruding polyethylenes having different densities can also be used as the base layer 1. A stretched film can be obtained, for example, by stretching a film obtained by forming a polyethylene film by a T-die method or an inflation method. The base layer 1 may be a uniaxially stretched film or a biaxially stretched film.

[0071] The haze of the base layer 1 is preferably 20% or less, and more preferably 10% or less. The haze is a value obtained by a method in accordance with JIS K7136:2000.

[0072] The thickness of the base layer 1 is preferably in the range of 10 μm to 200 μm. The thickness of the base layer 1 is, for example, in the range of 10 μm to 50 μm, or in the range of 15 μm to 50 μm, or in the range of 12 μm to 35 μm. If the base layer 1 is too thin, the strength of the laminate 10A1 is likely to be reduced. Also, if the base layer 1 is too thick, the processability of the laminate 10A1 is likely to be reduced.

[0073] The substrate layer 1 is preferably surface-treated. This treatment can improve the adhesion between the substrate layer 1 and a layer adjacent to the substrate layer 1.

[0074] The method of the surface treatment is not particularly limited, and examples of the surface treatment include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment, and chemical treatments such as oxidation treatment using chemicals.

[0075] The base layer 1 may further contain additives, such as crosslinking agents, antioxidants, antiblocking agents, slip agents, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0076] The proportion of polyethylene in the base layer 1 is preferably 50% by mass or more, and more preferably 80% by mass or more. In one example, the base layer 1 is made of polyethylene. In another example, the base layer 1 is made of polyethylene and an additive.

[0077] The substrate layer 1 may be colored, for example, white.

[0078] As described above, the base layer 1 has a crystallinity of 35% or more. The printed layer 4 is disposed on the inner surface side of the base layer 1, and images such as patterns and characters displayed by the printed layer 4 can be seen with good visibility. From this viewpoint, the crystallinity of the base layer 1 is preferably 40% or more, and more preferably 50% or more. According to one example, the crystallinity is in the range of 50% to 75%. In addition, the polyethylene-containing layer having a crystallinity of 35% or more has excellent puncture strength, as described below. From this viewpoint, the crystallinity of the base layer 1 is preferably 40% or more, and more preferably 50% or more.

[0079] Polyethylene is a crystalline polymer, so it has both crystalline and amorphous parts. Polyethylene with a high degree of crystallinity has a high ratio of crystalline parts. This crystalline part controls the elastic part in the viscoelastic behavior of the resin, so a high degree of crystallinity improves the rigidity of the film.

[0080] Due to the influence of this viscoelastic behavior, in films with a high degree of crystallinity, the strain associated with the plastic deformation of the resin is also large. As a result, the effect of suppressing the deformation of the resin in response to the strain generated by the momentary impact applied to the film is obtained, making it difficult for breakage to occur. For this reason, the laminate 10A1 having the base layer 1 containing polyethylene and having a crystallinity of 35% or more is excellent in resistance to momentary impact, and packaged articles using the laminate 10A1 as a packaging material are unlikely to be damaged (broken) by dropping. In other words, it has excellent resistance to breaking of the bag.

[0081] The polyethylene constituting the base layer 1 is preferably an ethylene-α-olefin copolymer copolymerized with an α-olefin. The reason for this is that when the crystallinity of the base layer 1 is adjusted to 35% or more, tie molecules are likely to form between the crystals. Not only is improved crystallinity imparting rigidity, but the formation of tie molecules is also expected to improve toughness, and when such a base layer 1 is used, the standing pouch is less likely to break (break) when dropped. In this case, the ethylene-α-olefin copolymer in the base layer 1 may be used alone or in a mixture with other polyethylenes.

[0082] The crystallinity of the base layer 1 can be adjusted by controlling the degree of stretching of the polyethylene film used in the base layer 1, or the thermal history during or after the production of the film. For example, slow cooling after film formation increases the crystallinity, while rapid cooling decreases the crystallinity. It is also possible to improve the crystallinity by adding an additive such as a crystal nucleating agent.

[0083] <Method for measuring crystallinity> The crystallinity of the substrate layer 1 is measured by X-ray diffraction using a parallel beam method. An example of a method for measuring the crystallinity will be described below.

[0084] First, the X-ray diffraction pattern of the base layer 1 is obtained by out-of-plane measurement using a wide-angle X-ray diffractometer manufactured by Rigaku Corporation, scanning the diffraction angle range of 10° to 30° with 2θ / θ. The characteristic X-ray CuKα is used as the X-ray, and the X-ray is collimated by a multilayer mirror and made incident on the base layer 1. A scintillation detector equipped with a flat collimator is used as the light receiving unit.

[0085] From the obtained X-ray diffraction pattern, the peak area of ​​the crystalline component and the halo pattern area of ​​the amorphous component are determined, and the ratio of the peak area of ​​the crystalline component to the total area is calculated as the degree of crystallinity. When the base layer 1 has a plurality of layers, the crystallinity of one of the outermost surfaces of the base layer 1 is measured.

[0086] When the base layer 1 is a polyethylene film, scanning at a diffraction angle range of 10° to 30° reveals two sharp crystalline component peaks corresponding to the (110) and (200) planes, as well as a broad halo pattern of amorphous components. These are then analyzed separately, and the areas of the crystalline component peaks and the halo pattern of the amorphous components are calculated, allowing the degree of crystallinity to be calculated using the following formula (1).

[0087] Crystallinity = crystalline component peak area / (crystalline component peak area + amorphous component halo pattern area) ... (1) The focusing method is known as an X-ray diffraction method other than the parallel beam method, but in the case of samples with uneven surfaces such as resin films, the focusing method is prone to affecting the measurement results, such as peak broadening due to misalignment of the measurement surface. In contrast, in the case of parallel beam methods, misalignment of the measurement surface has little effect on the measurement results, even in the case of samples with uneven surfaces.

[0088] On the other hand, the base layer 1 is preferably uniaxially or biaxially stretched, and as described above, the in-plane method using X-ray diffraction can be used to distinguish between them. In this in-plane method, the X-ray incidence angle θ and the angle 2θ at which the diffracted X-rays are detected by the detector are fixed to the angle θ and angle 2θ at which a diffraction peak corresponding to a specific crystal plane is detected in the out-of-plane method, for example, the diffraction peak corresponding to the (110) plane of a polyethylene film, respectively, and in this state, the film to be measured is scanned in the in-plane direction to obtain a diffraction pattern.

[0089] When in-plane measurements are performed on a uniaxially stretched film that has been uniaxially stretched in the machine direction (MD), a diffraction pattern can be obtained that has a sharp diffraction peak corresponding to the (110) plane at an angle 2θ of about ±90°, assuming that the MD direction is defined as 0°. On the other hand, in the case of a biaxially stretched film, the high-order structure obtained by uniaxial stretching is disturbed by the second stretching, and the anisotropy is reduced, so a diffraction pattern having a sharp diffraction peak corresponding to this (110) plane cannot be obtained. Therefore, in-plane measurements can be cited as one method for distinguishing uniaxially stretched films from biaxially stretched films.

[0090] <1.4> Sealant layer The sealant layer 2 faces the base layer 1. The sealant layer 2 contains polyethylene. Preferably, the sealant layer 2 is made of polyethylene. For example, the polyethylene contained in the base layer 1 may be any of those described above. The sealant layer 2 is preferably low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or very low-density polyethylene (VLDPE), and more preferably linear low-density polyethylene.

[0091] From the viewpoint of environmental load, the polyethylene is preferably biomass-derived polyethylene or recycled polyethylene.

[0092] The sealant layer 2 may further contain the additives described above. The proportion of polyethylene in the sealant layer 2 is preferably 50% by mass or more, and more preferably 80% by mass or more. In one example, the sealant layer 2 is made of polyethylene. In another example, the sealant layer 2 is made of polyethylene and an additive.

[0093] The sealant layer 2 may be transparent or opaque. In the latter case, the sealant layer 2 may be white, black, gray, sepia, or the like. In the sealant layer 2, these opaque layers may be formed alone, may form a multilayer structure including two or more of these, or may be combined with a transparent sealant. When the laminate 10A1 has a transparent sealant layer 2 and is used in a package, the contents are easily visible. When the laminate 10A1 has an opaque sealant layer 2 and is used in a package, the contents do not interfere with the visibility of the image displayed by the printing layer 4. In particular, the white sealant layer 2 improves the visibility of the image displayed by the printing layer 4.

[0094] The sealant layer can be colored white, gray, black, or the like by mixing a pigment or the like into the material resin. For example, the sealant layer will be white if titanium oxide is mixed into the material resin, black if carbon black is mixed into the material resin, and gray if both are mixed into the material resin. If the sealant layer is required to have light-shielding properties, it is preferably black, gray, or sepia. The light-shielding sealant contains, for example, carbon black.

[0095] The thickness of the sealant layer 2 can be appropriately set in consideration of the shape of the packaging bag to be manufactured, the mass of the contents to be contained, etc., but is preferably 30 μm or more, and more preferably 60 μm or more from the viewpoint of content retention. Also, from the viewpoints of bag manufacturing efficiency and cost, it is preferably 300 μm or less, and more preferably 200 μm or less.

[0096] The sealant layer 2 is, for example, an unstretched polyethylene resin film, or a layer formed by melt extrusion of polyethylene.

[0097] <1.5>Printing layer The printed layer 4 is provided on the surface of the base layer 1 facing the sealant layer 2, i.e., on the back surface of the base layer 1. The position at which the printed layer 4 is provided is not limited. That is, the printed layer 4 may be provided on the surface of the base layer 1, or may be provided at any position between the base layer 1 and the sealant layer 2. For example, when the laminate 10A1 further includes an intermediate layer described later, the printed layer 4 may be provided on any surface of the intermediate layer. The laminate 10A1 may also include multiple printed layers. The printed layer 4 may be omitted.

[0098] The printing ink used for the printing layer 4 is not particularly limited as long as it has adhesion to polyethylene. The printing layer 4 is composed of ink in which additives such as various pigments, extender pigments, plasticizers, drying agents, and stabilizers are added to conventionally used ink binder resins such as urethane-based, acrylic-based, nitrocellulose-based, rubber-based, and vinyl chloride-based inks. It is preferable to use an ink derived from biomass as the printing ink. As the printing method, for example, well-known printing methods such as offset printing, gravure printing, flexographic printing, and silk screen printing, and well-known coating methods such as roll coating, knife edge coating, and gravure coating can be used. From the viewpoint of environmental consideration, an aqueous solvent is preferable. In addition, a light-shielding ink can also be preferably used. Examples of the light-shielding ink include white ink, black ink, silver ink, and sepia ink. The light-shielding ink contains, for example, aluminum particles, titanium oxide, or carbon black.

[0099] <1.6>Adhesive layer The adhesive layer 3 bonds the base material layer 1 provided with the print layer 4 to the sealant layer 2. The adhesive layer 3 includes at least one type of adhesive. The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may be a solventless adhesive or a solvent-based adhesive.

[0100] Examples of the adhesive include epoxy adhesives such as polyether adhesives, polyester adhesives, silicone adhesives, and polyamine adhesives, urethane adhesives, rubber adhesives, vinyl adhesives, silicone adhesives, epoxy adhesives, phenol adhesives, and olefin adhesives. Adhesives containing biomass components can also be used. The adhesive is preferably a polyamine adhesive or a urethane adhesive having gas barrier properties. Specific examples of gas barrier adhesives include "Maxive" manufactured by Mitsubishi Gas Chemical Company, Inc. and "Paslim" manufactured by DIC Corporation.

[0101] The adhesive layer 3 may be a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. Such an adhesive layer 3 can further improve the oxygen barrier property and water vapor barrier property of the laminate 10A1.

[0102] The thickness of the adhesive layer 3 is preferably in the range of 0.1 μm to 20 μm, more preferably in the range of 0.5 μm to 10 μm, and further preferably in the range of 1 to 5 μm.

[0103] The adhesive layer 3 can be formed by applying and drying on the sealant layer 2 using a conventional method such as a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, or a transfer roll coating method.

[0104] <1.7> Effects The laminate 10A1 described above has excellent heat resistance and recyclability. Furthermore, the standing pouch 110 using this laminate 10A1 as the main films 111A and 111B and the bottom film 112 has excellent recyclability. These will be described below.

[0105] The manufacture of a package generally involves a process in which sealant layers of a laminate are brought into contact with each other, and the contacting portions are clamped with a jig and subjected to pressure and heat to thermally weld (heat seal) the contacting portions. The heat seal bar, which is a jig of the heat sealing machine, is heated to a high temperature, and the surface of the base material layer that is in direct contact with the jig is exposed to the high temperature.

[0106] As described above, the standing pouch has a structure in which a bottom film folded in half is sandwiched between a pair of main film laminates. Therefore, in the manufacture of the standing pouch, the bottom seal is performed on a structure having a thickness equivalent to four films, in which a bottom film laminate folded in half is sandwiched between a pair of main film laminates. Therefore, in the bottom seal, the surface of the base layer that directly contacts the jig is exposed to a higher temperature than in the side seal for heat-sealing the two main film laminates.

[0107] In addition, in a standing pouch, it is necessary to ensure that the mountain folds of the bottom film and the pair of main film bodies are heat-sealed on both sides in the width direction. In point sealing for this purpose, the surface of the base layer that directly contacts the jig may be exposed to a higher temperature than in bottom sealing.

[0108] Thus, in the production of a standing pouch, the surface of the base layer may be exposed to a higher temperature than in the production of other packages. Therefore, when polyethylene, which has poor heat resistance, is used for the base layer of a film for a standing pouch, the surface of the base layer may be affected by heat and may cause problems such as adhesion to a jig.

[0109] In addition, in the manufacture of a standing pouch, the two sections partitioned by the mountain fold of the bottom film laminate may undergo pseudo-fusion during the bottom sealing process. If this pseudo-fusion occurs, the bottom film of the standing pouch may not spread sufficiently during the filling process in which the contents are filled into the standing pouch, which may result in defective filling.

[0110] As described above, conventional laminates using polyethylene as a base layer had the problem that when used to manufacture standing pouches, the optimum bag-making temperature conditions were narrow, making it impossible to achieve high productivity.

[0111] This problem is particularly serious in the manufacture of spouted standing pouches. That is, in the manufacture of spouted standing pouches, when attaching a spout to the standing pouch body, the main body film needs to be softened by heat and deformed to conform to the shape of the spout attachment portion. Therefore, the optimum bag-making temperature conditions for spouted standing pouches are particularly narrow.

[0112] Furthermore, standing pouches, particularly extra-large standing pouches, have a problem in that they are easily broken when a packaged article filled with contents is dropped. One of the causes of this breakage is believed to be the breakage of the main film and bottom film along the point seal portion due to the impact applied when the pouch is dropped.

[0113] The reason why the point seal part is prone to breakage is that the point seal needs to be performed securely in order to provide drop resistance that can withstand the weight of the contents. If the heat resistance of the film at the point seal part is insufficient, this may cause breakage when dropped. In addition, at the boundary part between the heat sealed part and the unsealed part, which is represented by the point seal part, a difference in crystallinity occurs due to the difference in thermal history. If these areas with different crystallinity exist in the main film or bottom film, the boundary part between them may become the starting point of breakage when the packaged item is dropped.

[0114] The present inventors measured the crystallinity of various polyethylenes and found that when the crystallinity of the base layer 1 is 35% or more, the base layer 1 exhibits excellent heat resistance, and therefore the laminate 10A1 also exhibits excellent heat resistance, and particularly found that good heat sealability is achieved. In addition, when a base layer with a high crystallinity is used, in addition to improving heat resistance, even if excessive heat history is applied to the point seal portion, the difference in crystallinity between the sealed portion and the unsealed portion can be reduced, and therefore, destruction of the standing pouch due to the dropping of the packaged article can be made difficult to occur. Furthermore, by increasing the crystallinity, in addition to improving heat resistance, excessive softening of the main body film when heated can be suppressed, and as a result, it is possible to simultaneously achieve deformation of the main body film along the shape of the spout and sufficient sealing between the spout and the main body film.

[0115] In the laminate 10A1, polyethylene, which is generally considered to have poor heat resistance, is used as the base layer 1. However, by making the crystallinity of the base layer 1 35% or more, the temperature range of heat sealing performed for bag making is expanded, and the standing pouch 110 can be manufactured without causing a decrease in productivity or causing poor appearance due to shrinkage of the sealed portion.

[0116] Such excellent heat resistance can be confirmed by using the crystallinity of the base layer 1 as an index. The crystallinity of the base layer can be easily measured, and therefore the heat resistance of the laminate can be easily understood. Therefore, the quality as a packaging material can be easily stabilized.

[0117] Furthermore, since the laminate 10A1 includes the base layer 1 and the sheet heel layer mainly composed of polyethylene, it is easy to make the proportion of polyethylene 90% by mass or more. Therefore, the laminate 10A1 and the standing pouch 110 manufactured using the same are also excellent in recyclability.

[0118] <1.8> Variations The laminate 10A1 can be modified in various ways. Fig. 5 is a cross-sectional view that shows a schematic diagram of a modified example of the laminate shown in Fig. 4. The laminate 10A2 shown in Fig. 5 can also be used as the main films 111A and 111B and the bottom film 112.

[0119] The laminate 10A2 is similar to the laminate 10A1, except that it further includes an inorganic compound layer 5 interposed between the base layer 1 and the printed layer 4. The inorganic compound layer 5 is a thin film made of an inorganic compound, for example, an inorganic oxide such as aluminum oxide or silicon oxide, and functions as a gas barrier layer that suppresses the transmission of oxygen and water vapor.

[0120] The inorganic compound layer 5 can be provided on the outermost layer as shown in FIG. 5. When an intermediate layer is used, the inorganic compound layer 5 can also be provided on the intermediate layer. When the inorganic compound layer 5 is provided on the intermediate layer, it may be located on the outer layer side or on the sealant side. When the inorganic compound layer 5 is provided on the sealant layer, it is located on the outer layer side. When the inorganic compound layer 5 is provided on the sealant 2, the printed layer side surface of the base layer 1 provided with the printed layer 4 and the inorganic compound layer side surface of the sealant 2 provided with the inorganic compound layer 5 are bonded together via the adhesive layer 3.

[0121] <Inorganic compound layer> The inorganic compound layer 5 may be formed by coating, or may be formed by vapor deposition of an inorganic compound.

[0122] Examples of the inorganic compound contained in the inorganic compound layer 5 include metal oxides such as aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. The inorganic compound layer 5 is preferably a vapor deposition film made of a metal oxide. From the viewpoint of transparency and barrier properties, the metal oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. Furthermore, from the viewpoint of cost, the metal oxide is selected from aluminum oxide and silicon oxide. Furthermore, from the viewpoint of excellent tensile stretchability during processing, it is more preferable to use silicon oxide as the metal oxide. By making the inorganic compound layer 5 a vapor deposition film made of a metal oxide, high barrier properties can be obtained with a very thin layer within a range that does not affect the recyclability of the laminate 10A2.

[0123] A vapor-deposited film made of a metal oxide has the advantage of being transparent, and therefore less likely to cause a user holding a packaging material made of a laminate to mistakenly believe that a metal foil is used, compared to a vapor-deposited film made of a metal.

[0124] The thickness of the vapor-deposited film made of aluminum oxide is preferably 5 nm or more and 30 nm or less. When the thickness is 5 nm or more, sufficient gas barrier properties can be obtained. Furthermore, when the thickness is 30 nm or less, cracks caused by deformation due to internal stress of the thin film can be suppressed, and the deterioration of gas barrier properties can be suppressed. Note that, when the thickness exceeds 30 nm, the cost is likely to increase due to an increase in the amount of material used and a prolonged film formation time, and is therefore not preferable from an economical point of view. From the same viewpoint as above, the thickness of the vapor-deposited film made of aluminum oxide is more preferably 7 nm or more and 15 nm or less.

[0125] The thickness of the vapor-deposited film made of silicon oxide is preferably 10 nm or more and 50 nm or less. When the thickness is 10 nm or more, sufficient gas barrier properties can be obtained. Furthermore, when the thickness is 50 nm or less, the occurrence of cracks due to deformation caused by internal stress in the thin film can be suppressed, and the deterioration of gas barrier properties can be suppressed. Note that, when the thickness exceeds 50 nm, the cost is likely to increase due to an increase in the amount of material used and a prolonged film formation time, and is therefore not preferable from an economical point of view. From the same viewpoint as above, the thickness of the vapor-deposited film made of silicon oxide is more preferably 20 nm or more and 40 nm or less.

[0126] The inorganic compound layer 5 can be formed by, for example, vacuum film formation. In the vacuum film formation, physical vapor deposition or chemical vapor deposition can be used. Examples of physical vapor deposition include, but are not limited to, vacuum deposition, sputtering, and ion plating. Examples of chemical vapor deposition include, but are not limited to, thermal CVD (Chemical Vapor Deposition), plasma CVD, and photo CVD.

[0127] In the vacuum film formation, the resistance heating vacuum deposition method, the EB (Electron Beam) heating vacuum deposition method, the induction heating vacuum deposition method, the sputtering method, the reactive sputtering method, the dual magnetron sputtering method, the plasma enhanced chemical vapor deposition method (PECVD method), and the like are particularly preferably used. However, in terms of productivity, the vacuum deposition method is currently the most excellent. As the heating means for the vacuum deposition method, it is preferable to use any one of the electron beam heating method, the resistance heating method, and the induction heating method.

[0128] Metal vapor deposition films such as aluminum are suitable for disposal. If the required light-shielding and barrier properties are satisfied, an aluminum vapor deposition film can be used instead of the inorganic compound layer 5. The thickness of the aluminum vapor deposition layer is preferably 40 nm to 80 nm. The aluminum vapor deposition layer can be provided on the intermediate layer, the base layer, or the sealant layer. When the aluminum vapor deposition layer is provided on the sealant layer, it preferably has a thickness of about 40 nm, and when the aluminum vapor deposition layer is provided on the intermediate layer or the base layer, it preferably has a thickness of about 80 nm.

[0129] <Anchor coat layer> The laminate 10A2 may further include an anchor coat layer (not shown), as described in the second embodiment. The anchor coat layer can be formed on the surface of the base layer 1 on which the inorganic compound layer 5 is formed, using a known anchor coat agent. This can improve the adhesion of the inorganic compound layer 5 made of a metal oxide. Examples of the anchor coat agent include polyester polyurethane resin and polyether polyurethane resin. From the viewpoints of heat resistance and interlayer adhesive strength, the anchor coat agent is preferably a polyester polyurethane resin.

[0130] <Coating layer> Furthermore, as described in the second embodiment, the laminate 10A2 may further include a coating layer (not shown) between the inorganic compound layer 5 and the printing layer 4. The combination of the inorganic compound layer 5 and the coating layer may also function as a gas barrier layer. Hereinafter, the inorganic compound layer 5 may be referred to as a gas barrier layer, and the combination of the inorganic compound layer 5 and the coating layer may be referred to as a gas barrier layer.

[0131] The laminate 10A2 also has excellent heat resistance. In addition, since the inorganic compound layer 5 is substantially transparent, even if the inorganic compound layer 5 is provided between the base layer 1 and the printed layer 4, the image displayed by the printed layer 4 can be visually recognized from the front side. In addition, the laminate 10A2 also has excellent recyclability.

[0132] In order to impart light-shielding properties to the laminates 10A1 and 10A2, a metal vapor deposition layer may be provided between the base layer 1 and the sealant layer 2. When the laminate further includes an intermediate layer described below, a metal vapor deposition layer may be provided on either side of the intermediate layer. An example of the metal vapor deposition layer is an aluminum vapor deposition layer.

[0133] As already mentioned, the sealant layer 2 may be opaque, but the base layer 1 may also be opaque. For example, the base layer 1 may be white. When the laminate further includes an intermediate layer described later, the intermediate layer may be opaque. For example, the intermediate layer may be white.

[0134] <2> Second embodiment The packaging article and the standing pouch according to the second embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the second embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0135] <2.1> Laminate FIG. 6 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a second embodiment of the present invention. The laminate 10B shown in FIG. 6 includes a protective layer 6, a base material layer 1, a gas barrier layer 5, a printed layer 4, an adhesive layer 3, and a sealant layer 2, in this order. The gas barrier layer 5 included in the laminate 10B is composed of an inorganic compound layer, or an inorganic compound layer and a coating layer. The laminate 10B is similar to the laminate 10A1, except that it further includes a protective layer 6 provided on the surface of the base material layer 1, and a gas barrier layer 5 interposed between the base material layer 1 and the printed layer 4. The base material layer 1, the printed layer 4, the adhesive layer 3, and the sealant layer 2 included in the laminate 10B can be those described in the first embodiment.

[0136] <2.2>Protective layer The laminate 10B includes a protective layer 6 as the outermost layer. The protective layer 6 includes a thermosetting resin. The thermosetting resin is not particularly limited as long as it has heat resistance, and examples thereof include polyurethane resin, polyester resin, polyamide resin, polyamideimide resin, acrylic resin, epoxy resin, and water-soluble polymer. The protective layer 6 may include one type of thermosetting resin, or may include two or more types of thermosetting resin.

[0137] In one embodiment, the protective layer 6 preferably contains a water-soluble polymer, and is preferably an organic-inorganic composite layer further containing an organometallic compound.

[0138] Examples of the water-soluble polymer include polyvinyl alcohols, polysaccharides such as starch, methyl cellulose, carboxymethyl cellulose, and hydroxyl-containing polymers such as acrylic polyols. In one embodiment, the protective layer 6 preferably contains a polyvinyl alcohol-based hydroxyl-containing polymer that may be contained in a coating layer as the gas barrier layer 5 described later.

[0139] The protective layer 6 preferably contains at least one of a metal alkoxide, a hydrolysate of a metal alkoxide, and a reaction product of a metal alkoxide or the hydrolysate thereof as an organometallic compound. Examples of the metal alkoxide include compounds represented by the general formula M(OR), such as tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(OC3H7)3]. n Examples of the above-mentioned are represented by the following formula:

[0140] Moreover, the protective layer 6 preferably further contains, as the organometallic compound, at least one of a silane coupling agent, a hydrolysate of a silane coupling agent, and a reaction product of a silane coupling agent or a hydrolysate of a silane coupling agent.

[0141] In one embodiment, the protective layer 6 can be formed using a coating liquid for forming a coating layer as the gas barrier layer 5 described later. When the laminate 10B includes an inorganic compound layer and a coating layer as the gas barrier layer 5, the protective layer 6 may be a layer formed using the same coating liquid as the coating liquid used to form the coating layer.

[0142] The protective layer 6 reduces thermal damage to the surface of the laminate during heat sealing. The laminate 10B has the protective layer 6, which has excellent heat resistance, as the outermost layer, and therefore ensures heat sealability and productivity even though the laminate 10B uses polyethylene resin, which has poor heat resistance, as a base material.

[0143] The thickness of the protective layer 6 is preferably within the range of 0.3 μm to 3 μm. If the protective layer 6 is too thin, it tends to be difficult to achieve high heat resistance. If the protective layer 6 is too thick, it tends to be difficult to sufficiently dry the cured resin film in the manufacturing process of the laminate 10B.

[0144] <2.3> Gas barrier layer The gas barrier layer 5 improves, for example, the oxygen barrier property and water vapor barrier property of the layered product 10B. The gas barrier layer 5 is composed of an inorganic compound layer, or an inorganic compound layer and a coating layer. When the gas barrier layer 5 is composed of an inorganic compound layer and a coating layer, it is preferable that the inorganic compound layer and the coating layer are laminated in this order from the substrate layer 1 side. The gas barrier layer 5 may be formed by coating, or may be formed by depositing an inorganic compound. The inorganic compound layer is the same as the inorganic compound layer described in the modified example of the first embodiment. An aluminum deposition layer may be used instead of the inorganic compound layer.

[0145] The coating layer can be formed, for example, by coating. In this case, a coating liquid containing a resin such as polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, and epoxy resin can be used. Additives such as organic or inorganic particles, layered compounds, and curing agents may be added to the coating liquid.

[0146] The coating layer may be, for example, an organic-inorganic composite layer containing at least one of a metal alkoxide, a hydrolysate of a metal alkoxide, and a reaction product of a metal alkoxide or a hydrolysate of a metal alkoxide, and a water-soluble polymer. This organic-inorganic composite layer may further contain at least one of a silane coupling agent, a hydrolysate of a silane coupling agent, and a reaction product of a silane coupling agent or a hydrolysate of a silane coupling agent.

[0147] Examples of metal alkoxides and hydrolysates thereof contained in the organic-inorganic composite layer include compounds represented by the general formula M(OR), such as tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(OC3H7)3]. n and hydrolysates thereof. One of these may be contained alone, or two or more of them may be contained in combination.

[0148] The total content of the metal alkoxide, its hydrolysate or their reaction products in the coating liquid used to form the organic-inorganic composite layer may be, for example, 40% by mass or more, 50% by mass or more, or 65% by mass or more from the viewpoint of oxygen barrier property. The total content of the metal alkoxide, its hydrolysate or their reaction products in the coating liquid may be, for example, 70% by mass or less.

[0149] The water-soluble polymer contained in the organic-inorganic composite layer is not particularly limited, and examples thereof include polyvinyl alcohol-based polymers, polysaccharides such as starch, methyl cellulose, and carboxymethyl cellulose, and hydroxyl-containing polymers such as acrylic polyol-based polymers. From the viewpoint of further improving the oxygen gas barrier property, the water-soluble polymer preferably contains a water-soluble polymer of polyvinyl alcohol-based polymer. The number-average molecular weight of the water-soluble polymer is, for example, 40,000 to 180,000.

[0150] The polyvinyl alcohol-based water-soluble polymer contained in the organic-inorganic composite layer can be obtained, for example, by saponifying (including partial saponification) polyvinyl acetate. This water-soluble polymer may have several tens of percent of acetate groups remaining, or may have only a few percent of acetate groups remaining.

[0151] The content of the water-soluble polymer in the coating liquid used to form the organic-inorganic composite layer may be, for example, 15% by mass or more, or 20% by mass or more, from the viewpoint of oxygen barrier property. Also, the content of the water-soluble polymer in the coating liquid may be, for example, 50% by mass or less, or 45% by mass or less, from the viewpoint of oxygen barrier property.

[0152] The silane coupling agent used in the organic-inorganic composite layer may be a silane coupling agent having an organic functional group. Such silane coupling agents may be ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, etc. The silane coupling agent selected from these, its hydrolyzate, and their reaction product may be used alone or in combination of two or more.

[0153] It is preferable to use a silane coupling agent having an epoxy group as an organic functional group. Examples of silane coupling agents having an epoxy group include γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Silane coupling agents having an epoxy group may have an organic functional group different from the epoxy group, such as a vinyl group, an amino group, a methacryl group or a ureyl group, or an isocyanate group. These may also be derivatives, polyfunctionalized, or composites. The silane coupling agents selected from these, their hydrolyzates, and their reaction products may be used alone or in combination of two or more.

[0154] A silane coupling agent having an organic functional group, its hydrolysate or reaction product thereof can further improve the oxygen barrier property of the coating layer and the adhesion to the adjacent layer by the interaction between the organic functional group and the hydroxyl group of the water-soluble polymer. In particular, when the silane coupling agent, its hydrolysate or reaction product thereof has an epoxy group and the water-soluble polymer is polyvinyl alcohol (PVA), the oxygen barrier property and the adhesion to the adjacent layer can be further improved by the interaction between the epoxy group and the hydroxyl group of the PVA.

[0155] The total content of the silane coupling agent, its hydrolysate and their reaction products in the coating liquid used for forming the organic-inorganic composite layer may be, for example, 1% by mass or more, or 2% by mass or more, from the viewpoint of oxygen barrier property. Also, the total content of the silane coupling agent, its hydrolysate and their reaction products in the coating liquid may be, for example, 15% by mass or less, or 12% by mass or less, from the viewpoint of oxygen barrier property.

[0156] The thickness of the coating layer is preferably 50 nm to 1000 nm, more preferably 100 nm to 500 nm. When the thickness of the gas barrier coating layer is 50 nm or more, more sufficient gas barrier properties tend to be obtained, and when the thickness is 1000 nm or less, sufficient flexibility tends to be maintained.

[0157] The gas barrier layer 5 is preferably subjected to the above-mentioned surface treatment, which can improve the adhesion between the gas barrier layer 5 and the adjacent layers. The material for the gas barrier layer 5 may be a nanocomposite.

[0158] In the laminate 10B, the printed layer 4 is interposed between the gas barrier layer 5 and the adhesive layer 3, but may be provided at any position between the protective layer 6 and the sealant layer 2. Since the base layer 1 is transparent, for example, no matter where the printed layer 4 is located between the base layer 1 and the sealant layer 2, when the laminate 10B is observed from the protective layer 6 side, the pattern displayed by the printed layer 4 can be clearly seen.

[0159] <Anchor coat layer> The laminate 10B may further include an anchor coat layer (not shown) on the main surface of the base layer 1 that faces the gas barrier layer 5. This can improve the adhesion of the gas barrier layer 5. Examples of the anchor coat agent include polyester-based polyurethane resins and polyether-based polyurethane resins. From the viewpoints of heat resistance and interlayer adhesive strength, the anchor coat agent is preferably a polyester-based polyurethane resin.

[0160] The ratio of polyethylene in the laminate 10B is, for example, 90% by mass or more, which results in the laminate 10B being a highly recyclable mono-material.

[0161] <2.4> Effects Like the laminate 10A1, the laminate 10B includes a base layer 1 that contains polyethylene and has a crystallinity within the above range. Therefore, like the laminate 10A1, the laminate 10B has excellent heat resistance.

[0162] Moreover, the laminate 10B includes a protective layer 6 on the outermost layer. As described above, the protective layer 6 reduces thermal damage to the surface of the laminate during heat sealing. Therefore, the laminate 10B can achieve even better heat resistance, and in particular, better heat sealing suitability. Therefore, when the above-described configuration is adopted for the laminate 10B, the temperature range of the heat sealing performed for bag making is expanded, and it becomes even more difficult to cause a decrease in productivity or a defective appearance due to shrinkage of the sealed portion.

[0163] Furthermore, since the above-mentioned gas barrier layer 5, i.e., the inorganic compound layer and the coating layer, are substantially transparent, even if the gas barrier layer 5 is provided between the base material layer 1 and the printing layer 4, the image displayed by the printing layer 4 can be viewed from the surface side. That is, the laminate 10B has excellent heat resistance and recyclability. Furthermore, the standing pouch 110 using the laminate 10B as the main films 111A and 111B and the bottom film 112 also has excellent recyclability.

[0164] <3> Third embodiment The packaging article and the standing pouch according to the third embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the third embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0165] <3.1> Laminate FIG. 7 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a third embodiment of the present invention. The laminate 10C shown in FIG. 7 includes a protective layer 6, a base layer 1, an inorganic compound layer 5, a coating layer 7, a printed layer 4, an adhesive layer 3, and a sealant layer 2 in this order. The laminate 10C has a polyethylene ratio of 90% by mass or more. The laminate 10C has a layer structure similar to that of the laminate 10B according to the second embodiment described above, including an inorganic compound layer and a coating layer from the base layer 1 side as a gas barrier layer 5. The protective layer 6, base layer 1, inorganic compound layer 5, coating layer 7, printed layer 4, adhesive layer 3, and sealant layer 2 included in the laminate 10C can be those described in the second embodiment. In the laminate 10C, the inorganic compound layer 5, coating layer 7, and printed layer 4 can be omitted.

[0166] <Anchor coat layer> The laminate 10C may further include an anchor coat layer (not shown) on the main surface of the base layer 1 that faces the inorganic compound layer 5, similarly to the laminate 10B according to the second embodiment. This can improve the adhesion of the inorganic compound layer 5. Examples of the anchor coat agent include polyester polyurethane resin and polyether polyurethane resin. From the viewpoints of heat resistance and interlayer adhesive strength, the anchor coat agent is preferably a polyester polyurethane resin.

[0167] <3.3> Effects Since the laminate 10C has the same layer structure as the laminate 10B, it has the same effects as the laminate 10B. Furthermore, the standing pouch 110 using the laminate 10C as the main films 111A and 111B and the bottom film 112 has excellent recyclability.

[0168] <4> Fourth embodiment The packaging article and the standing pouch according to the fourth embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the fourth embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0169] <4.1> Laminate FIG. 8 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a fourth embodiment of the present invention. The laminate 10D shown in FIG. 8 includes a base layer 1, a first adhesive layer 3A, a gas barrier layer 5, an intermediate layer 8, a printed layer 4, a second adhesive layer 3B, and a sealant layer 2, in this order. The laminate 10D is similar to the laminate 10B, except for the following points. That is, the laminate 10D further includes an intermediate layer 8. The laminate 10D also includes a first adhesive layer 3A and a second adhesive layer 3B instead of the adhesive layer 3. The base layer 1, the printed layer 4, and the sealant layer 2 included in the laminate 10D can be those described in the first embodiment.

[0170] <4.2> Gas barrier layer The gas barrier layer 5 improves, for example, the oxygen barrier property and water vapor barrier property of the laminate 10D. The gas barrier layer 5 is, for example, a metal layer, an inorganic oxide layer, a resin-containing layer, or a combination of two or more thereof. When microwave heating using a microwave oven is assumed, the gas barrier layer 5 is preferably an inorganic oxide layer, a resin-containing layer, or a combination thereof.

[0171] The gas barrier layer 5 may be formed by coating, by melt molding, or by vapor deposition of an inorganic oxide. Alternatively, the gas barrier layer 5 may be a metal foil such as an aluminum foil, or may be vapor deposited with a metal such as aluminum.

[0172] As the inorganic oxide, for example, silicon oxide, boron oxide, or metal oxides such as aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, tin oxide, sodium oxide, titanium oxide, lead oxide, zirconium oxide, and yttrium oxide can be used.

[0173] The resin-containing layer can be formed, for example, by coating. In this case, a coating liquid containing a resin such as polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, and epoxy resin can be used. Additives such as organic or inorganic particles, layered compounds, and curing agents may be added to the coating liquid.

[0174] When the resin-containing layer is formed by melt molding, for example, extrusion molding techniques such as T-die and inflation can be used. In melt molding, for example, the above-mentioned resin or a mixture of the above-mentioned resin and additives is heated and melted, and a film or sheet to be used as the gas barrier layer 5 is obtained by T-die or inflation. Then, this film or sheet is bonded to the intermediate layer 8.

[0175] The thickness of the gas barrier layer 5 is preferably within the range of 1 nm to 200 nm, for example, in the case of an inorganic oxide layer. If the thickness is 1 nm or more, excellent oxygen barrier properties and water vapor barrier properties are obtained. If the thickness is 200 nm or less, the manufacturing cost can be kept low, and cracks due to external forces such as bending and pulling are unlikely to occur, and deterioration of the barrier properties can be suppressed. Also, for example, if the layer is a resin-containing layer, the thickness is preferably within the range of 0.1 μm to 10 μm, and more preferably within the range of 0.2 μm to 5 μm. If the thickness is 0.2 μm or more, excellent oxygen barrier properties and water vapor barrier properties can be obtained. If the thickness is 10 μm or less, the manufacturing cost can be kept low.

[0176] The gas barrier layer 5 is preferably subjected to the above-mentioned surface treatment, which can improve the adhesion between the gas barrier layer 5 and the adjacent layers. The material for the gas barrier layer 5 may be a nanocomposite.

[0177] <4.3> Middle class The intermediate layer 8 contains polyethylene. As the polyethylene, for example, the polyethylene contained in the base layer 1 described above can be used.

[0178] The polyethylene contained in the intermediate layer 8 may be the same as or different from the polyethylene contained in the base layer 1. In addition, the intermediate layer 8 may further contain the additives described above.

[0179] The proportion of polyethylene in the intermediate layer 8 is preferably 50% by mass or more, and more preferably 80% by mass or more. In one example, the intermediate layer 8 is made of polyethylene. In another example, the intermediate layer 8 is made of polyethylene and an additive.

[0180] The intermediate layer 8 has a crystallinity of 35% or more. The intermediate layer 8 preferably has a crystallinity of 40% or more, and more preferably has a crystallinity of 50% or more. In one example, the crystallinity of the intermediate layer 8 is in the range of 50% to 75%.

[0181] The intermediate layer 8 having a crystallinity of 35% or more increases the strength of the laminate 10D, particularly its puncture strength. Therefore, the laminate 10D has excellent strength, particularly its puncture strength. A laminate with a high proportion of polyethylene is weaker than other laminates, and therefore has many opportunities to be folded when used as a packaging material. When the laminate is folded more frequently, the possibility of pinholes occurring increases, but the laminate 10D having excellent puncture strength is less likely to have pinholes. From this perspective, the intermediate layer 8 having a crystallinity of 35% or more is preferably a stretched film, and it is more preferable that both the base layer 1 and the intermediate layer 8 are stretched films. In this case, the stretched film constituting the intermediate layer 8 may be the same as the stretched film constituting the base layer 1, or may be different.

[0182] The melting point of the intermediate layer 8 is preferably in the range of 100°C to 140°C, and more preferably in the range of 120°C to 140°C.

[0183] The thickness of the intermediate layer 8 is preferably in the range of 10 μm to 200 μm, and more preferably in the range of 15 μm to 50 μm.

[0184] The intermediate layer 8 may be colored, for example white.

[0185] The intermediate layer 8 can be produced by a known production method such as a casting method or an inflation method. A multilayer polyethylene film obtained by co-extruding polyethylenes having different densities can also be used as the intermediate layer 8. A stretched film can be obtained, for example, by stretching a film obtained by forming a polyethylene film by a T-die method or an inflation method.

[0186] In this embodiment, an intermediate layer having a crystallinity of less than 35% may be used. By using an intermediate layer having a crystallinity of less than 35%, the strength of the laminate 10D, particularly the drop strength, can be improved. The intermediate layer having a crystallinity of less than 35% is preferably a non-stretched film.

[0187] <4.4>Adhesive layer The adhesives for forming the first adhesive layer 3A and the second adhesive layer 3B may be the same or different. The adhesives for forming the first adhesive layer 3A and the second adhesive layer 3B include at least one type of adhesive.

[0188] The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. In addition, the adhesive may be a solventless adhesive or a solvent-based adhesive.

[0189] Examples of the adhesive include epoxy adhesives such as polyether adhesives, polyester adhesives, silicone adhesives, and polyamine adhesives, urethane adhesives, rubber adhesives, vinyl adhesives, silicone adhesives, epoxy adhesives, phenol adhesives, and olefin adhesives. Adhesives containing biomass components can also be used. The adhesive is preferably a polyamine adhesive or a urethane adhesive having gas barrier properties. Specific examples of gas barrier adhesives include "Maxive" manufactured by Mitsubishi Gas Chemical Company, Inc. and "Paslim" manufactured by DIC Corporation.

[0190] The first adhesive layer 3A and the second adhesive layer 3B may be a cured product of a resin composition containing a polyester polyol and an isocyanate compound, or may be a cured product of a resin composition further containing a phosphoric acid-modified compound as necessary. Among the resin compositions used for the first adhesive layer 3A and the second adhesive layer 3B, for example, a polyol as the main agent and an isocyanate compound as the curing agent, or a polyamine resin as the main agent and an epoxy compound as the curing agent, it is preferable that either one or both of the main agent and the curing agent have not only a straight-chain structure but also a bent structure, or contain a unit that can form such a structure. For example, by incorporating a compound having a substituent at the ortho-position or meta-position of an aromatic ring into these structures, it is possible to form not only a straight-chain crosslink but also a bent crosslinked structure in the cured coating. This bent crosslinked structure controls the orientation of the molecules, which can contribute to oxygen barrier properties and water vapor barrier properties. If necessary, an inorganic compound such as an inorganic layered compound may be blended into the resin composition to further improve the barrier properties. This can further improve the oxygen barrier property and water vapor barrier property of the layered product 10D.

[0191] The thickness of the first adhesive layer 3A and the second adhesive layer 3B is preferably in the range of 0.1 μm to 20 μm, more preferably in the range of 0.5 μm to 10 μm, and even more preferably in the range of 1 to 5 μm.

[0192] The first adhesive layer 3A and the second adhesive layer 3B can be formed by applying and drying on the base material layer 1 using a conventionally known method such as a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, or a transfer roll coating method.

[0193] In addition, in FIG. 8, the laminate 10D includes a gas barrier layer 5 between the first adhesive layer 3A and the intermediate layer 8, but the laminate 10D may also include a gas barrier layer 5 between the intermediate layer 8 and the second adhesive layer 3B.

[0194] 8, the printed layer 4 is provided between the intermediate layer 8 and the second adhesive layer 3B, but the printed layer 4 may be provided anywhere between the base layer 1 and the sealant layer 2. The printed layer 4 is preferably provided between the first adhesive layer 3A and the base layer 1. In this case, when the laminate 10B is observed from the base layer 1 side, the pattern displayed by the printed layer 4 is easily and clearly seen.

[0195] Furthermore, an anchor coat layer may be formed on the surface facing the first adhesive layer 3A, among the main surfaces of the base material layer 1. Furthermore, the gas barrier layer 5 and the printed layer 4 may be omitted.

[0196] The ratio of polyethylene in the laminate 10D is, for example, 90% by mass or more, which makes the laminate 10D a highly recyclable mono-material.

[0197] <4.5> Effects The laminate 10D described above, like the laminate 10A1, includes a base layer 1 that contains polyethylene and has a crystallinity within the above range. Therefore, like the laminate 10A1, the laminate 10D has excellent heat resistance.

[0198] Moreover, the laminate 10D includes an intermediate layer 8 having a crystallinity within the above range. The intermediate layer 8 increases the strength, particularly the puncture strength, of the laminate 10D. Therefore, the laminate 10D is excellent in strength, particularly the puncture strength.

[0199] The laminate 10D has excellent recyclability because the base layer 1, the intermediate layer 8, and the sealant layer 2 all contain polyethylene. Furthermore, the standing pouch 110 using the laminate 10D as the main films 111A and 111B and the bottom film 112 has excellent recyclability.

[0200] As described above, a laminate with a high polyethylene content is weaker than other laminates, and therefore is frequently folded when used as a packaging material. Frequent folding increases the likelihood of pinholes occurring, but laminate 10D, which has excellent puncture strength, is less likely to develop pinholes.

[0201] Here, the "piercing strength" of the laminate 10D is a value obtained by piercing the laminate 10D from the base layer 1 side in a method specified in JIS Z1707:2019 "General Rules for Food Packaging Plastic Films". Specifically, a needle having a diameter of 1 mm and a semicircular tip is pierced from the base layer 1 side of the laminate 10D at a speed of 50 mm / min, and the maximum force until the needle penetrates is measured. This measurement is performed multiple times, and the arithmetic average of the maximum forces is obtained as the piercing strength.

[0202] <5> Fifth embodiment The packaging article and the standing pouch according to the fifth embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the fifth embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0203] <5.1> Laminate FIG. 9 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a fifth embodiment of the present invention. The laminate 10E shown in FIG. 9 includes a protective layer 6, a base material layer 1, a printed layer 4, a first adhesive layer 3A, an intermediate layer 8, a gas barrier layer 5, a second adhesive layer 3B, and a sealant layer 2 in this order. The laminate 10E is similar to the laminate 10D except for the following points. That is, the laminate 10E further includes a protective layer 6. In the laminate 10E, the inorganic compound layer 5 is interposed between the second adhesive layer 3B and the intermediate layer 8. In the laminate 10E, the printed layer 4 is interposed between the base material layer 1 and the first adhesive layer 3A. As the base material layer 1, the printed layer 4, the first adhesive layer 3A, the intermediate layer 8, the second adhesive layer 3B, and the sealant layer 2 included in the laminate 10E, those described in the fourth embodiment can be used.

[0204] <5.2>Protective layer The protective layer 6 includes a thermosetting resin. The thermosetting resin is not particularly limited as long as it has heat resistance, and examples thereof include polyurethane resin, polyester resin, polyamide resin, polyamideimide resin, acrylic resin, epoxy resin, and water-soluble polymer. The protective layer 6 may include one type of thermosetting resin, or may include two or more types of thermosetting resin. The protective layer 6 may contain an inorganic filler, for example, for the purpose of improving heat resistance.

[0205] In one embodiment, the protective layer 6 is preferably an organic-inorganic composite layer containing a water-soluble polymer and an organometallic compound.

[0206] Examples of the water-soluble polymer include polyvinyl alcohols, polysaccharides such as starch, methyl cellulose, carboxymethyl cellulose, and hydroxyl-containing polymers such as acrylic polyols. In one embodiment, the protective layer 6 preferably contains a polyvinyl alcohol-based hydroxyl-containing polymer that may be contained in a coating layer as the gas barrier layer 5 described later.

[0207] The protective layer 6 preferably contains at least one of a metal alkoxide, a hydrolysate of a metal alkoxide, and a reaction product of a metal alkoxide or the hydrolysate thereof as an organometallic compound. Examples of the metal alkoxide include compounds represented by the general formula M(OR), such as tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(OC3H7)3]. n Examples of the above-mentioned are represented by the following formula:

[0208] Moreover, the protective layer 6 preferably further contains, as the organometallic compound, at least one of a silane coupling agent, a hydrolysate of a silane coupling agent, and a reaction product of a silane coupling agent or a hydrolysate of a silane coupling agent.

[0209] In one embodiment, the protective layer 6 can be formed using a coating liquid for forming a coating layer as the gas barrier layer 5 described later. In addition, when the laminate 10E includes an inorganic compound layer and a coating layer as the gas barrier layer 5, the protective layer 6 may be a layer formed using the same coating liquid as the coating liquid used to form the coating layer. The protective layer 6 is not limited to the method using the above-mentioned coating liquid, and can also be formed by co-extrusion of the polyethylene resin constituting the base layer 1 and a thermoplastic resin having a high melting point and heat resistance. In this case, resins having a high melting point such as polyester resin, polyamide resin, polypropylene resin, and polymethylpentene resin can be used as the thermoplastic resin having a high melting point. At this time, an adhesive resin can be interposed between the polyethylene resin constituting the base layer 1 and the thermoplastic resin having a high melting point and heat resistance, taking into consideration the adhesiveness between them.

[0210] The laminate 10E has the protective layer 6, which has excellent heat resistance, as the outermost layer, and therefore ensures heat sealability and productivity even though the laminate 10E uses polyethylene resin, which has poor heat resistance, as the base material.

[0211] Furthermore, the protective layer 6 is expected to not only prevent defects during bag production by imparting heat resistance to the base layer 1, but also to prevent pinholes during transportation.

[0212] The thickness of the protective layer 6 is preferably within the range of 0.3 μm to 3 μm. If the protective layer 6 is too thin, it tends to be difficult to achieve high heat resistance. If the protective layer 6 is too thick, it tends to be difficult to sufficiently dry the cured resin film in the manufacturing process of the laminate 10E.

[0213] <5.3> Gas barrier layer The gas barrier layer 5 improves, for example, the oxygen barrier property and water vapor barrier property of the layered product 10E. The gas barrier layer 5 is made of an inorganic compound layer or an inorganic compound layer and a coating layer. When the gas barrier layer 5 is made of an inorganic compound layer and a coating layer, the inorganic compound layer and the coating layer are preferably laminated in this order from the intermediate layer 8 side.

[0214] The gas barrier layer 5 may be formed by coating, or by vapor deposition of an inorganic compound.

[0215] Examples of the inorganic compound contained in the inorganic compound layer include metal oxides such as aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. The inorganic compound layer is preferably a vapor deposition film made of a metal oxide. From the viewpoint of transparency and barrier properties, the metal oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. Furthermore, from the viewpoint of cost, the metal oxide is selected from aluminum oxide and silicon oxide. Furthermore, from the viewpoint of excellent tensile stretchability during processing, it is more preferable to use silicon oxide as the metal oxide. By making the inorganic compound layer contained in the gas barrier layer 5 a vapor deposition film made of a metal oxide, high barrier properties can be obtained with a very thin layer within a range that does not affect the recyclability of the laminate 10E.

[0216] A vapor-deposited film made of a metal oxide has the advantage of being transparent, and therefore less likely to cause a user holding a packaging material made of a laminate to mistakenly believe that a metal foil is used, compared to a vapor-deposited film made of a metal.

[0217] The thickness of the vapor-deposited film made of aluminum oxide is preferably 5 nm or more and 30 nm or less. When the thickness is 5 nm or more, sufficient gas barrier properties can be obtained. Furthermore, when the thickness is 30 nm or less, cracks caused by deformation due to internal stress of the thin film can be suppressed, and the deterioration of gas barrier properties can be suppressed. Note that, when the thickness exceeds 30 nm, the cost is likely to increase due to an increase in the amount of material used and a prolonged film formation time, and is therefore not preferable from an economical point of view. From the same viewpoint as above, the thickness of the vapor-deposited film made of aluminum oxide is more preferably 7 nm or more and 15 nm or less.

[0218] The thickness of the vapor-deposited film made of silicon oxide is preferably 10 nm or more and 50 nm or less. When the thickness is 10 nm or more, sufficient gas barrier properties can be obtained. Furthermore, when the thickness is 50 nm or less, the occurrence of cracks due to deformation caused by internal stress in the thin film can be suppressed, and the deterioration of gas barrier properties can be suppressed. Note that, when the thickness exceeds 50 nm, the cost is likely to increase due to an increase in the amount of material used and a prolonged film formation time, and is therefore not preferable from an economical point of view. From the same viewpoint as above, the thickness of the vapor-deposited film made of silicon oxide is more preferably 20 nm or more and 40 nm or less.

[0219] The inorganic compound layer can be formed, for example, by vacuum film formation. In the vacuum film formation, physical vapor deposition or chemical vapor deposition can be used. Examples of physical vapor deposition include, but are not limited to, vacuum deposition, sputtering, and ion plating. Examples of chemical vapor deposition include, but are not limited to, thermal CVD (Chemical Vapor Deposition), plasma CVD, and photo CVD.

[0220] In the vacuum film formation, the resistance heating vacuum deposition method, the EB (Electron Beam) heating vacuum deposition method, the induction heating vacuum deposition method, the sputtering method, the reactive sputtering method, the dual magnetron sputtering method, the plasma enhanced chemical vapor deposition method (PECVD method), and the like are particularly preferably used. However, in terms of productivity, the vacuum deposition method is currently the most excellent. As the heating means for the vacuum deposition method, it is preferable to use any one of the electron beam heating method, the resistance heating method, and the induction heating method.

[0221] Instead of the inorganic compound layer, an aluminum vapor deposition layer can be provided. The thickness of the aluminum vapor deposition layer is preferably 40 nm to 80 nm. The aluminum vapor deposition layer can be provided on the intermediate layer, the substrate layer, or the sealant layer. When the aluminum vapor deposition layer is provided on the sealant layer, it preferably has a thickness of about 40 nm, and when the aluminum vapor deposition layer is provided on the intermediate layer or substrate layer, it preferably has a thickness of about 80 nm.

[0222] The coating layer can be formed, for example, by coating. In this case, a coating liquid containing a resin such as polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, and epoxy resin can be used. Additives such as organic or inorganic particles, layered compounds, and curing agents may be added to the coating liquid.

[0223] The coating layer may be, for example, an organic-inorganic composite layer containing at least one of a metal alkoxide, a hydrolysate of a metal alkoxide, and a reaction product of a metal alkoxide or a hydrolysate of a metal alkoxide, and a water-soluble polymer. This organic-inorganic composite layer may further contain at least one of a silane coupling agent, a hydrolysate of a silane coupling agent, and a reaction product of a silane coupling agent or a hydrolysate of a silane coupling agent.

[0224] Examples of metal alkoxides and hydrolysates thereof contained in the organic-inorganic composite layer include compounds represented by the general formula M(OR), such as tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(OC3H7)3]. n and hydrolysates thereof. One of these may be contained alone, or two or more of them may be contained in combination.

[0225] The total content of the metal alkoxide, its hydrolysate or their reaction products in the coating liquid used to form the organic-inorganic composite layer may be, for example, 40% by mass or more, 50% by mass or more, or 65% by mass or more from the viewpoint of oxygen barrier property. The total content of the metal alkoxide, its hydrolysate or their reaction products in the coating liquid may be, for example, 70% by mass or less.

[0226] The water-soluble polymer contained in the organic-inorganic composite layer is not particularly limited, and examples thereof include polyvinyl alcohol-based polymers, polysaccharides such as starch, methyl cellulose, and carboxymethyl cellulose, and hydroxyl-containing polymers such as acrylic polyol-based polymers. From the viewpoint of further improving the oxygen gas barrier property, the water-soluble polymer preferably contains a water-soluble polymer of polyvinyl alcohol-based polymer. The number-average molecular weight of the water-soluble polymer is, for example, 40,000 to 180,000.

[0227] The polyvinyl alcohol-based water-soluble polymer contained in the organic-inorganic composite layer can be obtained, for example, by saponifying (including partial saponification) polyvinyl acetate. This water-soluble polymer may have several tens of percent of acetate groups remaining, or may have only a few percent of acetate groups remaining.

[0228] The content of the water-soluble polymer in the coating liquid used to form the organic-inorganic composite layer may be, for example, 15% by mass or more, or 20% by mass or more, from the viewpoint of oxygen barrier property. Also, the content of the water-soluble polymer in the coating liquid may be, for example, 50% by mass or less, or 45% by mass or less, from the viewpoint of oxygen barrier property.

[0229] The silane coupling agent used in the organic-inorganic composite layer may be a silane coupling agent having an organic functional group. Such silane coupling agents may be ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, etc. The silane coupling agent selected from these, its hydrolyzate, and their reaction product may be used alone or in combination of two or more.

[0230] It is preferable to use a silane coupling agent having an epoxy group as an organic functional group. Examples of silane coupling agents having an epoxy group include γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Silane coupling agents having an epoxy group may have an organic functional group different from the epoxy group, such as a vinyl group, an amino group, a methacryl group or a ureyl group, or an isocyanate group. These may also be derivatives, polyfunctionalized, or composites. The silane coupling agents selected from these, their hydrolyzates, and their reaction products may be used alone or in combination of two or more.

[0231] A silane coupling agent having an organic functional group, its hydrolysate or reaction product thereof can further improve the oxygen barrier property of the organic-inorganic composite layer and the adhesion to adjacent layers by the interaction between the organic functional group and the hydroxyl group of the water-soluble polymer. In particular, when the silane coupling agent, its hydrolysate or reaction product thereof has an epoxy group and the water-soluble polymer is polyvinyl alcohol (PVA), the oxygen barrier property and the adhesion to adjacent layers can be further improved by the interaction between the epoxy group and the hydroxyl group of the PVA.

[0232] The total content of the silane coupling agent, its hydrolysate and their reaction products in the coating liquid used for forming the organic-inorganic composite layer may be, for example, 1% by mass or more, or 2% by mass or more, from the viewpoint of oxygen barrier property. Also, the total content of the silane coupling agent, its hydrolysate and their reaction products in the coating liquid may be, for example, 15% by mass or less, or 12% by mass or less, from the viewpoint of oxygen barrier property.

[0233] The gas barrier layer 5 is preferably subjected to the above-mentioned surface treatment, which can improve the adhesion between the gas barrier layer 5 and the adjacent layers. The material for the gas barrier layer 5 may be a nanocomposite.

[0234] The thickness of the coating layer is preferably 50 nm to 1000 nm, more preferably 100 nm to 500 nm. When the thickness of the gas barrier coating layer is 50 nm or more, more sufficient gas barrier properties tend to be obtained, and when the thickness is 1000 nm or less, sufficient flexibility tends to be maintained.

[0235] <Anchor coat layer> The laminate 10E may further include an anchor coat layer (not shown) on the surface of the intermediate layer 8 on which the gas barrier layer 5 is formed. Alternatively, the laminate 10E may further include an anchor coat layer (not shown) on the main surface of the substrate layer 1 facing the first adhesive layer 3A. The anchor coat layer can be formed using a known anchor coat agent. This can improve the adhesion of the inorganic compound layer made of metal oxide. Examples of the anchor coat agent include polyester polyurethane resin and polyether polyurethane resin. In addition, as the anchor coat layer, a polyurethane cured coating film in which an isocyanate compound is reacted with various hydroxyl group-containing polymers such as polyester polyol, polyether polyol, and acrylic polyol can also be provided. In addition, in order to improve the adhesion between the substrate and the layer formed by vapor deposition, the anchor coat agent can be blended with the various silane coupling agents described above. From the viewpoint of heat resistance and interlayer adhesive strength, the anchor coat agent is preferably a polyester polyurethane resin.

[0236] 9 includes the printed layer 4 between the base layer 1 and the first adhesive layer 3A, but the printed layer 4 may be included at any position between the protective layer 6 and the sealant layer 2. Since the base layer 1 and intermediate layer 8 included in the laminate 10E are transparent, the pattern displayed by the printed layer 4 can be clearly seen when the laminate 10E is observed from the protective layer 6 side, regardless of the position at which the printed layer 4 is included. According to one example, it is preferable that the printed layer 4 is included between the intermediate layer 8 and the protective layer 6, because this makes it easier to see the pattern displayed by the printed layer 4 more clearly.

[0237] In addition, in FIG. 9, the laminate 10E includes a gas barrier layer 5 on the side of the intermediate layer 8 facing the sealant layer 2, but the laminate 10E may also include a gas barrier layer 5 on the side of the intermediate layer 8 facing the base layer 1.

[0238] The ratio of polyethylene in the laminate 10E is, for example, 90% by mass or more, which makes the laminate 10E a highly recyclable mono-material.

[0239] <5.4> Effects Like the laminate 10A1, the laminate 10E described above includes a polyethylene-containing layer having a crystallinity within the above range as the base layer 1. Therefore, like the laminate 10A1, the laminate 10E has excellent heat resistance.

[0240] The laminate 10E also includes a protective layer 6. As described above, the protective layer 6 reduces thermal damage to the surface of the laminate during heat sealing. Therefore, the laminate 10E can achieve even better heat resistance, and in particular, better heat sealability. Therefore, when the above-described configuration is adopted for the laminate 10E, the temperature range of heat sealing performed for bag making is expanded, and a decrease in productivity is further prevented.

[0241] Moreover, the laminate 10E includes an intermediate layer 8 having a crystallinity within the above range. The intermediate layer 8 increases the strength, particularly the puncture strength, of the laminate 10E. Therefore, the laminate 10E is excellent in strength, particularly the puncture strength.

[0242] Since the base layer 1, the intermediate layer 8, and the sealant layer 2 of the laminate 10E all contain polyethylene, the laminate has excellent recyclability. Therefore, the standing pouch 110 using the laminate 10E as the main films 111A and 111B and the bottom film 112 also has excellent recyclability.

[0243] Furthermore, laminates with a high proportion of polyethylene are weaker than other laminates, and therefore are frequently folded when used as packaging materials. Frequent folding increases the likelihood of pinholes occurring, but laminate 10E, which has excellent puncture strength, is less likely to develop pinholes.

[0244] Moreover, since the base material layer 1 and the intermediate layer 8 in the laminate 10E are transparent, for example, no matter where the printed layer 4 is located between the base material layer 1 and the sealant layer 2, the pattern displayed by the printed layer 4 can be clearly seen when the printed layer 4 is observed from the protective layer 6 side. Moreover, the packaged article 100 including the above-mentioned laminate 10E has high visibility of the contents 120.

[0245] <6> Sixth embodiment The packaging article and the standing pouch according to the sixth embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the sixth embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0246] <6.1> Laminate FIG. 10 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a sixth embodiment of the present invention. 10 includes a protective layer 6, a base layer 1, a printed layer 4, a first adhesive layer 3A, an intermediate layer 8, a gas barrier layer 5, a second adhesive layer 3B, and a sealant layer 2, in this order. The laminate 10F is similar to the laminate 10E, except that the crystallinity of the intermediate layer 8 is less than 35%. Among the layers included in the laminate 10F, the layers other than the intermediate layer 8, i.e., the protective layer 6, the base layer 1, the printed layer 4, the first adhesive layer 3A, the gas barrier layer 5, the second adhesive layer 3B, and the sealant layer 2, can be those described in the fifth embodiment.

[0247] <6.2> Middle class The intermediate layer 8 contains polyethylene. As the polyethylene, for example, the above-mentioned polyethylene contained in the base layer 1 can be used. The intermediate layer 8 is, for example, high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or very low density polyethylene (VLDPE).

[0248] The polyethylene contained in the intermediate layer 8 may be the same as or different from the polyethylene contained in the base layer 1. In addition, the intermediate layer 8 may further contain the additives described above.

[0249] The proportion of polyethylene in the intermediate layer 8 is preferably 50% by mass or more, and more preferably 80% by mass or more. In one example, the intermediate layer 8 is made of polyethylene. In another example, the intermediate layer 8 is made of polyethylene and an additive.

[0250] The degree of crystallinity of the intermediate layer 8 is less than 35%. The degree of crystallinity of the intermediate layer 8 is preferably 30% or less. The degree of crystallinity of the intermediate layer 8 is preferably 15% or more.

[0251] The intermediate layer 8 having a crystallinity of less than 35% can increase the strength, particularly the drop strength, of the laminate 10F. A non-stretched film is preferable for such an intermediate layer 8. From the viewpoint of drop strength, it is preferable that the intermediate layer 8 is a non-stretched film having a crystallinity of less than 35%, and the base layer 1 is a stretched film having a crystallinity of 35% or more.

[0252] In this embodiment, an intermediate layer having a crystallinity of 35% or more may be used. When an intermediate layer having a crystallinity of 35% or more is used, the strength, particularly the puncture strength, of the laminate 10 can be improved. The intermediate layer having a crystallinity of 35% or more is preferably a stretched film.

[0253] The thickness of the intermediate layer 8 is preferably in the range of 10 μm to 200 μm, and more preferably in the range of 15 μm to 50 μm.

[0254] The intermediate layer 8 can be manufactured by known methods such as the casting method and inflation method described above, and it is also possible to use a multilayer polyethylene film as the base layer 1, in which polyethylenes of different densities are extruded by a coextrusion method.

[0255] <Anchor coat layer> The laminate 10F may further include an anchor coat layer (not shown) on the surface of the intermediate layer 8 on which the gas barrier layer 5 is formed. Alternatively, the laminate 10F may further include an anchor coat layer (not shown) on the surface facing the first adhesive layer 3A among the main surfaces of the base layer 1. As the anchor coat layer, the one described in the fifth embodiment can be used.

[0256] In addition, in FIG. 10, the laminate 10F includes a gas barrier layer 5 between the intermediate layer 8 and the second adhesive layer 3B, but the laminate 10F may also include a gas barrier layer 5 between the first adhesive layer 3A and the intermediate layer 8.

[0257] 10, the printed layer 4 is provided between the base layer 1 and the first adhesive layer 3A, but it is preferable that the printed layer 4 is provided between the protective layer 6 and the first adhesive layer 3A. In this case, when the laminate 10F is observed from the protective layer 6 side, the pattern displayed by the printed layer 4 is easily and clearly seen.

[0258] In addition, in the laminate 10F, the printed layer 4 and the gas barrier layer 5 may be omitted.

[0259] The ratio of polyethylene in the laminate 10F is, for example, 90% by mass or more, which makes the laminate 10F a highly recyclable mono-material.

[0260] <6.3> Effects In the above-described laminate 10F, the crystallinity of the base layer 1 is within the above range. Therefore, the laminate 10F has excellent heat resistance, similar to the laminate 10A1.

[0261] The laminate 10F also includes a protective layer 6. As described above, the protective layer 6 reduces thermal damage to the surface of the laminate during heat sealing. Therefore, the laminate 10F can achieve even better heat resistance, and in particular, better heat sealability. Therefore, when the above-described configuration is adopted for the laminate 10F, the temperature range of heat sealing performed for bag making is expanded, and a decrease in productivity is further prevented.

[0262] Moreover, the laminate 10F includes an intermediate layer 8 having a crystallinity within the above range. This intermediate layer 8 increases the strength, particularly the drop strength, of the laminate 10F. That is, in the laminate 10F, when used in a package, the intermediate layer 8 located on the inner side of the base layer 1 is softer than the base layer 1. This structure is suitable for absorbing the impact that occurs when a packaged article using the laminate 10F as a packaging material is dropped. Therefore, a packaged article using the laminate 10F as a packaging material is unlikely to be damaged (broken bag) by being dropped. Therefore, the laminate 10F has excellent strength, particularly the drop strength.

[0263] The laminate 10F has excellent recyclability because the base layer 1, the intermediate layer 8, and the sealant layer 2 all contain polyethylene. Therefore, the standing pouch 110 using the laminate 10F as the main films 111A and 111B and the bottom film 112 also has excellent recyclability.

[0264] <7> Seventh embodiment The packaging article and the standing pouch according to the seventh embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the seventh embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0265] <7.1> Laminate FIG. 11 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to a seventh embodiment of the present invention. The laminate 10G shown in FIG. 11 includes a protective layer 6, a base layer 1, a printed layer 4, a first adhesive layer 3A, an intermediate layer 8, an inorganic compound layer 5, a coating layer 7, a second adhesive layer 3B, and a sealant layer 2 in this order. The laminate 10G has a polyethylene ratio of 90% by mass or more. The laminate 10G is similar to the laminate 10E according to the fifth embodiment in which the gas barrier layer 5 includes an inorganic compound layer and a coating layer. The protective layer 6, the base layer 1, the printed layer 4, the first adhesive layer 3A, the intermediate layer 8, the inorganic compound layer 5, the coating layer 7, the second adhesive layer 3B, and the sealant layer 2 included in the laminate 10G can be those described in the fifth embodiment.

[0266] <7.2> Effects Like laminate 10A1, laminate 10G includes a polyethylene-containing layer having a crystallinity within the above range as base layer 1. Therefore, like laminate 10A1, laminate 10G has excellent heat resistance.

[0267] The laminate 10G also includes a protective layer 6. As described above, the protective layer 6 reduces thermal damage to the surface of the laminate during heat sealing. Therefore, the laminate 10G can achieve even better heat resistance, and in particular, better heat sealability. Therefore, when the above-described configuration is adopted for the laminate 10G, the temperature range of heat sealing performed for bag making is expanded, and a decrease in productivity is further prevented.

[0268] Moreover, the laminate 10G includes an intermediate layer 8 having a crystallinity within the above range. The intermediate layer 8 increases the strength, particularly the puncture strength, of the laminate 10G. Therefore, the laminate 10G is excellent in strength, particularly the puncture strength.

[0269] In the laminate 10G, the base layer 1, the intermediate layer 8, and the sealant layer 2 all contain polyethylene, and the proportion of polyethylene is 90% by mass or more. This laminate has excellent recyclability. In addition, the standing pouch 110 using the laminate 10G as the main films 111A and 111B and the bottom film 112 also has excellent recyclability.

[0270] Furthermore, laminates with a high proportion of polyethylene are weaker than other laminates, and therefore are often folded when used as packaging materials. The more often the laminate is folded, the higher the possibility of pinholes occurring. However, laminate 10G, which has excellent puncture strength, is less likely to develop pinholes.

[0271] Moreover, in the laminate 10G, since the base material layer 1 and the intermediate layer 8 are transparent, for example, no matter where the printed layer 4 is located between the base material layer 1 and the sealant layer 2, the pattern displayed by the printed layer 4 can be clearly seen when the printed layer 4 is observed from the protective layer 6 side. Moreover, the packaged article 100 including the above-mentioned laminate 10G has high visibility of the contents 120.

[0272] <8> Eighth embodiment The packaging article and the standing pouch according to the eighth embodiment are similar to the packaging article and the standing pouch according to the first embodiment, except that the following configurations are adopted. That is, in the eighth embodiment, instead of using the laminate 10A1, the following laminates are used as the main films 111A and 111B and the bottom film 112.

[0273] <8.1> Laminate FIG. 12 is a cross-sectional view that illustrates a laminate included in a standing pouch of a packaging article according to an eighth embodiment of the present invention. The laminate 10H shown in FIG. 12 includes a protective layer 6, a base layer 1, a printed layer 4, a first adhesive layer 3A, an intermediate layer 8, an inorganic compound layer 5, a coating layer 7, a second adhesive layer 3B, and a sealant layer 2 in this order. The laminate 10H has a polyethylene ratio of 90% by mass or more. The laminate 10H is similar to the laminate 10F according to the sixth embodiment in which the gas barrier layer 5 includes an inorganic compound layer and a coating layer. The protective layer 6, the base layer 1, the printed layer 4, the first adhesive layer 3A, the intermediate layer 8, the inorganic compound layer 5, the coating layer 7, the second adhesive layer 3B, and the sealant layer 2 included in the laminate 10H can be those described in the sixth embodiment.

[0274] <8.2> Effects In the laminate 10H, the crystallinity of the base layer 1 is within the above range. Therefore, the laminate 10H has excellent heat resistance, similar to the laminate 10A1.

[0275] Furthermore, the laminate 10H includes a protective layer 6. As described above, the protective layer 6 reduces thermal damage to the surface of the laminate during heat sealing. Therefore, the laminate 10H can achieve even better heat resistance, and in particular, better heat sealability. Thus, when the above-described configuration is adopted for the laminate 10H, the temperature range of heat sealing performed for bag making is expanded, and a decrease in productivity is further prevented.

[0276] Moreover, the laminate 10H includes an intermediate layer 8 having a crystallinity within the above range. This intermediate layer 8 increases the strength, particularly the drop strength, of the laminate 10H. That is, in the laminate 10H, when used in a package, the intermediate layer 8 located on the inner side of the base layer 1 is softer than the base layer 1. This structure is suitable for absorbing the impact that occurs when a packaged article using the laminate 10H as a packaging material is dropped. Therefore, a packaged article using the laminate 10H as a packaging material is unlikely to be damaged (broken bag) by being dropped. Therefore, the laminate 10H has excellent strength, particularly drop strength.

[0277] The laminate 10H has a polyethylene content of 90% by mass or more. Therefore, the laminate 10H has excellent recyclability. Therefore, the standing pouch 110 using the laminate 10H as the main films 111A and 111B and the bottom film 112 also has excellent recyclability.

[0278] The printing layer 4 may be provided on the surface of the base layer 1, on the surface of the intermediate layer 8, or on the back surface of the intermediate layer 8. In any case, the images such as patterns and characters displayed by the printing layer 4 can be viewed with good visibility. The printing layer 4 may be omitted.

[0279] <9> Other Variations The packaging article 100 and the standing pouch 110 described above can be modified in various ways. For example, the laminates used for the body films 111A and 111B and the bottom film 112 may be the same or different.

[0280] For example, the main films 111A and 111B may be made of one selected from the laminates according to the first to eighth embodiments and the laminates according to the modified examples described above, and the bottom film 112 may be made of another selected from the laminates according to the first to eighth embodiments and the laminates according to the modified examples described above.

[0281] The thickness of the sealant layer 2 may be different between the main film 111A and 111B and the bottom film 112. When a packaged article in which a large content is filled in a standing pouch is dropped, a large force is instantaneously applied to the bottom film. Therefore, the bottom film needs to have a certain thickness. For this reason, it may be preferable to make the sealant of the bottom film thicker. For example, when the main film has a three-layer structure and the bottom film has a two-layer structure, a packaged article with particularly excellent drop resistance can be realized by making the sealant layer of the bottom film thicker than the sealant layer of the main film.

[0282] The protective layer 6 may be provided on each of the laminate used for the main films 111A and 111B and the laminate used for the bottom film 112. Alternatively, the protective layer 6 may be provided only on the laminate used for the main films 111A and 111B, and omitted from the laminate used for the bottom film 112. Alternatively, the protective layer 6 may be provided only on the laminate used for the bottom film 112, and omitted from the laminate used for the main films 111A and 111B.

[0283] The protective layer 6 provided on the main film laminate makes it difficult for the surface of the main film laminate to melt during heat sealing, and further makes it difficult for the molten material to adhere to the heat seal bar. The protective layer 6 provided on the bottom film laminate enhances the effect of preventing the two parts partitioned by the mountain fold of the bottom film laminate from being falsely fused during bottom sealing.

[0284] The printed layer 4 may be provided only in the laminate used for the main films 111A and 111B, and may be omitted from the laminate used for the bottom film 112. The printed layer 4 can reduce the proportion of polyethylene in the standing pouch 110. From this point of view, therefore, the printed layer 4 may not be provided on the bottom film 112, and may be provided only on the main films 111A and 111B.

[0285] In one or more of the main films 111A and 111B and the bottom film 112, the laminate may further include a matte layer as the outermost layer on the side opposite to the sealant layer 2. The matte layer suppresses regular reflection and improves the visibility of the image displayed by the print layer 4. The matte layer may also exhibit a slip-proof effect when the packaged article 100 is held in the hand. The matte layer may be formed by applying a matte varnish to the print surface using a method such as gravure printing, to which an appropriate amount of a matte agent such as an olefin-based or alkyd-based synthetic resin or an inorganic material such as a silica-based or kaolin-based synthetic resin is added, and the matte agent imparts unevenness to the surface of the varnish, forming a matte layer with reduced gloss.

[0286] The matte layer can reduce the proportion of polyethylene in the standing pouch 110. From this viewpoint, therefore, it is also possible to provide a matte layer only on the main films 111A and 111B as the outermost layer on the side opposite to the sealant layer 2, without providing a matte layer on the bottom film 112.

[0287] The laminate may further include a light-shielding layer in one or more of the main films 111A and 111B and the bottom film 112. For example, the laminate used for the bottom film 112 may not have a light-shielding layer, and only the laminate used for the main films 111A and 111B may have a light-shielding layer. Alternatively, each of the laminates used for the main films 111A and 111B and the bottom film 112 may have a light-shielding layer.

[0288] The packaged article 100 is often placed on a shelf or the like in an upright state. Therefore, there is little opportunity for external light to be incident on the bottom film 112. The main body films 111A and 111B including a light-shielding layer make it difficult for external light to cause deterioration of the contents 120. In addition, the main body films 111A and 111B including a light-shielding layer also have the effect of preventing the contents 120 from being peeked at when the packaged article 100 is placed on a shelf or the like in an upright state.

[0289] The bottom film 112 including a light-shielding layer makes it difficult for the contents 120 to deteriorate due to external light, and can prevent the contents 120 from being peeked at, even when the packaged article 100 is displayed in a state where external light is incident on the bottom film 112. On the other hand, the bottom film 112 not including a light-shielding layer can make the contents 120 visible when the packaged article 100 is picked up and observed from the bottom.

[0290] According to one example, the light-shielding layer is a vapor-deposited layer made of a metal such as aluminum, etc. In order to achieve high light-shielding properties, a metal vapor-deposited layer is most suitable as the light-shielding layer.

[0291] In another example, the light-shielding layer is a sealant layer 2 or an intermediate layer 8 that is light-shielding. The sealant layer 2 or the intermediate layer 8 can be made light-shielding by adding a coloring pigment such as titania or carbon to the resin that constitutes the sealant layer 2 or the intermediate layer 8. When this configuration is adopted, a light-shielding layer having desired transmission characteristics, for example, a transmission wavelength range and a transmitted light intensity, can be realized by appropriately setting the type and amount of the coloring pigment.

[0292] In yet another example, the light-shielding layer is a printed layer formed of a light-shielding ink. The printed layer made of the light-shielding ink may be a continuous film that spreads over the entire surface of the film, or may be a pattern that spreads over a partial area of ​​the film. In the latter case, light-shielding properties can be imparted only to desired positions. Moreover, the printed layer can be separated from the plastic by using a deinking technique. Therefore, this configuration is advantageous in terms of recyclability.

[0293] The laminate may further include a laser light absorbing layer in one or more of the main films 111A and 111B and the bottom film 112. For example, the laminate used for the bottom film 112 may not be provided with a laser light absorbing layer, and only the laminate used for the main films 111A and 111B may be provided with a laser light absorbing layer.

[0294] The laser light absorbing layer enables the film to be half-cut by irradiation with laser light, and this can be utilized to provide an easy-open structure to, for example, the standing pouch 110.

[0295] According to one example, the laser light absorbing layer is a nylon film formed by coextrusion with a polyethylene film used as the substrate layer 1, the intermediate layer 8 or the sealant layer 2. Such a laser light absorbing layer has excellent transparency.

[0296] According to another example, the laser light absorbing layer is the sealant layer 2 or the intermediate layer 8 which is made laser light absorbing. The sealant layer 2 or the intermediate layer 8 can be made laser light absorbing by adding color pigments such as titania and carbon to the resin constituting the sealant layer 2 or the intermediate layer 8. Such a laser light absorbing layer can also play the role of the light shielding layer.

[0297] According to yet another example, the laser light absorbing layer is a printed layer formed with a laser light absorbing ink. Such a laser light absorbing layer can be separated from the plastic by using a deinking technique. Therefore, this configuration is advantageous in terms of recyclability.

[0298] In the present invention, the main film and the bottom film do not have to be laminates (films) of the same structure, as long as the base layer of the main film and the base layer of the bottom film are both films with a crystallinity of 35% or more, which is the ratio of the crystal peak area to the total peak area measured by the parallel beam method of X-ray diffraction at a diffraction angle range of 10° to 30°. For example, the main film may be a laminate (film) including a light-shielding layer, a vapor deposition layer having light-shielding performance, a light-shielding sealant, a printed layer, a matte layer, and a laser light-absorbing layer, and the bottom film may be a laminate (film) not including a light-shielding layer, a vapor deposition layer having light-shielding performance, a light-shielding sealant, a printed layer, a matte layer, and a laser light-absorbing layer. Furthermore, the main film may be a three-layer structure including a base material, an intermediate layer, and a sealant layer, and the bottom film may be a two-layer structure including a base material and a sealant layer. EXAMPLES

[0299] The results of tests carried out in relation to the present invention are described below. (1) Test A (1.1) Manufacturing of laminates and standing pouches (1.1.1) Example 1A The laminate 10A2 shown in FIG. 5 was produced by the following method. First, a polyethylene film having a thickness of 25 μm and a crystallinity of 58.5% was prepared as a base layer. The crystallinity shown in this example and the examples and comparative examples described below was measured by the above-mentioned measurement method.

[0300] Next, a silicon oxide (SiO x ) A vapor deposition film was formed. Then, a printing layer was formed on the inorganic compound layer.

[0301] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the base layer on which the print layer was formed, and a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was attached to the base layer as a sealant layer via this adhesive layer. In this manner, a laminate was produced.

[0302] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0303] (1.1.2) Example 2A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that no inorganic compound layer was provided. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0304] (1.1.3) Example 3A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a polyamine-based gas barrier adhesive was used as the adhesive instead of a dry lamination adhesive (urethane-based adhesive). A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0305] (1.1.4) Example 4A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a polyethylene film having a thickness of 25 μm and a crystallinity of 71.8% was used as the base layer instead of a polyethylene film having a thickness of 25 μm and a crystallinity of 58.5%. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0306] (1.1.5) Example 5A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a polyethylene film having a thickness of 25 μm and a crystallinity of 55.9% was used as the base layer instead of a polyethylene film having a thickness of 25 μm and a crystallinity of 58.5%. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0307] (1.1.6) Example 6A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a polyethylene film having a thickness of 20 μm and a crystallinity of 54.1% was used as the base layer instead of a polyethylene film having a thickness of 25 μm and a crystallinity of 58.5%. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0308] (1.1.7) Example 7A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a polyethylene film having a thickness of 30 µm and a crystallinity of 55.9% was used as the base layer instead of a polyethylene film having a thickness of 25 µm and a crystallinity of 58.5%. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0309] (1.1.8) Example 8A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a linear low density polyethylene resin (LLDPE) film having a thickness of 40 μm was used as the sealant layer instead of a linear low density polyethylene resin (LLDPE) film having a thickness of 60 μm. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0310] (1.1.9) Example 9A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that a linear low density polyethylene resin (LLDPE) film having a thickness of 120 μm was used as the sealant layer instead of a linear low density polyethylene resin (LLDPE) film having a thickness of 60 μm. A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0311] (1.1.10) Example 10A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that no inorganic compound layer was provided and that a polyamine-based gas barrier adhesive was used as the adhesive instead of the dry lamination adhesive (urethane adhesive). A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0312] (1.1.11) Example 11A The laminate 10A2 shown in Fig. 5 was produced in the same manner as in Example 1A, except that no inorganic compound layer was provided and a urethane-based gas barrier adhesive was used as the adhesive instead of the dry lamination adhesive (urethane-based adhesive). A standing pouch 110 was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0313] (1.1.12) Comparative Example 1A A laminate was produced in the same manner as in Example 1A, except that a polyethylene film having a thickness of 32 μm and a crystallinity of 14.8% was used as the base layer instead of a polyethylene film having a thickness of 25 μm and a crystallinity of 58.5%. A standing pouch was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0314] (1.1.13) Comparative example 2A A laminate was produced in the same manner as in Example 1A, except that a polyethylene film having a thickness of 25 μm and a crystallinity of 20.6% was used as the base layer instead of a polyethylene film having a thickness of 25 μm and a crystallinity of 58.5%. A standing pouch was produced in the same manner as in Example 1A, except that this laminate was used as the main film laminate and the bottom film laminate.

[0315] (1.2) Measurement and evaluation methods The substrate layer used in the production of the laminate was subjected to in-plane measurement by the wide-angle X-ray diffraction method described above, and it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0316] The laminate was also evaluated for sealing property, heat resistance, visibility, and gas barrier property. The standing pouch was also evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, and gas barrier property, and the drop strength are described below.

[0317] (1.2.1) Sealing performance evaluation method A sample cut into a 10 cm square of the laminate was folded in half so that the sealant layer was on the inside, and heat-sealed using a heat seal tester. Specifically, first, the bottom seal temperature was set to 100°C, the top seal temperature was set to 120°C, and a pressure of 0.1 MPa was applied for 1 second. Then, the presence or absence of melting of the seal surface was confirmed, and the area of ​​the top surface of the folded sample where the heat seal bar was applied was observed. If the seal surface was not melted and the top surface of the sample was not melted, the bottom seal temperature was fixed at 100°C, and the top seal temperature was increased by 10°C at a time, and the same pressure and observation were performed as above, until at least one of the seal surface and the top surface of the sample was melted. Then, the sealability was evaluated according to the following criteria. A: There was no melting on the top surface of the sample, and there were no problems with the appearance. B: The upper surface of the sample was melted, and there was a problem with the appearance.

[0318] (1.2.2) Heat resistance evaluation method A sample cut into a 10 cm square of the laminate was folded in half so that the sealant layer was on the inside. Next, the lower seal temperature of the heat seal tester was set to 30°C, and the upper seal temperature was set to 170°C, and a pressure of 0.2 MPa was applied to the folded sample for 1 second. Then, the presence or absence of melting of the seal surface was confirmed, and the area of ​​the upper surface of the folded sample that was touched with the heat seal bar was observed to see if it was attached to the heat seal bar, and the heat resistance was evaluated according to the following criteria. A: The upper surface of the sample did not adhere to the heat seal bar. B: The top surface of the sample adhered to the heat seal bar.

[0319] (1.2.3) Visibility evaluation method The pattern displayed by the print layer was visually observed from the substrate layer side, and the visibility was evaluated according to the following criteria. A: The pattern displayed by the printing layer was clearly visible. B: The pattern displayed by the printing layer was blurred and unclear.

[0320] (1.2.4) Gas barrier property evaluation method The laminate was subjected to a boiling treatment, and then the oxygen transmission rate (OTR) was measured at 30°C and a relative humidity of 70%. This measurement was performed in accordance with JIS K-7126, Method B. The oxygen transmission rate was then evaluated for gas barrier properties with reference to the following criteria. A: The OTR was less than 10 cc / m2·day·atm. B: OTR was 10cc / m2·day·atm or more.

[0321] (1.2.5) Drop Strength Evaluation Method Each of the standing pouches of Examples 1A to 11A and Comparative Examples 1A and 2A was filled with 1200 mL of cold water at 5°C to produce packaged articles. Thirty packaged articles were produced for each example. The packaged articles were dropped from a height of 100 cm above the ground with the bottom film facing down (upright position). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0322] (1.3) Results The results of the above measurements and evaluations are summarized in Tables 1-1, 1-2, and 1-3 below.

[0323] [Table 1-1]

[0324] [Table 1-2]

[0325] [Table 1-3]

[0326] As shown in Tables 1-1 and 1-2, all of the laminates having a crystallinity of 35% or more in the base layer had good sealing properties, heat resistance, and visibility. In contrast, all of the laminates having a crystallinity of less than 35% in the base layer had insufficient sealing properties, heat resistance, and visibility.

[0327] Furthermore, as shown in Table 1-3, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0328] In addition, when a spout made of high-density polyethylene was molded by injection molding and a spout-equipped standing pouch was manufactured using a spout welding machine, the pouch could be manufactured without any problems when the laminates of Examples 1A to 11A were used for the main film and bottom film.

[0329] (2) Test B (2.1) Manufacturing of laminates and standing pouches (2.1.1) Example 1B 6 was produced by the following method. In this example, an anchor coat layer was further provided between the base layer 1 and the gas barrier layer 5, and an inorganic compound layer and a coating layer were provided as the gas barrier layer 5.

[0330] First, coating solutions for forming an anchor coating agent, a protective layer, and a covering layer were prepared by the following method: In this example, the protective layer and the covering layer were formed using the same coating solution.

[0331] (Preparation of anchor coating agent) Acrylic polyol and tolylene diisocyanate were mixed so that the number of NCO groups in tolylene diisocyanate was equal to the number of OH groups in the acrylic polyol, and diluted with ethyl acetate so that the total solid content (total amount of acrylic polyol and tolylene diisocyanate) was 5 mass%. β-(3,4-epoxycyclohexyl)trimethoxysilane was further added to the diluted mixture so that the amount was 5 mass parts per 100 mass parts of the total amount of acrylic polyol and tolylene diisocyanate, and these were mixed to prepare an anchor coating agent.

[0332] (Preparation of Coating Solution for Forming Protective Layer and Covering Layer) A coating liquid for forming a protective layer and a covering layer containing an organic / inorganic mixture (hereinafter, simply referred to as a "coating liquid") was prepared by mixing the following liquids A, B, and C in a mass ratio of 70 / 20 / 10, respectively. Liquid A: A hydrolysis solution with a solid content of 5 mass% (SiO2 equivalent) obtained by adding 72.1 g of 0.1N hydrochloric acid to 17.9 g of tetraethoxysilane (Si(OC2H5)4) and 10 g of methanol and stirring for 30 minutes. Liquid B: 5% by mass solution of polyvinyl alcohol in water / methanol (mass ratio of water:methanol is 95:5). Liquid C: A hydrolysis solution in which 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate was diluted with a mixture of water and isopropyl alcohol (water:isopropyl alcohol mass ratio 1:1) to a solid content of 5 mass%.

[0333] The substrate layer has a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.94 g / cm 3 The crystallinity shown in this example and the following examples and comparative examples was measured by the above-mentioned measuring method.

[0334] Next, one surface of the base layer was subjected to a corona treatment, and then the coating solution prepared above was applied to the corona-treated surface of the base layer by a gravure coating method and dried to form a protective layer made of an organic / inorganic mixture and having a thickness of 0.5 μm (in a dry state).

[0335] Next, the other surface of the base layer was subjected to a corona treatment. Subsequently, the above-mentioned anchor coating agent was applied to the corona-treated surface of the base layer by a gravure coating method to form an anchor coating layer having a thickness of 0.1 μm (in a dry state).

[0336] Next, an electron beam heating vacuum deposition apparatus was used to deposit silicon oxide (SiO x ) A vapor-deposited film having a thickness of 40 nm was formed. Next, the coating solution prepared above was applied to the inorganic compound layer to form a coating layer consisting of an organic-inorganic mixture having a thickness of 0.3 μm (in a dry state).

[0337] Thereafter, a water-based flexographic ink was pattern-printed on the coating layer to form a print layer.

[0338] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the base layer on which the print layer was formed, and a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was attached to the base layer as a sealant layer via this adhesive layer. In this manner, a laminate was produced.

[0339] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0340] (2.1.2) Example 2B The laminate 10B shown in FIG. 6 was fabricated by using a polyethylene film having a crystallinity of 58.5% as a base layer, instead of the polyethylene film having a crystallinity of 58.5% as described above, and using a polyethylene film having a thickness of 25 μm, a crystallinity of 55.9%, a haze of 5.9%, and a density of 0.95 g / cm 3 A standing pouch 110 was produced in the same manner as in Example 1B, except that a polyethylene film having a thickness of 100 mm was used. The polyethylene film was a biaxially stretched film, and one side of the film was subjected to a corona treatment. A standing pouch 110 was produced in the same manner as in Example 1B, except that the laminate was used as the main film laminate and the bottom film laminate.

[0341] (2.1.3) Example 3B The laminate 10B shown in Fig. 6 was produced in the same manner as in Example 2B, except that no protective layer was provided. A standing pouch 110 was produced in the same manner as in Example 1B, except that this laminate was used as the main film laminate and the bottom film laminate.

[0342] (2.1.4) Example 4B The laminate 10B shown in Fig. 6 was produced in the same manner as in Example 1B, except that a protective layer of 0.5 μm thickness made of a urethane resin was formed instead of forming a protective layer of 0.5 μm thickness by applying an organic / inorganic mixture. A standing pouch 110 was produced in the same manner as in Example 1B, except that this laminate was used as the main film laminate and the bottom film laminate.

[0343] (2.1.5) Example 5B The laminate 10B shown in Fig. 6 was produced in the same manner as in Example 1B, except that a protective layer of 1 μm thickness made of a urethane resin was formed instead of forming a protective layer of 0.5 μm thickness by applying an organic / inorganic mixture. A standing pouch 110 was produced in the same manner as in Example 1B, except that this laminate was used as the main film laminate and the bottom film laminate.

[0344] (2.1.6) Example 6B The laminate 10B shown in Fig. 6 was produced in the same manner as in Example 1B, except that a protective layer of 1 μm thickness made of ethylene-vinyl alcohol copolymer (EVOH) was formed instead of forming a protective layer of 0.5 μm thickness by applying an organic-inorganic mixture. A standing pouch 110 was produced in the same manner as in Example 1B, except that this laminate was used as the main film laminate and the bottom film laminate.

[0345] (2.1.7) Example 7B The laminate 10B shown in Fig. 6 was produced in the same manner as in Example 1B, except that instead of forming a 0.5 μm thick protective layer by applying an organic / inorganic mixture, a 1 μm thick protective layer made of acrylic resin was formed. A standing pouch 110 was produced in the same manner as in Example 1B, except that this laminate was used as the main film laminate and the bottom film laminate.

[0346] (2.1.8) Comparative example 1B The laminate 10B shown in FIG. 6 was produced in the same manner as in Example 1B, except for the following: no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film with a crystallinity of 58.5% as the base layer, a laminate with a thickness of 25 μm, a crystallinity of 27.5%, a haze of 21.5%, and a density of 0.950 g / cm was used. 3 A polyethylene film having a thickness of 100 mm was used. One side of the polyethylene film was corona-treated. A standing pouch was produced in the same manner as in Example 1B, except that this laminate was used as the main film laminate and the bottom film laminate.

[0347] (2.2) Measurement and Evaluation Methods The substrate layer used in the production of the laminate was subjected to in-plane measurement by the wide-angle X-ray diffraction method described above, and it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0348] The laminate was also evaluated for sealing property, heat resistance, visibility, and recyclability. Furthermore, the standing pouch was evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, and recyclability, and the drop strength are described below.

[0349] (2.2.1) Sealing performance evaluation method A sample of the laminate cut into a 10 cm square was folded in half with the sealant layer on the inside, and heat-sealed using a heat seal tester. Specifically, a temperature of 140°C and a pressure of 0.1 MPa were applied to the folded sample for 1 second. The area of ​​the sample surface where the heat seal bar was applied was observed, and the sealability was evaluated according to the following criteria. A: There was no melting on the surface of the sample, and there were no problems with the appearance. B: The surface of the sample was melted, and there was a problem with the appearance.

[0350] (2.2.2) Heat resistance evaluation method A sample cut into a 10 cm square of the laminate was folded in half so that the sealant layer was on the inside. Next, the lower seal temperature of the heat seal tester was set to 30°C, and the upper seal temperature was set to 170°C, and a pressure of 0.2 MPa was applied to the folded sample for 1 second. Then, the presence or absence of melting of the seal surface was confirmed, and the area of ​​the upper surface of the folded sample that was touched with the heat seal bar was observed to see if it was attached to the heat seal bar, and the heat resistance was evaluated according to the following criteria. A: The upper surface of the sample did not adhere to the heat seal bar. B: The top surface of the sample adhered to the heat seal bar. For the laminates having a protective layer, the heat resistance was further evaluated in the same manner as above, except that the top seal temperature was set to 190°C.

[0351] (2.2.3) Visibility evaluation method Visibility was evaluated using the method described in (1.2.3).

[0352] (2.2.4) Recyclability assessment method The percentage of polyethylene in the total mass of the laminate was calculated. This percentage was used to evaluate the recyclability with reference to the following criteria. Here, evaluation A means that the recyclability is excellent as a monomaterial. A: The proportion of polyethylene was 90 mass % or more. B: The proportion of polyethylene was less than 90% by mass.

[0353] (2.2.5) Drop Strength Evaluation Method Each of the standing pouches of Examples 1B to 7B and Comparative Example 1B was filled with 1200 mL of cold water at 5°C to produce a packaged article. For each example, 30 packaged articles were produced. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright position). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0354] (2.3) Results The results of the above measurements and evaluations are summarized in Tables 2-1 and 2-2 below.

[0355] [Table 2-1]

[0356] [Table 2-2]

[0357] As shown in Table 2-1, all of the laminates in which the crystallinity of the base layer is 35% or more had good heat resistance and visibility while being suitable for recycling. The laminates in which the crystallinity of the base layer is 35% or more and which have a protective layer also had excellent sealing properties. In contrast, the laminates in which the crystallinity of the base layer is less than 35% and which do not have a protective layer had insufficient sealing properties, heat resistance, and visibility.

[0358] Furthermore, as shown in Table 2-2, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0359] (3) Test C (3.1) Manufacturing of laminates and standing pouches (3.1.1) Example 1C 7 was produced by the following method. In this example, an anchor coat layer was further provided between the base material layer 1 and the inorganic compound layer 5. First, an anchor coating agent and a coating liquid for forming a covering layer were prepared in the same manner as in Example 1 B. In addition, an organic solvent solution of a polyamideimide resin (non-volatile component concentration 5% by mass) was prepared as a coating liquid for forming a protective layer.

[0360] The substrate layer has a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.950 g / cm 3 A polyethylene film having the following properties was prepared. This polyethylene film was subjected to corona treatment on both sides. The crystallinity shown in this example and the following examples and comparative examples was measured by the above-mentioned measuring method.

[0361] Next, the coating solution containing the polyamideimide prepared above was applied by gravure coating onto one of the corona-treated surfaces of the base layer, and then dried to form a protective layer having a thickness of 0.5 μm.

[0362] Next, the above-mentioned anchor coating agent was applied to the other corona-treated surface of the base layer by gravure coating to form an anchor coating layer having a thickness of 0.1 μm (in a dry state).

[0363] Next, an electron beam heating vacuum deposition apparatus was used to deposit silicon oxide (SiO x ) was deposited to a thickness of 40 nm. The coating solution for forming a coating layer prepared above was then applied to the inorganic compound layer to form a coating layer of an organic-inorganic mixture having a thickness of 0.3 μm (in a dry state).

[0364] Thereafter, an image was formed on the coating layer by a flexographic printing method using a water-based flexographic ink, thereby forming a print layer.

[0365] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the base layer on which the print layer was formed, and a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was attached to the base layer as a sealant layer via this adhesive layer. In this manner, a laminate was produced.

[0366] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0367] (3.1.2) Example 2C The laminate 10C shown in Fig. 7 was produced in the same manner as in Example 1C, except that the thickness of the protective layer was changed from 0.5 μm to 1 μm and no covering layer was provided. A standing pouch 110 was produced in the same manner as in Example 1C, except that this laminate was used as the main film laminate and the bottom film laminate.

[0368] (3.1.3) Example 3C The laminate 10C shown in Fig. 7 was produced in the same manner as in Example 1C, except that the thickness of the protective layer was changed from 0.5 μm to 3 μm. A standing pouch 110 was produced in the same manner as in Example 1C, except that this laminate was used as the main film laminate and the bottom film laminate.

[0369] (3.1.4) Example 4C The laminate 10C shown in Fig. 7 was produced in the same manner as in Example 1C, except that no protective layer was provided. A standing pouch 110 was produced in the same manner as in Example 1C, except that this laminate was used as the main film laminate and the bottom film laminate.

[0370] (3.1.5) Comparative example 1C The laminate 10C shown in FIG. 7 was produced in the same manner as in Example 1C, except for the following. That is, no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film with a crystallinity of 58.5%, a polyethylene film with a thickness of 25 μm, a crystallinity of 27.6%, and a haze of 21.5% was used as the base layer. A standing pouch was produced in the same manner as in Example 1C, except that this laminate was used as the main film laminate and the bottom film laminate.

[0371] (3.2) Measurement and Evaluation Methods The substrate layer used in the production of the laminate was subjected to in-plane measurement by the wide-angle X-ray diffraction method described above, and it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0372] The laminate was also evaluated for sealing property, heat resistance, visibility, and recyclability. Furthermore, the standing pouch was evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, and recyclability, and the drop strength are described below.

[0373] (3.2.1) Sealing performance evaluation method The sealing performance was evaluated by the method described in (1.2.1).

[0374] (3.2.2) Heat resistance evaluation method Heat resistance was evaluated by the method described in (2.2.2).

[0375] (3.2.3) Visibility Evaluation Method Visibility was evaluated using the method described in (1.2.3).

[0376] (3.2.3) Recyclability assessment method Recyclability was evaluated using the method described in (2.2.4).

[0377] (3.2.4) Drop Strength Evaluation Method Each of the standing pouches of Examples 1C to 4C and Comparative Example 1C was filled with 1200 mL of cold water at 5°C to produce a packaged article. For each example, 30 packaged articles were produced. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright state). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0378] (3.3) Results The results of the above measurements and evaluations are summarized in Tables 3-1 and 3-2 below.

[0379] [Table 3-1]

[0380] [Table 3-2]

[0381] As shown in Table 3-1, all of the laminates in which the crystallinity of the base layer is 35% or more had good heat resistance and visibility while being suitable for recycling. The laminates in which the crystallinity of the base layer is 35% or more and which have a protective layer also had excellent sealing properties. In contrast, the laminates in which the crystallinity of the base layer is less than 35% and which do not have a protective layer had insufficient sealing properties, heat resistance, and visibility.

[0382] Furthermore, as shown in Table 3-2, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0383] (4) Test D (4.1) Manufacturing of laminates and standing pouches (4.1.1) Example 1D The laminate 10D shown in FIG. 8 was produced by the following method. First, the substrate layer and the intermediate layer had a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.94 g / cm 3 The crystallinity shown in this example and the following examples and comparative examples was measured by the above-mentioned measuring method.

[0384] Next, on the intermediate layer, silicon oxide (SiO x ) A vapor-deposited film was formed to a thickness of 50 nm.

[0385] A dry lamination adhesive (urethane adhesive) was applied onto the base layer to form a first adhesive layer. The base layer and the intermediate layer were bonded together so that the base layer and the inorganic compound layer faced each other with the first adhesive layer sandwiched therebetween. Next, a print layer was formed on the reverse side of the surface of the intermediate layer on which the inorganic compound layer was formed.

[0386] Next, a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was prepared as a sealant layer, and a dry lamination adhesive (urethane adhesive) was applied onto the sealant layer to form a second adhesive layer. The base layer and the sealant layer were bonded together with the second adhesive layer sandwiched between them so that the sealant layer and the print layer faced each other.

[0387] In this manner, a laminate was produced.

[0388] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0389] (4.1.2) Example 2D The laminate 10D shown in Fig. 8 was produced in the same manner as in Example 1D, except that a gas-barrier polyamine-based adhesive was used instead of a urethane-based adhesive as the adhesive used in the first adhesive layer and the second adhesive layer. A standing pouch 110 was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0390] (4.1.3) Example 3D The laminate 10D shown in FIG. 8 was fabricated by using a polyethylene film having a crystallinity of 71.8%, a haze of 4.1%, and a density of 0.95 g / cm3 as a base layer instead of the polyethylene film having a crystallinity of 58.5%. 3 A standing pouch 110 was produced in the same manner as in Example 1D, except that a polyethylene film having a thickness of 100 mm was used. This polyethylene film was a longitudinally uniaxially stretched film, and one side of the film was subjected to a corona treatment. A standing pouch 110 was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0391] (4.1.4) Example 4D Laminate 10D shown in Figure 8 was produced in the same manner as in Example 1D, except for the following: instead of using the above-mentioned polyethylene film with a crystallinity of 58.5% as the substrate layer, a laminate with a thickness of 25 μm, a crystallinity of 55.9%, a haze of 5.9, and a density of 0.95 g / cm 3The polyethylene film was a biaxially stretched film, and was corona-treated on one side. Furthermore, instead of using the above-mentioned polyethylene film with a crystallinity of 58.5%, a polyethylene film with a thickness of 25 μm, a crystallinity of 71.8%, a haze of 4.1, and a density of 0.95 g / cm was used as the intermediate layer. 3 A high density polyethylene film having a thickness of 100 mm was used. This polyethylene film was a longitudinally uniaxially stretched film, and one side of the film was subjected to a corona treatment. A standing pouch 110 was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0392] (4.1.5) Example 5D The laminate 10D shown in FIG. 8 was fabricated using a polyethylene film having a thickness of 25 μm, a crystallinity of 14.8%, a haze of 21.5%, and a density of 0.950 g / cm 3 instead of the above-mentioned polyethylene film having a crystallinity of 58.5% as the intermediate layer. 3 A standing pouch 110 was produced in the same manner as in Example 1D, except that a polyethylene film having a thickness of 100 mm was used. This polyethylene film was corona-treated on one side. A standing pouch 110 was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0393] (4.1.6) Example 6D The laminate 10D shown in Fig. 8 was produced in the same manner as in Example 1D, except that no gas barrier layer was provided. A standing pouch 110 was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0394] (4.1.7) Comparative Example 1D The laminate 10D shown in FIG. 8 was fabricated by using a polyethylene film having a thickness of 25 μm, a crystallinity of 14.8%, a haze of 21.5%, and a density of 0.950 g / cm3 as a base layer instead of the polyethylene film having a crystallinity of 58.5%. 3A standing pouch was produced in the same manner as in Example 1D, except that a polyethylene film having a thickness of 100 mm was used. This polyethylene film was corona-treated on one side. A standing pouch was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0395] (4.1.8) Comparative example 2D The laminate 10D shown in FIG. 8 was fabricated using a polyethylene film having a thickness of 25 μm, a crystallinity of 14.8%, a haze of 21.5%, and a density of 0.950 g / cm instead of the above-mentioned polyethylene film having a crystallinity of 58.5% as the base layer and intermediate layer. 3 A standing pouch was produced in the same manner as in Example 1D, except that a polyethylene film having a thickness of 100 mm was used. This polyethylene film was corona-treated on one side. A standing pouch was produced in the same manner as in Example 1D, except that this laminate was used as the main film laminate and the bottom film laminate.

[0396] (4.1.9) Comparative example 3D Laminate 10D shown in Figure 8 was produced in the same manner as in Example 1D, except for the following: instead of using the above polyethylene film with a crystallinity of 58.5% as the substrate layer, a laminate with a thickness of 25 μm, a crystallinity of 14.8%, a haze of 21.5%, and a density of 0.950 g / cm 3 A polyethylene film having a thickness of 100 mm was used. One side of the polyethylene film was corona-treated. Furthermore, no gas barrier layer was provided. A standing pouch was produced in the same manner as in Example 1D, except that this laminate was used as the laminate for the main film and the laminate for the bottom film.

[0397] (4.2) Measurement and Evaluation Methods The substrate layer and intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method described above. Then, it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0398] The laminate was also evaluated for sealing property, heat resistance, visibility, puncture strength, and gas barrier property. The standing pouch was also evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, puncture strength, and gas barrier property, and the drop strength are described below.

[0399] (4.2.1) Sealing performance evaluation method The sealing performance was evaluated by the method described in (2.2.1).

[0400] (4.2.2) Heat resistance evaluation method Heat resistance was evaluated by the method explained in (1.2.2).

[0401] (4.2.3) Visibility Evaluation Method Visibility was evaluated using the method described in (1.2.3).

[0402] (4.2.4) Evaluation method for puncture strength A needle with a radius of 0.5 mm and a hemispherical tip is pressed against the laminate from the base layer side at a speed of 50 mm / min, and the maximum force until the needle penetrates is measured. This measurement was performed multiple times, and the arithmetic average of the maximum forces was obtained as the penetration strength.

[0403] (4.2.5) Gas barrier property evaluation method The gas barrier properties were evaluated by the method explained in (1.2.4).

[0404] (4.2.6) Drop Strength Evaluation Method Each of the standing pouches of Examples 1D to 6D and Comparative Examples 1D to 3D was filled with 1200 mL of cold water at 5°C to produce a packaged article. Thirty packaged articles were produced for each example. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright state). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0405] (4.3) Results The results of the above measurements and evaluations are summarized in Tables 4-1, 4-2 and 4-3 below.

[0406] [Table 4-1]

[0407] [Table 4-2]

[0408] [Table 4-3]

[0409] As shown in Tables 4-1 and 4-2, all of the laminates having a crystallinity of 35% or more in the base layer had good sealability and heat resistance. In addition, the laminates having a crystallinity of 35% or more in the base layer and intermediate layer also had excellent visibility and puncture strength. In contrast, the laminates having a crystallinity of less than 35% in the base layer had insufficient sealability, heat resistance, and visibility. In addition, as shown in Table 4-3, none of the standing pouches manufactured from the laminates having a crystallinity of 35% or more in the base layer burst, and had excellent drop resistance.

[0410] (5) Test E (5.1) Manufacturing of laminates and standing pouches (5.1.1) Example 1E 9 was produced by the following method. In this example, an anchor coat layer was further provided between the intermediate layer 8 and the gas barrier layer 5, and an inorganic compound layer and a coating layer were provided as the gas barrier layer 5.

[0411] First, an anchor coating agent, a coating liquid for forming a covering layer, and a coating liquid for forming a protective layer were prepared in the same manner as in Example 1B. In this example, the protective layer and the covering layer were formed using the same coating liquid as in Example 1B.

[0412] The substrate layer and the intermediate layer have a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.94 g / cm 3 The crystallinity shown in this example and the following examples and comparative examples was measured by the above-mentioned measuring method.

[0413] Next, one surface of the base layer was subjected to a corona treatment, and then the above-prepared protective layer forming coating solution was applied to the corona-treated surface of the base layer by a gravure coating method and dried to form a protective layer of an organic / inorganic mixture having a thickness of 0.5 μm.

[0414] Next, the other surface of the base layer was subjected to a corona treatment. Next, a water-based flexographic ink was pattern-printed on the corona-treated surface of the base layer to form a print layer.

[0415] One surface of the intermediate layer was subjected to a corona treatment. Then, the above-mentioned anchor coating agent was applied to the corona-treated surface of the intermediate layer by gravure coating to form an anchor coating layer having a thickness of 0.1 μm (in a dry state).

[0416] Next, an electron beam heating vacuum deposition apparatus was used to deposit silicon oxide (SiO x ) was formed on the anchor coat layer to a thickness of 40 nm. Next, the coating solution for forming a coating layer prepared above was applied to the inorganic compound layer to form a coating layer of an organic-inorganic mixture having a thickness of 0.3 μm (in a dry state).

[0417] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the intermediate layer opposite to the surface on which the inorganic compound layer was formed to form a first adhesive layer. The base layer and the intermediate layer were bonded together so that the printed layer and the intermediate layer faced each other with the first adhesive layer sandwiched therebetween.

[0418] Next, a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was prepared as a sealant layer. A dry lamination adhesive (urethane adhesive) was applied onto the sealant layer to form a second adhesive layer. The base layer and the sealant layer were bonded together with the second adhesive layer sandwiched between them so that the sealant layer and the coating layer faced each other.

[0419] In this manner, a laminate was produced.

[0420] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0421] (5.1.2) Example 2E Laminate 10E shown in Fig. 9 was produced in the same manner as in Example 1E, except for the following: instead of using the above-mentioned polyethylene film with a crystallinity of 58.5% as the base layer and intermediate layer, a laminate with a thickness of 25 µm, a crystallinity of 55.9%, a haze of 5.9%, and a density of 0.95 g / cm 3 A polyethylene film having a thickness of 100 mm was used. This polyethylene film had been subjected to a corona treatment on one side. A standing pouch 110 was produced in the same manner as in Example 1E, except that this laminate was used as the laminate for the main film and the laminate for the bottom film.

[0422] (5.1.3) Example 3E A laminate 10E shown in FIG. 9 was produced in the same manner as in Example 2E, except for the following: no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film with a crystallinity of 55.9% as the intermediate layer, a laminate 10E having a thickness of 25 μm, a crystallinity of 27.5%, a haze of 21.5%, and a density of 0.950 g / cm3 was used. 3A polyethylene film having a thickness of 100 mm was used. This polyethylene film had been subjected to a corona treatment on one side. A standing pouch 110 was produced in the same manner as in Example 1E, except that this laminate was used as the laminate for the main film and the laminate for the bottom film.

[0423] (5.1.4) Comparative Example 1E A laminate 10E shown in Fig. 9 was produced in the same manner as in Example 1E, except for the following: no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film with a crystallinity of 58.5% as the base layer and intermediate layer, a laminate 10E having a thickness of 25 µm, a crystallinity of 27.5%, a haze of 21.5%, and a density of 0.950 g / cm3 was used. 3 A polyethylene film having a thickness of 100 mm was used. One side of the polyethylene film was corona-treated. A standing pouch was produced in the same manner as in Example 1E, except that this laminate was used as the main film laminate and the bottom film laminate.

[0424] (5.2) Measurement and Evaluation Methods The substrate layer and intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method described above. Then, it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0425] The laminate was evaluated for sealing property, heat resistance, visibility, puncture strength, and recyclability. The standing pouch was also evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, puncture strength, and recyclability, and the drop strength are described below.

[0426] (5.2.1) Sealing performance evaluation method The sealing property (heat resistance) was evaluated by the method explained in (2.2.1).

[0427] (5.2.2) Heat resistance evaluation method Heat resistance was evaluated by the method described in (2.2.2).

[0428] (5.2.3) Visibility Evaluation Method Visibility was evaluated using the method described in (1.2.3).

[0429] (5.2.4) Evaluation method for puncture strength The puncture strength was evaluated by the method described in (4.2.4).

[0430] (5.2.5) Recyclability assessment method Recyclability was evaluated using the method described in (2.2.4).

[0431] (5.2.6) Drop Strength Evaluation Method Each of the standing pouches of Examples 1E to 3E and Comparative Example 1E was filled with 1200 mL of cold water at 5°C to produce a packaged article. For each example, 30 packaged articles were produced. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright position). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0432] (5.3) Results The results of the above measurements and evaluations are summarized in Tables 5-1 and 5-2 below.

[0433] [Table 5-1]

[0434] [Table 5-2]

[0435] As shown in Table 5-1, all of the laminates in which the crystallinity of the base layer was 35% or more were good in heat resistance, visibility, and puncture strength. In addition, the laminates in which the crystallinity of the base layer and intermediate layer was 35% or more and which were provided with a protective layer also had excellent sealing properties and further improved puncture strength. In contrast, the laminates in which the crystallinity of the base layer was less than 35% and which were not provided with a protective layer were insufficient in sealing properties, heat resistance, visibility, and puncture strength.

[0436] Furthermore, as shown in Table 5-2, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0437] (6) Test F (6.1) Manufacturing of laminates and standing pouches (6.1.1) Example 1F 10 was produced by the following method. In this example, an anchor coat layer was further provided between the intermediate layer 8 and the gas barrier layer 5, and an inorganic compound layer and a coating layer were provided as the gas barrier layer 5.

[0438] First, an anchor coating agent, a coating liquid for forming a covering layer, and a coating liquid for forming a protective layer were prepared in the same manner as in Example 1B. In this example, the protective layer and the covering layer were formed using the same coating liquid as in Example 1B.

[0439] The substrate layer has a thickness of 25 μm, a crystallinity of 58.5%, and a density of 0.950 g / cm 3 A polyethylene film having the following composition was prepared. One side of the polyethylene film was subjected to a corona treatment. The crystallinity shown in this example and the following examples and comparative examples was measured by the above-mentioned measuring method.

[0440] Next, one surface of the base layer was subjected to a corona treatment, and then the above-prepared protective layer forming coating solution was applied to the corona-treated surface of the base layer by a gravure coating method and dried to form a protective layer of an organic / inorganic mixture having a thickness of 0.5 μm.

[0441] Next, the other surface of the base layer was subjected to a corona treatment. Next, a water-based flexographic ink was pattern-printed on the corona-treated surface of the base layer to form a print layer.

[0442] Next, as the intermediate layer, a thickness of 25 μm, a crystallinity of 27.5%, and a density of 0.950 g / cm 3 A polyethylene film having the following characteristics was prepared. One side of this polyethylene film was subjected to a corona treatment.

[0443] The above-mentioned anchor coating agent was applied by gravure coating to form an anchor coating layer having a thickness of 0.1 μm (in a dry state).

[0444] Next, as an inorganic compound layer, silicon oxide (SiO x ) was formed on the anchor coat layer to a thickness of 40 nm. Next, the coating solution for forming a coating layer prepared above was applied to the inorganic compound layer to form a coating layer of an organic-inorganic mixture having a thickness of 0.3 μm (in a dry state).

[0445] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the intermediate layer opposite to the surface on which the inorganic compound layer was formed to form a first adhesive layer. The base layer and the intermediate layer were bonded together so that the printed layer and the intermediate layer faced each other with the first adhesive layer sandwiched therebetween.

[0446] Next, a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was prepared as a sealant layer. A dry lamination adhesive (urethane adhesive) was applied onto the sealant layer to form a second adhesive layer. The base layer and the sealant layer were bonded together with the second adhesive layer sandwiched between them so that the sealant layer and the coating layer faced each other.

[0447] In this manner, a laminate was produced.

[0448] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0449] (6.1.2) Example 2F Laminate 10F shown in Fig. 10 was produced in the same manner as in Example 1F, except for the following: instead of using the above-mentioned polyethylene film with a crystallinity of 58.5% as the base layer, a laminate having a thickness of 25 µm, a crystallinity of 55.9%, a haze of 21.5%, and a density of 0.95 g / cm 3 A polyethylene film having a thickness of 100 mm was used. This polyethylene film had been subjected to corona treatment on one side. A standing pouch 110 was produced in the same manner as in Example 1F, except that this laminate was used as the main film laminate and the bottom film laminate.

[0450] (6.1.3) Example 3F Laminate 10F shown in Fig. 10 was produced in the same manner as in Example 1F, except for the following: no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film having a crystallinity of 58.5% as the base layer and the above-mentioned polyethylene film having a crystallinity of 27.5% as the intermediate layer, a laminate having a thickness of 25 µm, a crystallinity of 55.9%, and a density of 0.95 g / cm3 was used. 3 A polyethylene film having a thickness of 100 mm was used. This polyethylene film had been subjected to corona treatment on one side. A standing pouch 110 was produced in the same manner as in Example 1F, except that this laminate was used as the main film laminate and the bottom film laminate.

[0451] (6.1.4) Comparative Example 1F Laminate 10F shown in FIG. 10 was produced in the same manner as in Example 1F, except for the following: no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film with a crystallinity of 58.5%, a laminate with a thickness of 25 μm, a crystallinity of 27.5%, and a density of 0.950 g / cm was used as the base layer. 3 A polyethylene film having a thickness of 25 μm, a crystallinity of 55.9%, and a density of 0.95 g / cm was used as the intermediate layer instead of the above polyethylene film having a crystallinity of 27.5%. 3 A polyethylene film having a thickness of 100 mm was used. One side of the polyethylene film was corona-treated. A standing pouch was produced in the same manner as in Example 1F, except that this laminate was used as the main film laminate and the bottom film laminate.

[0452] (6.2) Measurement and Evaluation Methods The substrate layer and intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method described above. Then, it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0453] The laminate was evaluated for sealing property, heat resistance, drop strength, and recyclability. The standing pouch was also evaluated for drop strength. The evaluation methods for sealing property, heat resistance, drop strength, and recyclability, and the evaluation method for drop strength are described below.

[0454] (6.2.1) Sealing performance evaluation method The sealing performance was evaluated by the method described in (2.2.1).

[0455] (6.2.2) Heat resistance evaluation method Heat resistance was evaluated by the method described in (2.2.2).

[0456] (6.2.3) Drop Strength Evaluation Method 1 The laminate was cut to a predetermined size, and the periphery was heat-sealed to prepare 10 bags. An opening was provided in each bag to insert the contents. The dimensions of the bags were 100 mm x 150 mm. Next, 200 mL of tap water was filled into each bag, and the opening was heat-sealed to obtain a packaged article. Next, each packaged article was stored at 5°C for one day, and then dropped 50 times from a height of 1.5 m. The ratio of the number of packaged articles whose bags were broken within 50 times to the total number of packaged articles (10) was calculated as the drop strength.

[0457] (6.2.4) Recyclability assessment method Recyclability was evaluated using the method described in (2.2.4).

[0458] (1.2.5) Drop Strength Evaluation Method 2 Each of the standing pouches of Examples 1F to 3F and Comparative Example 1F was filled with 1200 mL of cold water at 5°C to produce a packaged article. Thirty packaged articles were produced for each example. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright state). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0459] (6.3) Results The results of the above measurements and evaluations are summarized in Tables 6-1 and 6-2 below.

[0460] [Table 6-1]

[0461] [Table 6-2]

[0462] As shown in Table 6-1, all of the laminates in which the crystallinity of the base layer was 35% or more had good heat resistance while being suitable for recycling. In addition, the laminates in which the crystallinity of the base layer was 35% or more, the crystallinity of the intermediate layer was less than 35%, and the protective layer was also excellent in sealability and drop strength. In contrast, the laminates in which the crystallinity of the base layer was less than 35% and the protective layer was not provided had insufficient sealability, heat resistance, and drop strength.

[0463] Furthermore, as shown in Table 6-2, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0464] (7) Test G (7.1) Manufacturing of laminates and standing pouches (7.1.1) Example 1G 11 was produced by the following method. In this example, an anchor coat layer was further provided between the intermediate layer 8 and the inorganic compound layer 5.

[0465] First, a coating liquid for forming an anchor coat layer and a coating liquid for forming a cover layer were prepared in the same manner as in Example 1B. In addition, a solution of polyamideimide resin in an organic solvent (non-volatile component concentration: 5% by mass) was prepared as a coating liquid for forming a protective layer.

[0466] The substrate layer and the intermediate layer have a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.950 g / cm 3 A polyethylene film having the following formula was prepared. This polyethylene film has a three-layer structure (HDPE / MDPE / HDPE) and is subjected to corona treatment on both sides. The crystallinity shown in this example and the examples and comparative examples described below was measured by the above-mentioned measurement method.

[0467] Next, the protective layer forming coating solution prepared above was applied by gravure coating to one side of the base layer that had been subjected to the corona treatment, and dried to form a protective layer having a thickness of 0.5 μm. Subsequently, a water-based flexographic ink was pattern-printed on the other side of the base layer that had been subjected to the corona treatment to form a printing layer.

[0468] Next, the above-mentioned anchor coating agent was applied by gravure coating to one of the corona-treated surfaces of the intermediate layer to form an anchor coating layer having a thickness of 0.1 μm (in a dry state).

[0469] Next, as an inorganic compound layer, a transparent silicon oxide (SiO x A vapor-deposited film having a thickness of 40 nm was formed on the anchor coat layer. The O / Si ratio of the vapor-deposited film was set to 1.8 by adjusting the type of material used for vapor deposition.

[0470] Next, the coating solution for forming a coating layer prepared above was applied to the inorganic compound layer to form a coating layer consisting of an organic / inorganic mixture and having a thickness of 0.3 μm (in a dry state).

[0471] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the intermediate layer opposite to the surface on which the inorganic compound layer was formed to form a first adhesive layer. The base layer and the intermediate layer were bonded together so that the printed layer and the intermediate layer faced each other with the first adhesive layer sandwiched therebetween.

[0472] Next, a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was prepared as a sealant layer. A dry lamination adhesive (urethane adhesive) was applied onto the sealant layer to form a second adhesive layer. The base layer and the sealant layer were bonded together with the second adhesive layer sandwiched between them so that the sealant layer and the coating layer faced each other.

[0473] In this manner, a laminate was produced.

[0474] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0475] (7.1.2) Example 2G The laminate 10G shown in Fig. 11 was produced in the same manner as in Example 1G, except that the thickness of the protective layer was changed from 0.5 μm to 1 μm. A standing pouch 110 was produced in the same manner as in Example 1G, except that this laminate was used as the main film laminate and the bottom film laminate.

[0476] (7.1.3) Example 3G The laminate 10G shown in Fig. 11 was produced in the same manner as in Example 1G, except that the thickness of the protective layer was changed from 0.5 μm to 3 μm. A standing pouch 110 was produced in the same manner as in Example 1G, except that this laminate was used as the main film laminate and the bottom film laminate.

[0477] (7.1.4) Example 4G The laminate 10G shown in FIG. 11 was produced in the same manner as in Example 1G, except for the following. That is, no protective layer was provided. Furthermore, instead of using the polyethylene film with a crystallinity of 58.5% as the intermediate layer, a polyethylene film with a thickness of 25 μm, a crystallinity of 27.6%, and a haze of 21.5% was used. A standing pouch 110 was produced in the same manner as in Example 1G, except that this laminate was used as the laminate for the main film and the laminate for the bottom film.

[0478] (7.1.5) Comparative Example 1G The laminate 10G shown in FIG. 11 was produced in the same manner as in Example 1G, except for the following. That is, no protective layer was provided. Furthermore, instead of using the polyethylene film with a crystallinity of 58.5% as described above, a polyethylene film with a thickness of 25 μm and a crystallinity of 27.6% was used as the base layer and intermediate layer. A standing pouch was produced in the same manner as in Example 1G, except that this laminate was used as the main film laminate and the bottom film laminate.

[0479] (7.2) Measurement and Evaluation Methods The substrate layer and intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method described above. Then, it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0480] The laminate was evaluated for sealing property, heat resistance, visibility, puncture strength, and recyclability. The standing pouch was also evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, puncture strength, and recyclability, and the drop strength are described below.

[0481] (7.2.1) Sealing performance evaluation method The sealing performance was evaluated by the method described in (1.2.1).

[0482] (7.2.2) Heat resistance evaluation method Heat resistance was evaluated by the method described in (2.2.2).

[0483] (7.2.3) Visibility Evaluation Method Visibility was evaluated using the method described in (1.2.3).

[0484] (7.2.4) Evaluation method for puncture strength The puncture strength was evaluated by the method described in (4.2.4).

[0485] (7.2.5) Recyclability assessment method Recyclability was evaluated using the method described in (2.2.4).

[0486] (7.2.6) Drop Strength Evaluation Method Each of the standing pouches of Examples 1G to 4G and Comparative Example 1G was filled with 1200 mL of cold water at 5°C to manufacture packaged articles. Thirty packaged articles were manufactured for each example. The packaged articles were dropped from a height of 100 cm above the ground with the bottom film facing down (upright position). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0487] (7.3) Results The results of the above measurements and evaluations are summarized in Tables 7-1 and 7-2 below.

[0488] [Table 7-1]

[0489] [Table 7-2]

[0490] As shown in Table 7-1, all of the laminates in which the crystallinity of the base layer was 35% or more had good heat resistance and visibility while being suitable for recycling. In addition, the laminates in which the crystallinity of the base layer and intermediate layer was 35% or more and which had a protective layer also had excellent sealing properties and puncture strength. In contrast, the laminates in which the crystallinity of the base layer was less than 35% and which did not have a protective layer had insufficient sealing properties, heat resistance, visibility, and puncture strength.

[0491] Furthermore, as shown in Table 7-2, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0492] (8) Test H (8.1) Manufacturing of laminates and standing pouches (8.1.1) Example 1H 12 was produced by the following method. In this example, an anchor coat layer was further provided between the intermediate layer 8 and the inorganic compound layer 5.

[0493] First, a coating liquid for forming an anchor coat layer and a coating liquid for forming a cover layer were prepared in the same manner as in Example 1B. In addition, a solution of polyamideimide resin in an organic solvent (non-volatile component concentration: 5% by mass) was prepared as a coating liquid for forming a protective layer.

[0494] A polyethylene film having a thickness of 25 μm, a crystallinity of 58.5%, and a haze of 1.6% was prepared as the substrate layer. This polyethylene film was subjected to corona treatment on both sides. The crystallinity shown in this example and the examples and comparative examples described below was measured by the above-mentioned measurement method.

[0495] Next, the protective layer forming coating solution prepared above was applied by gravure coating to one side of the base layer that had been subjected to the corona treatment, and dried to form a protective layer having a thickness of 0.5 μm. Subsequently, a water-based flexographic ink was pattern-printed on the other side of the base layer that had been subjected to the corona treatment to form a printing layer.

[0496] As the intermediate layer, a polyethylene film having a thickness of 25 μm, a crystallinity of 27.6%, and a haze of 21.5% was prepared. This polyethylene film was subjected to corona treatment on both sides. Next, the above-mentioned anchor coating agent was applied by gravure coating to one of the corona-treated sides of the intermediate layer to form an anchor coating layer having a thickness of 0.1 μm (in a dry state).

[0497] Next, as an inorganic compound layer, a transparent silicon oxide (SiO xA vapor-deposited film having a thickness of 40 nm was formed on the anchor coat layer. The O / Si ratio of the vapor-deposited film was set to 1.8 by adjusting the type of material used for vapor deposition.

[0498] Next, the coating solution for forming a coating layer prepared above was applied to the inorganic compound layer to form a coating layer consisting of an organic / inorganic mixture and having a thickness of 0.3 μm (in a dry state).

[0499] Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the intermediate layer opposite to the surface on which the inorganic compound layer was formed to form a first adhesive layer. The base layer and the intermediate layer were bonded together so that the printed layer and the intermediate layer faced each other with the first adhesive layer sandwiched therebetween.

[0500] Next, a linear low-density polyethylene resin (LLDPE) film (thickness 60 μm) was prepared as a sealant layer. A dry lamination adhesive (urethane adhesive) was applied onto the sealant layer to form a second adhesive layer. The base layer and the sealant layer were bonded together with the second adhesive layer sandwiched between them so that the sealant layer and the coating layer faced each other.

[0501] In this manner, a laminate was produced.

[0502] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0503] (8.1.2) Example 2H The laminate 10H shown in Fig. 12 was produced in the same manner as in Example 1H, except that the thickness of the protective layer was changed from 0.5 μm to 1 μm and no covering layer was provided. A standing pouch 110 was produced in the same manner as in Example 1H, except that this laminate was used as the main film laminate and the bottom film laminate.

[0504] (8.1.3) Example 3H The laminate 10H shown in Fig. 12 was produced in the same manner as in Example 1H, except that the thickness of the protective layer was changed from 0.5 μm to 3 μm. A standing pouch 110 was produced in the same manner as in Example 1H, except that this laminate was used as the main film laminate and the bottom film laminate.

[0505] (8.1.4) Example 4H The laminate 10H shown in FIG. 12 was produced in the same manner as in Example 1H, except for the following. That is, no protective layer was provided. Furthermore, instead of using the polyethylene film with a crystallinity of 27.6% as the intermediate layer, a polyethylene film with a thickness of 25 μm, a crystallinity of 58.5%, and a haze of 1.6% was used. This polyethylene film was subjected to corona treatment on both sides. A standing pouch 110 was produced in the same manner as in Example 1H, except that this laminate was used as the laminate for the main film and the laminate for the bottom film.

[0506] (8.1.5) Comparative Example 1H The laminate 10H shown in FIG. 12 was produced in the same manner as in Example 1H, except for the following. That is, no protective layer was provided. Furthermore, instead of using the above-mentioned polyethylene film having a crystallinity of 58.5%, a polyethylene film having a thickness of 25 μm, a crystallinity of 27.6%, and a haze of 21.5% was used as the base layer. This polyethylene film was subjected to corona treatment on both sides. Furthermore, instead of using the above-mentioned polyethylene film having a crystallinity of 27.6%, a polyethylene film having a thickness of 25 μm, a crystallinity of 58.5%, and a haze of 1.6% was used as the intermediate layer. This polyethylene film was subjected to corona treatment on both sides. A standing pouch was produced in the same manner as in Example 1H, except that this laminate was used as the laminate for the main film and the laminate for the bottom film.

[0507] (8.2) Measurement and Evaluation Methods The substrate layer and intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method described above. Then, it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0508] The laminate was evaluated for sealing property, heat resistance, visibility, drop strength, and recyclability. The standing pouch was also evaluated for drop strength. The methods for evaluating the sealing property, heat resistance, visibility, drop strength, and recyclability, and the drop strength are described below.

[0509] (8.2.1) Sealing performance evaluation method The sealing performance was evaluated by the method described in (1.2.1).

[0510] (8.2.2) Visibility Evaluation Method Visibility was evaluated using the method described in (1.2.2).

[0511] (8.2.3) Drop Strength Evaluation Method The drop strength was evaluated by the method described in (6.2.3).

[0512] (8.2.4) Recyclability assessment method Recyclability was evaluated using the method described in (2.2.4).

[0513] (8.2.5) Drop Strength Evaluation Method Each of the standing pouches of Examples 1H to 4H and Comparative Example 1H was filled with 1200 mL of cold water at 5°C to produce a packaged article. For each example, 30 packaged articles were produced. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright position). The packaged articles that underwent the drop test were checked for the presence or absence of rupture of the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0514] (8.3) Results The results of the above measurements and evaluations are summarized in Tables 8-1 and 8-2 below.

[0515] [Table 8-1]

[0516] [Table 8-2]

[0517] As shown in Table 8-1, all of the laminates in which the crystallinity of the base layer was 35% or more had good heat resistance and visibility while being suitable for recycling. In addition, the laminates in which the crystallinity of the base layer was 35% or more, the crystallinity of the intermediate layer was less than 35%, and the protective layer was also excellent in sealability and drop strength. In contrast, the laminates in which the crystallinity of the base layer was less than 35% and the protective layer was not provided had insufficient sealability, heat resistance, and visibility.

[0518] Furthermore, as shown in Table 8-2, none of the standing pouches manufactured from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance.

[0519] (9) Test I (9.1) Manufacturing of laminates and standing pouches (9.1.1) Example 1I A laminate (not shown) was produced by the following method. First, the substrate layer and the intermediate layer had a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.94 g / cm 3 The crystallinity shown in this example and the following examples and comparative examples was measured by the above-mentioned measuring method.

[0520] Next, a water-based flexographic ink was pattern-printed on the base layer to form a print layer. Then, a dry lamination adhesive (urethane adhesive) was applied to one surface of the intermediate layer to form a first adhesive layer. With the first adhesive layer sandwiched between them, the surface of the base layer facing the printed layer and the intermediate layer were bonded together.

[0521] Next, a linear low-density polyethylene resin (LLDPE) film (thickness: 60 μm) was prepared as a sealant layer, and an aluminum vapor deposition layer was formed on the sealant layer to a thickness of 50 nm.

[0522] Next, a dry lamination adhesive (urethane adhesive) was applied onto the aluminum vapor deposition layer of the sealant layer to form a second adhesive layer. With the second adhesive layer sandwiched between them, the aluminum vapor deposition layer of the sealant layer was attached to the intermediate layer side of the laminate of the base layer and the intermediate layer.

[0523] In this manner, a laminate was produced.

[0524] This laminate was used as the main film laminate and the bottom film laminate, and two rolls of the main film laminate and a roll of the bottom film laminate were placed in a bag making machine. The bag making machine was then operated to produce a standing pouch 110 that was 240 mm long, 160 mm wide, had a seal width of 5 mm, and a bottom seal fold width of 40 mm, and could accommodate 1200 mL of content.

[0525] (9.1.2) Example 2I A laminate was produced in the same manner as in Example 1I, except for the following: A polyamine-based gas barrier adhesive was used instead of the dry lamination adhesive (urethane adhesive). A standing pouch 110 was produced in the same manner as in Example 1I, except that this laminate was used as the main film laminate and the bottom film laminate.

[0526] (9.1.3) Example 3I A laminate was produced in the same manner as in Example 1I, with the following exceptions: an intermediate layer had a thickness of 25 μm, a crystallinity of 58.5%, a haze of 1.6%, and a density of 0.94 g / cm 3 Instead of using a polyethylene film having a thickness of 25 μm, a crystallinity of 27.5%, a haze of 21.5%, and a density of 0.950 g / cm 3 A standing pouch 110 was produced in the same manner as in Example 1I, except that this laminate was used as the main film laminate and the bottom film laminate.

[0527] (9.1.4) Example 4I A laminate was produced in the same manner as in Example 3I, except for the following: A polyamine-based gas barrier adhesive was used instead of the dry lamination adhesive (urethane-based adhesive). A standing pouch 110 was produced in the same manner as in Example 1I, except that this laminate was used as the main film laminate and the bottom film laminate.

[0528] (9.2) Measurement and Evaluation Methods The substrate layer and intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method described above. Then, it was examined whether the diffraction pattern obtained by this measurement had a sharp diffraction peak corresponding to the (110) plane.

[0529] As a result, it was confirmed that the diffraction patterns obtained by the above measurement for both the base layer and intermediate layer used in the production in Examples 1I and 2I had a sharp diffraction peak corresponding to the (110) plane. In addition, it was confirmed that the diffraction patterns obtained by the above measurement for the base layer used in the production in Examples 3I and 4I had a sharp diffraction peak corresponding to the (110) plane, whereas it was not confirmed that the diffraction patterns obtained by the above measurement for the intermediate layer used in the production in Examples 3I and 4I had a sharp diffraction peak corresponding to the (110) plane.

[0530] The standing pouch was also evaluated for drop strength. The method for evaluating drop strength is described below.

[0531] (9.2.1) Drop Strength Evaluation Method Each of the standing pouches of Examples 1I to 4I was filled with 1200 mL of cold water at 5°C to produce a packaged article. For each example, 30 packaged articles were produced. The packaged article was dropped from a height of 100 cm above the ground with the bottom film facing down (upright position). The packaged articles that underwent the drop test were checked for the presence or absence of rupture at the intersection seal portion (point seal portion). Cases in which some packaged articles ruptured were marked as "Yes", and cases in which no packaged articles ruptured were marked as "No".

[0532] (9.3) Result The results of the above evaluations are summarized in Table 9 below.

[0533] [Table 9]

[0534] As shown in Table 9, none of the standing pouches produced from the laminates in which the crystallinity of the base layer was 35% or more burst, and they had excellent drop resistance. [Explanation of symbols]

[0535] 1...base material layer, 2...sealant layer, 3...adhesive layer, 3A...first adhesive layer, 3B...second adhesive layer, 4...printed layer, 5...gas barrier layer (inorganic compound layer), 6...protective layer, 7...coating layer, 8...intermediate layer, 10A1...laminate, 10A2...laminate, 10B...laminate, 10C...laminate, 10D...laminate, 10E...laminate, 10F...laminate, 10G...laminate, 10H...laminate, 100...packaged article, 110...standing pouch, 111A...main body film, 111B...main body film, 112...bottom film, 120...contents, HS1...heat sealed portion, HS2A...heat sealed portion, HS2B...heat sealed portion, HS3...heat sealed portion, MF...mountain fold portion.

Claims

1. A pair of a main film and a bottom film is provided, Each of the pair of main films and the bottom film includes a base layer containing polyethylene, a sealant layer containing polyethylene provided on the base layer, and an adhesive layer interposed between the base layer and the sealant layer, In each of the pair of main films and the bottom film, the base layer has a crystallinity of 35% or more, which is the ratio of a crystalline peak area to a total peak area measured by a parallel beam method of X-ray diffraction at a diffraction angle range of 10° to 30°; At least one of the pair of body films and the bottom film comprises a laser light absorbing layer.

2. A standing pouch as described in claim 1, wherein at least one of the pair of main body films and the bottom film including the laser light absorbing layer includes a half-cut portion.

3. A standing pouch as described in claim 1, wherein the laser light absorbing layer is a nylon film formed together with the base layer or the sealant layer by coextrusion.

4. A standing pouch as described in claim 1, wherein the laser light absorbing layer is the sealant layer.

5. A standing pouch as described in claim 1, wherein the laser light absorbing layer is a printed layer formed from a laser light absorbing ink.

6. 2. The standing pouch according to claim 1, wherein at least one of the pair of main films and the bottom film further comprises an intermediate layer containing polyethylene and interposed between the base layer and the sealant layer.

7. A standing pouch as described in claim 6, wherein the laser light absorbing layer is a nylon film formed together with the intermediate layer by coextrusion.

8. A standing pouch as described in claim 6, wherein the laser light absorbing layer is the intermediate layer.

9. 7. The standing pouch according to claim 6, wherein the intermediate layer has a degree of crystallinity, which is the ratio of a crystalline peak area to a total peak area, of 35% or more when measured by a parallel beam method of X-ray diffraction at a diffraction angle range of 10° to 30°.

10. 7. The standing pouch according to claim 6, wherein the intermediate layer has a degree of crystallinity, which is the ratio of a crystalline peak area to a total peak area, of less than 35% when measured by a parallel beam method of X-ray diffraction in a diffraction angle range of 10° to 30°.

11. The standing pouch according to claim 1 , wherein at least one of the pair of main films and the bottom film further comprises a protective layer as an outermost layer facing the sealant layer with the base layer sandwiched therebetween.

12. The standing pouch according to claim 11 , wherein the protective layer comprises a thermosetting resin.

13. The standing pouch according to claim 1 , wherein the base layer of at least one of the pair of main films and the bottom film is a biaxially oriented film.

14. The standing pouch according to claim 1 , wherein the base layer of at least one of the pair of main films and the bottom film is a uniaxially stretched film.

15. The standing pouch according to claim 1 , wherein at least one of the pair of main films and the bottom film further comprises a gas barrier layer interposed between the base layer and the sealant layer.

16. The standing pouch according to claim 1 , wherein the adhesive layer in at least one of the pair of main films and the bottom film has gas barrier properties.

17. 2. The standing pouch according to claim 1, wherein the sealant layer is white in at least one of the pair of body films and the bottom film.

18. 2. The standing pouch according to claim 1, wherein the proportion of polyethylene in the film in at least one of the pair of main films and the bottom film is 90% by mass or more.

19. The standing pouch according to claim 1, wherein at least one of the pair of main films and the bottom film further includes an intermediate layer containing polyethylene and interposed between the base material layer and the sealant layer, and includes a first adhesive layer and a second adhesive layer as the adhesive layer, the first adhesive layer being interposed between the base material layer and the intermediate layer, and the second adhesive layer being interposed between the intermediate layer and the sealant layer.

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