Packaging bags

Abstract

The present invention provides a packaging bag that, despite being made of a single material and being easily recyclable, does not have its channel formation portion ruptured by heat during the molding of the channel during manufacturing, allowing for high yield production, and enables smooth dispensing of contents through the formed channel. [Solution] A two-layer laminate was prepared by dry lamination using a two-component curing urethane adhesive to laminate a 25 μm thick biaxially oriented high-density polyethylene film as a polyolefin resin layer and a 120 μm thick linear low-density polyethylene as a sealant layer. Subsequently, a flow channel was molded using the laminate by compressed air molding under predetermined preheating temperature and molding pressure conditions. Furthermore, a standing pouch of a predetermined size was created using the laminate after the flow channel molding.

Description

Technical Field

[0001] The present invention relates to a packaging bag formed of a synthetic resin film.

Background Art

[0002] Conventionally, packaging bags using synthetic resin films have been known as packaging bags for packaging and storing various liquids such as foods, pharmaceuticals, cosmetics, and detergents. In addition, some of such packaging bags are provided with a spout to facilitate pouring out the contents (for example, Patent Document 1).

[0003] In recent years, in order to facilitate the recycling of packaging bags made of the above-described synthetic resin films, monomaterialization, in which the materials used for the packaging bag are a combination of resins of the same family, has been promoted (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0005] However, the above-described conventional monomaterialized packaging bag with a spout made of a synthetic resin film has a problem that the yield during production is poor. That is, the flow path of the spout of the packaging bag is formed by thermoforming the packaging material, but when the material of the packaging bag is made monomaterial, heat-resistant materials can no longer be used as different types of materials, which leads to a decrease in the heat resistance of the packaging material, and the situation where the flow path of the spout is broken by heat frequently occurs during the molding of the spout in the manufacturing process.

[0006] The object of the present invention is to solve the problems of the conventional packaging bags described above, and to provide a packaging bag in which the constituent material is monomaterial and easy to recycle, yet the flow channel formation part does not tear due to heat during the molding of the flow channel during manufacturing, allowing for high yield production, and the contents can be smoothly dispensed through the formed flow channel. [Means for solving the problem]

[0007] The invention described in claim 1 of the present invention is a synthetic resin packaging bag having a spout for extracting contents, formed by laminating two laminate laminates, each made of at least one polyolefin resin layer and a sealant layer made of polyolefin resin, with the sealant layers of the two laminates overlapping with the sealant layers facing inward and the edges heat-sealed, wherein a channel is formed in the spout by molding the laminate laminate to bulge outward, and at least one of the polyolefin resin layers constituting the laminate laminate is a biaxially oriented film.

[0008] The invention described in claim 2 is characterized in that, in the invention described in claim 1, two polyolefin resin layers are provided.

[0009] The packaging bag according to claim 3 is characterized in that, in the invention according to claim 1 or 2, only the polyolefin resin layer adjacent to the sealant layer via an adhesive layer is a biaxially oriented film. The adhesive layer referred to herein also includes a resin layer consisting of a dry laminating adhesive and a resin solidified after melt extrusion, which substantially adheres the sealant layer and the polyolefin resin layer (biaxially oriented film).

[0010] The invention described in claim 4 is characterized in that, in the invention described in claim 1 or 2, the polyolefin resin is polyethylene.

[0011] The invention described in claim 5 is characterized in that, in the invention described in claim 1 or 2, the inner diameter of the flow path is 5 mm or more and 15 mm or less.

[0012] The invention described in claim 6 is characterized in that, in the invention described in claim 1 or 2, a cylindrical auxiliary member constituting a part of the flow path is arranged within the flow path.

[0013] The invention described in claim 7 is characterized in that, in the invention described in claim 1 or 2, the flow path of the spout is formed by compressed air molding or plug molding. [Effects of the Invention]

[0014] The packaging bag described in claim 1 is made of a laminated material formed by laminating a polyolefin resin layer and a sealant layer made of a polyolefin resin, and is monomaterialized and easy to recycle, yet can be molded during manufacturing without tearing the flow path of the spout, and can be manufactured with good yield.

[0015] The packaging bag described in claim 2 has two layers of polyolefin resin in the laminate, which makes it easier to adjust properties such as strength and barrier properties.

[0016] The packaging bag described in claim 3 can be constructed at a lower cost because only the polyolefin resin layer adjacent to the sealant layer is a biaxially oriented film, and unstretched films can be used for the other polyolefin resin layers.

[0017] The packaging bag described in claim 4 can be recycled more easily because the polyolefin resin is polyethylene, and it can be manufactured at a very low cost.

[0018] The packaging bag according to Claim 5 has the inner diameter of the flow path adjusted to a predetermined numerical range, so that the extraction of the contents is smoother, and breakage during molding of the flow path at the spout can be prevented with higher accuracy, enabling production with an extremely high yield.

[0019] In the packaging bag according to Claim 6, a cylindrical auxiliary member constituting a part of the flow path is disposed inside the flow path, so that the extraction of the contents is extremely smooth.

[0020] In the packaging bag according to Claim 7, since the flow path of the spout is molded by air pressure forming or plug forming, breakage during molding of the flow path can be prevented with extremely high accuracy, and the packaging bag can be manufactured with an extremely high yield. [Brief Description of the Drawings]

[0021] [Figure 1] It is a front view of a packaging bag (standing pouch with auxiliary member). [Figure 2] It is a vertical cross-sectional view of the spout installation portion of the packaging bag (cross-sectional view taken along line A-A in Fig. 1). [Figure 3] It is a cross-sectional view of a laminate constituting the packaging bag. [Figure 4] It is a cross-sectional view of a laminate constituting the packaging bag. [Figure 5] It is a front view of a packaging bag (standing pouch with groove-shaped ribs). [Figure 6] It is a vertical cross-sectional view of the spout installation portion of the packaging bag (cross-sectional view taken along line A-A in Fig. 5). [Modes for Carrying Out the Invention]

[0022] Hereinafter, embodiments of the packaging bag according to the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. In the respective drawings, common parts may be denoted by the same reference numerals and description thereof may be omitted. In addition, the scale of each member in each drawing may differ from the actual one.

[0023] Furthermore, in this specification and drawings, deviations in directions such as orthogonal are permitted to the extent that they do not impair the function and effect of the embodiment. The shape of the corners is not limited to right angles, but may be rounded in an arc shape. Orthogonal directions may include approximately orthogonal directions.

[0024] <First Embodiment> Figure 1 shows a packaging bag (pouch) according to the first embodiment. The packaging bag 1 is formed from a pair of laminated bodies 2 on the front and back, and has a spout 14 and a flow path 15. Figure 2 shows a vertical cross-section of the portion of the spout 14 where the flow path 15 is installed. The packaging bag according to the present invention is not limited to the pouch shown in Figure 1, and may have various shapes other than a pouch, such as a two-sided bag, a three-sided bag, or a gusseted bag. It is preferable that the packaging bag be a standing pouch (also called a self-standing pouch) because it can be filled with a large amount of contents and has good productivity.

[0025] On the other hand, Figure 3 shows an example of a laminated structure 2 that constitutes the packaging bag 1. The laminated structure 2 can consist of at least one polyolefin resin layer (biaxially oriented) 2A, an adhesive layer 2B, and a sealant layer 2C, laminated in that order. Alternatively, as shown in Figure 4, the laminated structure 2 can consist of a polyolefin resin layer (uniaxially oriented) 2D, an adhesive layer 2B, a polyolefin resin layer (biaxially oriented) 2A, an adhesive layer 2B, and a sealant layer 2C, laminated in that order. Furthermore, the laminated structure can consist of three or more polyolefin resin layers (each layer bonded together with adhesive), an adhesive layer, and a sealant layer, laminated in that order, including at least one biaxially oriented polyolefin resin layer. In these laminated structures 2, the sealant layer 2C is laminated to the polyolefin resin layer (biaxially oriented) 2A via the adhesive layer 2B. In addition to the polyolefin resin layer and sealant layer, the laminate 2 may also have a printed layer, barrier layer, anchor coat layer, vapor-deposited layer, functional layer, surface coat layer, etc. laminated to it.

[0026] In addition, when using two polyolefin resin layers, the biaxially stretched polyolefin resin layer can be positioned on the outermost side, or it can be positioned inside the surface layer so as to be adjacent to the sealant layer. However, as shown in Figure 4, positioning the biaxially stretched polyolefin resin layer 2A inside the uniaxially stretched polyolefin resin layer (or unstretched polyolefin resin layer) 2D is preferable because it makes it possible to prevent breakage of the outlet channel during molding with extremely high precision.

[0027] Furthermore, while the stretching ratio of the biaxially oriented polyolefin resin layer (such as a biaxially oriented polyolefin resin film) contained within the polyolefin resin layer is not particularly limited, it is preferable that both the longitudinal and widthwise stretching ratios be between 2 and 10 times, as this results in good handling and heat resistance of the laminate.

[0028] On the other hand, examples of polyolefin resins that constitute the polyolefin resin layers (2A, 2D) include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (L-LDPE), low-density polyethylene (LDPE), and polypropylene (PP).

[0029] Furthermore, in recent years, there has been a growing demand for environmentally friendly materials, and it is also preferable to use a polyolefin resin containing biomass-derived resin components as the polyolefin resin constituting the polyolefin resin layer 2A. The biomass-derived polyolefin resin referred to here is a polyolefin resin manufactured using biomass-derived ethanol as a raw material. In particular, a polyolefin resin made from biomass-derived fermented ethanol obtained from plant materials such as corn, sugarcane, beets, and manioc is preferably used. Additionally, recycled resin can be used as the polyolefin resin constituting the polyolefin resin layers (2A, 2D).

[0030] Furthermore, the thickness of the polyolefin resin layers (2A, 2D) (or total thickness if there are multiple layers) is not limited, but for example, a thickness of 10 μm or more and 60 μm or less is preferable because it results in good strength and handling properties for the packaging bag.

[0031] On the other hand, the adhesive layer 2B can be formed, for example, by a sandwich lamination method using polyethylene resin or a dry lamination method using an adhesive. Alternatively, these methods may be used in combination. Suitable adhesives include two-component curing urethane adhesives, polyester urethane adhesives, polyether urethane adhesives, acrylic adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, and the like.

[0032] Furthermore, from the viewpoint of adhesion, it is preferable to use one of the following adhesives: a two-component curing urethane adhesive, a polyester urethane adhesive, a polyether urethane adhesive, or an epoxy adhesive, with a two-component curing urethane adhesive being particularly preferred. From the viewpoint of environmental considerations, it is also preferable to use a two-component curing urethane adhesive that contains plant-derived components or is a solvent-free type.

[0033] On the other hand, when a printed layer (not shown) is provided on the laminate 2, the printed layer can be formed by printing and coating an ink material onto the surface of the base layer. This makes the printed layer visible from the outside of the packaging bag. The printed layer can be mainly composed of one or more types of ordinary ink vehicles.

[0034] Furthermore, the printed layer can be formed by preparing an ink composition by adding one or more additives such as plasticizers, stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, and fillers to the main raw materials such as the ink vehicle, and further adding colorants such as dyes and pigments, and thoroughly mixing them with a solvent, diluent, etc. The printed layer can then be formed using this ink composition. Moreover, using this ink composition, a desired printed pattern consisting of characters, figures, symbols, patterns, etc. can be formed using printing methods such as gravure printing, offset printing, letterpress printing, screen printing, transfer printing, and flexographic printing.

[0035] On the other hand, the laminate 2 may also be provided with a barrier layer (not shown). This barrier layer provides the packaging bag with high water vapor barrier and gas barrier properties to prevent the enclosed contents from coming into contact with moisture and oxygen. As such a barrier layer, a vapor-deposited film obtained by depositing a metal or metal oxide onto a resin film, or a resin layer having barrier properties such as an ethylene vinyl alcohol copolymer can be used.

[0036] As the vapor-deposited film for forming the barrier layer, polyethylene films having a metal vapor-deposited layer such as aluminum or an inorganic vapor-deposited layer such as alumina or silica, or polypropylene films having a metal vapor-deposited layer such as aluminum or an inorganic vapor-deposited layer such as alumina or silica can be used.

[0037] Furthermore, the laminate 2 may also be provided with an anchor coat layer (not shown). This anchor coat layer is a thin film layer for improving the adhesion of the adhesive layer. For example, the anchor coat layer can be formed as a thin film layer by coating and heat-drying an aqueous dispersion of a polyolefin copolymer resin containing an unsaturated carboxylic acid or its anhydride. In particular, when laminating a barrier layer and a substrate layer using a polyethylene resin sandwich lamination method, it is preferable to use a barrier layer that has the anchor coat layer laminated on it beforehand.

[0038] On the other hand, a sealant film made of polyolefin resin can be used as the sealant layer 2C of the laminate 2. The sealant layer 2C can be laminated with an adhesive layer 2B sandwiched between it and the polyolefin resin layer 2A.

[0039] Furthermore, the sealant layer 2C can be formed from a mixture of biomass-derived polyolefin resin and petroleum-derived polyolefin resin, or it can be formed using either of these polyolefin resins alone. Among these, forming it using only biomass-derived polyolefin resin is preferable from an environmental perspective.

[0040] Furthermore, the sealant layer 2C may consist of two or more layers. When the sealant layer 2C is composed of multiple layers, a laminated film with a three-layer structure is preferably used as the sealant layer 2C, which is formed by sequentially laminating an inner sealant layer that is on the inside of the packaging bag, an intermediate sealant layer, and a base material side sealant layer that is in contact with the base material film. The intermediate sealant layer can also be formed from recycled polyolefin resin.

[0041] The thickness of the sealant layer 2C is not particularly limited, but can be 15 μm or more and 300 μm or less, and preferably 25 μm or more and 200 μm or less.

[0042] Furthermore, as shown in Figure 1, the packaging bag 1 can be composed of a pair of laminated bodies 2,2 (front and back body materials) having the same planar shape, and a bottom film 3 that is folded in half along the fold line 3A. That is, the pair of laminated bodies 2,2 can be overlapped so that the sealant layers 2C,2C described above are on the inside, and the edges can be heat-sealed to form a bag (pouch).

[0043] In the packaging bag 1 shown in Figure 1, the bottom film 3 is folded so that the fold line 3A faces inward, forming it between the lower parts of a pair of laminate layers 2,2. The pair of laminate layers 2,2 and the bottom film 3 are stacked in this way, and the periphery of the pair of laminate layers 2,2 is heat-sealed, except for the filling opening 13, thereby forming a single pouch.

[0044] The packaging bag 1 formed as described above has side seal portions 1B, 1B and a bottom seal portion 1A. The side seal portions 1B, 1B are formed by heat sealing the left and right side edges. The bottom seal portion 1A is formed by heat sealing the lower sides of each laminate stack 2, 2 and the bottom film 3 at the lower edges of the opposing surfaces. In Figure 1, the area of ​​the seal portion is hatched.

[0045] Furthermore, an unsealed portion 15A is provided between the upper corner of the packaging bag 1, i.e., the side seal portion 1B and the top edge 14E, where the pair of laminate layers 2,2 are not heat-sealed. The flow path 15 of the spout 14 is provided at the upper edge of one side (left side in Figure 1) of the unsealed portion 15A, so as to be inclined upward at a predetermined angle from the center in the width direction outwards (inclined at approximately 40° with respect to the width direction of the packaging bag 1). The portion of the unsealed portion 15A excluding the flow path 15 constitutes the space 1C in which the contents are contained.

[0046] Furthermore, a spout 14 is provided on the upper edge of one side (left side in Figure 1) of the packaging bag 1. The spout 14 is composed of channel-forming seal portions 18A and 18B that form both sides of the channel 15 after the packaging bag 1 has been opened, a channel-sealing seal portion 18C that seals the channel 15 before opening, and a pull tab 16 that serves as a handle during opening. The spout 14 is formed by heat-sealing laminate layers 2, 2 together continuously from the top to the bottom of one side edge seal portion 1B.

[0047] Furthermore, the flow path 15 provided in the spout 14 constitutes the flow path of the spout 14 (i.e., the space through which the contents flow when the contents are dispensed). The flow path 15 is formed by heat-sealing a pair of laminated bodies 2, 2, each molded to bulge outwards in a portion (the portion that forms the flow path 15), with flow path forming seal portions 18A and 18B spaced apart on either side of the molded portion. In other words, the flow path 15 of the spout 14 is formed by molding a pair of laminated bodies 2, 2, each with a portion (the portion that forms the flow path 15) bulging outwards (outwards from the surface of the laminated body 2), and then heat-sealing the pair of molded laminated bodies 2, 2.

[0048] As described above, the method for forming a portion of the pair of laminated bodies 2,2 to form the flow path 15 of the packaging bag 1 is not particularly limited, but methods such as pressure molding or plug molding can be suitably used. In this specification, pressure molding is a molding method in which the sheet to be molded is pressurized with compressed air to transfer the shape of the mold. The pressurization in pressure molding may be carried out under vacuum.

[0049] For example, when forming a pair of laminated bodies 2,2 using compressed air molding, a method can be used in which the part of the sheet-like laminated body 2 intended for pouring is preheated to 100°C, then sandwiched between a convex mold and a concave mold, the convex mold and concave mold are brought into close contact by pressure, and then the convex mold and concave mold are separated to form the molded part (the part that functions as a flow channel 15). The width H1 and height (depth) H2 (see Figure 2) of the molded part are not particularly limited, but it is preferable that the width H1 is 5 mm or more and 15 mm or less, and the height H2 (depth) is 2.5 mm or more and 7.5 mm or less.

[0050] As described above, the height H2 (depth) of the molded section formed by compressed air corresponds to half the width of the flow path 15 of the outlet 14. Then, by heat sealing the pair of laminated bodies 2,2 on which such a molded section is provided, a flow path 15 composed of a portion of the pair of laminated bodies 2,2 is formed, as shown in Figures 1 and 2. Therefore, when the height (depth) H2 of the molded section is 2.5 mm or more and 7.5 mm or less, the inner diameter of the flow path 15 will be 5 mm or more and 15 mm or less. It is more preferable that the inner diameter of the flow path 15 be 7 mm or more and 13 mm or less, as this allows for smooth dispensing of an appropriate amount of contents, and it is particularly preferable that it be 9 mm or more and 11 mm or less.

[0051] Furthermore, in the packaging bag 1 shown in Figure 1, the leading edge of the flow path 15 is closed by the flow path sealing portion 18C. The space between the flow path forming sealing portion 18B and the other side end sealing portion 1B is open as a filling port 13, and contents can be filled (stored) into the packaging bag 1 through this filling port 13. After filling with contents, the packaging bag 1 can be sealed by heat-sealing the laminate layers 2,2 together at the periphery of the filling port 13 to form an upper sealing portion 13A, thereby closing the filling port 13.

[0052] Furthermore, in the packaging bag 1 shown in Figure 1, the spout 14 is provided with a first cut line 17, which consists of a laser-formed half-cut groove or the like, that crosses the unsealed portion 15A that forms the flow path 15, in order to facilitate opening. The pull tab (knob) 16 is formed by this first cut line 17. When the first cut line 17 is provided on the packaging bag 1, it is preferable to provide the first cut line 17 on each of the two laminate layers 2, 2 that include the spout 14.

[0053] On the other hand, in the packaging bag 1 shown in Figure 1, a first cut line 17 for initiating opening is provided in the seal portion above the unsealed portion 15A that forms the flow path 15 (between it and the top edge 14E). In addition, a second cut line (not shown) is provided in the seal portion to the side of the unsealed portion 15A that forms the flow path 15 (between it and the side edge seal portion 1B) for cutting away the unsealed portion 15A while leaving a predetermined width of flow path forming seal portion 18A between it and the unsealed portion 15A. With the packaging bag 1 thus formed, the spout 14 can be opened by cutting the pull tab 16 along the opening guide line (not shown), the first cut line 17, and the second cut line (not shown). When the spout 14 is opened, the flow path forming seal portions 18A and 18B each partition both sides of the flow path 15. That is, the unsealed portion 15A between one flow path forming seal portion 18A and the other flow path forming seal portion 18B functions as the flow path 15.

[0054] In addition, an auxiliary member 20 can be placed within the flow path 15 of the packaging bag 1, as shown in Figures 1 and 2. This auxiliary member 20 constitutes a part of the flow path 15. The auxiliary member 20 can be a cylindrical (or straw-shaped) tube having an inner circumferential surface that forms a flow path in the center. Furthermore, the shape of the auxiliary member 20 is not limited to such a straw shape; it may also be a half-straw shape obtained by splitting a cylinder lengthwise.

[0055] Furthermore, the dimensions of the auxiliary member 20 are not particularly limited. For example, if the auxiliary member 20 is a straw-shaped tube, the length of the auxiliary member 20 is 5 mm or more and 25 mm or less, preferably 10 mm or more and 20 mm or less. Furthermore, the inner diameter of the auxiliary member 20 is 2 mm or more and 20 mm or less, preferably 3 mm or more and 15 mm or less. In addition, the outer diameter of the auxiliary member 20 is 3 mm or more and 22 mm or less, preferably 4 mm or more and 17 mm or less, more preferably 5 mm or more and 15 mm or less. In this specification, the outer diameter of the auxiliary member 20 refers to the outer diameter of the auxiliary member 20 before it is placed in the flow path 15. The length of the outer circumference of the auxiliary member 20 is 9 mm or more and 70 mm or less, preferably 13 mm or more and 53 mm or less.

[0056] Furthermore, the material of the auxiliary member 20 is not particularly limited, but for example, polyolefin (polyethylene) can be suitably used, and it may contain 50% to 100% of biomass-derived polyolefin resin. In addition, the auxiliary member 20 has a density of 0.910 kg / m³ 3 More than 0.960kg / m 3 It can be set as follows: 0.915 kg / m 3 More than 0.940kg / m 3 The following is preferable:

[0057] Furthermore, as described above, when the auxiliary member 20 is placed within the flow path 15 of the packaging bag 1, a method can be adopted in which the laminated bodies 2, 2, which are stacked on top of each other via the auxiliary member 20, are sandwiched from above and below, heated, then cooled, and then the flow path forming seal portions 18A and 18B of the laminated bodies 2, 2 around where the auxiliary member 20 is placed are heat-sealed.

[0058] In the packaging bag 1 shown in Figure 1, the auxiliary member 20 is not heat-sealed to the laminated layers 2,2 along its entire circumference. Instead, a portion of the auxiliary member 20 in the circumference (point seal 9 and flow path forming seal portions 18A, 18B) is partially heat-sealed, thereby heat-fusing the auxiliary member 20 to the laminated layers 2,2. By employing this method, the auxiliary member 20 can be fixed while maintaining a gap between it and the laminated layers 2,2.

[0059] In addition, the dimensions of the packaging bag 1 formed as described above are not particularly limited, but a suitable range for a refillable container is approximately 100-500 mm in height, 70-300 mm in width (maximum width between the two end seals 1B, 1B), and a filling capacity of 50-5000 cm³. 3 The contents of packaging bag 1 are not particularly limited, but may include liquids, solids such as powders and granules, viscous substances, liquids, or mixtures thereof.

[0060] Furthermore, in the packaging bag 1 formed as described above, when dispensing the contents, the end of the flow path 15 on the spout 14 side becomes the tip side, and the end of the flow path 15 on the space 1C side becomes the base end (root side). The width of the end of the flow path 15 on the spout 14 side is not particularly limited, but for example, it is 6 mm or more and 28 mm or less, preferably 7 mm or more and 26 mm or less, and more preferably 9 mm or more and 24 mm or less. The width of the end on the space 1C side is not particularly limited, but for example, it is 10 mm or more and 32 mm or less, preferably 11 mm or more and 30 mm or less, and more preferably 13 mm or more and 28 mm or less.

[0061] Furthermore, in the packaging bag 1, the flow path forming seal portions 18A and 18B (a pair of seal portions) and the flow path 15 constitute a flow path forming portion 19, and the flow path forming portion 19 has an end on the spout side 14 and an end on the space 1C side in the longitudinal direction of the flow path 15. When dispensing the contents of the packaging bag 1, the end of the flow path forming portion 19 on the spout side 14 becomes the tip side, and the end of the flow path forming portion 19 on the space 1C side becomes the base end (root side).

[0062] The width of the end of the flow channel forming section 19 on the outlet side 14 is not particularly limited, but for example, it is 12 mm or more and 34 mm or less, preferably 13 mm or more and 32 mm or less, and more preferably 15 mm or more and 30 mm or less. The width of the end of the flow channel forming section 19 on the space 1C side is not particularly limited, but for example, it is 16 mm or more and 38 mm or less, preferably 17 mm or more and 36 mm or less, and more preferably 19 mm or more and 34 mm or less.

[0063] Furthermore, the width of each sealing portion (flow channel forming sealing portion 18A, 18B) provided on either side of the flow channel 15 is not particularly limited, but for example, it is 2 mm or more and 10 mm or less, preferably 2.5 mm or more and 9 mm or less, and more preferably 3 mm or more and 8 mm or less. By adjusting the width of each sealing portion provided on either side of the flow channel 15 in this way, it is possible to prevent the cylindrical auxiliary member 20 from being crushed during the manufacturing of the packaging bag 1 (when the flow channel 15 is molded) while suppressing the occurrence of rupture at the flow channel forming sealing portion 18A, 18B. Therefore, by adjusting the width of each sealing portion provided on either side of the flow channel 15 in this way, the manufactured packaging bag 1 will not have the space of the flow channel 15 crushed, and the contents will be easy to pour out even if the contents contained are a highly viscous liquid.

[0064] <Second Embodiment> Figure 5 shows a packaging bag (pouch) according to the second embodiment, in which packaging bag 1' is formed by using a plug molding method instead of a compressed air molding method to form a part of the laminate 2,2 (the part forming the flow channel 15') similar to that of the first embodiment. In this specification, plug molding is a molding method in which the sheet to be molded is vacuum-suctioned to make it evenly adhere to the mold, and at the same time an auxiliary plug is pressed down from above to make the molded body of uniform thickness.

[0065] The packaging bag 1' of the second embodiment is provided with groove-shaped ribs 34 formed by partially extending a pair of laminate layers 2,2 outward along the flow path 15' of the spout 14', and the base end (inner portion) of the ribs 34 is bifurcated. Furthermore, as shown in Figure 6, the ribs 34 are formed by creating multiple linear deformations in the pair of laminate layers 2,2 to create grooves, and are formed so as not to return to a flat state, and are formed in a convex shape so as to protrude from the film surface when viewed from the outside of the bag. The width H3 and height (depth) H4 (see Figure 6) of the molded part are not particularly limited, but it is preferable that the width H3 is 0.5 mm or more and 5 mm or less, and the height (depth) H4 is 0.5 mm or more and 5 mm or less.

[0066] Furthermore, embossed portions 30A and 30B are provided on both sides of the rib 34, formed by crystallizing (hardening by heating and cooling) a portion of the resin constituting the pair of laminate layers 2,2. These embossed portions 30A and 30B are formed planarly between the rib 34 and the flow path forming seal portions 18A' and 18B', respectively. The inner portions of the embossed portions 30A and 30B are located outside the bifurcated portion of the rib 34 (located outside at a predetermined distance (approximately 3-5 mm) from the bifurcated portion), and the inner edges of the embossed portions 30A and 30B are bent in accordance with the shape of the rib 34.

[0067] On the other hand, the tip of the channel 15' is closed by the sealing portion 18C'. Also, similar to the packaging bag 1 of the first embodiment, the space between the channel forming sealing portion 18B' and the side edge sealing portion 1B is opened as a filling port 13', allowing contents to be filled into the packaging bag 1' through the filling port 13'. Furthermore, the spout 14' is provided with an opening guide line 17A', which consists of a half-cut groove formed by a laser across the channel 15', in order to facilitate opening, and a tab (knob) 16' formed by a cut-out line (through-cut mark) 17B' is provided on one end of the opening guide line 17A'.

[0068] As described above, the packaging bag 1' has ribs 34 that are not hardened like the embossed portions 30A and 30B, and are easily bent. Therefore, when opening the bag (by tearing along the perforations) to dispense the contents, the weight (pressure) of the contents causes the embossed portions 30A and 30B on both sides to spread apart, with the flow path forming seal portions 18A' and 18B' acting as fulcrums, opening the spout 14'. Furthermore, since the packaging bag 1' has ribs 34 that are branched inward in a roughly Y-shape, the shape of the ribs 34 can be maintained for a long period of time, the spout 14' can remain open even if the flow rate of the contents decreases, and the contents can be dispensed very smoothly even when the remaining amount is small.

[0069] Even when the packaging bag according to the present invention has the shape of packaging bag 1' of the second embodiment described above, by making at least one of the polyolefin resin layers constituting the laminated structure a biaxially oriented film, it is possible to mold the bag in a way that prevents the flow path of the spout from being torn during manufacturing, even though it is monomaterialized and easy to recycle, and thus enable high-yield manufacturing. [Examples]

[0070] The present invention will be described in more detail below using examples, but the present invention is not limited in any way to the embodiments described herein, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, the physical properties and characteristics of the examples and comparative examples were evaluated by the following tests.

[0071] [Break in the channel] We visually inspected for tears in the laminated structure during molding in the flow path and performed a sensory evaluation in the following two stages. ○: No tears are visible. ×: Tears are visible.

[0072] [Pouring ability] As shown in Figure 1, a pair of laminated layers and a bottom film were stacked, and the edges of the pair of laminated layers were heat-sealed, excluding the filling opening, to create a packaging bag with a spout (a standing pouch having the shape of Figure 1, and a standing pouch having the shape of Figure 5). The packaging bag was then filled with water and sealed, and the ease of pouring (ease of pouring, etc.) when the spout was opened and the water was poured out was evaluated sensorily in the following two stages. ○: The spout can be poured without being crushed. ×: The spout is crushed and difficult to pour from.

[0073] [Recyclability] The laminate was evaluated in two stages based on the polyolefin ratio of the resin constituting the laminate. ○: The polyolefin raw material content is 80% by mass or more. ×: The polyolefin raw material content is less than 80% by mass.

[0074] [Example 1] A two-layer laminate was fabricated by dry lamination using a two-component curing urethane adhesive. A 25 μm thick biaxially oriented high-density polyethylene film was used as the polyolefin resin layer, and a 110 μm thick linear low-density polyethylene film was used as the sealant layer. Subsequently, a channel was molded using the two-layer laminate by compressed air molding under preheating conditions of 100°C. The channel was formed into a cylindrical shape with an inner diameter (width) of approximately 10 mm after the laminate layers were stacked and the edges were heat-sealed. Furthermore, the two laminate layers after channel molding (with the channels bulging in opposite directions) were stacked with their sealant layers facing inward, and the edges were heat-sealed to create a standing pouch of the shape shown in Figure 1, with the predetermined size (length × width = 150 mm × 100 mm). Furthermore, when stacking the laminated structures after channel molding and heat-sealing the periphery, a polyethylene auxiliary member measuring 15 mm in length, 10 mm in outer diameter, and 8 mm in inner diameter was inserted inside the channel-forming portion of the laminated structure, and the contact portion of the auxiliary member with the laminated structure was partially heat-sealed to achieve heat fusion. The characteristics of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the characteristics of the standing pouch in Example 1, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0075] [Example 2] A 25 μm thick uniaxially oriented high-density polyethylene film and a 25 μm thick biaxially oriented linear low-density polyethylene film were used as the polyolefin resin layer, and a 110 μm thick linear low-density polyethylene film was used as the sealant layer. These uniaxially oriented high-density polyethylene films, biaxially oriented linear low-density polyethylene films, and linear low-density polyethylene films were laminated in that order using a two-component curing urethane adhesive and a dry lamination method to create a three-layer laminate structure. Subsequently, a flow channel was formed using the three-layer laminate structure by compressed air molding under the same conditions as in Example 1. Then, a standing pouch having the same shape as in Example 1 was created using the laminated structure after flow channel formation in the same manner as in Example 1. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the standing pouch characteristics of Example 2 are shown in Table 1, along with the properties and manufacturing method of the standing pouch.

[0076] [Example 3] Except for using an 80 μm thick co-extruded film with linear low-density polyethylene on both sides of high-density polyethylene as the sealant layer, a three-layer laminate was obtained in the same manner as in Example 2. Under preheating conditions of 100°C, a roughly Y-shaped channel with a bifurcated base was formed by plug molding, as shown in Figure 5. The formed channel bulged outward so that the cross section perpendicular to the longitudinal direction was roughly trapezoidal, with a width of approximately 1.5 mm and a maximum bulge length of approximately 1 mm. Furthermore, the two laminate laminates after channel formation (with the channels bulging in opposite directions) were overlapped with their sealant layers facing inward, and the edges were heat-sealed to create a standing pouch with the shape shown in Figure 5 and a predetermined size (length × width = 150 mm × 100 mm). The characteristics of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the standing pouch characteristics of Example 3 are shown in Table 1, along with the properties and manufacturing method of the standing pouch.

[0077] [Example 4] A 20 μm thick biaxially oriented polypropylene film and a 20 μm thick vapor-deposited biaxially oriented polypropylene film were used as the polyolefin resin layer, and a 110 μm thick linear low-density polyethylene film was used as the sealant layer. These three layers were then laminated in that order using a two-component curing urethane adhesive and a dry lamination method to create a three-layer laminate structure. Subsequently, a channel was molded using the plug molding method under the same conditions as in Example 3, and then a standing pouch having the same shape as in Example 3 was created using the laminated structure after channel molding in the same manner as in Example 3. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the properties of the standing pouch of Example 4, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0078] [Example 5] As the polyolefin resin layer, a 20 μm thick uniaxially oriented high-density polyethylene film and a 20 μm thick biaxially oriented linear low-density polyethylene film were used and laminated by dry lamination using a two-component curing urethane adhesive. Next, as the sealant layer, an 80 μm co-extruded film with linear low-density polyethylene on both sides of high-density polyethylene was used, and a laminated laminate was fabricated by extruding a 20 μm thick linear low-density polyethylene resin and laminating it to the sealant layer. Subsequently, using this laminated laminate, a channel was molded by plug molding under the same conditions as in Example 3, and then, using the laminated laminate after channel molding, a standing pouch having the same shape as in Example 3 was fabricated in the same manner as in Example 3. The characteristics of the standing pouch were then evaluated using the evaluation method described above. Table 1 shows the evaluation results of the standing pouch characteristics of Example 5, along with the properties and manufacturing method of the standing pouch.

[0079] [Example 6] A laminate was prepared in the same manner as in Example 5, except that a 25 μm thick biaxially oriented high-density polyethylene film was used instead of the 20 μm thick biaxially oriented linear low-density polyethylene film used in Example 5. Subsequently, a channel was formed using the laminate by plug molding under the same conditions as in Example 3. Then, using the laminate after channel formation, a standing pouch having the same shape as in Example 3 was prepared in the same manner as in Example 3. The characteristics of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the characteristics of the standing pouch of Example 6, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0080] [Example 7] A laminate was prepared in the same manner as in Example 3, except that a 25 μm thick biaxially oriented linear low-density polyethylene film with vapor deposition was used instead of the 25 μm thick biaxially oriented linear low-density polyethylene film used in Example 3. Subsequently, a channel was formed using the laminate by plug molding under the same conditions as in Example 3. Then, using the laminate after channel formation, a standing pouch having the same shape as in Example 3 was prepared in the same manner as in Example 3. The characteristics of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the characteristics of the standing pouch of Example 7, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0081] [Comparative Example 1] A three-layer laminate was prepared by dry laminating a 12 μm thick biaxially oriented polyethylene terephthalate film, a 15 μm thick biaxially oriented nylon film, and a 110 μm thick linear low-density polyethylene film in that order, using a two-component curing urethane adhesive. Subsequently, a flow channel was formed using the three-layer laminate by compressed air molding under the same conditions as in Example 1. Then, a standing pouch having the same shape as in Example 1 was prepared using the laminate after flow channel formation in the same manner as in Example 1. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the properties of the standing pouch of Comparative Example 1, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0082] [Comparative Example 2] A two-layer laminate was prepared by dry lamination using a two-component curing urethane adhesive to laminate a 25 μm thick uniaxially oriented high-density polyethylene film as a polyolefin resin layer and a 110 μm thick co-extruded film with linear low-density polyethylene on both sides of the high-density polyethylene as a sealant layer. Subsequently, a flow channel was formed using the two-layer laminate by compressed air molding under the same conditions as in Example 1. Then, using the laminate after flow channel formation, a standing pouch having the same shape as in Example 1 was prepared in the same manner as in Example 1. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the properties of the standing pouch of Comparative Example 2, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0083] [Comparative Example 3] A two-layer laminate was prepared by dry lamination using a two-component curing urethane adhesive to laminate a 25 μm thick uniaxially oriented high-density polyethylene film as a polyolefin resin layer and a 110 μm thick co-extruded film with linear low-density polyethylene on both sides of the high-density polyethylene as a sealant layer. Subsequently, a channel was molded using the plug molding method under the same conditions as in Example 3, and then a standing pouch having the same shape as in Example 3 (as shown in Figure 5) was prepared using the laminate after channel molding in the same manner as in Example 3. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the properties of the standing pouch of Comparative Example 3, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0084] [Comparative Example 4] A two-layer laminate was prepared by laminating a 25 μm thick biaxially oriented linear low-density polyethylene film and a 110 μm thick linear low-density polyethylene film. Then, using this two-layer laminate, a standing pouch having the same shape as in Example 1 was prepared in the same manner as in Example 1, without forming a flow channel. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the properties of the standing pouch of Comparative Example 4, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0085] [Comparative Example 5] A laminate was prepared by laminating a 20 μm thick uniaxially oriented high-density polyethylene film as a polyolefin resin layer and a 90 μm thick linear low-density polyethylene film as a sealant layer using a 20 μm thick linear low-density polyethylene resin extrusion sandwich lamination method. Subsequently, using this two-layer laminate, a channel was molded by plug molding under the same conditions as in Example 3. Then, using the laminate laminate after channel molding, a standing pouch having the same shape as in Example 3 (as shown in Figure 5) was prepared in the same manner as in Example 3. The properties of the standing pouch were then evaluated using the evaluation method described above. The evaluation results of the properties of the standing pouch of Comparative Example 5, along with the properties and manufacturing method of the standing pouch, are shown in Table 1.

[0086] [Table 1]

[0087] Table 1 shows that the standing pouches of Examples 1 to 7, in which at least one layer of the polyolefin resin layer is made of biaxially oriented film and a channel is molded at the spout, have good recyclability, do not tear during channel molding, and have good pouring properties. In contrast, the standing pouch of Comparative Example 1, in which a resin layer other than polyolefin resin is laminated on the outside of the sealant layer, has poor recyclability, and the standing pouches of Comparative Examples 2, 3, and 5, which do not use biaxially oriented film in the polyolefin resin layer, tear occurs during channel molding regardless of whether the channel is molded by pressure molding or plug molding. Furthermore, the standing pouch of Comparative Example 4, which is made without molding a channel at the spout, has poor pouring properties. [Industrial applicability]

[0088] As the packaging bag according to the present invention exhibits the excellent effects described above, it can be suitably used as a component for packaging various substances and solids. [Explanation of Symbols]

[0089] 1,1'...Packaging bag 1A · Bottom seal section 1B ··Side edge seal section 1C··Space 2. Laminate 2A...Polyolefin resin layer (biaxially oriented) 2B...Adhesive layer 2C · Sealant layer 2D polyolefin resin layer (uniaxially oriented) 3. Bottom film 3A ··Fold line 9-point stickers 13. Filling port 14,14'... Outlet 14E ··Top edge 15. Channel 15A ··Unsealed section 16. Pull tab 17. First cut line 18A, 18A' ·· Flow channel forming seal section 18B, 18B' ·· Flow channel forming seal section 18C, 18C' ·· Flow channel sealing section 19,19' ··Flow channel forming section 20. Auxiliary component (straw) H1··Width H2··Height 30 Embossed

Claims

1. A synthetic resin packaging bag having a spout for extracting the contents, It is formed by stacking two laminated structures, each consisting of at least one polyolefin resin layer and a sealant layer made of polyolefin resin, with the sealant layers facing inward, and then heat-sealing the edges. A channel is formed in the aforementioned spout, which is made by molding the laminated material to bulge outwards, A packaging bag characterized in that at least one of the polyolefin resin layers constituting the laminate is a biaxially oriented film.

2. The packaging bag according to claim 1, characterized in that two layers of the polyolefin resin are provided.

3. The packaging bag according to claim 1 or 2, characterized in that only the polyolefin resin layer adjacent to the sealant layer via an adhesive layer is a biaxially oriented film.

4. The packaging bag according to claim 1 or 2, characterized in that the polyolefin resin is polyethylene.

5. The packaging bag according to claim 1 or 2, characterized in that the inner diameter of the flow path is adjusted to be 5 mm or more and 15 mm or less.

6. The packaging bag according to claim 1 or 2, characterized in that a cylindrical auxiliary member is arranged within the flow path so as to constitute a part of the flow path.

7. The packaging bag according to claim 1 or 2, characterized in that the flow channel is formed by compressed air molding or plug molding.

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