Packaging bag

Abstract

The present invention provides a packaging bag excellent in hand tearability along a half-cut line and pourability after opening in a mono-material structure of a polyolefin-based resin. More specifically, in a packaging bag 20 according to the present invention, a notch 31 for starting opening is formed on one side in the width direction of a flow path 25 of a spout 24, and a half-cut line 32 is formed in a body member surrounding the flow path 25, the half-cut line 32 being connected to or located near the notch 31 and extending across the flow path 25. The opening width over which the half-cut line 32 is arranged on the flow path 25 in the spout 24 is 8 mm or more and 30 mm or less as a straight-line distance, and the half-cut line 32 has an arc part having a radius R of 4 mm or more and less than 50 mm.

Description

Packaging bag

[0001] The present invention relates to a packaging bag.

[0002] In a packaging bag for pouring out contents such as liquid, a spout may be provided on a laminated film forming the packaging bag in order to facilitate pouring. For example, Patent Document 1 discusses the position for providing a cutting line formed by a half-cut line in a packaging bag using biaxially oriented nylon (ON), polyethylene terephthalate (PET) film or the like as a base film, in order to facilitate opening of the spout.

[0003] Japanese Patent No. 4268255

[0004] Regarding the collection of plastic containers and packaging after use, there is a problem that packaging bags containing two or more types of resin are difficult to recycle as plastic containers and packaging. In recent years, in order to facilitate recycling, monomaterial containers and packaging using a single resin have been proposed.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a packaging bag that is excellent in hand tearability along a half-cut line and pourability after opening, in a monomaterial configuration of polyolefin resin.

[0006] To solve the above problems, the present invention has the following configuration: [1] A packaging bag formed from a laminated film having a monomaterial structure of polyolefin resin, wherein the packaging bag has a body member formed from the laminated film, which includes a storage section for storing contents and a spout for dispensing contents, the spout includes a flow path surrounded by the body member and a sealing section formed by the sealing of the body member on at least one side in the width direction of the flow path and on the tip side of the flow path, a notch for initiating opening is formed in the sealing section on one side in the width direction of the flow path, a half-cut line is formed in the body member surrounding the flow path, connected to or adjacent to the notch and crossing the flow path, the opening width at which the half-cut line is positioned on the flow path is 8 mm or more and 30 mm or less in straight line distance, and the half-cut line has an arc portion with a radius of 4 mm or more and less than 50 mm. [2] The spout includes sealing portions formed by sealing of the body member on both sides in the width direction of the flow path, and an auxiliary line for initiating opening is formed in the sealing portion on one side in the width direction of the flow path, including a portion that penetrates the body member in the thickness direction, the auxiliary line is connected to an opening notch in the spout extension region that extends from the base side of the spout toward the tip side of the spout, and a half-cut line is formed in the body member surrounding the flow path, connected to the notch and crossing the flow path, and when a closure point is defined in the spout as the intersection of two mutually perpendicular straight lines that are in contact with the sealing portions on both sides in the width direction of the flow path, the half-cut line is arranged to pass closer to the base side of the spout than the closure point, the packaging bag according to [1]. [3] The packaging bag according to [1] or [2], wherein the spout has a spout center line defined midway between the boundary lines on both sides in the width direction of the flow path, and the line segment connecting the two points where the boundary lines on both sides in the width direction intersect with the half-cut line is at an angle of 80° or more and 100° or less with respect to the spout center line.[4] The packaging bag according to [3], wherein, on the surface including the body member, when the transverse direction (TD) perpendicular to the machine direction (MD) of the body member is defined as the up and down direction, the spout is positioned above the storage portion, the spout centerline is positioned in an upwardly inclined direction different from both the machine direction and the transverse direction, and the opening start direction from the notch where the half-cut line extends is at an angle of 15° or more from the machine direction, below the machine direction. [5] The packaging bag according to any one of [1] to [4], wherein the body member comprises an unstretched sealant layer, at least one stretched base material layer, and an adhesive layer that adheres the sealant layer to the base material layer. [6] The packaging bag according to [5], wherein the body member includes one or more base material layers, the base material layer laminated adjacent to the sealant layer being a biaxially stretched polyolefin resin film. [7] The packaging bag according to [6], wherein the body member comprises a plurality of base material layers, and the base material layers other than the base material layer adjacent to the sealant layer are polyolefin resin films uniaxially stretched in the mechanical direction (MD). [8] The packaging bag according to any one of [1] to [7], wherein the contents comprise a liquid. [9] The packaging bag according to any one of [1] to [8], wherein the packaging bag is a standing pouch comprising a bottom member joined to the body member below the containment portion.

[0007] According to the present invention, a packaging bag made of a single material of polyolefin resin can be provided that offers excellent tearability along the half-cut line and excellent pourability after opening.

[0008] This is a plan view showing an example of a packaging bag. This is a partially enlarged front view illustrating the range of the notch. This is a partially enlarged front view illustrating the opening width and pouring angle. This is a partially enlarged front view illustrating the radius of the arc and the angle of the tangent. This is a partially enlarged front view showing the spout of Comparative Example 1 (R=2 mm). This is a partially enlarged front view showing the spout of Comparative Example 2 (R=3 mm). This is a partially enlarged front view showing the spout of Example 1 (R=4 mm). This is a partially enlarged front view showing the spout of Example 2 (R=6 mm). This is a partially enlarged front view showing the spout of Example 3 (R=8 mm). This is a partially enlarged front view showing the spout of Example 4 (R=12 mm). This is a partially enlarged front view showing the spout of Example 5 (R=25 mm). This is a partially enlarged front view showing the spout of Comparative Example 3 (R=50 mm). This is a partially enlarged front view showing the spout of Comparative Example 4 (R=60 mm).

[0009] The present invention will be described below based on preferred embodiments. Note that the dimensional ratios and angles in the drawings are exaggerated for illustrative purposes and may differ from the actual dimensional ratios and angles.

[0010] Figure 1 is a plan view showing an example of a packaging bag 20. Figure 2 is a partially enlarged front view illustrating the range of the notch. Figure 3 is a partially enlarged front view illustrating the opening width and pouring angle. Figure 4 is a partially enlarged front view illustrating the radius of the arc and the tangent angle. In Figure 1, the notch 31 and the half-cut line 32 are not shown. In Figure 3, the portion of the half-cut line 32 over the flow path 25 is not shown.

[0011] The packaging bag of this embodiment is a packaging bag formed from a laminated film with a monomaterial structure of polyolefin resin. As shown in Figure 1, the body member 21 of the packaging bag 20 includes a storage section 20a for containing contents and a spout 24 for dispensing the contents. Furthermore, as described above, the body member 21 of the packaging bag 20 is formed from a laminated film with a monomaterial structure of polyolefin resin. The contents can be dispensed from the storage section 20a through the spout 24. The contents may include liquid. Note that "monomaterial structure of polyolefin resin" does not mean that it is formed solely from polyolefin resin, but rather that it is formed with polyolefin resin as the main component. For example, it is preferable that the total weight of the polyolefin resin constituting the laminated film is 80% by weight or more, and more preferably 90% by weight or more, relative to the weight of the laminated film.

[0012] In this specification, on the surface including the body member 21, the transverse direction (TD) perpendicular to the mechanical direction (MD) of the body member 21 is defined as the vertical direction. In the drawings, the MD direction is the left-right direction in Figure 1, and the TD direction is the vertical direction in Figure 1. In this case, the spout 24 is positioned above the housing portion 20a. Preferably, the body member 21 contains a polyolefin resin film that is uniaxially stretched in the MD direction.

[0013] The illustrated packaging bag 20 is a standing pouch that includes a bottom member 22 joined to the body member 21 at the lower side of the storage section 20a. In this case, the spout 24 is formed on the side of the body member 21 opposite to the side on which the bottom member 22 is located, in the vertical direction. If the packaging bag 20 does not have a bottom member 22, the side on which the spout 24 is located may be considered the upper side, and the side opposite to the spout 24 may be considered the lower side, in the vertical direction of the body member 21.

[0014] The spout 24 includes a flow path 25 surrounded by a body member 21, and a sealing portion on at least one side in the width direction of the flow path 25 and on the tip side of the flow path 25. In the illustrated example, the spout 24 has flow path forming sealing portions 25a and 25b on both sides in the width direction of the flow path 25, and a flow path sealing sealing portion 25c on the tip side of the flow path 25. However, if a sealing portion is provided on at least one side in the width direction of the flow path 25, it may be either a flow path forming sealing portion 25a or 25b. Both the flow path forming sealing portions 25a and 25b and the flow path sealing sealing portion 25c are formed by the sealing of two body members 21, front and rear. Note that "width direction of the flow path" means the direction perpendicular to the direction in which the contents such as liquid are poured from the storage portion 20a through the flow path 25 (spout 24), and "tip side of the flow path" means the side of the flow path that faces the storage portion 20a.

[0015] In the illustrated example, the boundary lines 25p and 25q on both sides in the width direction of the flow path 25 are defined by the boundary between the flow path forming seal portions 25a and 25b and the flow path 25. Although not specifically shown, a flow path forming seal portion may be provided on the side where the notch 31 is formed, and the boundary line of the flow path 25 may be formed on the opposite side by the fold line of the body member 21. When the fold line of the body member 21 is aligned with the MD direction of the body member 21, a fold line is formed at the upper end of the packaging bag 20, and the flow path forming seal portion 25b and the notch 31 are formed on the side of the packaging bag 20.

[0016] In the illustrated example, an auxiliary line 27 for initiating opening is formed on one side of the widthwise sealing portion of the flow path 25 (the flow path forming sealing portion 25a in the illustrated example). The auxiliary line 27 may penetrate the body member 21 in the thickness direction from the opening initiation portion 26 to the periphery of the tongue-shaped portion 28, except for one or more non-penetrating portions 27a, 27b. When the non-penetrating portions 27a, 27b are broken, the auxiliary line 27 may curve from the base side of the spout 24 toward the tip side of 24, forming the tongue-shaped portion 28.

[0017] The auxiliary line 27 is connected to or close to the opening start notch 31 in the spout extension region, which extends along the tongue-shaped portion 28 from the base side of the spout 24 towards the tip side of the spout 24. The spout extension region is located between the flow path 25 and the tongue-shaped portion 28. Furthermore, a half-cut line 32 is formed on the body member 21, connecting to or close to the notch 31 and traversing the flow path 25. The distance in the case of proximity is not particularly limited, but for example, it may be 1 mm or less.

[0018] The auxiliary line 27, notch 31, and half-cut line 32 are not particularly limited, but can all be formed by processing with a cutting tool or laser. If a flow channel forming seal portion 25a is not formed at the upper end of the packaging bag 20, and a flow channel forming seal portion 25b and a notch 31 are formed on the side of the packaging bag 20, the auxiliary line 27 may be formed on the flow channel forming seal portion 25b. If the auxiliary line 27 is omitted, the notch 31 may be formed from the opening start portion 26. For example, a shape corresponding to the tongue-shaped portion 28 may be punched out and removed from the flow channel forming seal portion 25a in advance.

[0019] The half-cut line 32 is formed on at least one of the pair of body members 21. For example, the half-cut line 32 may be formed at the same position on both body members 21 on the surface including the body members 21. In the thickness direction of the body member 21, the half-cut line 32 is formed only on a portion of the thickness without penetrating the body member 21 in the thickness direction. For example, the half-cut line 32 may be formed only on the outer surface of the body member 21 so as not to reach the inner surface of the body member 21.

[0020] In this embodiment, as shown in Figure 2, when two mutually perpendicular straight lines P1 and P2 are set as contact lines with the flow path forming seal portions 25a and 25b arranged on both sides in the width direction of the flow path 25 at the spout 24, and the closure point P is defined as the intersection of the reference lines P1 and P2, the half-cut line 32 is positioned to pass through the base side of the spout 24 beyond the closure point P. For this reason, the arc portion with radius R, which will be described later, protrudes in a convex shape toward the base side of the spout 24. Although not specifically shown, the arc portion with radius R, which will be described later, may also protrude in a convex shape toward the tip side of the spout 24. In this case, the half-cut line 32 may be positioned to pass through the tip side of the spout 24 beyond the closure point P.

[0021] Furthermore, in this embodiment, as shown in Figure 3, the opening width L in which the half-cut line 32 is positioned on the flow path 25 is 8 mm or more and 30 mm or less in straight line distance. Here, the opening width L is the straight line distance between the portions 32a and 32b in which the half-cut line 32 is positioned on the flow path forming seal portions 25a and 25b.

[0022] Furthermore, in this embodiment, as shown in Figure 4, the half-cut line 32 has a curved arc portion with a radius R of 4 mm or more and less than 50 mm. It is preferable that the center of the arc portion with radius R is positioned closer to the tip of the spout 24 than the half-cut line 32. The arc portion with radius R may also be positioned to pass through the spout center line 11, which will be described later.

[0023] Furthermore, in this embodiment, as shown in Figure 4, it is preferable that the angle φ between the tangent line 34 at the intersection 33 of the half-cut line 32 passing through the spout center line 11 and the opening start direction line 35 is 15° or more and 60° or less. Here, the opening start direction line 35 is a straight line that passes through the starting point 30 of the half-cut line 32, along the opening start direction in which the half-cut line 32 extends from the notch 31.

[0024] In this embodiment, as shown in Figure 3, the spout centerline 11 is defined midway between the boundary lines 25p and 25q of the flow path 25. When the two boundary lines 25p and 25q intersect, the spout centerline 11 is the bisector extending along the flow path 25 from the intersection point. If the two boundary lines 25p and 25q are parallel, the spout centerline 11 is set at a position equidistant from the boundary lines 25p and 25q.

[0025] Furthermore, in this embodiment, as shown in Figure 3, when defining the pouring angle θ as the angle between the line segment having the opening width L and the spout centerline 11, it is preferable that the pouring angle θ is 80° or more and 100° or less. Here, the line segment having the opening width L is the line segment connecting the two points where the boundary lines 25p and 25q intersect with the half-cut line 32. If the two lines intersect at a non-right angle, any value of 80° or more and less than 90° or greater than 90° and less than or equal to 100° may be adopted.

[0026] Furthermore, in this embodiment, it is preferable that the spout 24 is positioned above the housing 20a, and that the spout centerline 11 is positioned in an upward-sloping direction, different from the MD direction and the TD direction.

[0027] Furthermore, in this embodiment, it is preferable that the opening start direction line 35, from which the half-cut line 32 extends from the notch 31, is positioned below the MD direction and has an angle of 15° or more from the MD direction. As described above, the MD direction is the left-right direction in Figures 1 to 4.

[0028] The body member 21 may have an unstretched sealant layer, at least one stretched base layer, and an adhesive layer that bonds the sealant layer and the base layer. The body member 21 includes one or more base layers, of which the base layer laminated adjacent to the sealant layer may be a biaxially stretched polyethylene resin film. Furthermore, among the multiple base layers, the base layers other than the base layer adjacent to the sealant layer may be a polyolefin resin film uniaxially stretched in the MD direction.

[0029] The polyolefin resin monomaterial laminated film (hereinafter referred to as "PO laminated film") used in the packaging bag 20 is not particularly limited, but examples include laminated films containing two or more polyolefin resin films, such as a sealant layer and a base layer. The PO laminated film is not limited to combinations of polyethylene (PE) resin films (PE laminated film) or polypropylene (PP) resin films (PP laminated film), but may also include combinations of PE resin film and PP resin film. Furthermore, a polyolefin resin layer other than the film may be laminated to the resin film (a resin layer that can be manufactured as a product on its own) as an extruded resin layer, etc. The extruded resin layer is a resin layer that is molten by heat during lamination and is cooled and solidified after lamination.

[0030] A PO-based laminated film may have, in the thickness direction, at least one base layer, an extruded resin layer, and a sealant layer in this order. Before the auxiliary lines 27, notches 31, and half-cut lines 32 are formed on the PO-based laminated film, the resin layers such as the base layer, extruded resin layer, and sealant layer may be laminated with substantially uniform thickness over the entire surface of the laminated film.

[0031] The polyolefin resin is not particularly limited, but examples include linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and polypropylene (PP).

[0032] Examples of materials for the base layer include LLDPE, MDPE, HDPE, and PP. The thickness of the base layer is not particularly limited, but is typically around 10 to 50 μm. The base layer is not limited to a single-layer film, but may also be a multilayer film produced by co-extrusion or the like. The base layer preferably includes a stretched polyolefin resin layer. The stretching direction is not particularly limited, but examples include uniaxial stretching in the MD or TD direction, and biaxial stretching in the MD and TD directions. The stretching ratio is typically around 2 to 10 times.

[0033] Examples of materials for the extruded resin layer include HDPE, LLDPE, LDPE, PP, or unstretched polyolefin resins. The thickness of the extruded resin layer is not particularly limited, but is typically around 10 to 50 μm. Examples of materials for the sealant layer include HDPE, LLDPE, LDPE, PP, or unstretched polyolefin resins. The thickness of the sealant layer is not particularly limited, but is typically around 50 to 180 μm.

[0034] When using a polyethylene resin layer as a polyolefin resin layer such as a base layer, extruded resin layer, and sealant layer, one type of polyethylene resin may be used alone, or two or more types of polyethylene resins may be blended and used. The polyethylene resin may be a homopolymer of ethylene, or a copolymer mainly composed of ethylene. Examples of monomers other than ethylene (comonomers) include one or more types of α-olefins such as 1-butene, 1-hexene, and 1-octene, cyclic olefins such as norbornene, and vinyl monomers such as vinyl acetate, vinyl chloride, and acrylic acid. When comonomers are used in the polyethylene resin, there may be one or more types of comonomers. The proportion of ethylene in the constituent monomers of the polyethylene resin is preferably 50% by weight or more, for example, it may be 80 to 100% by weight. The polyethylene resin may contain resins derived from fossil resources such as petroleum, resins derived from biomass such as plants, or resins obtained through recycling.

[0035] When a polypropylene resin layer is used as a polyolefin resin layer such as a base layer, an extruded resin layer, and a sealant layer, one type of polypropylene resin may be used alone, or two or more types of polypropylene resins may be blended and used. The polypropylene resin may be a homopolymer of propylene (homoPP), or a random copolymer (randomPP) or block copolymer (blockPP) of propylene-ethylene copolymer, etc. Examples of monomers other than propylene (comonomers) include one or more types of α-olefins such as ethylene, 1-butene, 1-hexene, and 1-octene, and vinyl monomers such as vinyl acetate, vinyl chloride, and acrylic acid. When comonomers are used in the polypropylene resin, there may be one or more types of comonomers. The proportion of propylene in the constituent monomers of the polypropylene resin is preferably 50% by weight or more, for example, 80 to 100% by weight. The polypropylene resin layer may also contain recycled polypropylene.

[0036] The polyolefin resin layer may contain resins or additives other than polyolefin resins. The additives are not particularly limited, but examples include antioxidants, lubricants, antiblocking agents, flame retardants, UV absorbers, light stabilizers, antistatic agents, colorants, crosslinking agents, compatibilizers, and laser absorbers.

[0037] The PO-based laminated film may include an adhesive layer or an anchor coat layer between the resin layers. The adhesive or anchor coat agent is not particularly limited, but examples include urethane compounds, epoxy compounds, isocyanate compounds, polyethyleneimine, and organotitanium compounds such as titanium alkoxide. The thickness of the adhesive layer or anchor coat layer can be, for example, about 0.1 to 10 μm, about 1 to 6 μm, or about 3 to 4 μm.

[0038] PO-based laminated films may include a printed layer. The printed layer can be formed by printing ink in a solid or patterned manner using printing methods such as gravure printing, letterpress printing, offset printing, screen printing, or inkjet printing. The thickness of the printed layer is not particularly limited, but examples include approximately 0.5 to 10 μm, 1 to 6 μm, or 1 to 4 μm. Inks containing laser absorbers can also be used.

[0039] The PO-based laminated film may include layers of barrier resins such as ethylene-vinyl alcohol copolymer (EVOH), metals such as aluminum, and inorganic compounds such as silica and alumina. These barrier materials are preferably formed into thin layers by vapor deposition, co-extrusion, or the like. Depending on the application, these barrier layers made of different materials may be omitted. Examples of barrier properties include oxygen barrier properties and water vapor barrier properties.

[0040] In a PO-based laminated film, it is preferable that the total weight of the polyolefin resin is 80% by weight or more and the total weight of the dissimilar materials is 20% by weight or less, and more preferably that the total weight of the polyolefin resin is 90% by weight or more and the total weight of the dissimilar materials is 10% by weight or less. Here, dissimilar materials refer to materials other than polyolefin resin.

[0041] In a laminated film having a monomaterial structure of polyethylene resin (PE laminated film), it is preferable that the total weight of polyethylene resin is 80% by weight or more and the total weight of materials other than polyethylene resin is 20% by weight or less, and more preferably that the total weight of polyethylene resin is 90% by weight or more and the total weight of materials other than polyethylene resin is 10% by weight or less.

[0042] A laminated film having a monomaterial configuration of a polypropylene-based resin (PP-based laminated film) preferably has a total weight of the polypropylene-based resin of 80% by weight or more and a total weight of materials other than the polypropylene-based resin of 20% by weight or less relative to the weight of the PP-based laminated film, and more preferably has a total weight of the polypropylene-based resin of 90% by weight or more and a total weight of materials other than the polypropylene-based resin of 10% by weight or less.

[0043] The packaging bag 20 shown in Figure 1 is a standing pouch as described above, and is formed from a pair of body members 21 and a bottom member 22 folded in two along a folding line 22a. Above the folding line 22a, the front and rear body members 21 are joined by the left and right body seal portions 21a and 21b. Below the folding line 22a, the bottom member 22 is joined to the body member 21 to form a bottom seal portion 22b. The bottom member 22 of the packaging bag 20 may be omitted to form a flat bag.

[0044] The packaging bag 20 in the illustrated example has an upper seal portion 23 at the upper part of the packaging bag 20 where the space between the front and rear body members 21 is sealed. The left and right sides of the storage portion 20a may be sealed by the body seal portions 21a and 21b, the content may be filled in a state where the filling port at the upper part of the storage portion 20a is open, and the filling port may be sealed as the upper seal portion 23 after filling.

[0045] When opening the spout 24, after breaking the non-penetrating portions 27a and 27b of the auxiliary line 27, the tongue-shaped portion 28 may be pinched to tear the body member 21 from the notch 31 along the half-cut line 32. When pouring out the content from the opening along the half-cut line 32, the mouth of the container to which the content is poured may be locked to the locking portion 29 disposed on the opposite side of the tongue-shaped portion 28 via the flow path 25. Note that the locking portion 29 is not an essential configuration and may be omitted.

[0046] Hereinafter, the present invention will be specifically described with reference to examples.

[0047] <Materials Used> MDOPE: MD direction uniaxially stretched film of HDPE BOPE: Biaxially stretched film of LLDPE LLDPE: Sealant layer or extruded resin layer of LLDPE

[0048] (Comparative Example 1) After bonding between MDOPE (25 µm thick) and BOPE (25 µm thick) by dry lamination (in Table 1, the adhesive is not shown and indicated by " / / "), the resulting laminate was laminated with a sealant layer (LLDPE, 70 µm thick) via an extruded resin layer (LLDPE, 20 µm thick). Using the obtained laminated film as a body member, the packaging bag 20 shown in Fig. 1 was produced. As shown in Fig. 5, a half-cut line was formed from the outer side by laser processing such that the half-cut line 32 had an arc portion with a radius R = 2 mm.

[0049] (Comparative Examples 2 to 4, Examples 1 to 5) In Comparative Example 2, as shown in Fig. 6, the radius R of the arc portion was set to 3 mm. In Example 1, as shown in Fig. 7, the radius R of the arc portion was set to 4 mm. In Example 2, as shown in Fig. 8, the radius R of the arc portion was set to 6 mm. In Example 3, as shown in Fig. 9, the radius R of the arc portion was set to 8 mm. In Example 4, as shown in Fig. 10, the radius R of the arc portion was set to 12 mm. In Example 5, as shown in Fig. 11, the radius R of the arc portion was set to 25 mm. In Comparative Example 3, as shown in Fig. 12, the radius R of the arc portion was set to 50 mm. In Comparative Example 4, as shown in Fig. 13, the radius R of the arc portion was set to 60 mm. In all cases, packaging bags were produced using the same materials and methods as in Comparative Example 1, except for the shape of the half-cut line.

[0050] (Hand-tearability: Sensory Evaluation) The hand-tearability (sensory evaluation) of the packaging bags was evaluated according to the following criteria. ・Excellent (○): Can be torn without applying force. ・Good (△): Can be torn by applying a small amount of force. ・Poor (×): Cannot be torn without applying strong force.

[0051] (Hand-tearability: Line Followability) The hand-tearability (line followability) of the packaging bags was evaluated according to the following criteria. ・Excellent (○): 7 or more out of 10 bags can be torn by hand along the line. ・Good (△): 5 to 6 out of 10 bags can be torn by hand along the line. ・Poor (×): Less than 5 out of 10 bags can be torn by hand along the line.

[0052] (Pouring Ease) The pouring ease of the packaging bags was evaluated according to the following criteria: • Excellent (○): All 10 bags can be poured without blockage. • Good (△): One to four out of ten bags are blocked. • Poor (×): Five or more out of ten bags are blocked and difficult to pour.

[0053]

[0054] As shown in Table 1, forming a half-cut line with an arc section having a radius R of 4 mm or more and less than 50 mm results in excellent tearability along the half-cut line and superior pourability after opening.

[0055] θ... pouring angle, φ... tangent angle, L... opening width, P... closure point, P1, P2... reference line, R... radius of the arc, 11... spout center line, 20... packaging bag, 20a... storage section, 21... body member, 21a, 21b... body seal section, 22... bottom member, 22a... fold line, 22b... bottom seal section, 23... top seal section, 24... spout, 25... flow path, 25a, 25b... flow path forming seal section, 25c... flow path sealing seal section, 25p, 25q... boundary line, 26... opening start section, 27... auxiliary line, 27a, 27b... non-penetrating section, 28... tongue-shaped section, 29... locking section, 30... starting point, 31... notch, 32... half-cut line, 32a, 32b... portion above the seal section, 33... intersection, 34... tangent, 35... opening start direction line.

Claims

A packaging bag formed from a laminated film having a monomaterial structure of polyolefin resin, The packaging bag has a body member formed from the laminated film, which includes a storage section for containing the contents and a spout for dispensing the contents. The spout includes a flow path surrounded by the body member, and a sealing portion formed by the seal of the body member on at least one side in the width direction of the flow path and on the tip side of the flow path. A notch for initiating opening is formed in the sealing portion on one side in the width direction of the aforementioned flow path. The body member surrounding the flow path has a half-cut line formed in it that crosses the flow path, connected to or adjacent to the notch. The opening width at which the half-cut line is positioned on the flow path is 8 mm or more and 30 mm or less in straight line distance. The packaging bag is characterized in that the half-cut line has an arc portion with a radius of 4 mm or more and less than 50 mm. 　 The spout includes sealing portions formed by the sealing of the body member on both sides in the width direction of the flow path. An auxiliary line for initiating opening is formed on one side of the sealing portion in the width direction of the flow path, including a portion that penetrates the body member in the thickness direction. The auxiliary line is connected to the opening start notch in the spout extension region that extends from the base side of the spout toward the tip side of the spout, The body member surrounding the flow path has a half-cut line formed on it that connects to the notch and crosses the flow path. The packaging bag according to claim 1, characterized in that, when the closure point is defined as the intersection of two mutually perpendicular straight lines that are in contact with the sealing portions on both sides in the width direction of the flow path at the spout, the half-cut line is arranged to pass closer to the base of the spout than the closure point. 　 The packaging bag according to claim 1 or 2, characterized in that, in the spout, a spout center line is defined midway between the boundary lines on both sides in the width direction of the flow path, and the line segment connecting the two points where the boundary lines on both sides in the width direction intersect with the half-cut line is at an angle of 80° or more and 100° or less with respect to the spout center line. 　 On the surface including the body member, when the horizontal direction (TD) perpendicular to the mechanical direction (MD) of the body member is defined as the vertical direction, the spout is positioned above the housing portion. The center line of the spout is positioned in an upward-sloping direction, which is different from both the machine direction and the lateral direction. The packaging bag according to claim 3, characterized in that the opening initiation direction from which the half-cut line extends from the notch is at an angle of 15° or more from the machine direction and is lower than the machine direction. 　 The packaging bag according to any one of claims 1 to 4, characterized in that the body member comprises an unstretched sealant layer, at least one stretched base material layer, and an adhesive layer that adheres the sealant layer and the base material layer. 　 The packaging bag according to claim 5, wherein the body member includes one or more base material layers, and the base material layer laminated adjacent to the sealant layer is a biaxially oriented polyolefin resin film. 　 The packaging bag according to claim 6, wherein the body member includes a plurality of base material layers, and the base material layers other than the base material layer adjacent to the sealant layer are polyolefin resin films uniaxially stretched in the mechanical direction (MD). 　 The packaging bag according to any one of claims 1 to 7, characterized in that the contents include a liquid. 　 The packaging bag according to any one of claims 1 to 8, characterized in that the packaging bag is a standing pouch including a bottom member joined to the body member at the lower side of the storage portion.

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