Packaging bags

Abstract

To provide a packaging bag that enables monomaterial packaging, prevents spillage even when tilted, and allows for smooth dispensing of the contents. [Solution] A packaging bag comprising opposing surface laminates and back laminates, comprising: a storage section for containing contents; a sealing section formed around the storage section; and a dispensing section including a spout from which contents can be dispensed when opened, wherein the dispensing section has an opening line defining the opening of the spout, and a weak sealing line located on the storage section side relative to the opening line, where the surface laminate and back laminate are linearly fused, and the width of the fused section is 40 to 100 μm.

Description

[Technical Field]

[0001] This disclosure relates to packaging bags. [Background technology]

[0002] Packaging bags for containing cosmetics, shampoos, conditioners, body soaps, and laundry detergents are known. Such packaging bags are provided with a spout for dispensing the contents.

[0003] In such packaging bags, if one attempts to transfer the contents into the main container by tilting the bag after opening the spout, the contents may sometimes leak from the spout before the bag is inserted into the main container, depending on the viscosity of the liquid contents and the angle at which the bag is tilted.

[0004] In this context, Patent Document 1 discloses a specific packaging bag that has a dispensing adjustment section and an initial flow path in the dispensing section, which is used to prevent the contents from splashing out forcefully. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6878026 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, packaging bags formed using laminated films made of different materials are not easy to separate by material after being collected as waste. Therefore, in order to improve their recyclability, research is underway on packaging materials made from a single material, so-called monomaterial packaging.

[0007] The inventors selected polyethylene resin as the material for realizing monomaterial packaging.

[0008] This disclosure provides a packaging bag that enables the realization of monomaterial packaging, prevents contents from spilling even when tilted, and allows for good dispensing of contents. [Means for solving the problem]

[0009] One aspect of this disclosure provides the following packaging bags. [1] A packaging bag comprising opposing surface laminates and back laminates, A compartment for storing contents, A sealing portion formed around the above-mentioned housing portion, A dispensing section including a spout from which the above contents can be dispensed when opened, Equipped with, The dispensing section has an opening line that defines the opening of the dispensing spout, and a weak seal line located on the housing side with respect to the opening line, which is a fused section formed by linearly fusing the surface laminate and the back laminate. The above surface laminate and the above back surface laminate each have a laminated structure comprising a base layer, an adhesive layer, and a sealant layer in this order. The above-mentioned base layer is made of polyethylene film. The above sealant layer contains a polyethylene resin, A packaging bag in which the width of the fused portion is 40 to 100 μm. [2] The packaging bag according to [1], wherein, when the packaging bag is viewed in plan in the thickness direction, at a position overlapping with the weak seal line, at least one of the surface laminate and the back laminate has a first linear void between the base material layer and the sealant layer. [3] The packaging bag according to [1] or [2], wherein, as the planned opening line, at least one of the surface laminate and the back laminate has a second linear void between the base material layer and the sealant layer. [4] The packaging bag according to any one of [1] to [3], wherein the surface laminate and the back laminate each further comprises an intermediate layer made of polyethylene film between the base material layer and the sealant layer. [5] The packaging bag according to any one of [1] to [4], wherein the front surface laminate and the back surface laminate each further include a vapor deposition layer. [6] The packaging bag according to any one of [1] to [5], wherein the weak seal line is a solid line or a broken line. [7] The packaging bag according to any one of [1] to [6], wherein the weak seal line is a straight line or a curve. [8] Further comprising an initial flow path in which the front surface laminate and the back surface laminate are not fused, The packaging bag according to any one of [1] to [7], wherein the weak seal line and the initial flow path are present along the flow path width direction intersecting the pouring direction of the content. [9] The packaging bag according to any one of [1] to [8], comprising 6 to 8 weak seal lines.

[10] The packaging bag is a self-standing packaging bag formed by heat-sealing a bottom tape and a pair of main body parts, The packaging bag according to any one of [1] to [9], wherein the pair of main body parts are composed of the front surface laminate and the back surface laminate.

[11] The packaging bag according to any one of [1] to

[10] , wherein the content of the polyethylene-based resin is 90% by mass or more based on the total amount of the packaging bag. [Advantages of the Invention]

[0010] According to the present disclosure, a single-material packaging material can be realized, and a packaging bag is provided in which the content is difficult to spill even when tilted and the content can be poured out well. [Brief Description of the Drawings]

[0011] [Figure 1] FIG. 1 is a front view schematically showing a packaging bag according to an embodiment. [Figure 2] FIG. 2 is a perspective view schematically showing a pair of main body parts and a bottom tape constituting the packaging bag shown in FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view schematically showing the configuration of the packaging bag shown in FIG. 1. [Figure 4] FIG. 4 is a plan view showing an enlarged view of the vicinity S1 of the pouring outlet 21 of the packaging bag shown in FIG. 1. [Figure 5] FIG. 5 is a plan view showing an enlarged view of the planned opening line and the vicinity S2 of the weak seal line shown in FIG. 4. [Figure 6] FIG. 6 is an end view taken along the virtual line A-A of FIG. 5. [Figure 7] FIG. 7(a) is a front view schematically showing an example of the first packaging bag. FIG. 7(b) is a front view schematically showing an example of the second packaging bag. [Figure 8] FIG. 8(a) is an end view taken along the virtual line B-B of FIG. 7(a). FIG. 8(b) is an end view schematically showing a state in which a planned opening line is formed by irradiating the first packaging bag with a laser beam along the virtual line B-B of FIG. 7(a). FIG. 8(c) is an end view schematically showing a state after irradiating the first packaging bag with a laser beam along the virtual line B-B of FIG. 7(a). FIG. 8(d) is an end view schematically showing a state in which a weak seal line is formed by irradiating the first packaging bag with a laser beam along the virtual line B-B of FIG. 7(a). FIG. 8(e) is an end view taken along the virtual line C-C of FIG. 7(b).

DETAILED DESCRIPTION OF THE INVENTION

[0012] <PACKAGING BAG>[[ID=二十]] [[ID=二十一]]The standing pouch (self-standing packaging bag) as the packaging bag according to an embodiment of the present disclosure will be described. The standing pouch is used as a refill pouch for cosmetics, shampoo, conditioner, body soap, laundry detergent, and the like. [[ID=二十二]] [[ID=二十三]]

[0013] [[ID=二十四]] [[ID=二十五]]<<STANDING POUCH>>[[ID=二十六]] [[ID=二十七]]FIG. 1 is a front view schematically showing the packaging bag (standing pouch) according to the present embodiment. FIG. 2 is an exploded perspective view schematically showing a pair of main body portions and a bottom tape constituting the packaging bag shown in FIG. 1. FIG. 3 is a cross-sectional view schematically showing the configuration of the packaging bag shown in FIG. 1. [[ID=二十八]] [[ID=二十九]]

[0014] [[ID=三十]] As shown in Figure 1, the packaging bag 10 (standing pouch) comprises a storage section 11 for storing (or being able to store) predetermined contents, a sealing section 12 formed around the storage section 11, an injection section 13 having an injection port for injecting contents into the storage section 11, and an injection section 20 for dispensing contents when opened. The sealing section 12 has a first sealing section 12a provided on one side of the storage section 11 (the left side in the figure), a second sealing section 12b provided on the other side of the storage section 11 (the right side in the figure), and a third sealing section 12c provided on the bottom of the storage section 11. The injection section 13 is heat-sealed and closed after contents have been stored in the storage section 11.

[0015] In such a packaging bag 10, as shown in Figure 2, laminates 35A (front laminate) and 35B (back laminate), cut to a predetermined shape, are arranged facing each other. Laminate 35A becomes the front surface of the packaging bag 10, and laminate 35B becomes the back surface of the packaging bag 10. As shown in Figure 6, the laminate 35 has a laminated structure comprising a base layer L1, an adhesive layer L5a, an intermediate layer L2, a vapor-deposited layer L4, an adhesive layer L5b, and a sealant layer L3 in this order. Details of each layer will be described later.

[0016] The laminates 35A and 35B are heat-sealed at predetermined locations with the sealant layer L3 facing inward. In the packaging bag 10, the bottom tape 40 is heat-sealed between the laminates 35A and 35B at the bottom. The formation of the packaging bag by heat sealing can be carried out in the same way as conventional methods.

[0017] The bottom tape 40 has one mountain fold portion 41. That is, when the packaging bag 10 is standing upright, the bottom tape 40 is arranged in an inverted V shape (see Figures 2 and 3). The third seal portion 12c at the bottom of the packaging bag 10 is composed of a heat seal portion 14 and a heat seal portion 15, as shown in Figure 3. The heat seal portion 14 is the portion where the bottom 31a of the laminate 35A and one bottom 41a of the bottom tape 40 are heat-sealed. The heat seal portion 15 is the portion where the bottom 31b of the laminate 35B and the other bottom 41b of the bottom tape 40 are heat-sealed. As shown in Figure 1, the laminates 35A, 35B and the bottom tape 40 are heat-sealed so that the bottom of the area that contains the contents is curved and the upper side is arc-shaped.

[0018] As described above, the sealing portion 12 on the side of the packaging bag 10 has a first sealing portion 12a provided on the dispensing portion 20 side and a second sealing portion 12b provided on the opposite side of the first sealing portion 12a in the horizontal direction (or MD). The widths of the first sealing portion 12a and the second sealing portion 12b of the sealing portion 12 are, for example, 5 to 18 mm, or 7 to 15 mm. A width of 5 mm or more for each sealing portion 12 tends to achieve sufficient sealing strength, while a width of 18 mm or less tends to make it easier to secure a sufficient amount of contents in the packaging bag 10.

[0019] As shown in Figure 1, the packaging bag 10 has fused portions 16 and 17 on both sides of the bottom (third seal portion 12c). In this embodiment, two fused portions 16 are formed vertically on one side of the packaging bag 10, and two fused portions 17 are formed vertically on the other side. The fused portions 16 and 17 join the laminate 35A and the laminate 35B. The fused portions 16 and 17 are areas where the sealant layers L3 of the laminates 35A and 35B are locally fused together through notches 44 and 45 provided in the bottom tape 40. As shown in Figure 2, the notches 44 and 45 of the bottom tape 40 are in the region between the mountain fold portion 41 and the bottom edges 42 and 43, and are provided on the side of the bottom tape 40. The provision of fused sections 16 and 17 on both sides of the bottom further improves the self-supporting ability and drop resistance of the packaging bag 10. While this example illustrates the case where two pairs of notches 44 and 45 are provided on one side of the bottom tape 40 to form two fused sections 16 and 17, for example, a pair of notches may be provided on one side of the bottom tape 40 to form one fused section 16 or 17.

[0020] From the viewpoint of recyclability, it is preferable that the polyethylene resin content in the packaging bag 10 be 90% by mass or more. From the viewpoint of achieving a higher degree of monomaterialization, it is more preferable that the polyethylene resin content in the packaging bag 10 be 92% by mass or more, and even more preferable that be 95% by mass or more.

[0021] Next, the dispensing section 20 of the packaging bag 10 will be described in detail with reference to Figures 1, 4 to 6. Figure 4 is a plan view showing an enlarged view of the area S1 near the dispensing section 20 of the packaging bag shown in Figure 1. Figure 5 is a plan view showing an enlarged view of the area S2 near the opening line and weak seal line shown in Figure 4. Figure 6 is an end view along the dashed line AA in Figure 5. The dispensing section 20 has a spout 21, a gripping tab 22, a first dispensing seal section 23, a second dispensing seal section 24, a connecting seal section 25, an opening line 26, a notch 27, and a weak seal line 28. The dispensing section 20 is provided adjacent to the seal section 13a of the injection section 13.

[0022] The spout 21 is the part for dispensing the contents from the opening 21a when the dispensing section 20 is opened along the planned opening line 26, and includes the flow path 21b from the storage section 11. The spout 21 is defined by the first dispensing seal section 23 and the second dispensing seal section 24, which extend in a direction slightly oblique to the vertical direction, and the portion including the flow path 21b is defined.

[0023] The gripping tab 22 is a gripping portion used to pull the dispensing portion 20 when opening it to transfer the contents contained in the storage portion 11. The gripping tab 22 is sealed on three sides, excluding the side facing the dispensing spout 21. By pulling the gripping tab 22 along the opening line 26 in the direction of arrow A, the opening 21a of the dispensing spout 21 opens, and the dispensing portion 20 is opened. The gripping tab 22 has a protruding portion 22a that extends outward from the packaging bag 10, and the gripping tab 22 is designed to be pulled from the outside inward. The sealed portion of the gripping tab 22 is connected to the first dispensing seal portion 23 and the second dispensing seal portion 24.

[0024] The first dispensing seal portion 23 is a vertically extending seal portion provided on the outer edge side of the packaging bag 10, with its upper end connected to the gripping tab 22 and its lower end connected to the first seal portion 12a via a connecting seal portion 25. The second dispensing seal portion 24 is a vertically extending seal portion provided inward from the first dispensing seal portion 23, with its upper end connected to the gripping tab 22 and its lower end connected to the seal portion 13a of the injection portion 13 via a curved surface portion. The first dispensing seal portion 23 and the second dispensing seal portion 24, like the first seal portion 12a and the second seal portion 12b, are portions where the sealant layers L3 of the laminates 35A and 35B are sealed together. The width of the first dispensing seal portion 23 and the second dispensing seal portion 24 in the machine direction may be, for example, 3 mm or more (or 4 mm or more).

[0025] As described above, the first dispensing seal portion 23 is connected to the first seal portion 12a via the connecting seal portion 25. In this case, the angle α formed by the outer edge of the first dispensing seal portion 23 and the outer edge of the connecting seal portion 25 is, for example, 90 degrees or more and 180 degrees or less, forming an obtuse angle.

[0026] The second dispensing seal portion 24 is formed to be short such that the distance D2 from the base 24a connected to the seal portion 13a to the tip 24b connected to the gripping tab 22 is, for example, 5 mm or more and 10 mm or less. For example, the length D2 of the second dispensing seal portion 24 may be shorter than half the length D1 of the first dispensing seal portion 23. Also, the second dispensing seal portion 24 is formed adjacent to the seal portion 13a of the injection portion 13, and for example, the shortest separation distance (distance between their outer edges) at the point where the second dispensing seal portion 24 and the seal portion 13a face each other may be 5 mm or less.

[0027] The opening line 26 is a line used to tear and cut the dispensing section 20 when opening it to transfer the contents of the storage section 11 to another container. The packaging bag 10 can be easily opened by the opening line 26. The opening line 26 is a second linear void H2. The void H2 is formed by irradiating the packaging bag with laser light, as will be described later. The void H2 is located between the vapor-deposited layer L4 and the adhesive layer L5b in the laminates 35A and 35B. In the packaging bag 10, the opening line 26 is the linear void closest to the notch 27 among the linear voids located on the storage section 11 side relative to the notch 27, and the linear void located on the opposite side of the storage section 11 relative to the said linear void.

[0028] The opening line 26 may be a solid line or a dashed line. The opening line 26 may be a straight line or a curved line. It is preferable that the opening line 26 be provided in a straight line along the MD of the laminates 35A and 35B because it provides even better tear resistance.

[0029] The opening line 26 extends from the first dispensing seal section 23, across the dispensing outlet 21, to the second dispensing seal section 24. This makes the packaging bag even easier to open. The opening line 26 may extend from the end of the first dispensing seal section 23 opposite to the dispensing outlet 21. The opening line 26 may extend from the end of the second dispensing seal section 24 opposite to the dispensing outlet 21.

[0030] The dispensing section 20 has two opening lines 26 on the front side of the packaging bag 10. In other words, the laminated body 35A has two second linear voids H2 that become the opening lines 26. The dispensing section 20 also has one opening line 26 on the back side of the packaging bag 10. In other words, the laminated body 35A has one second linear void H2 that becomes the opening line 26. The number of opening lines on the dispensing section 20 is preferably two or more, and more preferably three or more. In the manufacturing process of the packaging bag, the notch may be misaligned from the intended position relative to the opening line. Even in such cases, having two or more opening lines on the dispensing section 20 allows one of the opening lines to assist in opening. Therefore, the packaging bag 10 tends to have improved tear resistance. The number of opening lines on the packaging bag is preferably four or less, and more preferably three or less. This tends to improve the manufacturing efficiency of the packaging bag 10 by shortening the laser irradiation time.

[0031] Since the dispensing section 20 has opening lines 26 on both the front and back sides of the packaging bag 10, the packaging bag 10 will have excellent tear resistance whether the gripping tab 22 is pulled towards the front side of the packaging bag 10 or towards the back side of the packaging bag 10.

[0032] When the packaging bag 10 is viewed in plan view in the thickness direction, the opening line 26 on the front side and the opening line 26 on the back side of the packaging bag 10 are offset from each other. The offsetting of the opening lines 26 on the front and back sides means that, as shown in Figure 5, the opening lines 26 on the front and back sides are similar in shape, but are positioned so as not to overlap when the packaging bag 10 is viewed in plan view in the thickness direction. For example, if the opening line 26 is a straight line, the opening lines 26 on the front and back sides may be parallel when the packaging bag 10 is viewed in plan view in the thickness direction. For example, if the opening line 26 is a curve, the opening lines 26 on the front and back sides may be offset in the height direction of the packaging bag when the packaging bag 10 is viewed in plan view in the thickness direction.

[0033] When the packaging bag 10 is viewed in plan in the thickness direction, the shortest distance between the opening line on the front side and the opening line on the back side is preferably 0.2 mm or more, and more preferably 0.3 mm or more, from the viewpoint of preventing the packaging bag from becoming difficult to open due to fusion. When the packaging bag 10 is viewed in plan in the thickness direction, the shortest distance between the opening line on the front side and the opening line on the back side is preferably 1.5 mm or less, and more preferably 1.0 mm or less, from the viewpoint of ensuring sufficient tearability without the misalignment of the opening lines on the front and back sides becoming too wide.

[0034] If the dispensing section 20 has two or more opening lines 26 on the front side of the packaging bag 10, the distance between adjacent opening lines may be, for example, 0.6 to 2.0 mm. If the dispensing section 20 has two or more opening lines 26 on the back side of the packaging bag 10, the distance between adjacent opening lines may be, for example, 0.6 to 2.0 mm.

[0035] The length of the void H2 in the thickness direction of the laminated structures 35A and 35B may be 40 to 150 μm.

[0036] In the thickness direction of the packaging bag 10, at positions overlapping with the void H2, there is a second fused portion M2 where the sealant layers of the laminates 35A and 35B are fused. The shape of the fused portion M2 may be substantially the same as that of the void H2. The fused portion M2 is a straight line. The fused portion M2 may be a solid line or a dashed line. The fused portion M2 may be a straight line or a curve. The width W2 of the fused portion M2 may be 40 μm or more, 50 μm or more, or 60 μm or more. From the viewpoint of suppressing the difficulty of opening the packaging bag due to fusion, the width W2 is preferably 150 μm or less, more preferably 120 μm or less, and even more preferably 100 μm or less. The width W2 is the longest length of the fused portion M2 in a direction perpendicular to the thickness direction of the laminates 35A and 35B and the extension direction of the fused portion M2. The width W2 may be a value measured by observing the cross-sections of the surface laminate and the back laminate with an optical microscope at a magnification of 500x.

[0037] In the thickness direction of the packaging bag 10, at positions where it overlaps with the void H2, the base layer L1 has through-holes T that penetrate in the thickness direction. The through-holes T, together with the void H2, serve as the starting point for tearing. As a result, the packaging bag 10 has even better tear resistance.

[0038] The packaging bag 10 has a notch 27. The notch 27 is located at one end of the intended opening line 26 and is the starting point for opening the packaging bag 10, guiding the user when opening the packaging bag 10. The notch 27 may have the shape of a cut, notch, or indentation. In the example shown in the figure, the notch 27 is located just below the gripping tab on the outside of the packaging bag 10, but the notch 27 may be located elsewhere as long as it can guide the user to the intended opening line 26.

[0039] In the packaging bag 10, a notch 27 is provided at one end of the opening line 26. This allows for guidance during the opening process, thereby improving the opening performance.

[0040] The weak seal line 28 consists of a first fused portion M1 where the sealant layers of the laminates 35A and 35B are fused in a linear fashion. After tearing and cutting the dispensing portion 20 along the opening line 26, it is necessary to tilt the packaging bag 10 in order to insert the dispensing portion 20 into the container body to which the contents will be transferred. At this time, the weak seal line 28 prevents the contents from spilling. Then, the packaging bag 10 is pressed while it is inserted into the container body to which the contents will be transferred. As a result, the weak seal line 28 peels off due to the flow force of the contents or air pressure, and the contents can be dispensed from the spout 21 and transferred to the container body.

[0041] The weak seal line 28 is formed by irradiating the packaging bag with laser light, as described later. The weak seal line 28 may be a solid line or a dashed line. The weak seal line 28 may be a straight line or a curved line. The weak seal line 28 may be approximately parallel to the opening line 26. The weak seal line 28 extends from one end to the other end of the spout 21 in the direction of the flow path width intersecting the direction of dispensing the contents. The weak seal line 28 may be a solid line or a dashed line. The weak seal line 28 may be a straight line or a curved line.

[0042] If the dispensing section 20 has two or more weak seal lines 28, the distance between adjacent weak seal lines 28 may be, for example, 0.2 mm or more, 0.5 mm or more, or 1.0 mm or more. If the dispensing section 20 has two or more weak seal lines 28, the distance between adjacent weak seal lines 28 may be, for example, 10 mm or less, 3 mm or less, or 1 mm or less.

[0043] The width W1 of the fused portion M1 (weak seal line 28) is 40 μm or more. A width W1 of 40 μm or more of the fused portion M1 makes it difficult for the contents to spill even when the packaging bag is tilted. From a similar viewpoint, a width W1 of 50 μm or more is preferable. The width W1 of the fused portion M1 (weak seal line 28) is 100 μm or less. A width W1 of 100 μm or less of the fused portion M1 allows the weak seal line 28 to detach due to the flow force of the contents or air pressure when the packaging bag 10 is pressed with the dispensing part inserted into the container body, allowing the contents to be dispensed from the dispensing port 21 and transferred to the container body. A width W1 of 80 μm or less is preferable as it allows for better dispensing of the contents. The width W1 is the longest length of the fused portion M1 in a direction perpendicular to the thickness direction of the laminates 35A and 35B and the extension direction of the fused portion M1 (weak seal line 28). The width W1 may be a value measured by observing the cross-sections of the surface laminate and the back laminate with an optical microscope at a magnification of 500x.

[0044] In the thickness direction of the packaging bag 10, at positions overlapping with the weak seal line 28, the laminate 35A or laminate 35B has a first linear void H1. The void H1 is located between the vapor-deposited layer L4 and the adhesive layer L5b in the laminates 35A and 35B. As described later, the void H1 is formed in the laminate on the side irradiated with the laser when forming the weak seal line 28. The shape of the void H1 may be substantially the same as that of the weak seal line 28. The void H1 is a straight line. The void H1 may be a solid line or a dashed line. The void H1 may be a straight line or a curve. In the thickness direction of the packaging bag 10, at positions overlapping with the weak seal line 28, if laminate 35A has a void, laminate 35B does not. In the thickness direction of the packaging bag 10, at positions overlapping with the weak seal line 28, if laminate 35B has a void, laminate 35A does not.

[0045] When the packaging bag 10 is viewed in plan in the thickness direction, the void H1 in the laminate 35A and the void H1 in the laminate 35B are offset from each other. The statement that the void H1 in the laminate 35A and the void H1 in the laminate 35B are offset from each other means that, when the packaging bag 10 is viewed in plan in the thickness direction, the void H1 in the laminate 35A and the void H1 in the laminate 35B are positioned so that they do not overlap.

[0046] When the packaging bag 10 is viewed in plan in the thickness direction, the distance between the void H1 in the laminate 35A and the void H1 in the laminate 35B may be the same as the distance between adjacent weak seal lines 28.

[0047] The length of the void H1 in the thickness direction of the laminated bodies 35A and 35B may be 40 to 150 μm.

[0048] The dispensing section 20 may have an initial channel where the sealant layers L3 are not fused together, along with a weak seal line. The weak seal line and the initial channel may be located along the channel width direction intersecting the dispensing direction of the contents.

[0049] In the packaging bag 10, the width of the first dispensing seal portion 23 and the second dispensing seal portion 24 of the dispensing portion 20 in the machine direction is 3 mm or more. In this case, the rigidity of the dispensing outlet 21 of the dispensing portion 20 is increased, and when the dispensing portion 20 of the packaging bag 10 is inserted into the container to be refilled, dispensing can be performed stably. This makes the refilling work easier.

[0050] In the packaging bag 10, the first dispensing seal portion 23 is provided on the outer edge side of the packaging bag 10, and the second dispensing seal portion 24 is provided inside the first dispensing seal portion 23, with the length D2 of the second dispensing seal portion 24 being shorter than half the length D1 of the first dispensing seal portion 23. Furthermore, the shortest separation distance D3 between the second dispensing seal portion 24 and the seal portion 13a of the injection portion 13 is 5 mm or less. In this case, even when using a relatively soft material such as polyethylene resin, rigidity can be ensured in the dispensing portion 20, making it possible to perform the refilling operation using the dispensing portion 20 more reliably.

[0051] In the packaging bag 10, the dispensing section 20 has a gripping tab 22 that can be grasped by the user of the packaging bag 10. The gripping tab 22 protrudes outward from the packaging bag 10. This makes it easier to open the dispensing section 20.

[0052] The capacity of the packaging bag 10 may be, for example, 80 to 800 ml.

[0053] <Laminate>

[0054] [Base material layer L1] The base layer L1 consists of a stretched polyethylene film. Here, an unstretched polyethylene film is a polyethylene film in which no stretching treatment is performed during film formation, and which has a structure in which spherical crystals (spherulites) of about 10 to 100 μm, composed of randomly folded polyethylene molecular chains, are linked together by amorphous molecules. A stretched polyethylene film, on the other hand, is a polyethylene film in which a stretching treatment is performed during film formation, and which has an arranged structure.

[0055] The polyethylene resin content in the base layer L1 may be 50% by mass or more, 80% by mass or more, or 100% by mass, based on the total amount of the base layer L1. Using polyethylene resin as the material for the base layer L1 is preferable from the viewpoint of recyclability. Furthermore, the higher the polyethylene resin content in the base layer L1, the better the recyclability.

[0056] The polyethylene resin contained in the base layer L1 may be acid-modified polyethylene obtained by graft-modifying polyethylene with an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, etc.

[0057] The density of the polyethylene resin contained in the base layer L1 is 0.910 g / cm³. 3 Preferably, it should be 0.930 g / cm³ or more. 3 It is more preferable that the amount be greater than or equal to 0.950 g / cm³. 3 It is even more preferable that the density of the polyethylene resin is 0.910 g / cm³. 3 As a result, when the laminate is heat-sealed to form a bag, only the sealant layer L3 is easily fused, thus improving bag-making suitability. Furthermore, the density of the polyethylene resin is 0.910 g / cm³. 3 When the above conditions are met, the printability is good when forming a printed layer on the substrate layer L1. Furthermore, the density of the polyethylene resin is 0.910 g / cm³. 3 This makes it easier to suppress the stretching and wrinkling of the base material layer L1 during roll processing.

[0058] The base layer L1 may be a multilayer structure comprising multiple unstretched films, each containing polyethylene of different densities as its main component. The base layer L1 may be multilayered as appropriate, taking into consideration the processability, rigidity, stiffness, heat resistance, and powder shedding during transport of the films constituting the base layer L1. Furthermore, the content of slip agents, antistatic agents, etc., may be varied in each layer during lamination. The base layer L1 comprising multiple layers can be laminated into a film by extrusion molding, co-extrusion molding, sheet molding, co-extrusion blow molding, etc. The total thickness of the base layer L1 comprising multiple layers is preferably about 10 to 100 μm, and more preferably 15 to 50 μm.

[0059] The stretched film constituting the base layer L1 may have a molecular orientation degree (MOR) of 1.07 or less, 1.05 or less, or 1.04 or less. The lower the molecular orientation degree, the better the isotropy of the film. When the molecular orientation degree is 1.07 or less, the adhesion (peel resistance) of the base layer L1 in the laminate tends to be good. The molecular orientation degree can be measured using a molecular orientation meter.

[0060] The thermal shrinkage rate of the base material layer L1 after heating at 100°C for 15 minutes in the machine direction (hereinafter simply referred to as MD) and the perpendicular direction (hereinafter simply referred to as TD) is preferably 3% or less, more preferably 2% or less, and even more preferably 1.5% or less. When the thermal shrinkage rate of the base material layer L1 is within the above range, it is easier to suppress the stretching and wrinkling of the base material layer L1 during roll processing, and it is also easier to suppress the occurrence of cracks in the vapor-deposited layer L4 when a vapor-deposited layer L4 is provided on the base material layer L1.

[0061] Here, the thermal shrinkage rate (%) is a value calculated by the following formula. Thermal shrinkage rate (%) = {(Length before heating - Length after heating) / Length before heating} × 100 The procedure for measuring the thermal shrinkage rate is as follows: (1) Cut out a 20cm x 20cm piece of the base layer L1 to use as a measurement sample. (2) Draw a 10cm line on the MD or TD of the measurement sample (length before heating). (3) Heat the sample to be measured at 100°C for 15 minutes. (4) Measure the length of the MD or TD of the written line (length after heating). (5) Calculate the thermal shrinkage rate using the above formula.

[0062] The thickness of the base layer L1 is not particularly limited. Depending on the application, the thickness can be 6 to 200 μm. From the viewpoint of ensuring strength, the thickness of the base layer L1 is preferably 10 μm or more, and more preferably 20 μm or more. The thickness of the base layer L1 is preferably 50 μm or less, and more preferably 30 μm or less, as forming through holes penetrating the base layer L1 further improves tear resistance.

[0063] From the viewpoint of improving adhesion with adjacent layers, the substrate layer L1 may be subjected to various pretreatments such as corona treatment, plasma treatment, low-temperature plasma treatment, flame treatment, chemical treatment, solvent treatment, and ozone treatment on its laminated surface, to the extent that it does not impair barrier performance, or a coating layer such as an easy-adhesion layer may be provided.

[0064] The substrate layer L1 may contain additives such as fillers, antiblocking agents, antistatic agents, plasticizers, lubricants, and antioxidants. These additives may be used individually or in combination of two or more.

[0065] [Adhesive layer L5a, L5b] The adhesive used to form the adhesive layers L5a and L5b can be selected according to the bonding method, but urethane-based adhesives, polyester-based adhesives, etc., can be used. By providing adhesive layers L5a and L5b, the adhesion between the base layer L1 and the intermediate layer L2, and between the intermediate layer L2 and the sealant layer L3 is improved, making delamination less likely and maintaining the pressure resistance and impact resistance of the packaging bag.

[0066] Adhesive layers L5a and L5b are preferably chlorine-free. The absence of chlorine in adhesive layers L5a and L5b prevents discoloration of the adhesive and recycled resin after recycling, and prevents odor generation during heat treatment. From an environmental perspective, using biomass materials for adhesive layers L5a and L5b is preferable. Biomass polyethylene can also be used instead of polyethylene. From an environmental perspective, solvent-free adhesives are preferable.

[0067] The thickness of the adhesive layers L5a and L5b may be, for example, 0.1 to 10 μm, 0.1 to 5.0 μm, or 0.2 to 2.0 μm.

[0068] The adhesive layers L5a and L5b may be composed of adhesive resin. Such adhesive layers L5a and L5b can be formed by extrusion lamination of adhesive resin. Furthermore, the sealant can also be formed together with the adhesive layer of adhesive resin by co-extrusion lamination.

[0069] As the adhesive resin, for example, polyethylene resin may be used. If adhesion is important, the adhesive resin may include, for example, acid-modified polyethylene. The sealant formed by co-extrusion lamination can use the same materials as the sealant described later.

[0070] [Middle layer L2] The laminate 35 has an intermediate layer, and since the intermediate layer is an unstretched polyethylene film, voids H are formed while suppressing damage to the sealant layer. Furthermore, since the sealant layer is not exposed in the packaging bag containing such a laminate 35, the occurrence of delamination is suppressed. In addition, packaging bags containing such a laminate 35 tend to suppress the occurrence of bag rupture caused by internal pressure when dropped or crushed.

[0071] The intermediate layer L2 is made of an unoriented polyethylene film. The thickness of the intermediate layer L2 is, for example, 5 to 800 μm, and may be 5 to 500 μm or 10 to 50 μm.

[0072] The polyethylene resin content in the intermediate layer L2 may be 50% by mass or more, 80% by mass or more, or 100% by mass, based on the total amount of the intermediate layer L2. Using polyethylene resin as the material for the intermediate layer L2 is preferable from the viewpoint of recyclability. Furthermore, the higher the polyethylene resin content in the intermediate layer L2, the better the recyclability.

[0073] The polyethylene resin contained in the intermediate layer L2 may be acid-modified polyethylene obtained by graft-modifying polyethylene with an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, etc.

[0074] The melting point of the intermediate layer L2 is preferably 120°C or higher, and more preferably 125°C or higher. Examples of polyethylene constituting the intermediate layer L2 include high-density polyethylene (HDPE) and medium-density polyethylene (MDPE). Of these, HDPE and MDPE with a density of 0.925 g / cm³ are preferred from the viewpoint of heat resistance. 3 It is preferable to use the above materials. In particular, materials with a density of 0.93 to 0.98 g / cm³ are preferred. 3 It is preferable to use high-density polyethylene within the specified range.

[0075] The intermediate layer L2 may contain components other than polyethylene resin. Examples of such components include those similar to those in the base layer L1.

[0076] [Sealant layer L3] The sealant layer L3 contains a polyethylene resin. The polyethylene resin content in the sealant layer L3 may be 50% by mass or more, 80% by mass or more, or 100% by mass, based on the total amount of the sealant layer L3. Using a polyethylene resin as the material for the sealant layer L3 is preferable from the viewpoint of recyclability. Furthermore, the higher the polyethylene resin content in the sealant layer L3, the better the recyclability.

[0077] The thickness of the sealant layer L3 is, for example, 40 to 150 μm, and may be 20 to 250 μm. The melting point of the sealant layer L3 is preferably 120°C or lower, and more preferably 95 to 110°C. The sealant layer L3 has a density of less than 0.925 g / cm 3 (more preferably 0.900 to 0.920 g / cm 3 ) and is preferably composed of a polyethylene-based resin. Specific examples include linear low-density polyethylene (LLDPE) and very-low-density polyethylene (VLDPE). These polyethylenes may be blended and used.

[0078] The polyethylene-based resin constituting the sealant layer L3 is preferably C4-LLDPE because it has even better tear resistance. C4-LLDPE is a type of LLDPE (linear low-density polyethylene) composed of a copolymer of ethylene and 1-butene, and has a molecular structure in which the main chain of LLDPE derived from ethylene has a side chain with 4 carbon atoms derived from 1-butene. C4-LLDPE has shorter side chains and a lower melt flow rate (MFR) than C6-LLDPE and C8-LLDPE, and thus has relatively low tensile impact strength, tensile strength, and tensile modulus. Therefore, when the polyethylene-based resin constituting the sealant layer L3 is C4-LLDPE, the laminate 35 has even better MD tear resistance.

[0079] As part or all of the polyethylene-based resin contained in the sealant layer L3, biomass polyethylene using biomass-derived ethylene as a raw material may be used. Such a sealant film is disclosed, for example, in JP-A-2013-177531. The sealant layer L3 may contain mechanically recycled polyethylene using used polyethylene products or resin (so-called burrs) generated in the manufacturing process of polyethylene products as raw materials.

[0080] [Vapor deposition layer L4] Examples of constituent materials for the vapor-deposited layer L4 include inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoint of transparency and barrier properties, the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. Furthermore, from the viewpoint of excellent tensile stretchability during processing, it is preferable that the vapor-deposited layer L4 is a layer containing silicon oxide. By using the vapor-deposited layer L4, high barrier properties can be obtained with a very thin layer that does not affect the recyclability of the laminate.

[0081] The O / Si ratio of the vapor-deposited layer L4 is preferably 1.7 or higher. When the O / Si ratio is 1.7 or higher, the content of metallic Si is suppressed, making it easier to obtain good transparency. Furthermore, the O / Si ratio is preferably 2.0 or lower. When the O / Si ratio is 2.0 or lower, the crystallinity of SiO is increased, which prevents the vapor-deposited layer L4 from becoming too hard, and good tensile strength can be obtained. This makes it possible to suppress the occurrence of cracks in the vapor-deposited layer L4 when laminating the adhesive layer L5b. In addition, even after forming into a packaging bag, the base layer L1 may shrink due to the heat during the boiling process, but when the O / Si ratio is 2.0 or lower, the vapor-deposited layer L4 can easily follow the above shrinkage, and the decrease in barrier properties can be suppressed. From the viewpoint of obtaining these effects more fully, the O / Si ratio of the vapor-deposited layer L4 is preferably 1.75 or higher and 1.9 or lower, and more preferably 1.8 or higher and 1.85 or lower.

[0082] The O / Si ratio of the deposited layer L4 can be determined by X-ray photoelectron spectroscopy (XPS). For example, the measurement can be performed using an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., product name: JPS-90MXV) with a non-monochromatic MgKα (1253.6 eV) X-ray source and an X-ray output of 100 W (10 kV-10 mA). For quantitative analysis to determine the O / Si ratio, relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p can be used.

[0083] The thickness of the vapor-deposited layer L4 is preferably between 10 nm and 50 nm. A thickness of 10 nm or more provides sufficient gas barrier properties. A thickness of 50 nm or less suppresses crack formation due to deformation caused by internal stress in the thin film, thereby suppressing a decrease in gas barrier properties. Furthermore, a thickness of 50 nm or less is preferable from an economic standpoint because it makes it easier to suppress cost increases due to increased material usage and longer film formation times. From the same viewpoint as above, a thickness of 20 nm or more and 40 nm is more preferable.

[0084] The vapor-deposited layer L4 can be formed, for example, by vacuum deposition. Vacuum deposition can be performed using either physical vapor deposition or chemical vapor deposition. Examples of physical vapor deposition methods include vacuum deposition, sputtering, and ion plating, but are not limited to these. Examples of chemical vapor deposition methods include thermal CVD, plasma CVD, and photoCVD, but are not limited to these.

[0085] In the vacuum deposition methods described above, resistance heating vacuum deposition, EB (Electron Beam) heating vacuum deposition, induction heating vacuum deposition, sputtering, reactive sputtering, dual magnetron sputtering, and plasma chemical vapor deposition (PECVD) are particularly preferred. However, considering productivity, vacuum deposition is currently the most superior method. For the heating means in vacuum deposition, it is preferable to use one of the following methods: electron beam heating, resistance heating, or induction heating.

[0086] The laminate 35 has a void H between the vapor-deposited layer L4 and the adhesive layer L5b. The maximum length of the void H may be, for example, 20 to 40 mm. The void H is preferably provided in a straight line along the MD of the laminate 35 because it provides even better tear resistance. If the sealant layer L3 contains C4-LLDPE, the void H is preferably provided in a straight line along the MD of the laminate 35 because it provides even better tear resistance to the laminate 35.

[0087] From the viewpoint of recyclability, the total content of polyethylene resin in the laminate 35 is preferably 90% by mass or more, based on the total mass of the laminate 35. From the viewpoint of achieving a higher degree of monomaterialization, the polyethylene resin content in the laminate 35 is more preferably 92% by mass or more, and even more preferably 95% by mass or more.

[0088] Although a packaging bag according to one embodiment has been described in detail above, the packaging bags of this disclosure are not limited to the above embodiments and examples. For example, the packaging bags of this disclosure may be packaging bags other than standing pouches. The packaging bags of this disclosure may be, for example, two-sided bags, three-sided bags, four-sided bags, gusseted bags or foldable bags. The packaging bags of this disclosure can be subjected to heat sterilization treatment such as boiling.

[0089] Furthermore, in the packaging bag 10, at a position overlapping with the weak seal line in the thickness direction of the packaging bag, only one of the surface laminate and the back laminate has the first linear void H1. However, in the packaging bag of this disclosure, at a position overlapping with the weak seal line in the thickness direction of the packaging bag, both the surface laminate and the back laminate may have the first linear void. In the packaging bag of this disclosure, at a position overlapping with the weak seal line in the thickness direction of the packaging bag, at least one of the surface laminate and the back laminate may have the first linear void.

[0090] Furthermore, although the opening lines 26 on the front and back surfaces of the packaging bag 10 are offset from each other, the opening lines on the front and back surfaces of the packaging bag of this disclosure do not have to be offset from each other. In other words, the opening lines on the front and back surfaces of the packaging bag of this disclosure may be positioned to overlap when the packaging bag is viewed in plan in the thickness direction. As opening lines, at least one of the front laminate and the back laminate may have a second linear void between the base material layer and the sealant layer.

[0091] Furthermore, while the opening line 26 of the packaging bag 10 is a second linear void H2, the opening line of the packaging bag in this disclosure does not have to be a void.

[0092] Furthermore, the base layer of the laminate used in the packaging bag may be made of unoriented polyethylene film. Using unoriented polyethylene film for the base layer makes it less likely for defects to penetrate the base layer during the formation of voids H1 and H2. This suppresses delamination caused by defects. Additionally, packaging bags containing such laminates tend to be less prone to rupture caused by internal pressure from drops or crushing. In this case, the base layer does not need to have through holes.

[0093] Furthermore, the intermediate layer of the laminate used in the packaging bag may be made of stretched polyethylene film. The polyethylene film may be uniaxially stretched or biaxially stretched. Also, the laminate used in the packaging bag does not need to have an intermediate layer.

[0094] Furthermore, the laminate used in the packaging bag may further comprise other layers in addition to the base layer, intermediate layer, sealant layer, adhesive layer, and vapor-deposited layer.

[0095] [Other layers] The laminate may have an anchor coat layer between the base layer L1 and the sealant layer L3. The anchor coat layer may be a very thin layer that does not affect the recyclability of the laminate, and can be formed using an anchor coat agent. Examples of anchor coat agents include acrylic resin, epoxy resin, acrylic urethane resin, polyester polyurethane resin, polyether polyurethane resin, and polyvinyl alcohol resin. From the viewpoint of heat resistance and interlayer adhesion strength, acrylic urethane resin and polyester polyurethane resin are preferred as anchor coat agents.

[0096] The laminate may further include, for example, a printed layer. The printed layer may be provided on the surface of the base layer L1 opposite to the adhesive layer L5a, between the base layer L1 and the adhesive layer L5a, or between the adhesive layer L5a and the intermediate layer L2. The inclusion of a printed layer in the laminate increases the size of the through-holes formed in the base layer. As a result, the tear resistance of the laminate tends to be even better.

[0097] When a printed layer is provided, it is preferable to use a printing ink that does not contain chlorine, from the standpoint of preventing discoloration or odor generation when the printed layer is remelted. Furthermore, from the standpoint of environmental consideration, it is preferable to use biomass materials in the compounds contained in the printing ink.

[0098] For example, the laminate does not need to have adhesive layers L5a and L5b.

[0099] The following describes in detail a method for manufacturing a packaging bag according to one embodiment of this disclosure.

[0100] <Manufacturing method for packaging bags> A method for manufacturing a packaging bag according to one embodiment of this disclosure will be described, specifically a method for manufacturing a standing pouch.

[0101] The method for manufacturing a packaging bag according to this embodiment comprises the following steps (a), (b), and (c). A second packaging bag is obtained through the following steps (a), (b), and (c). Step (a): Step of preparing the first packaging bag Step (b): Step of forming an opening line on the first packaging bag to assist in opening. Step (c): Step of forming a weak seal line on the first packaging bag.

[0102] <<Process (a)>> Figure 7(a) is a schematic front view showing an example of the first packaging bag. Figure 8(a) is an end view along the dashed line BB in Figure 7(a). The laminate 2 constituting the first packaging bag 1 has a laminated structure comprising a base layer L1, an adhesive layer L5a, an intermediate layer L2, a vapor-deposited layer L4, an adhesive layer L5b, and a sealant layer L3 in this order. The laminate 2 may be the same as the laminate 35 described above, except that it does not have voids or through holes. The first packaging bag 1 may be the same as the packaging bag 10 described above, except that the surface laminate is laminate 2A, the back laminate is laminate 2B, and it does not have an opening line or a weak seal line.

[0103] <<Process (b)>> Figure 8(b) is a schematic end view showing the process of irradiating the first packaging bag with laser light along the dashed line BB in Figure 7(a) to form an opening line. Figure 8(c) is a schematic end view showing the state after irradiating the first packaging bag with laser light along the dashed line BB in Figure 8(a). In step (b), as shown in Figure 8(b), laser light a2 is irradiated onto the first packaging bag 1 from the light source a1 to volatilize a portion of the laminates 2A and 2B, thereby forming a linear void H2 that will become the opening line. The laser light is absorbed by the adhesive layer L5a, the vapor-deposited layer L4, and the adhesive layer L5b, generating heat. As a result, a portion of these layers and adjacent layers volatilizes. Laser light a2 is irradiated onto the packaging bag 1 from both the front (laminated layer 2A) side and the back (laminated layer 2B) side. At this time, when the packaging bag 10 is viewed in plan in the thickness direction, the laser beam is irradiated such that the opening lines 26 on the front and back surfaces of the packaging bag 10 are offset from each other (do not overlap). In other words, when the first packaging bag is viewed in plan in the thickness direction, the laser beam is irradiated to a different area on the back surface of the first packaging bag than the area irradiated on the front surface of the first packaging bag. For example, if the opening line 26 is a straight line, when the first packaging bag is viewed in plan in the thickness direction, the straight areas irradiated with laser beam on the front and back surfaces may be parallel to each other and do not overlap. For example, if the opening line 26 is a curve, when the first packaging bag is viewed in plan in the thickness direction, the curved areas irradiated with laser beam on the front and back surfaces may be offset in the height direction of the packaging bag and do not overlap. Irradiation with laser beam can cause the sealant layers L3 to fuse together and form a fused portion M2.

[0104] Since polyethylene resin does not absorb laser light, the energy penetrates the laminate located in front of the laser light source and reaches the sealant layer of the laminate located behind it. When the packaging bag 1 is viewed in plan in the thickness direction, if the area on the front side of the packaging bag 1 irradiated with laser light and the area on the back side irradiated with laser light are in the same position, the sealant layers are strongly fused together. As a result, even when the packaging bag is pressed, the fused part is difficult to peel off, and the contents are difficult to pour out. On the other hand, when the packaging bag 1 is viewed in plan in the thickness direction, if the areas on the front side of the packaging bag 1 irradiated with laser light and the areas on the back side irradiated with laser light are misaligned, a weakly fused part M2 is formed where the sealant layers are fused together. The fused part M2 can be easily peeled off by pressing the packaging bag. In addition, the void H2 formed by the laser light becomes an opening line that assists in opening the bag. As a result, a packaging bag is obtained that has sufficient tearability while allowing for good dispensing of the contents.

[0105] The base layer L1 of the laminates 2A and 2B is made of polyethylene film. Polyethylene film absorbs laser light less readily than films made of other resins. Therefore, the second packaging bag 1 is more likely to form second linear voids compared to packaging bags that use films made of other resins as the base layer. In the packaging bag manufacturing method according to this embodiment, the second linear voids are easily formed, making it possible to increase the laser light scanning speed. Therefore, the packaging bag manufacturing method according to this embodiment is highly efficient in terms of production. Furthermore, because the laser light scanning speed can be increased, it is possible to make the shape of the second linear voids long curves or to increase the distance between the second linear voids. In other words, the packaging bag manufacturing method according to this embodiment is a highly versatile manufacturing method.

[0106] Furthermore, because the base layer L1 is a stretched polyethylene film, through holes T are created in the base layer L1 as voids form. If the laminate does not have an intermediate layer, damage occurs to the sealant layer during the through-hole formation process. On the other hand, laminate 2 has an intermediate layer, and since the intermediate layer is an unstretched polyethylene film, damage to the sealant layer is less likely to occur.

[0107] Specifically, the laser light to be irradiated can be a laser emitted from a carbon dioxide laser or a YAG laser, and from the viewpoint of productivity, the laser light emitted from a carbon dioxide laser is preferred.

[0108] The wavelength of the laser light to be irradiated may be, for example, 9.2 to 10.8 μm.

[0109] The scanning speed of the irradiated laser beam may be 100 to 1000 mm / second.

[0110] The output power of the laser beam used for irradiation may be between 20 and 80 watts.

[0111] <<Process (c)>> Figure 7(b) is a schematic front view showing an example of the second packaging bag. Figure 8(d) is a schematic end view showing the formation of a weak seal line by irradiating the first packaging bag with laser light along the dashed line BB in Figure 7(a). Figure 8(e) is an end view along the dashed line CC in Figure 7(b). In step (c), as shown in Figure 8(d), a laser beam a2 is irradiated onto the first packaging bag 1 from a light source a1 to form a linear fused portion M1 that will become a weak seal line. The laser beam is absorbed by the adhesive layer L5a, the vapor-deposited layer L4, and the adhesive layer L5b, generating heat. This causes the sealant layer L3 to fuse together. The laser beam a2 is irradiated onto the packaging bag 10 from both the front (laminated 2A) side and the back (laminated 2B) side of the packaging bag 1. At this time, when the packaging bag 10 is viewed in plan in the thickness direction, the laser beam is irradiated so that the position where the laser beam is irradiated on the front side (laminated 2A) of the packaging bag 1 and the position where the laser beam is irradiated on the back side (laminated 2B) of the packaging bag 1 are offset. Since polyethylene resin does not absorb laser light, the energy penetrates the laminate located in front of the laser light source and reaches the sealant layer of the laminate located behind it. When the packaging bag 10 is viewed in plan in the thickness direction, if the position where the laser beam is irradiated on the front side of the packaging bag 1 and the position where the laser beam is irradiated on the back side of the packaging bag 1 are the same, the sealant layers will fuse together firmly. By irradiating the laser beam so that the position where the laser beam is irradiated on the front side of the packaging bag 1 and the position where the laser beam is irradiated on the back side of the packaging bag 1 are offset, a fused portion M1 (weak seal line) is formed where the sealant layers are weakly fused together. The fused portion M1 can be easily peeled off by pressing the packaging bag. The fused portion M1 formed in this way makes it less likely for the contents to spill even when the packaging bag is tilted, and the fused portion M1 can be easily peeled off by pressing the packaging bag.

[0112] The base layer L1 of the laminates 2A and 2B is made of polyethylene film. Polyethylene film absorbs laser light less readily than films made of other resins. Therefore, the first packaging bag 1 is more likely to form fused portions M1, which are weak seal lines, compared to packaging bags using films made of other resins as the base layer. In the packaging bag manufacturing method according to this embodiment, because fused portions are easily formed, it is possible to increase the scanning speed of the laser beam. Therefore, the packaging bag manufacturing method according to this embodiment is highly efficient in terms of production. In addition, because the scanning speed of the laser beam can be increased, it is possible to make the shape of the weak seal line a long curve or to increase the distance between weak seal lines. In other words, the packaging bag manufacturing method according to this embodiment is a highly versatile manufacturing method.

[0113] When forming a weak seal portion by heat sealing, it is necessary to arrange a heat seal bar to match the shape of the dispensing portion 20. On the other hand, in the packaging bag manufacturing method according to this embodiment, a weak seal line is formed by laser light, so such arrangement is not necessary, and the shape of the weak seal line can be easily changed.

[0114] In step (c), the laser light is absorbed by the adhesive layer L5a, the vapor-deposited layer L4, and the adhesive layer L5b, generating heat. As a result, these layers and parts of adjacent layers volatilize. Consequently, linear voids H2 are formed.

[0115] Furthermore, because the base layer L1 is a stretched polyethylene film, through-holes are created in the base layer L1 as voids form. If the laminate does not have an intermediate layer, damage occurs to the sealant layer during the through-hole formation process. On the other hand, laminate 2 has an intermediate layer, and since the intermediate layer is an unstretched polyethylene film, damage to the sealant layer is less likely to occur.

[0116] Specifically, the laser light to be irradiated can be a laser emitted from a carbon dioxide laser or a YAG laser, and from the viewpoint of productivity, the laser light emitted from a carbon dioxide laser is preferred.

[0117] The wavelength of the laser light to be irradiated may be, for example, 9.2 to 10.8 μm.

[0118] The scanning speed of the irradiated laser beam may be 100 to 1000 mm / second.

[0119] The output power of the laser beam used for irradiation may be between 20 and 80 watts.

[0120] Although a method for manufacturing a packaging bag according to one embodiment has been described in detail above, the method for manufacturing a packaging bag according to this disclosure is not limited to the above embodiment. For example, the first packaging bag may be a packaging bag other than a standing pouch. Examples of such packaging bags include two-sided bags, three-sided bags, four-sided bags, gusseted bags, or fold-over bags. Furthermore, the laminate used in the packaging bag is not limited to the above examples.

[0121] Furthermore, the method for manufacturing a packaging bag according to this disclosure may involve performing step (b) before step (c), or performing step (b) and step (c) simultaneously.

[0122] Furthermore, the method for manufacturing the packaging bag of this disclosure does not necessarily have to include step (b). In this case, a packaging bag having an opening line may be used as the first packaging bag. [Examples]

[0123] The present disclosure will be further described below with reference to examples, but the present disclosure is not limited to the following examples.

[0124] <Fabrication of laminates> <<Example 1>> The following materials were prepared as the base layer, first adhesive layer, intermediate layer, second adhesive layer, and sealant layer. • Substrate layer: Biaxially oriented HDPE film (thickness: 25 μm, density: 0.948 g / cm³) 3 (Melting point: 127.8℃) • First adhesive layer: Urethane-based adhesive • Intermediate layer: Unoriented HDPE film (thickness: 32 μm, density: 0.948 g / cm³) 3(Melting point: 135℃) • Second adhesive layer: Urethane-based adhesive • Sealant layer: C4-LLDPE (thickness: 100 μm, density: 0.916 g / cm³) 3 MFR: 4g / 10min, melting point: 104℃)

[0125] A silica vapor-deposited film (vapor-deposited layer) was formed on one of the main surfaces of the intermediate layer by vacuum deposition.

[0126] The substrate layer and the surface of the intermediate layer that does not have a vapor-deposited layer were bonded together via a first adhesive layer (thickness: 1-2 μm). Then, the vapor-deposited layer and the sealant layer were bonded together via a second adhesive layer (thickness: 1-2 μm) to obtain a laminate.

[0127] Three laminates were prepared and used as the main body (laminated 35A, 35B) and bottom material (bottom tape 40), respectively, to create the first packaging bag 1 (standing pouch) with the configuration shown in Figure 7(a). The pouch size was as follows. ·Top and bottom: 230mm ·Width: 140mm • Fold width: 40mm

[0128] An opening guideline 26 was formed on the first packaging bag, extending from the first dispensing seal section 23 across the dispensing outlet 21 to the second dispensing seal section 24. The opening guideline 26 was formed to follow the MD. The opening guideline 26 was a solid line and a straight line. The opening guideline 26 was formed by irradiating laser light from both the front and back sides of the packaging bag. At this time, when the packaging bag 1 was viewed in the thickness direction from above, the laser light was irradiated so that the opening guidelines 26 on the front and back sides of the packaging bag 10 were offset from each other. The laser light irradiation conditions were as follows: Two opening guidelines 26 were formed on the front surface of the packaging bag. One opening guideline 26 was formed on the back side of the packaging bag. The distance between adjacent opening guidelines on the front surface of the packaging bag was 1 mm when the packaging bag 10 was viewed in above. When the packaging bag 10 was viewed in above, the shortest distance between the opening guideline on the front and the opening guideline on the back was 0.5 mm.

[0129] • Laser: LP-430U (product name, manufactured by Panasonic Corporation) • Laser beam power: 80% (24W) • Scanning speed: 300mm / second • Laser light wavelength: 10.6 μm

[0130] Furthermore, five weak seal lines 28 were formed on the first packaging bag, extending from one end to the other of the spout 21, so as to be approximately parallel to the intended opening line 26. Specifically, laser light was irradiated onto two linear regions from the surface (laminated body 2A) side of the packaging bag, and onto three linear regions from the back side (laminated body 2B) side of the packaging bag. At this time, when the packaging bag is viewed in plan in the thickness direction, the laser light was irradiated so that the linear regions irradiated from the surface side of the packaging bag and the linear regions irradiated from the back side of the packaging bag were offset. When the packaging bag is viewed in plan in the thickness direction, the distance between adjacent linear regions irradiated with laser light on the surface of the packaging bag was 1 mm. On the back side of the packaging bag, the distance between adjacent linear regions irradiated with laser light was 1 mm. When the packaging bag is viewed in plan view in the thickness direction, the shortest distance between the linear area on the surface irradiated with laser light and the linear area on the back surface irradiated with laser light was set to 0.5 mm. The weak seal line 28 was a solid line and a straight line. The laser light irradiation conditions were as follows. This resulted in obtaining a second packaging bag.

[0131] • Laser: LP-430U (product name, manufactured by Panasonic Corporation) • Laser beam power: 80% (24W) • Scan speed: 450mm / second • Laser light wavelength: 10.6 μm

[0132] <<Example 2>> A first packaging bag was prepared in the same manner as in Example 1. An opening line 26 was also formed on the first packaging bag in the same manner as in Example 1. Three weak seal lines 28 were formed on the first packaging bag, extending from one end of the spout 21 to the other, approximately parallel to the opening line 26. The laser beam was irradiated only from the surface side of the packaging bag. When the packaging bag was viewed in plan in the thickness direction, the distance between adjacent linear regions irradiated with laser light on the surface of the packaging bag was 1 mm. The weak seal lines 28 were solid lines and straight. The laser beam irradiation conditions were the same as in Example 1. This resulted in the acquisition of a second packaging bag.

[0133] <<Example 3>> A second packaging bag was obtained in the same manner as in Example 2, except that three weak sealing lines 28 were formed by irradiating the packaging bag with laser light only from the back side.

[0134] <<Example 4>> A second packaging bag was obtained in the same manner as in Example 2, except that the laser scanning speed was set to 400 mm / second to form a weak sealing line 28.

[0135] <<Comparative Example 1>> A first packaging bag was obtained in the same manner as in Example 1, except that the following materials were used for the base layer and intermediate layer. An opening line 26 was formed on the first packaging bag in the same manner as in Example 1. Laser light was irradiated onto five linear regions on both the front and back sides of the first packaging bag, so as to be approximately parallel to the opening line 26. This obtained a second packaging bag. When the packaging bag is viewed in plan in the thickness direction, the laser light was irradiated so that there was no misalignment between the linear regions irradiated from the front side of the packaging bag and the linear regions irradiated from the back side of the packaging bag. The laser light irradiation conditions were the same as in Example 1. Since the ONY film of the base layer and the VM-PET film of the intermediate layer absorb the laser light, the laser light did not reach the sealant layer, and no laser-fused parts were formed on the packaging bag. The same was true in Comparative Examples 2 to 4 described later. • Substrate layer: ONY film (thickness: 15 μm) • Intermediate layer: VM-PET film (product name, PET film with aluminum vapor deposition, manufactured by Toray Film Processing Co., Ltd., film thickness 12 μm)

[0136] <<Comparative Example 2>> A second packaging bag was obtained by irradiating it with laser light in the same manner as in Example 1, except that the same materials as in Comparative Example 1 were used for the base layer and the intermediate layer.

[0137] <<Comparative Example 3>> A second packaging bag was obtained by irradiating it with laser light in the same manner as in Example 2, except that the same materials as in Comparative Example 1 were used for the base layer and the intermediate layer.

[0138] <<Comparative Example 4>> A second packaging bag was obtained by irradiating it with laser light in the same manner as in Example 3, except that the same materials as in Comparative Example 1 were used for the base layer and the intermediate layer.

[0139] <<Comparative Example 5>> A first packaging bag was prepared in the same manner as in Example 1. An opening line 26 was formed on the first packaging bag in the same manner as in Example 1. Five sealing lines were formed on the first packaging bag, extending from one end to the other of the spout 21, so as to be approximately parallel to the opening line 26. Specifically, laser light was irradiated onto five linear regions from both the front and back sides of the packaging bag. At this time, when the packaging bag was viewed in plan in the thickness direction, the laser light was irradiated so that there was no misalignment between the linear regions irradiated from the front side of the packaging bag and the linear regions irradiated from the back side of the packaging bag. The laser light irradiation conditions were the same as in Example 1. A second packaging bag was obtained as a result.

[0140] <<Comparative Example 6>> A second packaging bag was obtained in the same manner as in Example 2, except that the laser scanning speed was set to 300 mm / second to form a weak sealing line 28.

[0141] <<Comparative Example 7>> A second packaging bag was obtained in the same manner as in Example 2, except that the laser scanning speed was set to 500 mm / second to form a weak sealing line 28.

[0142] <Evaluation of tear resistance> For each example and comparative example, the second packaging bag was gripped by hand and pulled along the intended opening line. The tear resistance was evaluated according to the following criteria. The results are shown in Table 1. (standard) A: It will be opened along the designated opening line. B: It opens along the designated opening line when pressure is applied. C: Cannot be opened

[0143] <Evaluation of how easily the contents spill when the packaging bag is tilted> For each example and comparative example, 400 ml of water was filled into the second packaging bag to obtain a package. The dispensing portion was torn by pinching the gripping tab with one hand and pulling along the opening line. The package was tilted with both hands to fit the dispensing portion into the mouth of the bottle to be refilled. The presence or absence of spillage of the contents at this time was checked. The results are shown in Table 1.

[0144] <Evaluation of ease of dispensing contents when the packaging bag is pressed> For each example and comparative example, 400 ml of water was filled into the second packaging bag to obtain a package. The dispensing section was torn by pinching the gripping tab and pulling along the opening line. The dispensing section was fitted into the mouth of the bottle to be refilled, and the contents were dispensed by pressing the body of the packaging bag. The ease of dispensing the contents was evaluated according to the following criteria. The results are shown in Table 1. (standard) A: The contents are pushed out with light force. B: When you press down hard, the contents will be pushed out. C: Even when pressed with force, the contents do not come out.

[0145] <Cross-sectional observation> The cross-sections of the surface laminate and back laminate of the second packaging bag in each example and comparative example, specifically the areas where the intended opening line and weak seal line were formed, were observed using an optical microscope (observation magnification: 500x). Through-holes were confirmed to be formed in the base layer of the second packaging bag in each example and comparative example. Damage to the sealant layer was evaluated according to the following criteria. The width W1 of the fused portion M1 (weak seal line) was measured. The width W2 of the fused portion M2 (the fused portion overlapping the intended opening line) was also measured. The results are shown in Table 1. (standard) A: It has scratches. B: No scratches

[0146] <Evaluation of drop strength> 400 ml of cold water was filled into the second packaging bag of each example and comparative example, and it was dropped from a height of 1 m. After the drop, the area of ​​the second packaging bag irradiated with laser light was checked for damage and evaluated according to the following criteria. The results are shown in Table 1. (standard) A: It has scratches. B: No scratches

[0147] <Evaluation of recyclability> For each example and comparative example, the mass percentage of the same resin was calculated based on the total amount of the second packaging bag. Specifically, for Examples 1-3 and Comparative Example 5, the mass percentage of polyethylene-based resin was calculated, and for Comparative Examples 2-4, the mass percentage of nylon-based resin was calculated. The mass percentage of the resin was evaluated according to the following criteria. The results are shown in Table 1. (standard) A: The mass percentage of the same resin system is 90% or more by mass. B: The mass percentage of the same resin system is less than 90% by mass.

[0148] Table 1 shows the number of linear fusion lines formed by laser light for the second packaging bag of each example and comparative example. The number of lines was evaluated according to the following criteria. The results are shown in Table 1. The base layer of the laminates in Examples 1 to 3 is polyethylene film. Polyethylene film absorbs laser light less readily than films made of other resins. Therefore, the first packaging bags in Examples 1 to 3 are more prone to forming fusion lines that become weak seal lines compared to packaging bags using films made of other resins as the base layer. In the packaging bag manufacturing methods of Examples 1 to 3, because fusion lines are easily formed, it is possible to increase the scanning speed of the laser light. Therefore, the packaging bag manufacturing methods of Examples 1 to 3 are highly efficient in terms of production. In addition, because the scanning speed of the laser light can be increased, it is possible to make the shape of the weak seal lines into long curves or to increase the distance between weak seal lines. In other words, the packaging bag manufacturing methods of Examples 1 to 3 are highly versatile manufacturing methods. In particular, the packaging bag manufacturing method of Example 1 is even more efficient in terms of production and versatility because laser light is irradiated from both the front and back surfaces of the packaging bag. (standard) A: 8 or more B: 7 or less

[0149] [Table 1] [Explanation of Symbols]

[0150] 1, 10…Packaging bag (standing pouch), 11…Storage section, 12…Seal section, 20…Dispensing section, 21…Dispensing spout, 21a…Opening, 26…Opening line, 28…Weak seal line, 35A…Laminate (surface laminate), 35B…Laminate (backside laminate), 40…Bottom tape, H1, H2…Void, L1…Base layer, L2…Intermediate layer, L3…Sealant layer, L4…Vapor deposition layer, L5a, L5b…Adhesive layer.

Claims

1. A packaging bag consisting of opposing surface laminates and back laminates, A compartment for storing contents, A sealing portion formed around the aforementioned housing portion, A dispensing section including a spout from which the contents can be dispensed when opened, Equipped with, The dispensing section has an opening line that defines the opening of the dispensing spout, and a weak seal line located on the housing side with respect to the opening line, which is a fused section formed by linearly fusing the surface laminate and the back laminate. The surface laminate and the back laminate each have a laminated structure comprising a base layer, an adhesive layer, and a sealant layer in this order. The aforementioned substrate layer is made of polyethylene film, The sealant layer contains a polyethylene resin, A packaging bag in which the width of the fused portion is 40 to 100 μm.

2. The packaging bag according to claim 1, wherein, when the packaging bag is viewed in plan in the thickness direction, at a position overlapping with the weak seal line, at least one of the surface laminate and the back laminate has a first linear void between the base material layer and the sealant layer.

3. The packaging bag according to claim 1 or 2, wherein, as the opening line, at least one of the surface laminate and the back laminate has a second linear void between the base material layer and the sealant layer.

4. The packaging bag according to claim 1 or 2, wherein the surface laminate and the back laminate each further comprise an intermediate layer made of polyethylene film between the base material layer and the sealant layer.

5. The packaging bag according to claim 1 or 2, wherein the surface laminate and the back laminate each further comprise a vapor-deposited layer.

6. The packaging bag according to claim 1 or 2, wherein the weak seal line is a solid line or a dashed line.

7. The packaging bag according to claim 1 or 2, wherein the weak seal line is a straight line or a curved line.

8. The system further comprises an initial channel in which the surface laminate and the back laminate are not fused together. The packaging bag according to claim 1 or 2, wherein the weak seal line and the initial flow path are located along the flow path width direction intersecting the dispensing direction of the contents.

9. The packaging bag according to claim 1 or 2, comprising 6 to 8 of the aforementioned weak sealing lines.

10. The packaging bag is a self-standing packaging bag formed by heat-sealing the bottom tape and a pair of main body parts, The packaging bag according to claim 1 or 2, wherein the pair of main body portions consist of the surface laminate and the back laminate.

11. The packaging bag according to claim 1 or 2, wherein the content of the polyethylene resin is 90% by mass or more based on the total amount of the packaging bag.

Images