Packaging bags

Abstract

To provide a packaging bag that has both excellent thermal adhesiveness (sealability) and easy-to-open properties, and further is excellent in appearance because a paper of an opening surface is prevented from peeling.SOLUTION: A packaging bag is formed by oppositely superposing two front and back laminated films, which have at least a paper layer, an adhesion layer adjacent to the paper layer, an intermediate layer and a sealant layer, on each other so that the sealant layer becomes an innermost layer and sealing peripheral edges thereof, and has opening scheduled lines made of fragile lines parallel to one side in the peripheral edge. Between at least the paper layer and the adhesion layer adjacent to the paper layer are formed, in a belt-line shape along the opening schedule lines, a wood filling varnish layer which contacts the paper layer and a peelable varnish layer near the adhesion layer on the wood filling varnish layer. The opening scheduled lines are formed of perforations penetrating from the paper layer side of either of the front and back laminated films to the wood filling varnish layer and the peelable varnish layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging bag which can be easily and smoothly opened, and which has an aesthetically pleasing opening surface without peeling off the paper. [Background technology]

[0002] Packaging bags, such as those for confectionery, are generally sealed by heat sealing using a sealant layer applied to the inner surface. Therefore, in order to achieve the above-mentioned object, the sealant layer must have sufficient sealing properties and sufficient heat seal strength so that the sealed portion does not peel off during transportation, etc.

[0003] However, the excessive heat seal strength required to protect the contents means that consumers cannot easily open the package by hand, and must use tools such as scissors. Even if the package can be opened, it requires a large amount of force, and the force can cause the contents to fly out at the moment of opening.

[0004] For example, in Patent Document 1, A self-supporting packaging bag is formed by heat-sealing a laminate into a bag shape. This self-supporting packaging bag is composed of a laminate including a paper base layer, and in order to make it easy to open the packaging bag by tearing it by hand, for example, the four sides are sealed and a V-shaped notch is cut into the intended opening area above the right side seal part in order to tear the upper edge, and the bag is opened by manually tearing along the half-cut line starting from this V-shaped notch.

[0005] However, when the bag is opened by manually tearing along the half-cut line starting from the V-shaped notch cut at the intended opening location, the tear strength is greater than the interlaminar strength of the paper, so the bag is torn at an angle, destroying the adherend paper, or the paper base material is peeled off, which is a problem that occurs easily. Figure 4 is an enlarged schematic diagram of the "paper peeling phenomenon" that occurred on the opening surface when a conventional packaging bag was opened. Not only is this unsightly, but it can also make the text unreadable. There is also a risk of paper powder and other substances getting into the contents. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-265854 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above technical background, and has an objective of providing a packaging bag that combines good thermal adhesion (sealing properties) with easy opening properties, and further has an aesthetically pleasing opening surface that does not peel off. [Means for solving the problem]

[0008] In order to achieve the above objectives, namely: According to claim 1 of the present invention, a laminated film is formed by stacking two sheets of laminated film, each having at least a paper layer, an adhesive layer adjacent to the paper layer, an intermediate layer, and a sealant layer, facing each other so that the sealant layer is the innermost layer, and sealing the periphery. parallel A packaging bag having an opening line consisting of a weakened line, Between at least the paper layer and the adhesive layer in contact with the paper layer, a sealing varnish layer in contact with the paper layer and a release varnish layer on the adhesive layer side on the sealing varnish layer are provided in a strip shape along the intended opening line, The opening line is at least on the front and back Two laminated filmsThis packaging bag is characterized in that it is formed by perforations that penetrate from one of the paper layer sides to the sealing varnish layer and the release varnish layer.

[0009] The "paper peeling phenomenon" occurs when the adhesive strength of the adhesive layer between the paper layer and the intermediate layer is stronger than the interlayer strength of the paper layer, causing the paper layer to peel off first. In the present invention, by laminating a sealing varnish layer and a release varnish layer between the paper layer and the adhesive layer, the release varnish layer and the adhesive layer do not adhere strongly to each other and are in an easily peelable state, making the adhesive strength between the release varnish layer and the adhesive layer weaker than the interlayer strength of the paper layer.

[0010] According to claim 2, there is provided the packaging bag according to claim 1, characterized in that the opening line has an opening start portion at an end thereof.

[0011] According to claim 3, the basis weight of the paper layer is 30 to 200 g / m 2 The packaging bag according to claim 1 or 2 is characterized in that: Effect of the Invention

[0012] According to the present invention, it is possible to provide a packaging bag which has both good thermal adhesiveness (sealing property) and easy opening, and further has an aesthetically pleasing opening surface which does not peel off. [Brief description of the drawings]

[0013] [Figure 1] 1 is a front view showing a packaging bag according to the present invention. [Diagram 2] 1A to 1C are diagrams showing a process of setting up an opening for the packaging bag according to the present invention, and an enlarged schematic diagram showing the configuration of the front sheet in the vicinity of the intended opening line. [Diagram 3] 1A and 1B are a development view and an assembly view showing a packaging bag according to the present invention. [Figure 4] 1A to 1C are diagrams showing the process of opening a conventional packaging bag and an enlarged schematic diagram of the opening surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a front view of an example of a packaging bag 20 of the present invention, in which a planned opening line 29 is formed by perforation on a standing pouch. Of course, it is not limited to a standing pouch, and may be a general-purpose packaging bag sealed on four sides or a packaging bag sealed on three sides. The packaging bag 20 is formed by facing the sealant surfaces of a front sheet 21 and a back sheet 22, and is formed of a top seal portion 24, a left seal portion 25, a right seal portion 26, and a bottom seal portion 27 in which a bottom sheet 23 folded with the sealant layer facing outward is sandwiched between the front sheet 21 and the back sheet 22 to form a gusset.

[0015] The packaging bag 20 according to the present invention is an easy-open packaging bag 20 using a laminated film 1 (see FIG. 2(b)) consisting of a paper layer 2, an intermediate layer 3, and a sealant layer 4, which are laminated via adhesive layers 5 and 6, and has a top seal portion 24. parallel The package has a straight opening line 29. Opening start parts 28 are provided on both the left and right ends of the opening line 29, and when opening the package, the upper part of the opening start part 28 can be grasped and torn as a trigger.

[0016] Figure 2(a) shows the process of gripping the upper part of the opening start portion 28 and starting to tear the gripped end of the sheet toward the front, and Figure 2(b) is an enlarged schematic diagram showing the configuration of the front sheet 21 near the intended opening line 29 in the first embodiment.

[0017] The front sheet 21 using the laminated film 1 of the present invention shown in FIG. 2(a) can be, for example, From the outside, the layers are stacked in the order of overprint varnish layer 10 / ink layer 9 / base material layer 2 (paper base material layer) / sealing varnish layer 7 / release varnish layer 8 / adhesive layer 5 / intermediate layer 3 / adhesive layer 6 / sealant layer 4. However, the ink layer 9, overprint varnish layer 10, sealing varnish layer 7, and release varnish layer 8 are applied only partially or locally, and the release varnish layer 8 in particular is a strip-shaped layer of a certain width. Here, a planned opening line 29 is applied deep in the thickness direction from the center of the ink layer 9. Here, half-punched perforations are applied. The end of the perforations is processed so that it reaches the depth of the release varnish layer 8.

[0018] FIG. 3(a) shows a development view of the front sheet 21 and the back sheet 22. The front sheet 21 and the back sheet 22 incorporate a paper layer as a base layer or an intermediate layer. In the first embodiment, paper is used for the base layer 2. Between the adhesive layer 5 adjacent to the base layer 2 of paper, a sealant varnish layer 7 is applied on the paper base layer 2 side, and a release varnish layer 8 is provided in a strip shape on the adhesive layer 5 side above it. The opening planned line 29 is processed only on the front sheet 21 side formed by a perforation that penetrates from the paper layer 2 side to the sealant varnish layer 7 and the release varnish layer 8, and is not processed on the back sheet 22. However, the sealant varnish layer 7 and the release varnish layer 8 are also processed in a strip shape on the back sheet 22 in the same position as this opening planned line 29. There is no problem if the opening planned line 29 is processed on the back sheet 22, but it is necessary to process it in the same position on the front and back. There are no particular limitations on the method for forming the intended opening line 29, and it may be a method using a blade or a die, or a method using a laser.

[0019] Figure 3(b) shows an assembly diagram of the front sheet 21 and the back sheet 22. As shown in Figure 3(b), the left and right ends of the film are aligned and fused so that the sealing varnish layer 7 and the release varnish layer 8 are in the same position on the front and back, and then the bottom is sealed (bottom seal part 28) to change the shape from a cylindrical shape to a bag shape, the contents are poured from the open top, and the upper side above the intended opening line 29 is fused to seal the top (top seal part 25).

[0020] <Paper peeling prevention mechanism> FIG. 2(a) shows the process of gripping the seal part where the front sheet 2 and the back sheet 3 are fused together, and pushing through the opening line 29 processed by perforation or the like, starting from the opening start part 28. The above-mentioned peeling varnish layer 8 and adhesive layer 5 are not strongly bonded and are in an easily peelable state. Therefore, the adhesive strength between the peeling varnish layer 8 and adhesive layer 5 is weaker than the interlayer strength of the paper, and when trying to push through the front sheet 21 along the opening line 29, the interfacial peeling begins between the peeling varnish layer 8 and adhesive layer 5 before the paper base layer 2, and there is no peeling between the paper base layers, so the paper peeling phenomenon does not occur. In this way, the perforation processing of the opening line 29 serves as a guide for starting peeling on the peeling varnish 8. This action solves the problems of the appearance after opening being unsightly and the printed characters becoming illegible due to peeling of the paper.

[0021] <Base material layer> The base layer used in the laminated film 1 constituting the packaging bag 20 of the present invention may be paper, an olefin-based resin film, a polyethylene terephthalate film, a polyamide film, or the like. When paper is used as the base layer, the basis weight is 30 g / m 2 ~200g / m 2 Paper of 50 g / m2 is used. 2 ~120g / m 2 This is a 30 g / m 2 The following papers require a thicker inner layer, but this would increase the proportion of plastic in the packaging bag, which would be environmentally problematic: 200g / m 2 This is because the above papers can cause problems such as excessive force being generated when torn, being too stiff and difficult to bend, which makes it difficult to make bags, having too high insulation properties which makes it difficult to fuse, and making the product expensive.

[0022] Olefin resins include low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene Possible materials include olefin-based resins, such as ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, and ionomer resins. Olefin-based resins are also difficult to break if they are too thick, so measures such as using thinner films, non-oriented resin films, or uniaxially oriented films that are easier to break are required. When using polyethylene terephthalate films or polyamide films, it is best to use thin films of 20 μm or less, or uniaxially oriented films with linear cutting properties. If paper is not used for the base layer, paper should be used for the intermediate layer. In this case, too, the basis weight should be 30 g / m2. 2 ~200g / m 2 It is recommended to use paper of this type.

[0023] <Print layer> When the laminated film 1 of the present invention is used for practical use as a packaging bag 20 or the like, a printed pattern layer 9 can usually be formed on the above-mentioned base layer. The printed pattern layer 9 can be formed by printing a desired printed pattern consisting of, for example, characters, figures, symbols, designs, and the like. Specifically, the printed pattern layer 9 can be formed by first using an ink vehicle consisting of one or more resins as the main component, optionally adding one or more additives such as plasticizers, stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, and the like, if necessary, and further adding colorants such as dyes and pigments, and thoroughly kneading with a solvent, a diluent, and the like to prepare an ink composition, and then using the ink composition to print a desired printed pattern consisting of characters, figures, symbols, designs, and the like using a known printing method such as gravure printing or offset printing, for example, to form the printed pattern layer 9.

[0024] <Middle Class> The intermediate layer 3 may also be made of paper, an olefin resin film, a polyethylene terephthalate film, a polyamide film, or the like. In the case of paper, the basis weight is 30 g / m 2 ~200g / m 2The use of paper is the same as for the base layer. For the olefin resin film, a thin film, a non-oriented resin film, or a uniaxially oriented film that is easy to break can be used. Furthermore, polyethylene terephthalate film, polyamide film, etc. can be used as a barrier layer to improve the storage stability of the contents, so in that case, it is better to use a thin film of 20 μm or less, or a uniaxially oriented film with linear cutting properties.

[0025] <Sealant layer> The sealant layer 4 is preferably made of a polyolefin resin. Specifically, polyolefin resins such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EAA), ionomer, and polypropylene can be used. These resins can be formed into a film using an extruder such as a T-die or inflation. It may be a single layer or multiple layers. The thickness of the film is preferably in the range of 50 to 200 μm. In particular, the use of a polyolefin resin having tearability further improves the cuttability.

[0026] <Adhesive layer> For the adhesive layer, a dry lamination adhesive can be used. For example, a two-component curing urethane adhesive, a polyester urethane adhesive, a polyether urethane adhesive, an acrylic adhesive, a polyester adhesive, a polyamide adhesive, an epoxy adhesive, etc. can be used. The lamination method using the above adhesive can be a dry lamination method. In addition, the sealant layer side may be laminated while forming a film using an extruder lamination machine, or sand polyethylene processing may be used.

[0027] <Varnish layer> The sealing varnish layer 7 is laminated on the paper layer as a base for the release varnish layer 8. Without a base layer, the release varnish will penetrate the paper fibers and cause shading. The sealing varnish layer 7 may be partially laminated with low density polyethylene, or polyvinyl alcohol or clay may be printed or applied with a coater. Below the top seal part, centered on the position of the intended opening line 29, parallel Then coat.

[0028] The release varnish layer 8 is formed by applying a silicone-based release agent or a non-silicone-based release agent, which does not have strong adhesive properties to the adhesive layer 5, in a strip shape by printing or the like. The sealing varnish layer 7 is placed on the strip-shaped coated surface, and the coating width is set to match the height position where the opening line 29 is to be processed.

[0029] In addition, if it is necessary to improve the physical properties of the laminate film 1, for example, to improve the rigidity, drop strength, puncture strength, etc. of the laminate film 1, or to improve the barrier properties against water vapor, oxygen gas, etc., a barrier layer can be provided.

[0030] The barrier layer may be, for example, an aluminum foil, an aluminum-deposited polyester film, an inorganic oxide-deposited polyester film, a polyamide film, etc. Of course, in order to laminate the barrier layer, it is possible to bond the layers together by a dry lamination method via an adhesive layer.

[0031] Examples of inorganic oxides that can be used for deposition include metal oxides such as silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, tin oxide, sodium oxide, boron oxide, titanium oxide, lead oxide, zirconium oxide, and yttrium oxide. Among these, silicon oxide, aluminum oxide, and magnesium oxide are preferred from the standpoints of productivity and cost.

[0032] The bottom sheet 23 may have the same structure as the front sheet 21 and the back sheet 22. However, from the viewpoint of ease of use and productivity, it is preferable to use a biaxially oriented film such as polyethylene terephthalate, polyamide, or polypropylene for the surface to be folded. The bottom sheet 23 may be made thinner than the front sheet 21 and the back sheet 22 to facilitate smooth opening and closing.

[0033] The packaging bag 20 using the laminated film 1 of the present invention is suitable for use as a packaging bag that combines good thermal adhesion (sealing property) and easy opening as the sealant layer 4, and is free of the so-called "paper peeling phenomenon" in which the adherend paper is destroyed due to excessive peel strength. Furthermore, in addition to packaging bags, the demand for turning plastic containers into paper has increased in response to environmental issues and amendments to the container recycling law, and the application can be expanded to cover paper containers and the like. EXAMPLES

[0034] The packaging bags having the following configuration were opened at the specified positions and checked for the presence or absence of peeling of the paper. <Example 1> The front and back sheets were made up of the following layers from the outside: overprint varnish / ink / paper base layer / sealing varnish layer / release varnish layer / adhesive 1 / polyethylene terephthalate (12 μm thick) / adhesive 2 / linear low-density polyethylene (60 μm thick). The paper base layer had a basis weight of 100 g / m 2 The sheet was cut into a square 200 mm long and 200 mm wide. At the same time, an easy-to-open tear line was created at a position 25 mm from the top end of the top seal side, with a half-punched perforation at a depth from the outside to the release varnish layer. Next, the edges of the front sheet and the back sheet were sealed to create a three-sided bag, and notches were made on the left and right of the easy-open tear line.

[0035] <Example 2> The front and back sheets are, from the outside, overprint varnish / ink / paper base layer / sealing varnish layer / peeling varnish layer / low-density polyethylene (thickness 18 μm) / polyethylene terephthalate. The sheet had a composition of talc (12 μm) / adhesive 2 / linear low-density polyethylene (thickness 60 μm), and the adhesive 1 portion of Example 1 was bonded with sand polyethylene that was bonded using molten polyethylene extruded through the T-die of an extrusion lamination machine. The rest of the process was the same as in Example 1.

[0037] <Example> 3 > The front sheet and back sheet were made of a sheet having the following composition from the outside: polyethylene terephthalate (thickness 12 μm) / adhesive / ink / paper base layer / sealing varnish layer / release varnish layer / adhesive / polyethylene terephthalate (thickness 12 μm) / adhesive / linear low-density polyethylene (thickness 60 μm). The rest of the processing was the same as in Example 1.

[0038] <Comparative Example 1> The front and back sheets were made of a composition consisting of overprint varnish / ink / paper base layer / adhesive / unstretched polypropylene (60 μm thick) from the outside, without a sealing varnish layer or a release varnish layer. The paper base layer had a basis weight of 100 g / m 2 The paper was used. The sheet was cut into a square with a length of 200 mm and a width of 200 mm. However, no easy-to-open tear line was provided. The rest of the process was the same as in Example 1.

[0039] <Comparative Example 2> The front sheet and the back sheet were made of polyethylene terephthalate (12 μm thick) / adhesive / 6-nylon (12 μm thick) / adhesive / linear low-density polyethylene (60 μm thick) from the outside, and did not include a paper layer. The sheet was cut into a square with a length of 200 mm and a width of 200 mm. However, no easy-to-open break line was processed. The rest of the processing was the same as in Example 1.

[0040] <Evaluation method> The left end of the top seal of the packaging bag and the area just below the cutout in the left seal were grasped, and the left end of the top seal was pulled forcefully toward the front to open the bag, and the presence or absence of peeling of the paper was confirmed. Those that did not have peeling of the paper were marked with an ◯, and those that had peeling of the paper were marked with an ×.

[0041] <Evaluation Results> Example 1, Example 2, Example In 3 In Comparative Example 1, paper peeling occurred. In Comparative Example 2, the paper peeling phenomenon did not occur because the composition did not include paper. The above results are summarized in Table 1.

[0042] [Table 1]

[0043] From the above results, by providing the front sheet and the back sheet with a sealing varnish coated area that contacts the paper layer in a band-like shape along the intended opening line, between the paper layer and the adhesive layer that contacts the paper layer, and a release varnish coated area on the adhesive layer side above the sealing varnish coated area, and by processing the intended opening line into the front sheet, a packaging bag that does not experience paper peeling when opened along the intended opening line was obtained. [Explanation of symbols]

[0044] 1. Laminated film 2...Base material layer (paper base material layer) 3. Middle layer 4. Sealant layer 5,6...Adhesive layer 7. Filler varnish layer 8. Peeling varnish layer 9. Printing pattern layer 10. Overprint varnish layer 20...Packaging bag 21 Front seat 22. Rear seat 23... Bottom sheet 24···Top seal part 25 Left side seal 26 Right side seal 27 Bottom seal 28...Opening start part 29...Opening line 30... Varnish layer

Claims

1. A packaging bag is formed by stacking two laminated films, one on each side, on either side, with at least a paper layer, an adhesive layer adjacent to the paper layer, an intermediate layer, and a sealant layer, so that the sealant layer is the innermost layer, and sealing the periphery, and has an opening line formed by a weakened line parallel to one side of the periphery, Between at least the paper layer and the adhesive layer in contact with the paper layer, a sealing varnish layer in contact with the paper layer and a release varnish layer on the adhesive layer side on the sealing varnish layer are provided in a strip shape along the intended opening line, A packaging bag characterized in that the intended opening line is formed by a perforation that penetrates from the paper layer side of at least one of the two laminated films, front and back, to the sealing varnish layer and the release varnish layer.

2. 2. The packaging bag according to claim 1, wherein the opening line has an opening start portion at an end thereof.

3. The basis weight of the paper layer is 30 to 200 g / m ２ 3. The packaging bag according to claim 1 or 2,

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