JP2022156814A - packaging bag - Google Patents

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 The present invention relates to a packaging bag which can be easily and smoothly opened, and which has an aesthetically pleasing opening surface without paper peeling.

A method of sealing by heat-sealing with a sealant layer applied to the inner surface is generally used for packaging bags typified by confectionery. Therefore, in order to achieve the above object, the sealant layer must have sufficient sealing properties, and must have sufficient heat-sealing strength so that the sealed portion does not peel off during transportation and other processes. is needed.

However, the excessive heat-sealing strength for protecting the contents makes it difficult for consumers to open the package easily by hand, sometimes requiring the use of tools such as scissors. Moreover, even if the package can be opened, a large amount of force is required to open the package, and there is a problem that the content jumps out due to excessive momentum at the moment of opening.

For example, in Patent Document 1,
A self-supporting packaging bag formed by heat-sealing a laminate into a bag shape, the self-supporting packaging bag being composed of a laminate including a paper base layer, and being torn by hand when the packaging bag is opened. In order to make it easy to open, for example, it is sealed on four sides, and in order to cut the upper side, a V-shaped notch is cut in the opening planned part on the upper side of the right side sealing part, starting from this V-shaped notch, It is to be opened by tearing by hand along the half-cut line.

However, if the V-shaped notch cut into the intended unsealing site is used as a starting point and the opening is manually torn along the half-cut line, the tearing strength is greater than the interlaminar strength of the paper. There is also a problem that the paper of the adherend is easily torn and destroyed, or that only the paper base material is peeled off, which is a so-called "paper peeling phenomenon". FIG. 4 is an enlarged schematic diagram of the "paper peeling phenomenon" that occurs on the unsealed surface of the conventional packaging bag when the bag is unsealed. These phenomena are not only aesthetically pleasing, but can also make characters illegible. Moreover, there is a possibility that paper dust or the like may be mixed into the contents.

JP 2008-265854 A

The present invention has been made in consideration of the above technical background, and has both good thermal adhesiveness (sealing property) and easy opening property, and furthermore, the opening surface does not peel off and is aesthetically pleasing. An object of the present invention is to provide a packaging bag.

In order to achieve the above tasks, i.e.
According to claim 1 of the present invention, two laminated films having at least a paper layer, an adhesive layer adjacent to the paper layer, an intermediate layer, and a sealant layer are laminated so that the sealant layer is the innermost layer. A packaging bag having a planned opening line consisting of a weakened line parallel to one side of the peripheral edge, which is formed by overlapping and sealing the peripheral edge,
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 on the side of the adhesive layer on the sealing varnish layer in a band shape along the line to be opened. providing a layer and
The packaging bag is characterized in that the planned opening line is formed by perforations penetrating from the paper layer side of at least one of the front and back sides to the sealing varnish layer and the release varnish layer.

The "paper peeling phenomenon" occurs when the adhesive layer between the paper layer and the intermediate layer has a stronger adhesive strength than the interlaminar strength of the paper layer, so that the paper layer peels first and the paper peels off. In the present invention, by laminating the sealing varnish layer and the release varnish layer between the paper layer and the adhesive layer, the release varnish layer and the adhesive layer are not strongly adhered to each other, but are easily peeled off, and the release varnish layer and the adhesive layer are adhered. The adhesive strength between layers is weaker than the interlayer strength of paper layers.

According to Claim 2, the packaging bag according to Claim 1 is characterized in that the planned opening line has an opening start portion at an end thereof.

According to Claim 3, the packaging bag according to Claim 1 or 2 is characterized in that the paper layer has a basis weight of 30 to 200 g/m ² .

According to the present invention, it is possible to provide a packaging bag that has both good thermal adhesiveness (sealing property) and easy-openability, and that has an aesthetically pleasing opening surface without paper peeling.

It is a front view which shows the packaging bag which concerns on this invention. FIG. 4A is an enlarged schematic diagram showing the process of opening the packaging bag according to the present invention and the configuration of the front sheet in the vicinity of the intended opening line. FIG. 2 is an exploded view and an assembly drawing showing the packaging bag according to the present invention; It is the figure of the process which opened the conventional packaging bag, and the enlarged schematic diagram of an opening surface.

An embodiment as an example of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a packaging bag 20 of the present invention, and is a front view of a standing pouch with a planned opening line 29 formed by perforation. Of course, instead of a standing pouch, a general-purpose four-side seal packaging bag or a three-side seal packaging bag may be used. The packaging bag 20 has a front sheet 21 and a back sheet 22 with the sealant surfaces facing each other, a top seal portion 24, a left seal portion 25, a right seal portion 26, and a bottom sheet folded with the sealant layer on the front side. 23 is sandwiched between the front sheet 21 and the back sheet 22 to form a gusset bottom seal portion 27. - 特許庁

A packaging bag 20 according to the present invention is composed of a paper layer 2, an intermediate layer 3, and a sealant layer 4, and is an easy-to-use laminated film 1 (see FIG. 2(b)) laminated via adhesive layers 5 and 6, respectively. The openable packaging bag 20 has a linear scheduled opening line 29 parallel to the top seal portion 24.例文帳に追加An opening start part 28 is provided at both left and right ends of the planned opening line 29, and when opening, the upper part of the opening start part 28 can be grasped and torn.

Fig. 2(a) shows a process in which the top of the opening start portion 28 is grasped and the edge of the grasped sheet is started to be torn toward the front, and Fig. 2(b) shows the front sheet near the planned opening line 29 in the first embodiment. 21 is an enlarged schematic diagram showing the configuration of 21. FIG.

For example, the front sheet 21 using the laminated film 1 of the present invention shown in FIG.
Overprint varnish layer 10/ink layer 9/base layer 2 (paper base layer)/filler varnish layer 7/release varnish layer 8/adhesive layer 5/intermediate layer 3/adhesive layer 6/sealant layer 4 in order from the outside are stacked in the order of However, the ink layer 9, the overprint varnish layer 10, the sealing varnish layer 7, and the release varnish layer 8 are applied only partially or locally. It has striped layers. Here, an unsealing line 29 is provided deep in the thickness direction from the center of the ink layer 9 . Here, half-punched perforation processing is performed. The tip of the perforation is processed so as to reach the depth of the release varnish layer 8 .

FIG. 3(a) shows a developed view of the front sheet 21 and the back sheet 22. FIG. A paper layer is incorporated in the front sheet 21 and the back sheet 22 as a base material layer or an intermediate layer. Paper is used for the base material layer 2 in the first embodiment. Between the adhesive layer 5 adjacent to the paper base layer 2, a filling varnish layer 7 is applied on the side of the paper base layer 2, and a release varnish layer 8 is applied on the side of the adhesive layer 5 thereon. , are provided in strips. The planned opening line 29 is processed only on the front sheet 21 side formed by perforations penetrating from the paper layer 2 side to the filling varnish layer 7 and the release varnish layer 8, and is processed on the back sheet 22 side. not However, the sealing varnish layer 7 and the peeling varnish layer 8 are processed in strips at the same positions on the back sheet 22 as to the planned opening line 29 . There is no problem even if the planned opening line 29 is processed on the back sheet 22, but it is necessary to process it at the same position on the front and back. There are no particular restrictions on the method of forming the planned opening line 29, and a method using a knife or a cutting die, or a method using a laser may be used.

FIG. 3(b) shows an assembly drawing of the front sheet 21 and the back sheet 22. As shown in FIG. As shown in FIG. 3B, the left and right ends of the film are aligned and fused so that the filling varnish layer 7 and the release varnish layer 8 are in the same position on the front and back, and then the bottom seal (bottom seal portion 28 ) to change the shape from a cylindrical shape to a bag shape, the content is injected from the open top, and the upper side of the projected unsealing line 29 is fused and top-sealed (top-seal portion 25).

<Paper peel prevention mechanism>
In FIG. 2(a), the sealed portion where the front sheet 2 and the back sheet 3 are fused is grasped, and the unsealing starting part 28 is used as the starting point of unsealing, along the planned unsealing line 29 processed with perforations or the like. It shows the process of pressing and cutting. The release varnish layer 8 and the adhesive layer 5 described above are not strongly adhered to each other and are in an easy-separable state. Therefore, the adhesive strength between the release varnish layer 8 and the adhesive layer 5 becomes weaker than the interlaminar strength of the paper. Interfacial peeling starts between 8 and the adhesive layer 5, and no peeling occurs between the paper substrate layers. In this manner, the perforation processing of the planned opening line 29 serves as a guide for starting peeling on the peeling varnish 8 . This action solves the problem that the printed characters cannot be read due to the cosmetic appearance after opening and the peeling of the paper.

<Base material layer>
Paper, an olefin-based resin film, a polyethylene terephthalate film, a polyamide film, and the like can be considered as the base material layer used for the laminated film 1 constituting the packaging bag 20 of the present invention. When paper is used as the substrate layer, paper with a basis weight of 30 g/m ² to 200 g/m ² is used, and paper with a basis weight of 50 g/m ² to 120 g/m ² is particularly preferred. Paper of 30 g/m ² or less needs to have a thick inner layer, but this causes an environmental problem that the percentage of plastic packaging bags increases too much. Paper with a weight of 200 g/m ² or more tends to generate excessive force when tearing, deteriorates bag-making properties such as being too stiff and difficult to fold, and becomes difficult to fuse due to excessive heat insulation. , the product price becomes too high.

Olefin resins include low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer. Polymers, ionomer resins and the like are contemplated. Olefin-based resins are also difficult to break if they are too thick, so countermeasures such as making them thinner, using non-stretched resin films, and using uniaxially stretched films that are easily broken are required. When using a polyethylene terephthalate film or a polyamide film, it is preferable to use a thin film of 20 μm or less, or a uniaxially stretched film having linear cuttability. When paper is not used for the base layer, paper is used for the intermediate layer. Even in that case, it is preferable to use paper with a basis weight of 30 g/m ² to 200 g/m ² .

<Print layer>
When the laminate film 1 of the present invention is used for practical use as a packaging bag 20 or the like, the print pattern layer 9 can be usually formed on the base material layer. The printed pattern layer 9 can be formed by printing a desired printed pattern including, for example, characters, figures, symbols, pictures, and the like. Specifically, the printed pattern layer 9 is mainly composed of an ink vehicle consisting of one or more resins, etc., and, if necessary, a plasticizer, a stabilizer and an antioxidant. agents, light stabilizers, ultraviolet absorbers, curing agents, cross-linking agents, lubricants, antistatic agents, fillers, and other additives may be optionally added. A coloring agent is added, and the mixture is sufficiently kneaded with a solvent, a diluent, etc. to prepare an ink composition. , characters, figures, symbols, pictures, etc., to form the printed pattern layer 9 .

<Middle layer>
Paper, olefin resin film, polyethylene terephthalate film, polyamide film, etc. can be considered for the intermediate layer 3 as well. In the case of paper, the use of paper having a basis weight of 30 g/m ² to 200 g/m ² is the same as for the base material layer. The olefin-based resin film is also made thin, a non-stretched resin film is used, or a uniaxially stretched film that is easily broken is used. Furthermore, polyethylene terephthalate film, polyamide film, etc. can also be used as a barrier layer to improve the storage stability of the contents. It's best to use film.

<Sealant layer>
As the sealant layer 4, a polyolefin resin is preferable. Specifically, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid Polyolefin resins such as ethyl copolymers (EAA), ionomers and polypropylene can be used. These resins can be formed into a film by a T-die or an extruder such as an inflation machine. It may be a single layer or multiple layers. The thickness of the film is preferably in the range of 50-200 μm. In particular, the cuttability is further improved by using a tearable polyolefin resin.

<Adhesive layer>
An adhesive for dry lamination can be used as the adhesive layer. 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, and the like can be used. . A dry lamination method can be used as a bonding method using the adhesive. In addition, lamination may be performed while the sealant layer side is formed into a film by an extruder lamination machine, or sand polyethylene processing may be performed.

<Varnish layer>
The filling varnish layer 7 is laminated on the paper layer as a base for the release varnish layer 8 . If there is no underlayer, the release varnish will permeate the paper fibers and create shades. The filling varnish layer 7 may be partially laminated with low-density polyethylene, or may be printed with polyvinyl alcohol or clay or coated with a coater. Below the top seal portion, the coating is applied in parallel with the top seal portion centering on the position of the planned unsealing line 29. - 特許庁

As the release varnish layer 8, a silicone-based release agent or a non-silicone-based release agent that does not have strong adhesiveness is applied to the adhesive layer 5 in a belt shape by printing or the like. It is placed on the strip-shaped coating surface coated with the sealing varnish layer 7, and the coating width is set so as to match the height position for processing the planned unsealing line 29. - 特許庁

In addition, if it is necessary to improve various physical properties of the laminated film 1, for example, to improve the rigidity, drop strength, puncture strength, etc. of the laminated film 1, to improve barrier properties against water vapor, oxygen gas, etc. can also be provided with a barrier layer.

As the barrier layer, for example, an aluminum foil, an aluminum-deposited polyester film, an inorganic oxide-deposited polyester film, a polyamide film, or the like can be used. Of course, in order to laminate the barrier layer, it is possible to bond them together by a dry lamination method via an adhesive layer.

Inorganic oxides to be deposited 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. Available. Among them, silicon oxide, aluminum oxide, magnesium oxide and the like are preferable from the viewpoint of productivity and cost.

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

The packaging bag 20 using the laminated film 1 of the present invention has both good thermal adhesiveness (sealing property) and easy opening property as the sealant layer 4, and furthermore, the peel strength is too strong, so that the paper of the adherend is broken. It is suitably used for packaging bags that do not cause so-called "paper peeling phenomenon". In addition to packaging bags, it is possible to develop applications such as lid materials for paper containers, as the demand for paper plastic containers is increasing in response to environmental issues and revisions to the Container Recycling Law.

Each packaging bag having the following configuration was opened at a specified position, and the presence or absence of paper peeling was confirmed.
<Example 1>
Overprint varnish/ink/paper base layer/filler varnish layer/release varnish layer/adhesive 1/polyethylene terephthalate (thickness: 12 μm)/adhesive 2/linear low density Sheets composed of polyethylene (60 μm thick) were used. Paper with a basis weight of 100 g/m ² was used for the paper base layer. The sheet was cut into squares with a length of 200 mm and a width of 200 mm. At the same time, the easy-open breaking line was processed so as to form a half-blanked perforation at a position 25 mm from the upper end on the side of the top seal portion, with a depth from the outside to the release varnish layer.
Next, the peripheries of the front sheet and the back sheet were sealed to produce a three-sided bag product, and cutouts were formed on the left and right sides of the easy-to-open breaking line.

<Example 2>
Overprint varnish/ink/paper base layer/filler varnish layer/release varnish layer/low density polyethylene (thickness 18 μm)/polyethylene terephthalate (12 μm)/adhesive 2/straight chain A sheet of low-density polyethylene (thickness 60 μm), and the adhesive 1 portion of Example 1 is laminated with sand polyethylene, which is bonded using molten polyethylene extruded with a T-die of an extrusion lamination machine. did.
Otherwise, the same processing as in Example 1 was performed.

<Example 3>
The structures of the front sheet and the back sheet were the same as in Example 1, but the perforation of the easy-to-open breaking line was not processed.
Otherwise, the same processing as in Example 1 was performed.

<Example 4>
As the front sheet and the back sheet, polyethylene terephthalate (thickness 12 μm)/adhesive/ink/paper base layer/filler varnish layer/release varnish layer/adhesive/polyethylene terephthalate (thickness 12 μm)/adhesive/ A sheet of linear low density polyethylene (thickness 60 μm) was prepared. Otherwise, the same processing as in Example 1 was performed.

<Comparative Example 1>
As the front sheet and the back sheet, sheets were used which did not include a filling varnish layer and a release varnish layer, consisting of overprint varnish/ink/paper base layer/adhesive/unstretched polypropylene (thickness: 60 μm) from the outside. Paper with a basis weight of 100 g/m ² was used for the paper base layer. The sheet was cut into squares with a length of 200 mm and a width of 200 mm. However, the easy-open breaking line was not processed. Otherwise, the same processing as in Example 1 was performed.

<Comparative Example 2>
As the front and back sheets, a sheet composed of polyethylene terephthalate (thickness 12 μm)/adhesive/6-nylon (thickness 12 μm)/adhesive/linear low-density polyethylene (thickness 60 μm) was used from the outside. , did not include the paper layer. The sheet was cut into squares with a length of 200 mm and a width of 200 mm. However, the easy-open breaking line was not processed. Otherwise, the same processing as in Example 1 was performed.

<Evaluation method>
The packaging bag was opened by grasping the left end of the top seal portion of the packaging bag and immediately below the notch of the left seal portion, and vigorously pulling the left end of the top seal portion toward the front to check for occurrence of paper peeling. A sample with no paper peeling was rated as ◯, and a sample with paper peeling was rated as x.

<Evaluation results>
In Examples 1, 2, 3, and 4, no paper peeling occurred. In Comparative Example 1, paper peeling occurred. Since Comparative Example 2 does not contain paper, there is no paper peeling phenomenon.
The above results are summarized in Table 1.

From the above results, the front sheet and the back sheet, between the paper layer and the adhesive layer in contact with the paper layer, are strip-shaped along the planned unsealing line, and the sealing varnish-coated portion in contact with the paper layer, A release varnish-coated portion is provided on the adhesive layer side of the sealing varnish-coated portion, and the planned opening line is processed on the front sheet, so that when opened along the planned opening line, the paper peeling phenomenon occurs. I got a packaging bag that didn't.

1 Laminated film 2 Base layer (paper base layer)
3 Intermediate layer 4 Sealant layers 5, 6 Adhesive layer 7 Sealing varnish layer 8 Release varnish layer 9 Printed pattern layer 10 Overprint varnish Layer 20 Packaging bag 21 Front sheet 22 Back sheet 23 Bottom sheet 24 Top seal portion 25 Left seal portion 26 Right seal portion 27 Bottom sealing portion 28 Opening start portion 29 Opening planned line 30 Varnish layer

Claims (3)

Two laminated films, each having at least a paper layer, an adhesive layer adjacent to the paper layer, an intermediate layer, and a sealant layer, are laminated facing each other so that the sealant layer is the innermost layer, and the peripheral edges are sealed. A packaging bag having a planned opening line consisting of a weakened line parallel to one side of the peripheral edge,
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 on the side of the adhesive layer on the sealing varnish layer in a band shape along the line to be opened. providing a layer and
The packaging bag, wherein the planned opening line is formed by a perforation penetrating from the paper layer side of at least one of the front and back sides to the sealing varnish layer and the release varnish layer. 2. The packaging bag according to claim 1, wherein the planned opening line has an opening start portion at its end. 3. The packaging bag according to claim 1, wherein the paper layer has a basis weight of 30 to 200 g/m ² .

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