JP7528452B2 - Packaging Containers - Google Patents

Description

The present invention relates to packaging containers for storing various liquids and powders, and in particular to packaging containers that are made primarily from paper, a renewable material, and that reduce the burden on the environment.

Conventionally, flexible packaging containers have been widely used for storing toiletries such as shampoo and conditioner, and various foods. Conventional flexible packaging containers have been made of synthetic resin film laminates made by laminating a synthetic resin film with relatively high heat resistance, such as polyethylene terephthalate (PET) resin film or nylon (Ny) film, with a synthetic resin film that melts at a relatively low temperature, such as low-density polyethylene (LDPE) resin, and then heat-sealing the laminate into a bag shape.

However, in recent years, issues such as global warming caused by fossil fuels and marine pollution caused by plastic materials have come to be seen as problems, and from the standpoint of protecting the global environment, there has been a growing interest in reducing the use of plastics made from fossil fuels as much as possible, and in favor of packaging materials made from paper made from wood, a renewable and sustainable resource. As wood absorbs carbon dioxide from the air during its growth, it is a carbon-neutral material, which means that carbon dioxide emissions when it is discarded are counted as essentially zero.

The refill pouch described in Patent Document 1 is a refill pouch for storing a relatively high-viscosity liquid, characterized in that at least one wall surface is formed from a laminated film including a paper layer, a cut line is provided at the upper edge for forming a pouring outlet for the contents, and a fold line is provided for folding the container vertically in half when pouring the contents.

The reason for using paper for the refill pouch described in Patent Document 1 is that when squeezing out highly viscous contents, it is easier to do so if the container wall is more rigid, and this is not done with any consideration for protecting the global environment.

The refill pouch described in Patent Document 1 uses a laminate containing a paper layer as the middle layer of at least one wall, but a large proportion of it is made up of plastic materials other than paper, which is insufficient from the perspective of sustainability. In addition, although a fold line is provided to make it easier to fold the container in half when pouring out the contents, the refilling process can be difficult depending on the container's opening diameter and the viscosity of the contents. Furthermore, no measures have been taken regarding filling and opening.

On the other hand, when filling a stand-up pouch, it is necessary that the bottom be easy to open, but if paper is used for the bottom, the strength becomes too hard, and the bottom does not open easily, resulting in a problem that the filling volume cannot be achieved.

JP 2001-31120 A

The problem that this invention aims to solve is to propose a packaging container that is easy to fill and open while using more than 50% paper, a renewable material.

As a means for solving the above problem, the invention described in claim 1 is a packaging container formed by opposing the sealant resin layers of a surface laminate and a back laminate, each of which has an ink layer, a paper layer, a base resin layer, and a sealant resin layer in that order, inserting a bottom material between them, which has a base resin layer and a sealant resin layer in that order and is folded into an inverted V shape with the sealant resin layer of the bottom laminate without paper laminate on the outside, and heat sealing the periphery to form a body and a bottom fold-in part, wherein the paper layer is uncoated paper, and the uncoated paper is cut so that the paper flow direction is the width direction of the container, and the tensile strength T of the paper layer in the width direction of the container is 5.72 kN/m or more as specified in JIS P8113, and the weight of the paper in the entire laminate constituting the body, periphery, and bottom fold-in part is heavier than the weight of the resin including the adhesive and ink layer.

The packaging container of the present invention is made up of more than 50% renewable paper by weight, making it a great contribution to protecting the global environment.

A second aspect of the present invention provides a packaging container according to the first aspect, further comprising a matte coating layer provided on the base resin layer of the bottom laminate .

The invention described in claim 3 is a packaging container as described in claim 1 or 2, characterized in that it has a pouring outlet forming portion in which a pouring outlet is formed by unsealing and removing a part of the peripheral portion in approximately the width direction of the container, and in that, with regard to the tensile strength specified in JIS P8113 of the paper layer included in the laminate constituting the body, when the tensile strength in the width direction of the container is T and the tensile strength in the top-to-bottom direction is Y, the tensile strength ratio Y/T is 0.8 or less.

The invention described in claim 4 is the packaging container described in claim 3, characterized in that the surface of the pouring outlet forming portion is subjected to a scratch treatment that does not penetrate all layers of the laminate.

The invention described in claim 5 is a packaging container described in any one of claims 1 to 4, characterized in that the paper layer is unbleached kraft paper or bleached kraft paper.

The packaging container of the present invention is made of paper, a renewable material, which accounts for more than 50% of the total weight, making it a great contribution to global environmental conservation. In addition, the packaging container is classified as a paper container under the legal system, reducing the burden on businesses.

The bottom material does not have a paper layer laminated on it, so the bottom opens smoothly when filling, and it is well suited for filling.

As in the invention described in claim 2, the container has a spout forming section in which a spout is formed by removing a portion of the periphery in the width direction of the container, and the tensile strength of the paper layer included in the laminate constituting the body, as specified in JIS P8113, is T, where T is the tensile strength in the width direction of the container and Y is the tensile strength in the top-bottom direction. If the tensile strength ratio Y/T is 0.8 or less, the laminate is prone to tearing in the horizontal direction, and the tear in the laminate that starts from the opening start section when opening progresses stably horizontally, so that the container can be opened without using scissors.

As in the invention described in claim 3, when the surface of the spout forming part is scratched in a way that does not penetrate all the layers of the laminate, the ease of opening is further improved.

When the base resin layer includes a gas barrier layer that inhibits the transmission of oxygen and water vapor, as in the invention described in claim 4, the packaging container can be made capable of preserving the contents for a long period of time.

FIG. 1 is a schematic plan view showing one embodiment of a packaging container according to the present invention. FIG. 2 is a schematic plan view showing another embodiment of the packaging container according to the present invention, which is an example having a spout forming portion. FIG. 3 is a schematic plan view showing another embodiment of the packaging container according to the present invention, which has a pouring outlet forming portion and has a scratch treatment on the surface of the pouring outlet forming portion that does not penetrate all layers of the laminate. FIG. 4 is a schematic cross-sectional view showing the AA' cross section of FIG. FIG. 5 is a schematic cross-sectional view showing an example of the layer configuration of the front surface laminate and the back surface laminate. FIG. 6 is a schematic cross-sectional view showing an example of the layer structure of the bottom layer.

The packaging container according to the present invention will be described in detail below with reference to the drawings. Fig. 1 is a schematic plan view showing one embodiment of a packaging container according to the present invention. Fig. 4 is a schematic cross-sectional view showing the A-A' cross section of Fig. 1. Figs. 5 and 6 are schematic cross-sectional views showing an example of the layer structure of a laminate used in a packaging container according to the present invention. Note that the adhesive layer is omitted in the schematic cross-sectional views shown in Figs. 5 and 6.

The packaging container 1 according to the present invention is a packaging container in which the sealant resin layers of a surface laminate 2 having an ink layer 26, a paper layer 25, a base resin layer 23, and a sealant resin layer 21 in this order are opposed to each other, and a back laminate 3 similarly having an ink layer 26, a paper layer 25, a base resin layer 23, and a sealant resin layer 21 in this order is placed between them, and a bottom material 5 having a base resin layer 24 and a sealant resin layer 22 in this order and folded in an inverted V shape with the sealant resin layer of the bottom surface laminate 4 without paper on the outside is inserted between them, and the periphery 6 is heat sealed to form a body 7 and a bottom fold 8. The weight of the paper in the entire laminate constituting the body 7, periphery 6, and bottom fold 8 is heavier than the weight of the resin including the adhesive and the ink layer.

The packaging container shown in FIG. 1 is a so-called standing pouch, which can stand on its own when the bottom is opened. The inclusion of a paper layer 25 in the front laminate 2 and back laminate 3 strengthens the stiffness of the laminate, improving its ability to stand on its own.

On the other hand, the bottom laminate 4 that forms the bottom surface does not include a paper layer, so it is highly flexible and the bottom surface opens easily with compressed air or the like when filling, making it suitable for filling and allowing for a large filling amount, so there is no need to design the bag larger than necessary.

By making the weight of the paper heavier than the weight of the plastic in this packaging container, more than half of it can be made from paper, a biomass material. Unlike materials derived from fossil fuels, biomass materials are carbon neutral in terms of carbon dioxide emissions, so even if the container is collected as waste and incinerated, the statistical amount of carbon dioxide emissions can be reduced.

In addition, because the weight of paper in this packaging exceeds 50% of the total weight, it is treated as a paper container under the law, and can be disposed of as a paper container. In fact, because it contains a large amount of paper, it is easily biodegradable even if it is left in the natural environment.

In this packaging container, by placing paper on the top surface of the laminate instead of in the middle layer, it has been possible to reduce the amount of unnecessary plastic used. Furthermore, the use of paper improves the stiffness of the laminate, making it possible to reduce the thickness of the plastic film layer, particularly the sealant resin layer. By providing an ink layer 26 by printing on the surface of the paper, the design of the packaging container can be ensured. Since the ink layer 26 is surface-printed, an ink with the necessary resistance for surface printing, such as scratch resistance, is used, but a transparent protective coating layer may also be provided on the top surface.

The bottom layer 4 that constitutes the bottom surface does not usually require an ink layer, but if necessary, an ink layer may be provided. When forming the bottom surface, the base resin layers of the bottom layer 4 are heat sealed facing each other, so a matte coat layer or the like may be provided to prevent adhesion.

The packaging container 1 shown in Figure 1 has a V-notch in the side seal as the opening start portion 11. The shape of the opening start portion is not limited to a V-notch and can be any shape such as a U-shape or an I-shape which is simply a cut.

Figure 2 is a schematic plan view showing another embodiment of the packaging container according to the present invention. In this example, the container has a spout forming portion 10 in which a spout is formed by opening and removing a portion of the peripheral portion 6 in the approximate width direction of the container. By forming a spout, when the container is used as a refill container, the operation of refilling the container becomes easier.

In the packaging container according to the present invention, the tensile strength of the paper layer included in the laminate of the front and back surfaces that constitute the body 7 is as specified in JIS P8113. If the tensile strength in the width direction of the container is T and the tensile strength in the top-to-bottom direction is Y, then the tensile strength ratio Y/T is 0.8 or less, so that the tensile strength in the width direction is stronger than the tensile strength in the top-to-bottom direction for the entire laminate.

As a result, when tearing the laminate from the opening start portion 11 of the packaging container 1 shown in Figure 1, for example, the tear does not run vertically but tends to progress horizontally. This improves ease of opening.

In general, the orientation of pulp fibers can be controlled by the papermaking method, and by increasing the degree of orientation in the paper's flow direction, it is possible to increase the tensile strength in the flow direction rather than the width direction. Therefore, by cutting the paper so that the flow direction of the paper produced in this way is the horizontal direction of the packaging bag, it is possible to create such a packaging container.

It has also been found that the generation of paper dust during the bag making process and transportation can be suppressed by orienting the paper fibers in the width direction of the container. In addition, in consideration of the tension resistance in the machine flow direction during processing and the surface layer damage resistance during transportation, the tensile strength T of the front and back surface laminate in the width direction of the container is preferably 4 kN/m or more.

To further improve the ease of opening, the base resin layer 23 and the sealant resin layer 21 that make up the front and back laminates may also be made of films that are easy to cut in the width direction of the packaging container.

Figure 3 is a schematic plan view showing another embodiment of the packaging container according to the present invention, which has a spout forming section 10 and has scratch processing 12 on the surface of the spout forming section that does not penetrate all layers of the laminate. This makes it even easier to open. The scratch processing can be done by die cutting using a blade, or by laser processing using a laser.

For the paper layer 25 used in the front and back laminates, uncoated paper such as unbleached kraft paper, bleached kraft paper, and uncoated printing paper is preferable. Of these, unbleached kraft paper and bleached kraft paper are suitable for the packaging container of the present invention. Coated paper is not preferable because it is prone to generating paper dust. The thickness of the paper is determined according to the capacity of the intended packaging container.

Various synthetic resin films can be used as the base resin layers 23 and 24. Specifically, synthetic resin films include polyolefin resins such as high density polyethylene resin (HDPE), polypropylene resin (PP), and polyolefin elastomers, polyester resins such as polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), and polyethylene naphthalate resin (PEN), cellulose resins such as cellophane and cellulose triacetate (TAC) resin, polymethyl methacrylate resin (PMMA), ethylene-vinyl acetate copolymer resin (EVA), ionomer resin, polybutene resin, polyacrylonitrile resin, polyamide resins such as nylon-6 and nylon-66, polystyrene resin (PS), polyvinyl chloride resin (PVC), polyvinylidene chloride resin (PVDC), polycarbonate resin (PC), fluorine resin, and urethane resin.

The base resin layers 23 and 24 of the laminate constituting the packaging container 1 may include a gas barrier layer that suppresses the transmission of oxygen and water vapor. Examples of the gas barrier layer include gas barrier films such as polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, gas barrier nylon film, and gas barrier polyethylene terephthalate (PET) film; metal deposition films in which a metal such as aluminum is deposited on a PET film; inorganic oxide deposition films in which an inorganic oxide such as aluminum oxide or silicon oxide is deposited on a PET film; gas barrier coating layers such as polyvinylidene chloride coating, resin layers made of a coating containing a water-soluble resin and an inorganic layered compound, or a coating in which a metal alkoxide or its hydrolyzate is reacted with an isocyanate compound; and metal foils such as aluminum foils.

Polyolefin resins are generally used for the sealant resin layers 21 and 22. Specifically, ethylene resins such as low-density polyethylene resin (LDPE), medium-density polyethylene resin (MDPE), linear low-density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-methacrylic acid resin copolymer, blend resins of polyethylene and polybutene, and polypropylene resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer are used.

The packaging container according to the present invention will be described in more detail below based on examples and comparative examples.

Example 1
The layer configuration of the front laminate and the back laminate was such that the paper layer was an unbleached kraft paper (Atlas Light Packaging, manufactured by Daio Paper Corporation) with a basis weight of 80 g/ ^m2 , and the surface was subjected to aqueous flexographic printing. The base resin layer was an inorganic vapor deposition gas barrier film (GL-Film, manufactured by Toppan Printing Co., Ltd.) in which silicon oxide was vapor-deposited on a 12 μm-thick PET film, and the sealant resin layer was an LLDPE film with a thickness of 50 μm. The paper layer, base resin layer, and sealant film layer were dry laminated via an adhesive layer with a thickness of about 3 μm to form the front laminate and the back laminate.

For the bottom surface layer, a 15 μm-thick nylon film was used as the base resin layer, and a 40 μm-thick LLDPE film was used as the sealant resin layer, which were then dry laminated. A matte coating was applied to the surface of the nylon film to prevent adhesion.

A packaging bag with the shape shown in Figure 1 was produced through a printing process, a dry lamination process, a rewinding slitter process, and a bag making process. The size of the packaging bag was a standing pouch with a height of 170 mm, a width of 110 mm, and a bottom material insertion width of 30 mm. A notch was placed in the side seal portion as the opening initiation portion. This packaging bag was filled with 130 ml of lotion in a filling machine.

Example 2
A front and back laminate was produced in the same manner as in Example 1, except that a bleached, glossy kraft paper with a basis weight of 70 g/ ^m2 (Nagoya Sararyuo, manufactured by Daio Paper Co., Ltd.) was used as the paper layer, and a 40 μm-thick LLDPE film was used as the sealant resin layer. For the bottom surface laminate, a 15 μm-thick nylon film was used as the base resin layer, and a 30 μm-thick LLDPE film was used as the sealant resin layer, and these were dry laminated. A matte coating was applied to the surface of the nylon film to prevent adhesion.

A packaging bag with the shape shown in Figure 2 was produced through the printing process, dry lamination process, rewinding slitter process, and bag making process. A pouring outlet was formed around the periphery of the upper end seal part by irregular sealing and punching. An embossed part was placed along the pouring flow path, and an opening notch was placed in the side seal part that intersects with the planned opening line. The size of the packaging bag is a standing pouch with a height of 205 mm, a width of 150 mm, and a bottom material insertion width of 35 mm. A notch was placed in the side seal part as the opening start part. This packaging bag was filled with 400 ml of shampoo in a filling machine.

<Comparative Example 1>
A packaging container was produced in the same manner as in Example 1, except that a laminate having the same paper layer as that used for the front and back surface laminate was used as the bottom surface laminate, and was evaluated in the same manner.

<Comparative Example 2>
A packaging container was prepared in the same manner as in Example 2, except that a coated paper (Ryuo Coat manufactured by Daio Paper Co., Ltd.) having a basis weight of 65 g/ ^m2 was used as the paper layer, and a 30 μm-thick LLDPE film was used as the sealant resin layer, and 400 ml of shampoo was filled in the same manner.

<Evaluation method>
[Bag making processability]: Checked for fuzz on the paper surface and the presence of paper dust (100,000 bags).
[Filling suitability]: Checked whether sufficient opening could be obtained with a bag feeder and filling machine (1000 shots performed).
[Durability during distribution]: The filled product was packed in a cardboard box with 12 bags per box, and after transporting it over land for 2000 km, the presence or absence of fluff on the paper surface was confirmed (5 cases were carried out).
[Opening Ease]: We confirmed the straight cutability when opening the bag in the width direction from the opening notch. (50 bags were tested.)

<Evaluation Results>
[Bag-making processability]: For Examples 1 and 2 and Comparative Example 1, the bag-making processability was good. However, for Comparative Example 2, when continuous bag making was performed, paper powder derived from the coating agent accumulated on the bag-making line and adhered to the product as foreign matter, and scratches were found on the product surface, resulting in other problems.

[Filling suitability]: Examples 1 and 2 and Comparative Example 2 had good filling suitability, but Comparative Example 1 had problems with the bottom fold of the bottom material not opening properly when inflating the pouch with air before filling the contents on the bag feeder and filling machine, causing the liquid level to rise when a certain volume of contents was filled, making it impossible to seal, etc.

[Flow resistance]: There were no problems in Examples 1 and 2, but in Comparative Example 1, the paper was damaged by creases in the center of the folded-in bottom material. In Comparative Example 2, the paper surface on the side was damaged by creases.

[Openability]: Examples 1 and 2 and Comparative Example 1 could be opened without any problems, but in Comparative Example 2, the opening line bent inwardly into the packaging bag, causing some liquid to spill out.

The specifications of the paper used in the examples and comparative examples, as well as the tensile strength in the T and Y directions, and the tensile strength ratio Y/T are summarized in Table 1. The evaluation results are summarized in Table 2.

These results confirm the superiority of the packaging container according to the present invention.

1: Packaging container 2: Surface laminate 3: Back laminate 4: Bottom laminate 5: Bottom material 6: Periphery 7: Body 8: Bottom fold-in portion 10: Pouring outlet forming portion 11: Opening start portion 12: Scratch processing 21, 22: Sealant resin layer 23, 24: Base resin layer 25: Paper layer 26: Ink layer

Claims (5)

a front surface laminate and a back surface laminate each having an ink layer, a paper layer, a base resin layer, and a sealant resin layer in this order, with the sealant resin layers facing each other;
Between them, a bottom surface material having a base resin layer and a sealant resin layer in this order and folded into an inverted V shape with the sealant resin layer of the bottom surface laminate not laminated with paper on the outside is inserted;
A packaging container having a body and a bottom fold-in portion formed by heat-sealing a peripheral portion,
The paper layer is an uncoated paper,
The uncoated paper is cut so that the paper flow direction is the width direction of the container,
Regarding the tensile strength of the paper layer as defined in JIS P8113, the tensile strength T in the width direction of the container is 5.72 kN/m or more;
A packaging container, characterized in that the weight of the paper in the entire laminate constituting the body portion, the peripheral portion and the bottom fold-in portion is greater than the weight of the resin including the adhesive and ink layers. 2. The packaging container according to claim 1, further comprising a matte coating layer provided on the base resin layer of the bottom laminate. a spout forming portion in which a spout is formed by removing a part of the peripheral portion in a substantially width direction of the container;
3. A packaging container according to claim 1 or 2, characterized in that, with respect to the tensile strength, as defined in JIS P8113, of a paper layer contained in the laminate constituting the body portion, when the tensile strength in the width direction of the container is T and the tensile strength in the top-to- bottom direction is Y, the tensile strength ratio Y/T is 0.8 or less. 4. The packaging container according to claim 3 , wherein a surface of the portion forming the pouring outlet is subjected to scratch processing that does not penetrate all layers of the laminate. The packaging container according to any one of claims 1 to 4, characterized in that the paper layer is unbleached kraft paper or bleached kraft paper.

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