JPH11227839A - Desiccant packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable small printed characters to be read clearly, to prevent ink or paper dust from attaching to food or the like to be packaged together and to prevent a fine powder of desiccant from coming out. SOLUTION: The desiccant packaging bag comprises an outer packaging material 1 comprising a biaxially oriented plastic layer, a print layer and a thermoplastic resin layer which are laminated sequentially from the exterior with small holes 4 formed, and an inner packaging material comprising a grid- mesh-like reinforcing material layer and an ethylene-vinyl acetate copolymer layer with a content of vinyl acetate of 6 to 30 wt.%, which are laminated sequentially from the exterior wherein the inner packaging material is overlaid on an internal face of the outer packaging layer 1 with the inner packaging material inside and their peripheral rims are sealed by a heat-bonded part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag for packaging a desiccant such as lime having no printed layer on its surface.

[0002]

2. Description of the Related Art Conventionally, as a packaging bag for packaging a desiccant such as lime, a printing layer is provided on the surface of a gas-permeable base material such as paper, and a polyethylene layer is laminated on the back surface. A structure in which a large number of pores that penetrate but do not penetrate a permeable substrate such as paper are provided, or a printed fiber is provided on the surface of a permeable substrate such as paper, and a split-fiber nonwoven fabric is provided with a polyethylene layer on the back surface After laminating a polyethylene layer on the split-fiber nonwoven fabric surface, a large number of pores that penetrate the polyethylene layer but do not penetrate a gas-permeable base material such as paper are generally used.

[0003] However, in any of the desiccant packaging bags having the above-described structure, since a printed layer is formed on the surface of the paper layer, if the desiccant is housed inside and packed together with food, The ink on the surface of the desiccant packaging bag comes into contact with the packaged food, and the ink may adhere to the food. Therefore, even when printing using ink that complies with the “Voluntary Regulations on Printing Inks for Food Packaging Materials” (NL regulation) established by the Printing Inks Association of Japan, “ It is necessary to use a resin that uses food coloring as a coloring agent and an ink binder that can come into contact with food, because inks may be transferred to foods and coloring may occur in foods. " This has the disadvantage that the color tone of the ink is limited and the cost of the ink makes the desiccant packaging bag expensive.
Also, since the desiccant packaging bag is made of inexpensive and breathable paper, paper dust may adhere to the packaged food,
Since pores are formed through the polyethylene layer, the paper is pierced and there is a disadvantage that the fine powder of the desiccant leaks out and adheres to the food.

[0004] As a desiccant packaging bag in which the above-mentioned disadvantage that the ink on the surface of the desiccant packaging bag comes into contact with the contents and the ink adheres to the contents, the outer surface of the desiccant packaging bag is used. A configuration in which a printing layer is formed on the inner surface of a paper layer is conceivable. However, in a desiccant packaging bag having a configuration in which a printing layer is provided on the back surface of a paper layer, even if the thickness of the paper layer is reduced to the minimum necessary for a desiccant packaging bag, the printing layer cannot be formed according to the PL method. In addition to the drawback that it is difficult to read through the paper layer when the necessary fine characters are included, the desiccant packaging bag is made of inexpensive and breathable paper, so that the packaged food is Since the powder adheres or the pores penetrating the polyethylene layer are formed, there is a disadvantage that the paper is easily broken through, and the disadvantage that the fine powder of the desiccant leaks out and adheres to the food cannot be eliminated.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for reading thin characters which are printed clearly, preventing ink or paper powder from adhering to food or the like to be packaged together, and using a desiccant. An object of the present invention is to provide a desiccant packaging bag in which fine powder does not leak.

[0006]

A biaxially stretched plastic layer, a printing layer, and a thermoplastic resin layer are laminated in this order from the outer surface to form a grid network reinforcing material layer and vinyl acetate-containing material on the inner surface of the exterior material in which pores are formed. A structure in which an interior material having no pores formed by laminating an ethylene-vinyl acetate copolymer layer having a ratio of 6 to 30% by weight is overlapped, and the periphery is sealed by a heat bonding part with the interior material inside. Since the printed layer is provided on the inner surface of the biaxially stretched plastic layer, the printed layer does not come into contact with food or the like packaged together, and fine characters are printed on the printed layer. Even in the case where there is, for example, it can be clearly read through the transparent biaxially stretched plastic layer. In addition, vinyl acetate content of 6
By laminating an ethylene-vinyl acetate copolymer layer of up to 30% by weight, the required moisture permeability can be obtained without forming pores, so that the fine powder of the desiccant does not leak from the pores. . Further, since no paper layer is used for the desiccant packaging bag, paper powder does not adhere to foods and the like.

In the desiccant packaging bag described above, the pores formed in the exterior material are formed as piercing holes, so that the pores can be formed by a simple perforating device in which a fine needle is embedded, and the pores can be formed. Since the moisture permeability of the exterior material can be adjusted by changing the number of pores to be formed, it is easy to cope with the case where the moisture permeability of the desiccant packaging bag needs to be changed depending on the application. In addition, since the pores are small, even if there are fine characters in the print layer, they can be read clearly without being affected by the pores.

[0008] In the above desiccant packaging bag, by setting the thickness of the ethylene-vinyl acetate copolymer layer to 10 to 20 µm, it is necessary to form the desiccant packaging bag without forming pores in the interior material. It is possible to secure an appropriate moderate moisture permeability.

In the above desiccant packaging bag, an ethylene-vinyl acetate copolymer layer having a vinyl acetate content of 6 to 30% by weight is laminated on both sides of the lattice net reinforcing material layer of the interior material. Thus, it is possible to prevent pinholes from being generated in the interior material, and to improve the thermal adhesion between the exterior material and the inner layer material, thereby making it possible to securely adhere the thermal bonding portion.

In the above desiccant packaging bag, at least a part of the heat bonding portion is formed at a position inside by a predetermined dimension from the edge of the bag, so that the outside of the heat bonding portion is heat bonded. The moisture absorption rate of the desiccant packaging bag can be changed by peeling the adhesive between the exterior material and the inner layer material from the non-existing portion.

In the desiccant packaging bag described above, the outer material and the inner material are overlapped and partially adhered to each other, and the peripheral edge is sealed by a heat bonding portion.
When the desiccant is automatically filled and packaged, trouble such as generation of wrinkles due to displacement between the exterior material and the interior material which are superimposed can be prevented, so that excellent packaging suitability can be obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a first embodiment,
2 is a sectional view taken along the line II in FIG. 1 showing the configuration of the first embodiment, FIG. 3 is a sectional view corresponding to FIG. 2 showing the configuration of the second embodiment, and FIG. 4 is a plan view showing the third embodiment. And FIG.
FIG. 5 is a sectional view taken along the line II in FIG. 4 showing the configuration of the embodiment, wherein 1 and 1 ′ are exterior materials, 2 and 2 ′ are interior materials, 3a and 3b are heat bonding portions, 4 is pores, and 5 is non-thermal. An adhesive portion, 11 is a biaxially stretched plastic layer, 12 is a printed layer, 13 and 13 'are thermoplastic resin layers, 21 is a lattice network reinforcing material layer, and 22 and 23 are ethylene-vinyl acetate copolymer layers, respectively.

The first embodiment of the desiccant packaging bag of the present invention is as shown in FIGS. As shown in FIG. 1, the planer shape is such that a quadrangular exterior material 1 and an interior material 2 are superimposed on each other, the interior material 2 is folded inward with the interior material 2 inside, and the peripheral edges other than the folds are bonded by heat bonding portions 3a, 3b The exterior material 1 and the interior material 2 are adhered and fixed at the thermal bonding portions 3a and 3b, and the exterior material 1 and the interior material 2 are separated from each other in a region other than the thermal bonding portions 3a and 3b. This is a configuration in which a gap is formed without being bonded. The exterior material 1 has a large number of penetrating pores 4 formed by piercing. Although the shape of the first embodiment is a three-side seal bag, the shape of the bag is arbitrary, and a four-side seal bag or a pillow type bag can be used.

As shown in FIG. 2, the laminated structure of the first embodiment comprises an exterior material 1 and an interior material 2, and the exterior material 1 comprises a biaxially stretched plastic layer 11, a printed layer 12, and a thermoplastic resin layer 13. The interior material 2 has a lattice network reinforcing material layer 21 and a vinyl acetate content of 6 to 3
It has a structure in which no fine pores are formed by a laminate with 0% by weight of the ethylene-vinyl acetate copolymer layer 22. On the surface of the thermoplastic resin layer 13 of the exterior material 1, a lattice mesh reinforcing material layer of the interior material 2
21 so that the interior material 2 is the inner surface.
By thermally bonding the folded peripheral portions, the thermoplastic resin 13 on the inner surface of the exterior material 1 and the grid net-like reinforcing material layer 21 on the outer surface of the interior material 2 adhere to each other at the peripheral thermal bonding portions 3a and 3b. The material 1 and the interior material 2 are integrated, and the exterior material 1 and the interior material 2 are separated from each other in a region other than the thermal bonding portions 3a and 3b without being bonded. In the first embodiment, the heat bonding portion 3
In the areas other than the areas a and 3b, the exterior material 1 and the interior material 2 are not bonded and are separated from each other to form a gap. The interior material 2 may be partially adhered and fixed. Since the lattice network reinforcing material layer 21 is generally made of a polyolefin resin, the thermoplastic resin layer 13 on the inner surface of the exterior material 1 and the lattice network reinforcing material layer 21 can be thermally bonded.

The interior material 2 is a laminate of a lattice network reinforcing material layer 21 and an ethylene-vinyl acetate copolymer layer 22 and has no pores 4 formed therein.
By using an ethylene-vinyl acetate copolymer having a vinyl acetate content of 6 to 30% by weight as 22, it is possible to increase the moisture permeability of the interior material 2. Just forming it, exterior material 1 and interior material 2
Are bonded at the peripheral thermal bonding portions 3a and 3b and polymerized to obtain the moisture permeability required for the desiccant packaging bag. Since the pores 4 are not formed in the interior material 2, the granules are initially hard granules, and there is no fear that the desiccant contained in the interior material is broken down into fine powder due to moisture absorption and leaks to the outside. . Further, since the printing layer 12 is formed on the inner surface of the biaxially stretched plastic layer 11, there is no possibility that the ink forming the printing layer 12 adheres to the food even when packaged with the food, and Even if there are fine characters in 12, the characters can be clearly read from the outside through the transparent biaxially stretched plastic layer 11.

A second embodiment of the desiccant packaging bag of the present invention is as shown in FIGS. The planar shape is the same as that of the first embodiment as shown in FIG. As shown in FIG. 3, the laminated structure of the second embodiment is the same as that of the first embodiment except that the exterior material 1 has a biaxially stretched plastic layer 11 and a printed layer 12.
And a thermoplastic resin layer 13 in which pores 4 are formed. The interior material 2 'has a vinyl acetate content of 6 to 3
It consists of a laminate of 0% by weight of an ethylene-vinyl acetate copolymer layer 23, a lattice network reinforcing material layer 21, and an ethylene-vinyl acetate copolymer layer 22 having a vinyl acetate content of 6 to 30% by weight, and has pores. The configuration is not formed. In the case of the second embodiment, the thermoplastic resin layer 13 on the inner surface of the exterior material 1 and the ethylene-vinyl acetate on the outer surface of the interior material 2 'are formed at the thermal bonding portions 3a and 3b on the periphery of the desiccant packaging bag. Since the surface of the polymer layer 23 is thermally bonded, the adhesiveness between the exterior material 1 and the interior material 2 is excellent. Also in the case of the second embodiment, the effect as the desiccant packaging bag is the same as that of the first embodiment.

As shown in FIG. 5, a packaging structure for a desiccant packaging bag according to a third embodiment of the present invention is such that an exterior material 1 ′ comprises a biaxially stretched plastic layer 11, a printed layer 12, and an easily peelable thermoplastic resin. layer
The interior material 2 is composed of a lattice network reinforcing material layer 21 and an ethylene-vinyl acetate copolymer layer 22 having a vinyl acetate content of 6 to 30% by weight.
And no pores are formed. In the third embodiment, the effect as the desiccant packaging bag is the same as that of the first embodiment. In the case of the third embodiment, the heat-bonded portion 3b where the exterior material 1 'and the interior material 2 are bonded is peeled off by using a region outside the heat-bonded portion 3b that is not heat-bonded as a trigger. There is an effect that the moisture permeability of the desiccant packaging bag can be adjusted. At the heat-bonded portions 3a and 3b around the periphery of the desiccant packaging bag, the grid-like reinforcing material layer on the thermoplastic resin layer 13 'surface on the inner surface of the exterior material 1' and the outer surface of the interior material 2
Since it is necessary to peel off the 21 side, the thermoplastic resin layer 1
It is necessary to use an easily peelable resin as 3 '.
Also in the case of the third embodiment, the interior material may be formed of a laminate of the ethylene-vinyl acetate copolymer layer 23, the lattice network reinforcing material layer 21, and the ethylene-vinyl acetate copolymer layer 22.

In the packaging bag for a desiccant according to the present invention, the printing layer 12 is provided on the inner surface of the biaxially stretched plastic layer 11 and is not exposed to the surface. "Voluntary Regulations on Printing Inks for Food Packaging Materials" (NL)
Can be printed using inks generally used for printing packaging materials that meet the regulations. It is necessary to use an edible dye as a coloring agent and a resin that can come into contact with food as a resin for an ink binder, as in a conventional desiccant packaging material in which a printed layer is formed on the surface of a paper layer. Therefore, an inexpensive ink having excellent printability can be used, and an ink having an arbitrary color tone can be used.

As the lattice network reinforcing material layer 21, for example, a net-like material made of polyethylene, polypropylene or the like such as Nisseki Warif (manufactured by Nippon Petrochemical), Klenet (manufactured by Kurabo), softnet, soft cloth (manufactured by Shin Nippon Sof) and the like. Can be used. The spacing between the lattices is suitably 1 to 5 mm. 1
In the case of 以下 mm or less, the lattice material occupies most of the packaging material area, so the area through which water vapor easily permeates is reduced, so the moisture permeability per unit area of the interior materials 2, 2 'decreases and the price increases. Is not practically preferable. on the other hand,
When the grid spacing is 6 mm or more, there is a problem that the granular material of the contents breaks through the space between the grids and the tear strength decreases. The most preferred spacing is in the range of 2-4 mm. By using polyethylene or polypropylene as a resin constituting the lattice network reinforcing material layer 21, the thermal adhesion between the lattice network reinforcing material layer 21 and the thermoplastic resin layers 13, 13 'on the inner surfaces of the exterior materials 1 and 1', And it is preferable because it has excellent adhesion to the ethylene-vinyl acetate copolymer layers 22 and 23.

The ethylene-vinyl acetate copolymer resin used in the ethylene-vinyl acetate copolymer layers 22 and 23 must have a vinyl acetate content of 6 to 30% by weight. When the vinyl acetate content is 6% by weight or less, the moisture permeability becomes small and cannot be used as the interior material 2 in which the pores 4 are not formed. On the other hand, when the vinyl acetate content is 30% by weight or more, the hot melt extruded ethylene-vinyl acetate copolymer layer has poor lubricity, is difficult to commercialize, and cannot be used because the vinyl acetate odor becomes strong. . The thickness of the ethylene-vinyl acetate copolymer layers 22 and 23 is preferable because the moisture permeability increases as the thickness decreases, but there is a problem in workability during extrusion lamination processing. The problem of workability at the time of processing is eliminated, but the moisture permeability decreases. Therefore, the thickness of the ethylene-vinyl acetate copolymer layers 22, 23 is suitably from 10 to 20 μm.

As the biaxially stretched plastic layer 11 constituting the exterior materials 1, 1 ', biaxially stretched polypropylene, biaxially stretched polyethylene terephthalate, or the like is suitable. Exterior material 1,1 '
The diameter of the pores 4 formed at about 0.1 to 1.0 m
It is formed by piercing with a needle having a thickness of m.
The size of the pores 4 formed by piercing is determined by the thickness of the needle, but the fineness is determined by the piercing depth of the pointed portion using a needle having a diameter of about 1.0 mm. The size of the hole 4 can be changed. The adjustment of the moisture permeability of the desiccant packaging bag of the first and second embodiments is performed by using an interior material.
The moisture permeability of 2,2 'is set so as to be the maximum moisture permeability required for the desiccant packaging bag, and the moisture permeability of the exterior material 1 depends on the size and number of the pores 4 formed in the exterior material 1. Can be adjusted. The moisture permeability of the desiccant packaging bag according to the third embodiment is adjusted by setting the moisture permeability of the interior materials 2 and 2 ′ to the maximum moisture permeability required for the desiccant packaging bag and the permeability of the exterior material 1 ′. Humidity is set so that it is the minimum moisture permeability required for the desiccant packaging bag, and the adhesive between the exterior material 1 'and the interior material 2, 2' is partially peeled off at the thermal bonding parts 3a, 3b. Thereby, the moisture permeability of the desiccant packaging bag can be adjusted to an appropriate moisture permeability suitable for the purpose of use.

In the method of manufacturing the desiccant packaging bag of the present invention, first, an exterior material and an interior material having no pores are prepared. In order to form pores in the exterior material, the exterior material can be formed by piercing with a needle in a step of cutting to a predetermined width, or can be formed by piercing with a needle in an automatic filling and packaging step of a desiccant. . When piercing holes are formed in the automatic filling and packaging process, the exterior material and the interior material each having no pores are supplied from separate rolls, and the pores are formed in the exterior material, and then the inner surface of the exterior material is formed. Automatic filling and packaging of the desiccant is performed by superimposing the interior material on the side and thermally bonding the periphery. The exterior material with pores formed in advance and the interior material without pores are supplied from separate rolls, and the interior material is overlapped with the interior material on the inner surface side of the exterior material and the peripheral edge is thermally bonded to form a desiccant. Automatic filling and packaging can also be performed. When applying to an automatic filling and packaging machine in a state where the exterior material and the interior material with pores formed are overlapped and partially adhered, after forming the predetermined pores in the exterior material in a wide state by piercing This is performed by a method in which the exterior material and the interior material are fixed by overlapping with the interior material and partially thermally bonding at a predetermined position, and then cut to a predetermined width. As a device for forming a piercing hole, it may be performed continuously using a roll in which needles of a predetermined thickness are embedded on the surface at predetermined intervals,
It may be performed intermittently using a piercing plate in which needles of a predetermined thickness are embedded at predetermined intervals.

Example 1 On one side of a biaxially oriented polypropylene film having a thickness of 20 μm, a green ink conforming to the “Self-regulation on Printing Inks for Food Packaging Materials” (NL regulation) established by the Printing Inks Association of Japan. After printing a pattern containing fine characters,
Using a 0.5 mm diameter needle to pierce a laminate obtained by extruding a 20 μm thick polyethylene by lamination on the printing surface to form pores at a rate of 2500 per 1 m ^2, and prepare an exterior material did. On the other hand, if the thickness is 5
On one side of a polyethylene cloth (manufactured by Hagiwara Kogyo) having a density of 8 × 8 / inch and having a size of 5 μm, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 19% by weight and an MI of 15 was added to 13
The interior material was manufactured by laminating with a thickness of μ by extrusion lamination. The exterior material and the interior material obtained above are cut into a predetermined width to form a roll, and the polyethylene layer surface and the polyethylene cloth surface of the interior material are overlapped so that they are in contact with each other. The parts were heat-bonded to produce a desiccant packaging bag. Fine characters printed on the resulting desiccant packaging bag could be clearly read through the biaxially oriented polypropylene film.

[0024]

According to the present invention, a biaxially stretched plastic layer, a printing layer, and a thermoplastic resin layer are laminated in this order from the outer surface, and the inner surface of the exterior material in which pores are formed has a lattice network reinforcing material layer and a vinyl acetate content of 6 to 6. 30% by weight of an ethylene-vinyl acetate copolymer layer and a non-porous interior material laminated on top of each other, and a drying agent having a configuration in which the interior material is inside and the periphery is sealed by a heat bonding portion. It is a packaging bag, and the printed layer is provided on the inner surface of the biaxially stretched plastic layer, so that the printed layer does not come into contact with food etc. packaged together and even if there are fine characters etc. in the printed layer. It can be read clearly through the transparent biaxially stretched plastic layer. In addition, by laminating an ethylene-vinyl acetate copolymer layer having a vinyl acetate content of 6 to 30% by weight on the interior material, necessary moisture permeability can be obtained without forming pores. Does not leak out. Furthermore,
Since the paper layer is not used for the desiccant packaging bag, the paper powder does not adhere to food or the like.

In the above desiccant desiccant packaging bag, by making the pores formed in the exterior material into piercing holes, the pores can be formed by a simple punching device, and the number of the formed pores can be easily changed. The desired moisture permeability required for the packaging bag for the agent can be easily obtained, and since the diameter of the pores is small, even if the printed layer has fine characters, it can be clearly read without being affected by the pores.

In the above desiccant packaging bag, by setting the thickness of the ethylene-vinyl acetate copolymer layer to 10 to 20 μm, it is necessary to form the desiccant packaging bag without forming pores in the interior material. Appropriate moisture permeability can be secured.

In the above desiccant packaging bag, the vinyl acetate content is 6 to 30 on both sides of the lattice mesh reinforcing material layer of the interior material.
By using a configuration in which a weight-% ethylene-vinyl acetate copolymer layer is laminated, it is possible to prevent pinholes from being generated in the interior material, and to improve the thermal adhesiveness between the exterior material and the inner layer material to thereby form a heat-bonded portion. Can be securely sealed.

In the above desiccant packaging bag, at least a part of the heat bonding portion is formed at a position inside the edge of the bag by a predetermined dimension, so that the heat bonding portion outside the heat bonding portion is not heat bonded. By peeling the adhesive between the exterior material and the inner layer material from the portion, it becomes possible to change the moisture absorption rate of the desiccant.

In the above desiccant packaging bag, the exterior material and the interior material are overlapped and partially adhered to each other, and the peripheral edge is sealed by a heat bonding portion, so that the desiccant is automatically filled and packaged. It is possible to prevent wrinkles and poor sealing of the bag from occurring due to the displacement of the exterior material and the interior material superimposed on each other.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II in FIG. 1 showing the configuration of the first embodiment of the present invention.

FIG. 3 is a sectional view corresponding to FIG. 2, showing a configuration of a second embodiment of the present invention;

FIG. 4 is a plan view showing a third embodiment of the present invention.

FIG. 5 is a sectional view taken along line II in FIG. 4 showing a configuration of a third embodiment of the present invention.

[Explanation of symbols]

 1, 1 'Exterior material 2, 2' Interior material 3a, 3b Thermal bonding part 4 Pores 5 Non-thermal bonding part 11 Biaxially stretched plastic layer 12 Printing layer 13, 13 'Thermoplastic resin layer 21 Lattice mesh reinforcement layer 22 , 23 Ethylene-vinyl acetate copolymer layer

Claims (6)

[Claims] 1. A lattice network reinforcing material layer and a vinyl acetate content of 6 to 5 are formed on the inner surface of an exterior material in which pores are formed by laminating a biaxially stretched plastic layer, a printing layer, and a thermoplastic resin layer in order from the outer surface. 30% by weight of an ethylene-vinyl acetate copolymer layer and a non-porous interior material laminated on top of each other, the interior material being on the inside, and the periphery being sealed by a heat bonding part. Characteristic packaging bag for desiccant. 2. The desiccant packaging material according to claim 1, wherein the pores formed in the exterior material are piercing holes. 3. The packaging material for a desiccant according to claim 1, wherein the thickness of the ethylene-vinyl acetate copolymer layer is 10 to 20 μm. 4. A structure in which an ethylene-vinyl acetate copolymer layer having a vinyl acetate content of 6 to 30% by weight is laminated on both sides of the lattice network reinforcing material layer of the interior material. Item 4. The desiccant packaging bag according to any one of Items 1 to 3. 5. The method according to claim 1, wherein at least a part of the heat bonding portion is formed at a position inside the edge of the bag by a predetermined dimension. Packaging bag for desiccant. 6. The apparatus according to claim 1, wherein the outer material and the inner material are overlapped and partially adhered to each other, and a peripheral edge is sealed by a heat bonding portion. A packaging bag for a desiccant according to the above.