Bubble cushioning material

Abstract

To provide a cushioning material capable of storing perishable foodstuffs such as fruits and vegetables in a container in a state in which deterioration is properly prevented.SOLUTION: The present invention relates to a bubble cushioning material A1 in which a bubble layer 20 having a plurality of bubbles is formed on one side of a base layer 10. The bubble cushioning material is formed by bonding a bubble forming film 21 having irregularities to one side of a base film 11. The base film 11 is formed by a material in which zinc oxide is added to a main material made of a synthetic resin. The zinc oxide is charged.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cushioning material used when storing fresh food in a container for transportation or the like. [Background technology]

[0002] When fresh food is packed in a container such as a cardboard box and transported, cushioning material is often used to prevent damage to the fresh food. One of them is bubble cushioning material, which generally has a base layer on one or both surfaces thereof, and has a bubble layer having a large number (plurality) of air bubbles (air bags) formed thereon.

[0003] It is known that ethylene gas is secreted from so-called fresh produce such as vegetables and fruits. Ethylene gas is a type of plant hormone that promotes the ripening of not only the fresh produce itself but also the surrounding fresh produce. However, if ethylene gas is secreted even after fruit or vegetables are fully ripe, it will cause the fruit and vegetables around it to over-ripen and deteriorate, eventually causing them to rot. Thus, ethylene gas is considered to be the root cause of the deterioration of fruit and vegetables. Therefore, when fruits and vegetables are stored in containers such as cardboard boxes, it is necessary to reduce the concentration of ethylene gas in the internal space of the container.

[0004] In addition, not only fruits and vegetables but also fresh food items including meat and fish are required to be stored in a manner that prevents bacterial growth, as these will deteriorate and rot.

[0005] Here, there is a prior art related to the present invention described in Patent Document 1. This document discloses a packaging sheet formed from a thermoplastic transparent resin containing fine particles of zinc oxide. When fruits and vegetables are wrapped in the wrapping sheet, the zinc oxide decomposes ethylene gas, thereby preventing deterioration of the fruits and vegetables. However, when ethylene gas is decomposed by zinc oxide, water is produced, and water droplets adhere to the inner surface of the packaging sheet, which has the problem of adversely affecting the fruits and vegetables. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-268242 A Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a cushioning material that enables fruits, vegetables, and other perishable foods to be stored in a container in a state in which deterioration is appropriately prevented. [Means for solving the problem]

[0008] In order to solve this problem, a first aspect of the present invention is an air bubble cushioning material in which an air bubble layer having a plurality of air bubbles is formed on one or both surfaces of a base layer, and the air bubble cushioning material is formed from a material in which zinc oxide is added to a main material made of synthetic resin.

[0009] The synthetic resin constituting the main material may be one or a combination of polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, and nylon, which also applies to other embodiments.

[0010] The air bubble cushioning material of this embodiment can achieve the following effects by being used as follows. When fresh food is placed in a container such as a cardboard box, this bubble cushioning material is placed between the fresh food items or between the fresh food items and the container. In the case of bubble cushioning in which a bubble layer is formed on only one side of the base layer, when the material is placed between fresh food items, the bubble layer is oriented toward the side most likely to come into direct contact with the fresh food items contained therein.

[0011] Since the bubble cushioning material is made of a material containing zinc oxide, the zinc oxide acts to decompose ethylene gas into water and carbon dioxide in the vicinity of the bubble cushioning material. Then, the concentration of ethylene gas in the container decreases due to the air flow inside the container. On the other hand, as described above, water generated in the vicinity of the bubble cushioning material generally first condenses on the bubble cushioning material. Here, if the bubble cushioning material has a bubble layer formed on only one side of the base layer, when it is placed between fresh food items, the bubble layer faces the side most likely to come into direct contact with the fresh food items contained therein (if the base layer has a bubble layer formed on both sides, the bubble layer faces both the side most likely to come into direct contact with the fresh food items contained therein and the side most likely to come into direct contact with the fresh food items contained therein). Furthermore, since the air bubble layer has a number of recesses and projections, some of the generated water condenses in the recesses, and the amount of water adhering to the fresh food is accordingly reduced. This limits the adverse effects of water produced by the decomposition of ethylene gas on fresh produce.

[0012] As described above, in this form of bubble cushioning material, the zinc oxide acts to reduce the concentration of ethylene gas inside containers such as cardboard boxes, thereby preventing the deterioration of fresh foods (in the case of fruits and vegetables), and the adverse effects of the water generated during the process on the fresh foods is limited. Similarly, zinc oxide provides an antibacterial effect on fresh food (not limited to fruits and vegetables), which also helps prevent the deterioration of fresh food.

[0013] A second aspect of the present invention is an air bubble cushioning material in which an air bubble layer having a plurality of air bubbles is formed on one surface of a base layer, the air bubble cushioning material being formed by adhering an air bubble-forming film having irregularities to one surface of a base film, the base film being formed from a material in which zinc oxide has been added to a main material made of synthetic resin.

[0014] The term "adhesion" includes "welding" and "sticking", etc. This also applies to other aspects of the present invention. A typical example of "the base film is formed from a material in which zinc oxide has been added to a main material made of synthetic resin" is "of the base film and the bubble-forming film, only the base film is formed from a material in which zinc oxide has been added to a main material made of synthetic resin."

[0015] The air bubble cushioning material of the present invention can provide the following effects by being used as follows. Like the bubble cushioning material of the first embodiment, this bubble cushioning material is placed between fresh food items or between the fresh food items and the container when the fresh food items are placed in the container such as a cardboard box. In this case, the base layer faces the side that is prevented from coming into direct contact with the fresh food items contained therein.

[0016] The base film forming this air bubble cushioning material is made of a material to which zinc oxide has been added, and as a result of the action of the zinc oxide, ethylene gas is decomposed into water and carbon dioxide in the vicinity of the base film of this air bubble cushioning material (particularly in the area not covered by the air bubble-forming film, etc.) Then, the concentration of ethylene gas in the container decreases due to the air flow in the container. On the other hand, in this embodiment (a representative example), as described above, water generated near the bubble cushioning material generally condenses first on the base layer. At that time, the bubble cushioning material faces the side that prevents the base layer from coming into direct contact with the fresh food contained therein, thereby preventing the water from adhering to the fresh food. More specifically, as described above, some of the moisture generated near the bubble cushioning material may adhere to the bubble layer due to the air flow in the container, but even in this case, the amount that adheres to the fresh food is very limited, as described in the first embodiment (more precisely, even more so). This also applies to the other embodiments of the present invention.

[0017] As described above, in the same way as the first embodiment of the bubble cushioning material, the zinc oxide in this embodiment of the bubble cushioning material reduces the concentration of ethylene gas inside a container such as a cardboard box, thereby preventing the deterioration of fresh foods (in the case of fruits and vegetables), and also prevents the water that is generated during the deterioration from having a detrimental effect on the fresh foods. Similarly, zinc oxide provides an antibacterial effect on fresh food (not limited to fruits and vegetables), which also helps prevent the deterioration of fresh food.

[0018] A third aspect of the present invention is an air bubble cushioning material in which air bubble layers having a plurality of air bubbles are formed on both surfaces of a base layer, and which is formed by adhering air bubble-forming films having unevenness to both surfaces of a base film, the base film and one of the air bubble-forming films being formed from a material in which zinc oxide has been added to a main material made of synthetic resin.

[0019] A typical example of "the base film and one of the air bubble-forming films are formed from a material in which zinc oxide has been added to a main material made of synthetic resin" is "of the base film and both of the air bubble-forming films, only the base film and one of the air bubble-forming films are formed from a material in which zinc oxide has been added to a main material made of synthetic resin."

[0020] The air bubble cushioning material of this embodiment can achieve the following effects by being used as follows. Like the bubble cushioning material of the first embodiment, this bubble cushioning material is placed between fresh food items or between the fresh food items and the container when the fresh food items are placed in the container such as a cardboard box. In this case, the air bubble layer formed by the one air bubble-forming film faces the side that is prevented from coming into direct contact with the fresh food to be contained.

[0021] Since the base film and one of the bubble-forming films forming this bubble cushioning material are made of a material containing zinc oxide, the zinc oxide acts to decompose ethylene gas into water and carbon dioxide in the vicinity of the base film and one of the bubble-forming films of this bubble cushioning material. Then, the concentration of ethylene gas in the container decreases based on the air flow in the container. On the other hand, in this embodiment (a representative example), as described above, water generated near the bubble cushioning material generally first condenses in the bubble layer formed by the one of the bubble-forming films. At that time, the bubble cushioning material faces the side that prevents the bubble layer formed by the one of the bubble-forming films from coming into direct contact with the fresh food contained therein, so that the water is prevented from adhering to the fresh food.

[0022] As described above, in the same way as the first embodiment of the bubble cushioning material, the zinc oxide in this embodiment of the bubble cushioning material reduces the concentration of ethylene gas inside a container such as a cardboard box, thereby preventing the deterioration of fresh foods (in the case of fruits and vegetables), and also prevents the water that is generated during the deterioration from having a detrimental effect on the fresh foods. Similarly, zinc oxide provides an antibacterial effect on fresh food (not limited to fruits and vegetables), which also helps prevent the deterioration of fresh food.

[0023] A fourth aspect of the present invention is a bubble cushioning material in which a bubble layer having a plurality of bubbles is formed between a pair of base layers, the bubble cushioning material being formed by adhering a base film to each of both sides of an air bubble-forming film having projections and recesses, the air bubble-forming film and one of the base films being formed from a material in which zinc oxide has been added to a main material made of synthetic resin.

[0024] The air bubble cushioning material of this embodiment can achieve the following effects by being used as follows. Like the bubble cushioning material of the first embodiment, this bubble cushioning material is placed between fresh food items or between the fresh food items and the container when the fresh food items are placed in the container such as a cardboard box. In this case, the base layer formed by the one base film faces the side that is prevented from coming into direct contact with the fresh food to be contained.

[0025] Since the bubble-forming film and the one base film that form this bubble cushioning material are made of a material containing zinc oxide, the zinc oxide acts to decompose ethylene gas into water and carbon dioxide in the vicinity of the bubble-forming film and the one base film of this bubble cushioning material. Then, the concentration of ethylene gas in the container decreases based on the air flow in the container. On the other hand, as described above, water generated near the bubble cushioning material generally first condenses on the base layer formed by the one of the base films. At that time, the bubble cushioning material faces the side where the base layer formed by the one of the base films is prevented from coming into direct contact with the fresh food contained therein, so that the water is prevented from adhering to the fresh food.

[0026] As described above, in the same way as the first embodiment of the bubble cushioning material, the zinc oxide in this embodiment of the bubble cushioning material reduces the concentration of ethylene gas inside a container such as a cardboard box, thereby preventing the deterioration of fresh foods (in the case of fruits and vegetables), and also prevents the water that is generated during the deterioration from having a detrimental effect on the fresh foods. Similarly, zinc oxide provides an antibacterial effect on fresh food (not limited to fruits and vegetables), which also helps prevent the deterioration of fresh food.

[0027] A fifth aspect of the present invention is the air bubble cushioning material according to any one of the first to fourth aspects, in which the zinc oxide is electrically charged.

[0028] In the bubble cushioning material of this aspect, in addition to the effects of any one of the first to fourth aspects, the following effects are obtained. It has been found that zinc oxide's ability to decompose ethylene gas increases when it is electrically charged (carries static electricity). Therefore, the effect of any one of the first to fourth aspects becomes greater. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view showing a bubble cushioning material according to a first embodiment of the present invention. [Diagram 2] 1A and 1B are diagrams showing the air bubble cushioning material of the first embodiment of the present invention, in which (a) is a vertical cross-sectional view and (b) is an exploded vertical cross-sectional view. [Diagram 3] FIG. 1 is an exploded perspective view showing a part of the bubble cushioning material according to a first embodiment of the present invention in a first state of use. [Figure 4] FIG. 1 is a vertical cross-sectional view showing a first state of use of the bubble cushioning material according to a first embodiment of the present invention. [Diagram 5] FIG. 2 is an exploded perspective view showing a part of the bubble cushioning material according to the first embodiment of the present invention in a second state of use. [Figure 6] FIG. 2 is a vertical cross-sectional view showing a second state of use of the bubble cushioning material according to the first embodiment of the present invention. [Figure 7]FIG. 1 is a perspective view showing a bubble cushioning material according to a second embodiment of the present invention. [Figure 8] 1A and 1B are diagrams showing a bubble cushioning material according to a second embodiment of the present invention, in which (a) is a vertical cross-sectional view and (b) is an exploded vertical cross-sectional view. [Figure 9] FIG. 11 is a perspective view showing a bubble cushioning material according to a third embodiment of the present invention. [Figure 10] 1 is a diagram showing a bubble cushioning material according to a third embodiment of the present invention, in which (a) is a vertical cross-sectional view and (b) is an exploded vertical cross-sectional view. [Figure 11] FIG. 1 is a diagram showing an apparatus and method for charging a workpiece such as zinc oxide in the first embodiment of the present invention. [Figure 12A] Photographs showing an embodiment of the present invention together with a comparative example. The photographs show the state before the test. (a1) and (a2) are photographs showing the embodiment, and (b1) and (b2) are photographs showing the comparative example. (a1) and (b1) show the state with the lid removed for convenience. [Figure 12B] 1 is a photograph showing an embodiment of the present invention together with a comparative example, showing the state after testing, (a) being a photograph showing the embodiment, and (b) being a photograph showing the comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] [Embodiment 1] Next, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2, this air bubble cushioning material A1 has a base layer 10, and an air bubble layer 20 having a plurality (a large number) of air bubbles (air bags) is formed only on one side of the base layer 10. And, in appearance, it is similar to conventional air bubble cushioning materials.

[0031] That is, as shown in FIG. 2, this air bubble cushioning material A1 is formed by a base film 11 and an air bubble-forming film 21, both of which have flexibility. The base film 11 is basically flat, and the air bubble-forming film 21 is uneven. The air bubble-forming film 21 is welded (bonded) to one surface of the base film 11. In this way, the base layer 10 is formed by the base film 11 and the portion of the bubble-forming film 21 that is welded to the base film 11, and a large number (multiple) air bubbles (symbols omitted) are formed in the portion where the base film 11 and the bubble-forming film 21 are separated, thereby forming the bubble layer 20.

[0032] Similarly to conventional bubble cushioning materials, both base film 11 and bubble-forming film 21 are formed from a main material to which additives have been mixed. The base material and additives are melted by heating in a mixed state, and the two are mixed in a molten state, stretched, and cooled to form a flat film. In this way, the base film 11 is formed. Furthermore, a concave and convex shape is imparted to the planar film, and the air bubble-forming film 21 is formed. Then, as described above, the two films 11 and 21 are welded together to form the air bubble cushioning material A1.

[0033] Both the base film 11 and the bubble-forming film 21 are mainly made of a thermoplastic resin. Examples of the thermoplastic resin include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, nylon, etc., and one or more of these are used.

[0034] In this air bubble cushioning material A1, the base film 11 contains zinc oxide. The particle size of the zinc oxide is preferably 200 μm or less, and more preferably 5 to 100 nm. The proportion of zinc oxide in the air bubble cushioning material A1 is 0.5 to 15 mass %.

[0035] This air bubble cushioning material A1 is manufactured as follows. The main raw material of the base film 11 is pellets of a thermoplastic resin. The raw material of the additive of the base film 11 is formed by mixing powdered zinc oxide and the like with pellets of thermoplastic resin. As described above, the particle size of the zinc oxide is preferably 200 μm or less, and more preferably 5 to 100 nm. The ratio of zinc oxide in the additive is 10 to 30 mass %. One or more of titanium oxide, magnesium oxide, silver oxide, silicon oxide, aluminum oxide, manganese oxide, copper oxide, and calcium oxide may be further mixed.

[0036] Like the base film 11, the main raw material of the bubble-forming film 21 is also pellets of a thermoplastic resin. On the other hand, the raw material of the additive for the base film 11 is mainly made of thermoplastic resin pellets, and does not contain zinc oxide. Titanium oxide, magnesium oxide, silver oxide, silicon oxide, aluminum oxide, manganese oxide, copper oxide, or calcium oxide is also not mixed in.

[0037] As mentioned above, the thermoplastic resin pellets in the main material and additives of the above-mentioned base film 11 and bubble-forming film 21 include, for example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, nylon, etc., and one or more of these are used.

[0038] Furthermore, the zinc oxide is charged at some stage. That is, the stage is before the powder is made into the powder having the above-mentioned predetermined particle size, after the powder is made into the powder having the above-mentioned predetermined particle size, and before the powder is mixed into the additive as one component of the additive (the additive is formed), or after the powder is mixed into the additive (the additive is formed). Note that, at the stage after the additive is formed, the additive as a whole is charged. This will be discussed in more detail later.

[0039] As described above, both the base film 11 and the air bubble-forming film 21 are formed by heating the main material and additives in a mixed state, mixing the molten material, stretching it, and cooling it (the air bubble-forming film 21 is given an uneven shape). As also described above, the air bubble cushioning material A1 is formed by welding the two films 11 and 12 to each other.

[0040] Next, a method for charging an object to be treated such as zinc oxide will be described with reference to FIG. The charging device CD has a metal plate 2, an insulator 3, and a power supply device (voltage application device) 4, and applies a voltage of one polarity to the workpiece 1 to charge the workpiece 1. The metal plate 2 is placed on an insulator 3. A terminal of one polarity (a positive voltage terminal or a negative voltage terminal) of a power supply device 4 is electrically connected to the metal plate 2.

[0041] As described above, the workpiece 1 is zinc oxide before it is pulverized to a predetermined particle size, or after it has been pulverized to a predetermined particle size and before it is mixed into the additive as one component of the additive (the additive is formed), or the additive in which zinc oxide of the predetermined particle size has been mixed in to form the additive.

[0042] The metal plate 2 is for applying one voltage (positive voltage or negative voltage) to the workpiece 1, and is made of a conductive metal as a main raw material. Examples of conductive metals include gold, silver, steel, iron, and aluminum. There are no particular limitations on the shape, but a plate-shaped plate is preferable. The insulator 3 is for preventing the workpiece 1 from being grounded (preventing the static electricity carried by the workpiece 1 from dissipating to the ground), and is made of a non-conductive material. Examples of non-conductive materials include plastic, rubber, glass, and ceramics. The power supply device 4 includes a step-up chopper circuit and applies a high voltage of one polarity to the metal plate 2, and a commercially available DC / DC converter can be used.

[0043] When applying a voltage of one polarity to the workpiece 1, a voltage terminal of one polarity of the power supply 4 is connected to the metal plate 2, and a voltage of one polarity is applied from the power supply 4 to the workpiece 1 via the metal plate 2. The workpiece 1 is placed on the metal plate 2, and a voltage is applied for a predetermined time. At this time, it is preferable that the area of ​​the workpiece 1 in contact with the metal plate 2 is as large as possible, but it is sufficient that at least a part of the workpiece 1 is in contact with the metal plate 2.

[0044] When applying a voltage of one polarity to the workpiece 1, it is important to create a base between the workpiece 1 and the ground using an insulator 3 such as rubber, which is a highly insulating material, and to place the workpiece 1 on the base so that it is not grounded. As a simple method, an insulating plastic pallet can be used as the base.

[0045] In this embodiment, the object 1 to be treated is preferably charged under conditions of a voltage in the range of 5,000 to 30,000 volts and a current of 50 milliamperes or less. In this embodiment, the charging step is preferably carried out for 1 hour or more, and more preferably within a range of 24 to 72 hours.

[0046] Next, as shown in Figs. 3 to 6, the method of use and the effects of this air bubble cushioning material A1 will be described. A case will be described in which fresh food F such as fruits and vegetables is contained together with bubble cushioning material A1 in a cardboard box B (container) and transported.

[0047] The first method of use is as follows, as shown in FIGS. As shown in Fig. 3, fresh food F is individually housed in a buffer net N. The buffer net N is formed by connecting thick strings of soft synthetic resin in a net shape. In this way, most of the fresh food F, including the lower part, is covered by the buffer net N. Therefore, when the fresh food F contained in the buffer net N is placed on a receiving surface, the fresh food F (its lower surface) is separated from the receiving surface by the string-like synthetic resin that forms the buffer net N. As shown in FIG. 4, the fresh food F is stored layer by layer with the air bubble cushioning material A1 sandwiched between the fresh food F or with the air bubble cushioning material A1 and the water absorbent sheet W sandwiched between the fresh food F and the water absorbent sheet W as follows.

[0048] First, multiple fresh foods F contained in a buffer net N are placed in one layer inside a cardboard box B. That is, the fresh foods F are placed on the bottom (the surface on which they are placed) of the cardboard box B and packed closely together without being stacked one on top of the other. In this way, a first layer of fresh foods F is formed.

[0049] Next, the bubble cushioning material A1 is placed on top of the first layer of fresh food F, with the base layer 10 (FIGS. 1 and 2) facing up and the bubble layer 20 facing down. On top of this bubble cushioning material A1, a water-absorbent sheet W is placed as required.

[0050] Next, a layer of fresh food F contained in a cushioning net N is placed on the water absorbent sheet W or bubble cushioning material A1 (receiving surface). In other words, the fresh food F is packed closely together without being stacked one on top of the other. In this way, a second layer of fresh food F is formed.

[0051] Next, the bubble cushioning material A1 is placed on top of the second layer of fresh food F, with the base layer 10 facing up and the bubble layer 20 facing down. On top of this bubble cushioning material A1, a water-absorbent sheet W is placed as required.

[0052] By repeating the above steps as necessary, fresh food F is placed in the cardboard box B, layer by layer, with the bubble cushioning material A1 (and the water-absorbent sheet W) sandwiched between the fresh food F and the cardboard box B.

[0053] The second method of use is as follows, as shown in FIGS. As shown in Fig. 5, fresh food F is stored in a tray T made of synthetic resin. The tray T is generally flat and has a size and shape corresponding to the bottom of the cardboard box B (Fig. 6), and is formed with a number of recesses (reference numbers omitted). Each recess is recessed downward to correspond to the size and shape of the fresh food F. Each recess accommodates one fresh food item F, so that a single tray T accommodates a plurality of fresh food items F, one level at a time. In this way, most of the fresh food F, including its lower part, is covered by the tray T (its recessed portion). As shown in FIG. 6, the fresh food F is stored in layers with the air bubble cushioning material A1 between them, or with the air bubble cushioning material A1 and the water absorbent sheet W between them, in the same manner as described above.

[0054] In any case, as shown in Figs. 4 and 6, the upper and lower surfaces of the bubble cushioning material A1 and the fresh food F contained in the cardboard box B have the following relationship. That is, the base layer 10 (upper surface) of the air bubble cushioning material A1 is prevented from directly contacting the fresh food F (its lower portion) to be contained. On the other hand, the air bubble layer 20 (lower surface) of the air bubble cushioning material A1 comes into direct contact with the fresh food F (its upper portion) to be contained.

[0055] By storing fresh food F in cardboard box B in the above-described manner, the following advantageous effects can be obtained. First, just as in the case of using ordinary bubble cushioning material, the bubble cushioning material A1 cushions the fresh food F and prevents it from being physically damaged.

[0056] If the fresh food F is fruit or vegetables, ethylene gas is generated from the fresh food F. The specific gravity of the ethylene gas is slightly lighter than that of air, so it rises. Here, in this air bubble cushioning material A1, zinc oxide is contained in base film 11, so that the ethylene gas is decomposed into carbon dioxide and water by the zinc oxide in the vicinity of base film 11 (FIG. 2). In this way, the amount of ethylene gas is reduced, preventing the fresh food F (fruit and vegetables) from ripening too much due to the ethylene gas, and preventing spoilage.

[0057] As described above, water generated by decomposition of ethylene gas in the vicinity of the base film 11 of the air bubble cushioning material A1 remains in the base film 11 (base layer 10) of the air bubble cushioning material A1. When the water-absorbent sheet W is present, the water (part or all of it) is absorbed by the water-absorbent sheet W. Here, since the fresh food F is contained in the cushioning net N or the tray T as described above, it is floating (separated) from the water-absorbent sheet W or the base layer 10 of the bubble cushioning material A1, and the water is prevented from coming into contact with the fresh food F. In this way, the fresh food F is prevented from deteriorating and spoiling due to the water produced by the decomposition of ethylene gas.

[0058] On the other hand, in this air bubble cushioning material A1, air bubble-forming film 21 (FIG. 2) does not contain zinc oxide, so ethylene gas is not decomposed in the vicinity of air bubble-forming film 21, and water is not generated. Therefore, the fresh food F comes into contact with the air bubble layer 20, but the fresh food F does not come into contact with the water. Strictly speaking, water may also adhere to the air bubble layer 20 due to air flow inside the cardboard box B. However, as described in a modification of this embodiment, and even more so, the amount of water that adheres to the fresh food F is limited. In this manner, the fresh food F is prevented from spoiling due to the water produced by the decomposition of ethylene gas.

[0059] In addition, since the zinc oxide contained in this bubble cushioning material A1 (its bubble-forming film 21) has an antibacterial effect, deterioration and spoilage are prevented not only when the fresh food F is fruit or vegetables, but also when it is other than fruit or vegetables (meat, fish, etc.).

[0060] [Modification of the first embodiment] Next, a modified example of the first embodiment of the present invention will be described with reference to Figs. 1 and 2 etc., focusing on the differences from the first embodiment. This air bubble cushioning material A1 is also formed of a base film 11 and an air bubble-forming film 21, both of which are flexible. In this air bubble cushioning material A1, zinc oxide is contained not only in the base film 11 but also in the air bubble-forming film 21.

[0061] As in the first embodiment, both the base film 11 and the bubble-forming film 21 are made of a main material to which an additive has been mixed. As in the first embodiment, the main raw material of the base film 11 and the bubble-forming film 21 is pellets of a thermoplastic resin. On the other hand, in both the base film 11 and the bubble-forming film 21, the raw material of the additive is formed by mixing powdered zinc oxide or the like into pellets of a thermoplastic resin.

[0062] This air bubble cushioning material A1 is used in the same manner as in embodiment 1, as shown in Figures 3 to 6. And, substantially the same effects as in embodiment 1 can be obtained.

[0063] In this bubble cushioning material A1, zinc oxide is contained not only in the base film 11 (Figure 2) but also in the bubble-forming film 21 (Figure 2), so that ethylene gas is also decomposed in these parts, and the ethylene gas is decomposed more efficiently.

[0064] For the same reason, water is also generated in the vicinity of the air bubble-forming film 21 (FIG. 2). However, since the air bubble layer 20 has unevenness due to the large number of air bubbles, some of the generated water is located in the concave portions, and the amount of water that adheres to the fresh food F is limited. Therefore, there may be cases where there is no problem with fresh food F.

[0065] [Embodiment 2] Next, a second embodiment of the present invention will be described with reference to FIGS. Since the second embodiment is also related to the first embodiment, the differences from the first embodiment will be mainly described. This air bubble cushioning material A2 has a base layer 10, and air bubble layers (first air bubble layer 20A, second air bubble layer 20B) having a plurality (a large number) of air bubbles (air bags) are formed on each surface of the base layer 10.

[0066] That is, as shown in FIG. 8, this air bubble cushioning material A2 is formed by a base film 11, both of which have flexibility, and a pair of air bubble-forming films (a first air bubble-forming film 21A and a second air bubble-forming film 21B). The base film 11 has a flat shape, and each of the air bubble-forming films 21A and 21B has an uneven shape. The first air bubble-forming film 21A is welded to one surface of the base film 11, and the second air bubble-forming film 21B is welded to the other surface. In this way, the base layer 10 is formed by the base film 11 and the portions of the first air bubble-forming film 21A and the second air bubble-forming film 21B that are welded to the base film 11, and a large number (multiple) air bubbles (symbols omitted) are formed on both sides of the base layer 10 in the portions where the base film 11 is separated from the first air bubble-forming film 21A and the second air bubble-forming film 21B, thereby forming the first air bubble layer 20A and the second air bubble layer 20B.

[0067] The base film 11, the first air bubble-forming film 21A and the second air bubble-forming film 21B are all made mainly of a thermoplastic resin. In this air bubble cushioning material A2, the base film 11 and the first air bubble-forming film 21A contain zinc oxide.

[0068] The main raw material of the base film 11, the first air bubble-forming film 21A, and the second air bubble-forming film 21B is pellets of a thermoplastic resin. The raw material of the additive for the base film 11 and the first bubble-forming film 21A is formed by mixing powdered zinc oxide or the like into pellets of thermoplastic resin. The raw material of the additive for the second bubble-forming film 21B is mainly thermoplastic resin pellets, and zinc oxide is not mixed in. Titanium oxide, magnesium oxide, silver oxide, silicon oxide, aluminum oxide, manganese oxide, copper oxide, and calcium oxide are also not mixed in.

[0069] This air bubble cushioning material A2 is used in substantially the same manner as the air bubble cushioning material A1 of the first embodiment. At that time, the first foam layer 20A is placed on top. As a result, the same effects as those of the air bubble cushioning material A1 of the first embodiment can be obtained.

[0070] [Modification of the second embodiment] Next, a modified example of the second embodiment of the present invention will be described with reference to FIGS. 7 and 8, focusing on the differences from the second embodiment.

[0071] As in the second embodiment, the base film 11, the first air bubble-forming film 21A and the second air bubble-forming film 21B are all made mainly of a thermoplastic resin. In this air bubble cushioning material A2, zinc oxide is contained not only in the base film 11 and the first air bubble-forming film 21A but also in the second air bubble-forming film 21B.

[0072] As in the second embodiment, the main raw material of the base film 11, the first air bubble-forming film 21A and the second air bubble-forming film 21B is pellets of a thermoplastic resin. On the other hand, in any of the base film 11, the first air bubble-forming film 21A and the second air bubble-forming film 21B, the raw material of the additive is formed by mixing powdered zinc oxide or the like into pellets of thermoplastic resin.

[0073] This air bubble cushioning material A2 is used in almost the same manner as the air bubble cushioning material A2 of embodiment 1 (including its modified example) and embodiment 2. And, the same effects as those of the modified example of embodiment 1 are obtained.

[0074] [Embodiment 3] Next, a third embodiment of the present invention will be described with reference to FIGS. Since the third embodiment is also related to the first embodiment, the differences from the first embodiment will be mainly described. This bubble cushioning material A3 has a pair of base layers (first base layer 10A, second base layer 10B), and an air bubble layer 20 having a plurality (a large number) of air bubbles (air bags) is formed between both base layers 10A, 10B.

[0075] That is, this air bubble cushioning material A3 is formed by a pair of base films (first base film 11A, second base film 11B) and an air bubble-forming film 21, both of which are flexible. Both base films (first base film 11A, second base film 11B) are flat, and air bubble-forming film 21 is uneven. First base film 11A is welded to one surface of air bubble-forming film 21, and second base film 11B is welded to the other surface. In this way, the first base layer 10A is formed by the first base film 11A and the portion of the air bubble-forming film 21 that is welded to the first base film 11A, the second base layer 10B is formed by the second base film 11B and the portion of the air bubble-forming film 21 that is welded to the second base film 11B, and multiple (many) air bubbles are formed in the portion between the first base layer 10A and the second base layer 10B, thereby forming the air bubble layer 20.

[0076] The first base film 11A, the second base film 11B and the air bubble-forming film 21 are all made mainly of a thermoplastic resin. In this air bubble cushioning material A3, the first base film 11A and the air bubble-forming film 21 contain zinc oxide.

[0077] The main raw material of the first base film 11A, the second base film 11B, and the air bubble-forming film 21 is pellets of a thermoplastic resin. The raw material of the additives for the first base film 11A and the air bubble-forming film 21 is formed by mixing powdered zinc oxide or the like into pellets of thermoplastic resin. The raw material of the additive of the second base film 11B is mainly made of thermoplastic resin pellets, and does not contain zinc oxide. Titanium oxide, magnesium oxide, silver oxide, silicon oxide, aluminum oxide, manganese oxide, copper oxide, or calcium oxide is also not mixed in.

[0078] This air bubble cushioning material A3 is used in substantially the same manner as the air bubble cushioning material A1 of the first embodiment. At that time, the first base film 11A is used facing upward. As a result, the same effects as those of the air bubble cushioning material A1 of the first embodiment can be obtained. EXAMPLES

[0079] Specific examples of the present invention will be described below together with comparative examples. As shown in Figures 12A and 12B, for the purpose of the experiment, in both the example and the comparative example, one peach (contained in a cushioning net N (Figure 3)) was placed in a synthetic resin cup, and the opening of the cup was closed with a lid and stored in a room temperature environment for eight days.

[0080] 12A(a1)(a2), in this example, the air bubble cushioning material A1 (FIGS. 1 and 2) of the first embodiment was placed on top of a peach, with the air bubble layer 20 facing downward. On the other hand, as shown in Fig. 12A (b1) and (b2), in the comparative example, peaches were wrapped in a packaging sheet made of a thermoplastic transparent resin containing zinc oxide fine particles.

[0081] After 8 days, the results for the Examples and Comparative Examples were as follows: As shown in Fig. 12B(a), in the example, some discoloration was observed on the surface of the peach, but there was almost no deterioration. This is because the concentration of ethylene gas in the cup was kept low, and the water droplets generated during the decomposition of ethylene gas adhered to the upper surface of the base layer 10 (Fig. 2) and the areas between the bubbles on the lower surface of the base layer 10, while the adhesion of water droplets to the bubble layer 20 (especially the part of the bubble layer that comes into contact with the peach) was limited, and almost no water droplets adhered to the surface of the peach. On the other hand, as shown in Fig. 12B(b), the peaches in the comparative example deteriorated significantly. This is because, although the concentration of ethylene gas in the cup was kept low, water droplets generated during the decomposition of ethylene gas adhered to the inner surface of the packaging sheet and then to the surface of the peaches.

[0082] It should be noted that the above is merely an embodiment of the present invention, and it goes without saying that the present invention can be embodied in various modified forms based on the knowledge of those skilled in the art.

[0083] The air bubble cushioning material A1 of the first embodiment is made up of one base film 11 and one air bubble-forming film 21, with an air bubble layer 20 formed on one surface of one base layer 10. The bubble cushioning material A2 of embodiment 2 consists of one base film 11 and two bubble-forming films (first bubble-forming film 21A, second bubble-forming film 21B), and bubble layers (first bubble layer 20A, second bubble layer 20B) are formed on both sides of the single base layer 10. The bubble cushioning material A3 of embodiment 3 is composed of two base films (first base film 11A, second base film 11B), and a bubble layer 20 is formed between two base layers (first base layer 10A, second base layer 10B). However, the present invention is not limited thereto, and may be made up of three base films and two bubble-forming films, have three base layers (first to third base layers), and have bubble layers formed between the first and second base layers and between the second and third base layers. That is, a base layer may be formed on each of the outer surfaces of the first and second bubble layers 20A and 20B of the bubble cushioning material A2 of the second embodiment. Furthermore, two sheets of the air bubble cushioning material A3 of the third embodiment may be laminated and welded together. [Explanation of symbols]

[0084] A1, A2, A3 bubble wrap 10 Base Layer 10A 1st base layer 10B Second base layer 11 Base film 11A First base film 11B Second base film 20 Bubble Layer 20A First air bubble layer 20B Second bubble layer 21 Air bubble forming film 21A First air bubble forming film 21B Second air bubble forming film

Claims

1. An air bubble cushioning material having an air bubble layer having a plurality of air bubbles formed on one or both surfaces of a base layer, It is made of a synthetic resin base material with zinc oxide added. Bubble wrap.

2. An air bubble cushioning material having an air bubble layer having a plurality of air bubbles formed on one surface of a base layer, The film is formed by adhering a bubble-forming film having projections and recesses to one surface of a base film, The base film is formed of a material in which zinc oxide is added to a main material made of synthetic resin. Bubble wrap.

3. An air bubble cushioning material having an air bubble layer having a plurality of air bubbles formed on each of both surfaces of a base layer, The film is formed by bonding a bubble-forming film having projections and recesses to both sides of a base film, The base film and one of the bubble-forming films are formed of a material in which zinc oxide is added to a main material made of synthetic resin. Bubble wrap.

4. An air bubble cushioning material having an air bubble layer having a plurality of air bubbles formed between a pair of base layers, The film is formed by bonding a base film to each of the two surfaces of the bubble-forming film having the unevenness, The air bubble-forming film and one of the base films are formed of a material in which zinc oxide is added to a main material made of synthetic resin, Bubble wrap.

5. The air bubble cushioning material according to any one of claims 1 to 4, The zinc oxide is electrically charged. Bubble wrap.

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