Packaging material for preserving the freshness of fruits and vegetables, package containing fruits and vegetables, method for packaging fruits and vegetables, and method for manufacturing packaging material for preserving the freshness of fruits and vegetables

Abstract

To provide a packaging material for keeping freshness of garden stuff, which can obtain a further stable effect of keeping freshness.SOLUTION: A packaging material 100 for keeping freshness of garden stuff is composed of a synthetic resin layer 2 and a paper layer 1 laminated on a part of the synthetic resin layer 2. A high-rigidity part 11 made of a laminate of a part of the synthetic resin layer 2 and the paper layer 1 is arranged so as to support a low-rigidity part 21 made of the synthetic resin layer 2. The area of the high-rigidity part 11 with respect to the total area of the high-rigidity part 11 and the low-rigidity part 21 is 50 to 95%. The low-rigidity part 21 has a through hole.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging material for preserving the freshness of fruits and vegetables, a package containing fruits and vegetables, a method for packaging fruits and vegetables, and a method for producing a packaging material for preserving the freshness of fruits and vegetables. [Background technology]

[0002] Vegetables, fruits, and other fresh produce continue to respire even after they are harvested. As a result, during storage, distribution, or preservation after harvest, the fresh produce consumes energy through their own respiration, causing a deterioration in freshness. As a method for preserving the freshness of fruits and vegetables, a method of appropriately suppressing the respiration of the fruits and vegetables to preserve their freshness is known. Such packaging bags used to preserve the freshness of fruits and vegetables are known as modified atmosphere (MA) packaging. Conventionally, a packaging material used for MA packaging has been known that is made of a synthetic resin layer 2 with through holes formed therein (for example, Patent Document 1).

[0003] On the other hand, there are many materials available for packaging food products. For example, Example 3 of Patent Document 2 discloses a moisture-permeable and breathable packaging material in which a layer of Japanese paper, a layer of PET film, etc. are laminated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-46749 [Patent Document 2] JP 2006-231723 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a conventional freshness-preserving packaging material for fruits and vegetables made of synthetic film resin as described in Patent Document 1, if the through-holes formed in the bag are deformed due to tension, gravity, etc. that occur when the fruits and vegetables are placed in the bag, this can cause the air permeability and moisture permeability of the bag to fluctuate, resulting in a decrease in the freshness-preserving effect of the fruits and vegetables. There is also concern that the through-holes formed in the freshness-preserving packaging material for fruits and vegetables may be deformed due to tension that occurs when so-called top-seal packaging is performed using the freshness-preserving packaging material for fruits and vegetables, and stress that is applied to the freshness-preserving packaging material for fruits and vegetables that becomes the lid after top-seal packaging (for example, stacking of products during transportation or display in stores).

[0006] On the other hand, packaging materials for preserving the freshness of fruits and vegetables must have visibility and transparency so that the packaged fruits and vegetables can be seen from the outside, a good appearance that does not discourage purchasing, adequate strength to protect the fruits and vegetables, and safety that does not pose any food hygiene problems even when they come into direct contact with food. Therefore, the present inventors conducted extensive research from the perspective of suppressing deformation of the through-holes formed in the freshness-preserving packaging material for fruits and vegetables and obtaining a more stable freshness-preserving effect while satisfying such requirements for the freshness-preserving packaging material for fruits and vegetables, and discovered that it is effective to laminate a synthetic resin layer having through-holes and a paper layer and control their arrangement in a plan view. That is, it was discovered that the exposed area of ​​the synthetic resin layer having through-holes functions as MA packaging and has a good appearance, while the exposed area of ​​the synthetic resin layer is supported by a high-rigidity area where part of the synthetic resin layer is laminated with the paper layer, thereby reducing the stress on the synthetic resin layer and maintaining the freshness-preserving effect, and thus the present invention was completed. [Means for solving the problem]

[0007] According to the present invention, A packaging material for preserving the freshness of fruits and vegetables, comprising a synthetic resin layer and a paper layer laminated on a part of the synthetic resin layer, a high-rigidity portion formed of a laminate of a part of the synthetic resin layer and the paper layer is disposed so as to support a low-rigidity portion formed of the synthetic resin layer; The area of ​​the high rigidity portion is 50 to 95% of the total area of ​​the high rigidity portion and the low rigidity portion, The low rigidity portion has through holes, thereby providing a packaging material for preserving the freshness of fruits and vegetables.

[0008] Further, according to the present invention, A package containing fruits and vegetables is provided by packaging the fruits and vegetables in the above-mentioned packaging material for preserving the freshness of the fruits and vegetables.

[0009] Further, according to the present invention, A method for packaging fruits and vegetables, in which fruits and vegetables are packaged with the above-mentioned packaging material for maintaining the freshness of fruits and vegetables, provides a package containing fruits and vegetables, in which fruits and vegetables are packaged with the packaging material for maintaining the freshness of fruits and vegetables.

[0010] Further, according to the present invention, a preparation step of preparing the synthetic resin layer having a paper layer partially laminated thereon; a perforation step of forming holes in a portion of the synthetic resin layer where the paper layer is not laminated; a sawing process for producing a freshness-preserving packaging material for fruits and vegetables using the synthetic resin layer having the holes; The present invention provides a method for producing a freshness-preserving packaging material for fruits and vegetables, comprising:

[0011] Further, according to the present invention, a perforation step of providing holes in the synthetic resin layer; laminating a paper layer on at least a portion of the synthetic resin layer having the holes; a sawing process for producing a freshness-preserving packaging material for fruits and vegetables using the synthetic resin layer on which the paper layer is laminated; Including, The method for producing the freshness-maintaining packaging material for fruits and vegetables is provided, in which the freshness-maintaining packaging material for fruits and vegetables has holes in the portions of the synthetic resin layer where the paper layer is not laminated. Effect of the Invention

[0012] According to the present invention, a technology is provided relating to a packaging material for preserving the freshness of fruits and vegetables, which can more stably obtain a freshness-preserving effect. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing a schematic cross section of a freshness-preserving packaging material for fruits and vegetables according to a first embodiment; [Diagram 2] FIG. 2 is a diagram showing a schematic diagram of an example of a method for manufacturing the freshness-preserving packaging material for fruits and vegetables according to the first embodiment. [Diagram 3] FIG. 2 is a diagram showing a schematic diagram of an example of a method for manufacturing the freshness-preserving packaging material for fruits and vegetables according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing a schematic diagram of an example of a method for manufacturing the freshness-preserving packaging material for fruits and vegetables according to the first embodiment. [Diagram 5] FIG. 2 is a perspective view showing a schematic diagram of a freshness-preserving packaging material for fruits and vegetables according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In all drawings, similar components are given similar symbols and descriptions thereof are omitted where appropriate. In order to avoid complexity, (i) when there are multiple identical components in the same drawing, only one of them will be given a symbol, and not all of them, or (ii) especially in Figure 2 and subsequent figures, components similar to those in Figure 1 will not be given a symbol again. All drawings are for illustrative purposes only. The shapes and dimensional ratios of each component in the drawings do not necessarily correspond to the actual objects.

[0015] In this specification, the term "approximately" means that a range taking into consideration manufacturing tolerances, assembly variations, and the like, is included, unless otherwise specified explicitly. In this specification, the expression "a to b" in the explanation of a numerical range means from a to b, unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass to 5% by mass."

[0016] First Embodiment [Packaging materials for preserving the freshness of fruits and vegetables] In the first embodiment, a case will be described in which the fruit and vegetable freshness-preserving packaging material 100 is a bag that contains fruit and vegetable inside. The bag is not particularly limited as long as it is used to contain fruit and vegetable, but specifically, it refers to a bag that has an opening for putting fruit and vegetable in and taking them out and has appropriate flexibility.

[0017] Fig. 1 shows a cross-sectional view of a freshness-preserving packaging material 100 for fruits and vegetables. Figs. 2(a) to (c) show a procedure for producing a bag 100a using the freshness-preserving packaging material 100 for fruits and vegetables of this embodiment. In this embodiment, the horizontal direction (left-right direction) of the freshness-preserving packaging material 100 for fruits and vegetables refers to the horizontal direction when a bag is made using the freshness-preserving packaging material 100 and the bag is placed vertically with the opening at the top, and the vertical direction (up-down direction) of the freshness-preserving packaging material 100 for fruits and vegetables refers to the vertical direction (perpendicular direction) when a bag is made using the freshness-preserving packaging material 100 and the bag is placed vertically with the opening at the top. In this embodiment, the freshness-preserving packaging material 100 for fruits and vegetables is rectangular, and the horizontal direction of the freshness-preserving packaging material 100 for fruits and vegetables is the longitudinal direction.

[0018] As shown in Figure 1, the packaging material 100 for preserving the freshness of fruits and vegetables is composed of a synthetic resin layer 2 and a paper layer 1 laminated to part of the synthetic resin layer 2, and has a high rigidity portion 11 consisting of a laminate of part of the synthetic resin layer 2 and the paper layer 1, and a low rigidity portion 21 consisting of the synthetic resin layer 2. In the packaging material 100 for preserving the freshness of fruits and vegetables of this embodiment, when viewed in a plane, the high rigidity portion 11 is arranged so as to support the low rigidity portion 21, and the area of ​​the high rigidity portion 11 is 50 to 95% of the total area of ​​the high rigidity portion 11 and the low rigidity portion 21. This makes it possible to prevent the through holes of the low rigidity portion 21 from being deformed by stress, and to maintain the freshness-preserving effect well.

[0019] Moreover, the area of ​​the high rigidity portion 11 relative to the total area of ​​the high rigidity portion 11 and the low rigidity portion 21 is preferably 55 to 90%, more preferably 60 to 85%, and further preferably 60 to 80%. By setting the area of ​​the high rigidity section 11 relative to the total area of ​​the high rigidity section 11 and the low rigidity section 21 to be equal to or greater than the above-mentioned lower limit, deformation of the through holes is suppressed while maintaining the good breathability and moisture permeability of the low rigidity section 21, thereby achieving a stable freshness-retaining effect. On the other hand, by setting the area of ​​the high rigidity portion 11 relative to the total area of ​​the high rigidity portion 11 and the low rigidity portion 21 to be equal to or less than the above-mentioned upper limit value, the low rigidity portion 21 can exhibit its good breathability and moisture permeability, thereby obtaining a good freshness-retaining effect and improving visibility.

[0020] Here, the area of ​​high stiffness portion 11 and low stiffness portion 21 refers to the area in a plan view of freshness-preserving packaging material 100 for fruits and vegetables. In the present embodiment, freshness-preserving packaging material 100 for fruits and vegetables is in a bag shape without a gusset, so the area is the total area calculated by adding up the front and back surfaces excluding heat-sealed portion 31 formed to form the bag shape.

[0021] The ratio of the thickness (μm) of the low stiffness portion to the thickness (μm) of the high stiffness portion is preferably 0.1 to 0.4, and more preferably 0.15 to 0.30. This allows the fruit or vegetable freshness-preserving packaging material 100 to maintain a good balance between appropriate flexibility and stiffness, making it easier to obtain a freshness-preserving effect.

[0022] Regarding the positional relationship between the high rigidity portion 11 and the low rigidity portion 21 in a plan view, for example, it is preferable that at least a part of the high rigidity portion 11 extends from one end to the other end of the freshness-preserving packaging material 100 for fruits and vegetables. As an example, FIG. 2(a) shows the freshness-preserving packaging material 100 for fruits and vegetables in which the low rigidity portion 21 is arranged in the short side direction (longitudinal direction) of the freshness-preserving packaging material 100 for fruits and vegetables, and the high rigidity portion 11 is arranged at both ends of the low rigidity portion 21. Both the low rigidity portion 21 and the high rigidity portion 11 are strip-shaped or rectangular-shaped reaching from the upper end to the lower end of the freshness-preserving packaging material 100 for fruits and vegetables. This allows the high rigidity portion 11 to stably support the low rigidity portion 21, making it easier to reduce deformation of the through-holes. Furthermore, low-rigidity portion 21 is located approximately in the center in the longitudinal direction of fruit and vegetable freshness-keeping packaging material 100, but is not limited to this. From the viewpoint of making it easier to visually confirm the contents of a product in which fruit and vegetable freshness-keeping packaging material 100 of this embodiment is used to store fruit and vegetable freshness-keeping packaging material 100 and is displayed in a storefront, low-rigidity portion 21 is preferably located on the surface, i.e., the front, of bag-shaped fruit and vegetable freshness-keeping packaging material 100.

[0023] 2(a) shows the heat-sealed portion 31 and the folded-back portion 41. The heat-sealed portion 31 and the folded-back portion 41 will be described in detail later.

[0024] The width of the band-shaped low-rigidity portion 21 is preferably 20 to 70% of the width of the freshness-preserving packaging material 100 for fruits and vegetables, and more preferably 30 to 60%.

[0025] The positional relationship between the low-rigidity portion 21 and the high-rigidity portion 11 in a plan view is not limited to the above. Modifications will be described below.

[0026] 3(a), a rectangular low-rigidity section 21 may be arranged approximately at the center of the surface of the freshness-preserving packaging material 100 for fruits and vegetables, i.e., at the front of the bag, and a high-rigidity section 11 may be arranged to surround it. The longitudinal direction of the rectangular low-rigidity section 21 is parallel to the longitudinal direction (lateral direction) of the freshness-preserving packaging material 100 for fruits and vegetables. The low-rigidity section 21 is not limited to being arranged approximately at the center of the freshness-preserving packaging material 100 for fruits and vegetables, and may be arranged biased toward the upper end or lower end. In this case, at least a part of the high rigidity portion 11 extends from one side end to the other side end of the fruit and vegetable freshness-keeping packaging material 100. In the fruit and vegetable freshness-keeping packaging material 100 shown in Fig. 3(a), the high rigidity portion 11 is disposed continuously from the left end to the right end (horizontally) of the fruit and vegetable freshness-keeping packaging material 100. The length of the low-rigidity portion 21 in the longitudinal direction is not particularly limited, but is preferably 20 to 70% of the length of the fruit or vegetable freshness-preserving packaging material 100 in the longitudinal direction, and more preferably 30 to 60%.

[0027] Also, for example, as shown in Figure 4(a), a cross-shaped low-rigidity portion 21 may be arranged approximately in the center of the packaging material 100 for preserving the freshness of fruits and vegetables, i.e., at the front of the bag, and a portion of the low-rigidity portion 21 may extend from the upper end to the lower end of the packaging material 100 for preserving the freshness of fruits and vegetables.

[0028] Each layer constituting the fruit or vegetable freshness-preserving packaging material 100 will be described in detail below.

[0029] (High rigidity part) The high stiffness portion 11 of this embodiment is composed of a laminate of a paper layer 1 and a synthetic resin layer 2, and constitutes a part of the freshness-preserving packaging material 100 for fruits and vegetables. The high stiffness portion 11 of this embodiment is intended to have a stiffness higher than that of the low stiffness portion 21 described later. The rigidity in this embodiment refers to the tensile modulus obtained when a tensile test is carried out in accordance with JIS K7128 under conditions of 23° C. and a load speed of 2 mm / min.

[0030] The high rigidity portion 11 is arranged so as to support the low rigidity portion 21. Supporting the low rigidity portion 21 is intended to maintain the shape of the low rigidity portion 21 in order to prevent the through hole formed in the low rigidity portion 21 from being deformed by external stress.

[0031] The high rigidity portion 11 of this embodiment has a tensile modulus of elasticity obtained when a tensile test is performed in accordance with JIS K7128 at 23°C and a load speed of 2 mm / min, of preferably 500 to 3500 MPa, more preferably 1000 to 2500 MPa, and even more preferably 1500 to 2500 MPa. By setting the lower limit of the tensile elastic modulus of the high stiffness portion 11 to be equal to or higher than the above lower limit, the effect of preserving the freshness of the contents can be easily obtained. On the other hand, by setting the upper limit value of the tensile modulus of the high stiffness portion 11 to the above upper limit value or less, it is possible to maintain a good balance between the appearance of the packaging material and the freshness of the contents.

[0032] The stress at the yield point of the high-rigidity portion 11 of this embodiment, obtained when a tensile test is performed in accordance with JIS K7128 at 23° C. and a load speed of 500 mm / min, is preferably 10 N or more, more preferably 15 N or more, and even more preferably 20 N or more. This makes it easier to obtain a freshness-preserving effect for the contents.

[0033] The basis weight of the high stiffness portion 11 is preferably 20 to 150 g / m 2 and more preferably 25 to 120 g / m 2 The basis weight of the high stiffness portion 11 may be the total basis weight of the synthetic resin layer 2 and the paper layer 1, and if an adhesive layer or the like is included between the synthetic resin layer 2 and the paper layer 1, the total basis weight includes the adhesive layer or the like.

[0034] The thickness (μm) of the high rigidity portion 11 is preferably 15 to 150 μm, and more preferably 20 to 130 μm.

[0035] (paper layer) The basis weight of the paper layer 1 is not particularly limited, but is, for example, 10 to 150 g / m 2 and preferably 15 to 130 g / m 2 , more preferably 20 to 100 g / m 2 It is also possible to use the following. By setting the basis weight of the paper layer 1 to be equal to or more than the above lower limit, it is possible to improve the rigidity and mechanical strength and make it easier to support the low rigidity portion 21. On the other hand, by setting the basis weight of the paper layer 1 to be equal to or less than the above upper limit, it is possible to maintain the rigidity and mechanical strength to obtain a freshness-preserving effect, while improving the handleability of the fruit and vegetable freshness-preserving packaging material 100.

[0036] The paper layer 1 is not particularly limited as long as it is used for packaging food, and any known paper can be used.

[0037] (Low rigidity part) The low rigidity portion 21 in this embodiment is a layer other than the paper layer 1, and is made of a synthetic resin layer 2. The low rigidity portion 21 has a lower rigidity than the high rigidity portion 11. The low rigidity portion 21 also has a through hole.

[0038] The low rigidity portion 21 has a tensile modulus of elasticity obtained when a tensile test is performed in accordance with JIS K7128 at 23°C and a load speed of 2 mm / min, of preferably 50 to 1600 MPa, more preferably 100 to 1500 MPa, and even more preferably 500 to 1300 MPa. By setting the lower limit of the tensile elastic modulus of the low stiffness portion 21 to be equal to or greater than the above lower limit, it becomes possible to maintain a good balance between the appearance of the packaging material and the freshness of the contents. On the other hand, by setting the upper limit value of the tensile elastic modulus of the low stiffness portion 21 to the above upper limit value or less, the effect of preserving the freshness of the contents can be easily obtained.

[0039] The low-rigidity portion 21 preferably comprises a film containing one or more resins selected from the group consisting of polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, and / or a stretched version of the film. Details will be described in the synthetic resin layer 2.

[0040] (Synthetic resin layer) The synthetic resin layer 2 is made of a synthetic resin film, and is preferably transparent or semi-transparent, more preferably transparent, so that the fruit or vegetable can be visually recognized from the outside. In addition, the synthetic resin layer 2 may be printed for the purpose of identifying the fruit or vegetable.

[0041] The synthetic resin constituting the synthetic resin layer 2 is not particularly limited as long as it can be used for packaging fruits and vegetables, and any known synthetic resin can be used. Examples include various polyethylenes and ethylene copolymers, polypropylene, polyvinyl chloride, polystyrene, acrylic resins, polyester resins such as polyethylene terephthalate and polylactic acid, and polyamide resins such as nylon 6. These may be homopolymers, copolymers of two or more kinds, or blends containing two or more kinds of these homopolymers or copolymers. Specific examples of the various polyethylenes and ethylene copolymers include ethylene-vinyl alcohol copolymers, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, metallocene-linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-α-olefin copolymer, and other copolymers or ionomers. These may be contained alone or in combination of two or more, or may be mixed with other resins.

[0042] Among these, from the viewpoint of appropriately controlling the water vapor transmission rate, polyester resins such as polyethylene, ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, and polylactic acid, and polyamide resins such as nylon are preferred, and ethylene-vinyl alcohol copolymer, polystyrene, polylactic acid, and nylon are more preferred.

[0043] From the viewpoints of cost and physical properties, it is preferable to use a heat-sealable anti-fogging stretched polypropylene film, a low-density polyethylene film, a linear low-density polyethylene film, or a metallocene-catalyzed polyethylene film.

[0044] The synthetic resin layer 2 may be used as a single layer, or may be used as a multi-layer structure having two or more layers.

[0045] For example, from the viewpoint of obtaining sufficient strength for packaging fruits and vegetables, it is preferable to use a multilayer film made of polyethylene by dry lamination, extrusion lamination, or coextrusion in addition to a film such as non-oriented polypropylene, oriented polypropylene, non-oriented nylon, oriented nylon, or oriented polyester.

[0046] The average thickness of the synthetic resin layer 2 is preferably 15 μm or more and 150 μm or less, more preferably 18 μm or more and 100 μm or less, and even more preferably 20 μm or more and 80 μm or less. By making the average thickness of the synthetic resin layer 2 equal to or greater than the above lower limit, it becomes easier to control the oxygen permeability and water vapor permeability to a higher degree, and the strength of the freshness-keeping packaging material for fruits and vegetables can be increased. On the other hand, by making the average thickness of the synthetic resin layer 2 equal to or less than the above upper limit, the handling properties of the freshness-keeping packaging material for fruits and vegetables can be improved, appropriate water vapor permeability and oxygen permeability can be imparted, and production costs can be reduced.

[0047] (Through hole) The synthetic resin layer 2 has through holes, which can effectively preserve the freshness of fruits and vegetables.

[0048] The planar shape of the through-hole may be, for example, a circle, a polygon, or a slit. The circle is not limited to a perfect circle, but includes an approximately circular shape. In addition to the circle, the through-hole may be a semicircle or a crescent shape. The polygon may be a shape surrounded by three or more line segments, such as a triangle, a rectangle, or a pentagon. The slit is a cut or narrow gap penetrating the synthetic resin layer 2, and may be a straight line, a curve, an L-shape, an X mark, or the like, and its length is not particularly limited.

[0049] The average diameter of the through holes is preferably 30 μm to 1000 μm, more preferably 40 μm to 500 μm, and further preferably 50 μm to 200 μm. By making the average diameter of the through holes equal to or greater than the lower limit, the water vapor permeability and oxygen permeability are improved, and the occurrence of mold can be suppressed while the freshness can be easily maintained. On the other hand, by making the average diameter of the through holes equal to or less than the upper limit, the intrusion of humid outside air, which can easily cause mold, can be suppressed. In addition, the freshness-preserving packaging material for fruits and vegetables of this embodiment can take in an appropriate amount of oxygen while minimizing the effect on the specific water vapor permeability. The average diameter of the through holes is calculated from the open area of ​​the through holes, assuming that the through holes are perfect circles.

[0050] In this embodiment, the number of through holes is appropriately adjusted depending on the size of the through holes. From the viewpoint of obtaining a stable amount of water vapor transmission, the number of through holes is adjusted to 0.001 holes / cm with respect to the area (internal surface area) of the freshness-preserving packaging material 100 for fruits and vegetables. 2 More than 100 pieces / cm 2 It is preferable that the number of particles is 0.002 particles / cm or less. 2 More than 50 pieces / cm 2 It is more preferable that:

[0051] The above-mentioned through holes may be formed in the synthetic resin layer 2 in advance when manufacturing the packaging material for preserving the freshness of fruits and vegetables, or may be formed after the synthetic resin layer 2 is formed into a bag shape, or may be formed before or after the synthetic resin layer 2 is formed into a bag shape. The through holes can be formed by any known method, such as a processing method using a hot needle, a method of perforating with a laser beam, or a method using a mold such as a roll cutter.

[0052] The oxygen permeability of the synthetic resin layer 2 at 23° C. and 60% RH is preferably 100 cc / m from the viewpoint of maintaining the respiration of fruits and vegetables and preserving their freshness. 2 ·day·atm or more, and more preferably 500c / m 2 ·day·atm or more, and more preferably 1000cc / m 2 ·day·atm or higher. On the other hand, the oxygen permeability of the synthetic resin layer 2 at 23° C. and 60% RH is preferably 50,000 cc / m from the viewpoint of preserving the quality and freshness of fruits and vegetables. 2 ·day·atm or less, and more preferably 10000cc / m 2 ·day·atm or less, and more preferably 5000cc / m 2 ·day·atm or less.

[0053] In addition, the oxygen permeability of the synthetic resin layer 2 can be adjusted by controlling the selection of the material of the synthetic resin layer 2 described above, the manufacturing method of the synthetic resin layer 2, the layer structure of the synthetic resin layer 2, the presence or absence of through holes, and the average diameter and number of the through holes, etc.

[0054] Next, other configurations of the fruit or vegetable freshness-preserving packaging material 100 will be described in detail.

[0055] (Fruits and vegetables) The fruits and vegetables in question are not particularly limited, but examples thereof include osmanthus, spinach, komatsuna, mizuna, mibuna, asparagus, swiss cabbage, lettuce, thyme, sage, parsley, Italian parsley, rosemary, oregano, lemon balm, chives, lavender, salad burnet, lamb's ear, rocket, dandelion, nasturtium, basil, arugula, watercress, molokheiya, celery, kale, green onion, cabbage, Chinese cabbage, chrysanthemum, and salad. Examples of vegetables that can be used include lettuce, lettuce, butterbur, turnip, bok choy, mitsuba, Japanese parsley, brussels sprouts, broccoli, cauliflower, myoga, radish, carrot, burdock, radish, turnip, sweet potato, potato, Chinese yam, taro, jinenjo, yamatoimo, bell pepper, paprika, shishito, cucumber, eggplant, tomato, cherry tomato, pumpkin, bitter melon, okra, sweet corn, edamame, snow peas, green beans, broad beans, fungi, and mushrooms. Fruits and cut flowers such as citrus fruits, apples, pears, grapes, blueberries, persimmons, and strawberries are also effective. Cut vegetables and fruits are also effective. Among them, from the viewpoint of enabling effective preservation, vegetables that are mainly eaten without heating are preferred, and cut vegetables are more preferred. Cut vegetables refer to unheated vegetables that have been harvested in the fields and have had inedible parts such as roots, stems, or flowers removed, and have been cut by a known method to improve ease of eating and appearance.

[0056] [Manufacturing method for packaging materials to keep fruits and vegetables fresh] The method for producing the freshness-preserving packaging material 100 for fruits and vegetables of this embodiment includes, for example, the following steps. A preparation step of preparing a synthetic resin layer 2 having a paper layer 1 partially laminated thereon; a perforation step of providing holes in the synthetic resin layer 2 in a portion where the paper layer 1 is not laminated; A sawing process for producing a freshness-preserving packaging material 100 for fruits and vegetables using a synthetic resin layer 2 having holes formed therein. That is, the holes are provided after the synthetic resin layer 2 and the paper layer 1 are laminated together. This allows for greater freedom in designing the hole density in the low-rigidity portion 21. It also makes it easier to change the design of the fruit or vegetable freshness-preserving packaging material 100 depending on the application.

[0057] Each step will now be described in more detail.

[0058] (preparation process) In the preparation step, any resin film that can be normally used for packaging fruits and vegetables is prepared as the synthetic resin layer 2. The resin constituting the resin film is not particularly limited as long as it can be used for packaging fruits and vegetables, and those described above for the synthetic resin layer 2 can be used. An appropriate selection can be made from the viewpoints of the type of fruits and vegetables to be packaged, processability (e.g. ease of bag making), cost, etc.

[0059] The method for producing the resin film (film-forming method) is not particularly limited. Known methods such as extrusion, inflation, and calendaring can be applied. When the resin film has a multi-layer structure, known methods such as coextrusion (extrusion using a multi-die) and various lamination methods can be appropriately applied.

[0060] When producing a resin film, additives such as an anti-fogging agent may be mixed or applied as necessary. Two or more types of resins may be blended. When forming the film, stretching treatment, annealing treatment, etc. may be performed. An additional layer such as a sealant layer may be provided on the surface of the resin film, or the surface may be coated or treated to impart some function. Further, a method in which the resin film has a multi-layer structure and an anti-fogging agent is contained in one of the surface layers can be used. Specific examples of the anti-fogging agent include glycerin laurate, diglycerin laurate, decaglycerin laurate, glycerin monostearate, and sorbitan stearate.

[0061] Next, the paper layer 1 is laminated on the resin film (synthetic resin layer 2) to prepare a packaging film. The lamination method can be a known method, for example, a method in which an adhesive is applied onto the resin film unwound from a winding roll, and a paper layer is laminated and adhered thereon. In addition, at this time, in the finally obtained packaging material for freshness-preserving fruits and vegetables, the high stiffness portion 11 consisting of a laminate of a part of the synthetic resin layer 2 and the paper layer 1 is arranged so as to support the low stiffness portion 21 consisting of the synthetic resin layer 2, and it is preferable that the area of ​​the high stiffness portion 11 is controlled to be 50 to 95% of the total area of ​​the high stiffness portion 11 and the low stiffness portion 21.

[0062] (Printing process) A printed layer may be provided by printing ink on at least a part of the packaging film. The printed layer may be provided in either the low rigidity portion 21 or the high rigidity portion 11 of the packaging film, or in both the low rigidity portion 21 and the high rigidity portion 11, but from the viewpoint of improving productivity, it is preferable that it be provided only in the low rigidity portion 21.

[0063] The printing step can be carried out by any method, such as gravure printing, offset printing, flexographic printing, inkjet printing, screen printing, pad printing, or the like.

[0064] The thickness of the printing layer may be adjusted appropriately depending on the type and concentration of the ink used, the printing method, the material of the resin film, the desired printing concentration, etc., but is preferably 0.01 to 50 μm, more preferably 0.05 to 5 μm. When the thickness of the printing layer is 0.01 μm or more, sufficient printing concentration is easily obtained. In addition, when the thickness of the printing layer is 50 μm or less, it is possible to obtain advantages such as more appropriate perforation as described below, more neat perforation (less likely to become irregular holes), and the formed holes can be appropriately expanded or narrowed depending on the environmental temperature, making it easier to obtain a good MA environment using the packaging material for freshness preservation of fruits and vegetables (for information on the expansion and narrowing of holes depending on temperature, please refer to, for example, the description of Patent No. 5889854).

[0065] In particular, when the perforation step described below is performed using a laser, the perforation can be performed more satisfactorily by adjusting the absorbance of the laser light in the portion where the printing layer is provided. Specifically, the absorbance of light having a wavelength of 10 μm in the portion of the packaging film on which the printing layer is provided is preferably 0.004% or more, more preferably 0.01 to 90%, and even more preferably 0.04 to 80%. The appropriate absorbance of light having a wavelength of 10 μm allows for better perforation, particularly when perforation is performed with a CO2 pulse laser as described below. The absorbance can be adjusted, for example, by appropriately selecting the type of ink used in the printing process, by adding an appropriate light-absorbing component to the ink, or by appropriately adjusting the thickness of the printed layer.

[0066] The ink for forming the printing layer is not particularly limited, and may be appropriately selected from commercially available gravure inks and offset inks suitable for printing on resin films. Typically, ink contains a colorant such as a pigment as an essential component. Ink can also contain other ingredients such as solvents (typically organic solvents, but environmentally friendly water-based solvents are also possible), resins, oils and fats (drying oils, etc.), anti-friction materials, driers, viscosity modifiers, and rheology modifiers.

[0067] The printing layer can display any characters or figures, such as the type of fruit or vegetable to be packaged, the number of pieces, the weight, the producer, the seller, a trademark, a logo, a barcode, or a two-dimensional code.

[0068] After providing a printed layer on the surface of the packaging film in the printing step, a step (drying step) for volatilizing volatile components such as solvent remaining in the printed layer may be performed. For example, between the printing step and the perforation step, air at a temperature not high enough to damage the packaging film may be applied to the packaging film to promote drying of the volatile components remaining in the printed layer.

[0069] The printing step may be carried out simultaneously with the punching step described below.

[0070] (Drilling process) The method for perforating the packaging film is not particularly limited, but for example, the packaging film can be unwound in a roll at a constant speed, allowed to run, and perforated by irradiating laser light onto the parts where no paper layer is present.

[0071] The running speed of the packaging film may be set appropriately within the range of, for example, 0.001 to 50 m / s, preferably 0.02 to 20 m / s. A faster running speed is preferable in terms of productivity. The running speed may be changed appropriately depending on the number (density) of holes provided in the packaging film, the pulse frequency of the laser light, etc.

[0072] The type and output of the laser light source are not particularly limited as long as they can perforate the resin film. Examples include ruby ​​laser, neodymium YAG laser, neodymium glass laser, and carbon dioxide gas laser. Among these, the carbon dioxide gas laser is preferred because it has high energy efficiency, is easy to achieve high output, and is advantageous in generating heat and melting the resin film to form holes.

[0073] (Lumber processing) In this embodiment, the fruit or vegetable freshness-preserving packaging material 100 is in a bag shape, so a method for making the bag shape will be described.

[0074] 2 to 4 show the procedure for producing a bag-shaped freshness-preserving packaging material 100 for fruits and vegetables using a packaging film. As shown in Fig. 2(a), Fig. 3(a), and Fig. 4(a), respectively, a packaging film is cut into a rectangle of an appropriate size. Next, as shown in Fig. 2(b), Fig. 3(b), and Fig. 4(b), respectively, the left and right ends are overlapped to form a heat-sealed portion 31b, and the heat-sealed portion 31b is heat-sealed to form a tube. At this time, it is preferable that the synthetic resin layer 2 is on the inside and the paper layer 1 is on the outside. Next, as shown in Figures 2(c), 3(c), and 4(c), respectively, the lower end of the packaging film is heat-sealed so that folding lines 41a, 42b become the left and right sides of the bag, forming heat-sealed portion 31c, and a bag-shaped packaging material 100 for preserving the freshness of fruits and vegetables is obtained. That is, in the bag-shaped freshness-preserving packaging material 100 for fruits and vegetables of this embodiment, the low-rigidity portion 21 is located on the front side of the bag, and the heat-sealed portion 31b is located on the back side of the bag. The heat seal width is, for example, about 10 mm to 20 mm. It should be noted that other methods may be used to create the bag-shaped container, and the position of the heat seal is not limited to this.

[0075] The size of the bag may be about 50 mm×50 mm to 600 mm×800 mm for packaging fruits and vegetables for general consumers.

[0076] The method for producing the freshness-preserving packaging material for fruits and vegetables is not limited to the above method. For example, the manufacturing method of the freshness-keeping packaging material for fruits and vegetables may include the following steps: However, even in this case, the freshness-keeping packaging material for fruits and vegetables has holes in the portion of the synthetic resin layer 2 where the paper layer 1 is not laminated (low-rigidity portion 21). a drilling step of forming holes in the synthetic resin layer 2; A step of laminating a paper layer 1 onto a part of a synthetic resin layer 2 having holes; A sawing process in which a freshness-preserving packaging material for fruits and vegetables is produced using a synthetic resin layer 2 laminated with a paper layer 1. That is, by providing holes in the synthetic resin layer 2 before lamination, the holes can be formed stably. Furthermore, when forming the holes, the holes may be formed after determining in advance the areas where the paper layer 1 will not be laminated, or the holes may be formed evenly (at equal intervals) in the synthetic resin layer 2 and then the paper layer 1 may be laminated so as not to cover at least some of the holes. From the viewpoint of facilitating mass production, it is preferable to form evenly (at equal intervals) holes in the synthetic resin layer 2 and then laminate the paper layer 1 so as not to cover at least some of the holes, i.e., so that at least one hole is formed in the low stiffness portion 21.

[0077] Furthermore, the freshness-preserving packaging material for fruits and vegetables is not limited to having holes only in the synthetic resin layer 2, but may have holes in the high-rigidity portion 11 where the synthetic resin layer 2 and the paper layer 1 are laminated. This prevents the holes in the high-rigidity portion 11 from deforming, making it easier to obtain a freshness-preserving effect.

[0078] [Package containing fruits and vegetables] The fruit and vegetable-containing package of this embodiment is intended to mean fruit and vegetable contained in freshness-preserving packaging material 100. The amount of fruit and vegetable that can be contained is appropriately set according to the size and weight of the fruit and vegetable, and the area of ​​freshness-preserving packaging material 100.

[0079] The package containing fresh produce of this embodiment is preferably sealed after the fresh produce is placed inside, and a heat sealing process may be applied to the open portion, or materials such as back sealing tape, cable ties, rubber bands, crimps, etc. may be used. In the fruit and vegetable-containing package of this embodiment, the opening of the bag-shaped fruit and vegetable freshness-preserving package 100 is heat-sealed to form a heat-sealed portion 31a and then sealed.

[0080] In order to stably maintain the freshness of the fruits and vegetables, it is preferable that the fruits and vegetables are washed with water after harvesting and have had moisture removed. Alternatively, in order to remove the effects of moisture on the fruits and vegetables as early as possible, moisture adhering to the fruits and vegetables may be removed by vacuum pre-cooling or the like.

[0081] In this embodiment, the total open area of ​​the package containing fruits and vegetables is 0.001 to 100 mm per 100 g of fruits and vegetables. 2 It is preferable that the thickness is 0.002 to 50 mm. 2 It is more preferable that:

[0082] In this embodiment, the inner surface area of ​​the package containing fruits and vegetables per 100 g of fruits and vegetables is 100 to 5000 cm 2 It is preferable that the wavelength is 150 to 4000 cm or less. 2 More preferably, the range is 200 to 2500 cm. 2 More preferably, the range is 250 to 1000 cm. 2 It is particularly preferred that:

[0083] The weight retention rate of the fruit and vegetable package in this embodiment is preferably 95% or more, more preferably 97% or more, and even more preferably 98% or more. By achieving such a value, the freshness retention effect of the fruit and vegetable can be improved.

[0084] <Second embodiment> [Packaging materials for preserving the freshness of fruits and vegetables] In the first embodiment, the freshness-preserving packaging material 100 for fruits and vegetables is described as a bag for storing fruits and vegetables inside, but in the second embodiment, a case where the packaging material is a lid for a container for storing fruits and vegetables inside will be described. In the following, explanations of the same configuration and effects as those of the first embodiment will be omitted.

[0085] As shown in FIG. 5, the freshness-preserving packaging material 200 for fruits and vegetables of this embodiment is a lid for a container 201 that contains fruits and vegetables therein, and is attached to the container 201 by heat sealing. For example, the planar shape of the fruit or vegetable freshness-preserving packaging material 200 in this embodiment is circular, but is not limited to this, and may be substantially rectangular, polygonal, or elliptical.

[0086] The container 201 is not particularly limited as long as it is used for packaging food, and a retail product can be used. In particular, the container 201 is preferably made of a material suitable for so-called top sealing processing.

[0087] In the fruit and vegetable freshness-preserving packaging material 200 of this embodiment, the number of through holes is appropriately adjusted depending on the volume of the container 201, the size of the through holes, and the amount of water vapor transmission. From the viewpoint of obtaining a stable amount of water vapor transmission, the number of through holes is set to 0.1 holes / m with respect to the area of ​​the fruit and vegetable freshness-preserving packaging material 200. 2 More than 50 pieces / m 2 It is preferable that the number of pieces is less than 1 piece / m 2 More than 40 pieces / m 2 It is more preferable that:

[0088] In the second embodiment, the fruit and vegetable freshness-preserving packaging material 200 may further include an easy-peel layer to improve peelability from the container 201. The easy-peel layer improves peelability, and a known easy-peel layer can be used. Even when the fruit and vegetable freshness-preserving packaging material 200 is used by repeatedly opening and closing, the fruit and vegetable freshness-preserving packaging material 200 has a predetermined high rigidity portion, which suppresses deformation of the through-holes and provides a more pronounced freshness-preserving effect.

[0089] [Package containing fruits and vegetables] In this embodiment, the total open area and the inner surface area of ​​the package containing fruits or vegetables per 100 g of fruits or vegetables can be the same as in the first embodiment.

[0090] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included in the present invention.

[0091] For example, the position, size, and shape of the low-rigidity portion 21 are merely examples and are not limited to these. For example, the shape of the low-rigidity portion 21 may be a circle, an ellipse, a snowman, a geometric pattern, a symbol, a sign, etc. in addition to a rectangle or a polygon. Furthermore, there may be a plurality of low-rigidity portions 21 that are spaced apart from one another. For example, two to four rectangular low-rigidity portions 21 may be arranged in parallel and spaced apart from one another, or may be arranged in a lattice pattern. Below, examples of reference forms are given. 1. A packaging material for preserving the freshness of fruits and vegetables, which is composed of a synthetic resin layer and a paper layer laminated to a part of the synthetic resin layer, a high-rigidity portion formed of a laminate of a part of the synthetic resin layer and the paper layer is disposed so as to support a low-rigidity portion formed of the synthetic resin layer; The area of ​​the high rigidity portion is 50 to 95% of the total area of ​​the high rigidity portion and the low rigidity portion, The packaging material for preserving the freshness of fruits and vegetables, wherein the low rigidity portion has through holes. 2. The packaging material for preserving the freshness of fruits and vegetables described in 1., wherein the rigidity of the low rigidity portion is a tensile modulus obtained when a tensile test is conducted in accordance with JIS K7128 under conditions of 23°C and a load speed of 2 mm / min. 3. The packaging material for preserving the freshness of fruits and vegetables according to 1 or 2, wherein the through holes in the low rigidity portion have an average pore size of 30 to 1000 μm. 4. A packaging material for preserving the freshness of fruits and vegetables as described in any one of 1. to 3., wherein the tensile modulus of the low rigidity portion obtained when a tensile test is conducted in accordance with JIS K7128 at 23°C and a load speed of 2 mm / min is 50 MPa or more and 1600 MPa or less at 23°C. 5. A packaging material for preserving the freshness of fruits and vegetables described in any one of 1. to 4., wherein the low rigidity portion comprises a film containing one or more types selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, and / or a stretched version of such a film. 6. The packaging material for preserving the freshness of fruits and vegetables according to any one of 1 to 5, wherein the ratio of the thickness (μm) of the low rigidity portion to the thickness (μm) of the high rigidity portion is 0.1 to 0.4. 7. The basis weight of the high stiffness portion is 20 to 150 g / m 2 The packaging material for preserving the freshness of fruits and vegetables according to any one of 1. to 6. 8. A packaging material for preserving the freshness of fruits and vegetables described in any one of 1 to 7, wherein at least a portion of the high rigidity portion extends from one end of the packaging material for preserving the freshness of fruits and vegetables to the other end. 9. A packaging material for preserving the freshness of fruits and vegetables described in any one of 1 to 8, wherein at least a portion of the high rigidity portion extends from one side end to the other side end of the packaging material for preserving the freshness of fruits and vegetables. 10. A packaging material for preserving the freshness of fruits and vegetables described in any one of 1. to 9., which is a bag for containing fruits and vegetables inside. 11. A packaging material for preserving the freshness of fruits and vegetables described in any one of 1. to 9., which is a lid material for a container body that contains fruits and vegetables. 12. A package containing fresh produce, the package being made by packaging fresh produce using a packaging material for preserving the freshness of fresh produce described in any one of 1. to 11. 13. The total opening area of ​​the package containing fruits and vegetables is 0.001 to 100 mm per 100 g of fruits and vegetables. 2 12. The package containing fruits and vegetables according to claim 12. 14. The internal surface area of ​​the package containing fruits and vegetables per 100 g of the fruit and vegetables is 100 to 5,000 cm 2 A package containing fruits and vegetables as described in 12. or 13. below. 15. A method for packaging fruits and vegetables, comprising packaging the fruits and vegetables with a packaging material for preserving the freshness of the fruits and vegetables described in any one of 1. to 11. 16. A preparation step of preparing a synthetic resin layer having a paper layer partially laminated thereon; a perforation step of forming holes in a portion of the synthetic resin layer where the paper layer is not laminated; a sawing process for producing a freshness-preserving packaging material for fruits and vegetables using the synthetic resin layer having the holes; A method for producing a packaging material for preserving the freshness of fruits and vegetables, comprising the steps of: 17. A drilling step of forming holes in the synthetic resin layer; laminating a paper layer on the portion of the synthetic resin layer in which the holes are provided; a sawing process for producing a freshness-preserving packaging material for fruits and vegetables using the synthetic resin layer on which the paper layer is laminated; Including, The method for producing a freshness-keeping packaging material for fruits and vegetables, wherein the freshness-keeping packaging material for fruits and vegetables has holes in the portions of the synthetic resin layer where the paper layer is not laminated. 18. A method for producing a packaging material for preserving the freshness of fruits and vegetables as described in 16. or 17., wherein in the perforation step, the holes are made by laser irradiation or a hot needle. 19. The method for producing a packaging material for preserving the freshness of fruits and vegetables described in 18, wherein the perforation step includes a step of irradiating the synthetic resin layer with a laser while the synthetic resin layer is being transported at a substantially constant speed. EXAMPLES

[0092] The embodiments of the present invention will be described in detail based on examples and comparative examples. However, the present invention is not limited to the examples.

[0093] <Examples and Comparative Examples> [Making bags] Using the procedure described below, a paper layer was laminated onto a synthetic resin layer and the packaging material was cut to produce bags so that the (a) width of the low stiffness portion, (b) the area of ​​the high stiffness portion relative to the total area of ​​the high stiffness portion and low stiffness portion combined, and (c) bag size (inner dimensions) were as shown in Table 1.

[0094] First, the following synthetic resin layers and paper layers were prepared. Synthetic resin layer: Biaxially oriented polypropylene film "SVS2" (Gunze Co., Ltd.), basis weight: 18g / m 2 , Thickness: 20 μm, Perforations were made by laser processing. Paper layer: "AFT" (Tenma Tokushu Paper Co., Ltd.), basis weight: 71g / m 2 , Thickness: 80μm

[0095] Next, an anchor coating agent (manufactured by Henkel Japan, product number: LOCTITE LIOFOL LA3640 / LA6800=50 / 1) was applied to the paper layer, and dry laminated to a part of the synthetic resin layer to obtain a packaging material. Next, the obtained packaging material was cut to produce a bag as shown in Fig. 2(c) by the procedure shown in Fig. 2. That is, the low-rigidity portion was a substantially rectangular portion extending from the lower end to the upper end of the bag, and was arranged so that the lateral center of the low-rigidity portion was located at the lateral center of the bag (packaging material).

[0096] In Comparative Example 1, no paper layer was provided, and in Comparative Example 2, the paper layer was only on a portion of the back surface of the bag, and the low rigidity portion extended from the front surface to a portion of the back surface of the bag.

[0097] The following measurements were carried out on the obtained freshness-preserving packaging material (bag) for fruits and vegetables. The results are shown in Table 1.

[0098] <Tensile modulus> A tensile test was carried out in accordance with JIS K7128 at 23°C and a load speed of 2 mm / min.

[0099] <Yield stress (N)> The yield stress is obtained when a tensile test is conducted in accordance with JIS K7128 at 23°C and a load speed of 500 mm / min. If the upper yield point is clearly defined on the SS curve, the yield point is obtained from the maximum stress before and after the point. If the yield point is unclear, the yield point is obtained from the intersection of two tangents drawn from points before and after the inflection point on the SS curve.

[0100] -Oxygen permeability of packaging material at 23℃ and 60% RH (cc / m 2 ·day·atm) measurement (1) Nitrogen gas filling After sealing the bag with a heat seal or the like, the bag was degassed using an aspirator or the like. Degassing was continued until both sides of the bag were stuck together. Next, this bag was filled with nitrogen gas (purity 99.9% or more) using a white hard syringe. The amount of nitrogen gas injected was adjusted to the bag size, and as much as possible was injected within the range where the film constituting the bag was not tensioned by the injected nitrogen gas and was slightly loose, and was measured using the scale on the white hard syringe. The degassing and injection of nitrogen gas was carried out, for example, by piercing the bag with a syringe needle. When inserting the syringe needle, double-sided tape was applied to the film constituting the bag, and an adhesive tape made of polypropylene film (hereinafter referred to as "PP tape") was further applied on top of this. After the syringe needle was removed, the pinhole was quickly sealed with PP tape. The tape applied to the bag was 4.5 cm long. 2 It fits within the following area: Furthermore, when the film constituting the bag was a microporous film, the micropores were not blocked with tape. (2) Initial oxygen concentration measurement The initial oxygen concentration (C0) in the bag was measured immediately after filling with nitrogen gas (t=0). The gas in the bag was sampled, and the initial oxygen concentration (C0) in the bag was determined by gas chromatography (TCD). C0 was 0.2% or less, and if it exceeded this, the process was repeated. The amount of sampling gas used for oxygen concentration measurement was 10cc or less. When injected into gas chromatography, a fixed amount of approximately 1cc was injected. In addition, measurements of standard gases (two or more points including approximately 1% and approximately 10% oxygen) were also performed by injecting the same amount of gas, and a calibration curve was created. (3) Storage of bags The bags used to measure the initial oxygen concentration were stored at 23°C and 60% RH (in a temperature and humidity chamber). The bags were placed so that no objects were placed on top of them and the air from the temperature and humidity chamber fan did not directly hit the bags. (4) Measurement of oxygen concentration in the bag during storage and calculation of oxygen transmission rate The oxygen concentration inside the bag is measured at 3 to 5 points in total, at least 2 points within the range of 1% to 7% immediately after filling with nitrogen gas and after 3 hours or more have passed, and a proportional relationship (correlation coefficient of 0.98 or more) must be established between the elapsed time t (hr) and the oxygen concentration inside the bag. If the correlation coefficient does not hold, the test was repeated. If the oxygen transmission rate of the film constituting the bag is too high and the oxygen concentration inside the bag increases too quickly and this condition cannot be met, a bag can be created by laminating a part of the film with a smaller oxygen transmission rate than the film being measured and a known film of the same material, and the same procedure can be repeated. In this case, the surface area of ​​the bag is excluding the part that is laminated with another known film, and the oxygen transmission rate of the measured film is determined by subtracting the oxygen transmission rate of the known film part from the calculated oxygen transmission rate. The oxygen transmission rate was calculated using the value for the longer elapsed time according to the following formula (1). F = 1.143 × (Ct-C0) × V / t (1) However, F: oxygen permeation rate (cc / bag day atm) Ct: Oxygen concentration in the bag t hours after filling with nitrogen gas (%) C0: Oxygen concentration in the bag immediately after filling with nitrogen gas (%) V: Amount of nitrogen gas filled (cc) t: Time elapsed since gas filling (hr)

[0101] <Evaluation of freshness retention of fruits and vegetables> 100g of shredded cabbage was placed into the bag through the opening, and the opening was sealed with a heat seal. Next, the top and bottom of the bag were chucked using a Tensilon universal testing machine, and the bag was stretched at 2mm / min for 1 minute, and then stored at 10℃ for 3 days. After that, the cabbage was removed from the bag and evaluated by 4 experts according to the following criteria, and the average score was calculated. ·standard 4: Fresh (discoloration is suppressed) 3: Limit of purchase (slightly discolored) 2: Limit of consumption (discoloration, do not eat) 1: Corruption

[0102] [Table 1] [Explanation of symbols]

[0103] 1 paper layer 2 Synthetic resin layer 11 High rigidity part 21 Low rigidity part 31 Heat seal section 31a Heat seal section 31b Heat seal section 31c Heat seal section 41 Folding lines 41a Folding line 41b Folding line 100 Packaging materials for preserving freshness of fruits and vegetables 200 Packaging materials for preserving freshness of fruits and vegetables 201 Container

Claims

1. A packaging material for preserving the freshness of fruits and vegetables, comprising a synthetic resin layer and a paper layer laminated on a part of the synthetic resin layer, The synthetic resin layer has an oxygen permeability of 100 cc / m at 23° C. and 60% RH. ２ ・Day・ATM or more, 50000cc / m ２ ・Day・atm or less, a high-rigidity portion formed of a laminate of a part of the synthetic resin layer and the paper layer is disposed so as to support a low-rigidity portion formed of the synthetic resin layer; an area of ​​the high stiffness portion is 50% to 95% of a total area of ​​the high stiffness portion and the low stiffness portion; A packaging material for preserving the freshness of fruits and vegetables, wherein the low rigidity portion has a through hole (excluding those that are housed in an outer casing for use).

2. 2. The packaging material for preserving the freshness of fruits and vegetables according to claim 1, wherein the rigidity of the low rigidity portion is a tensile modulus obtained when a tensile test is carried out in accordance with JIS K7128 at 23°C and a load speed of 2 mm / min.

3. 3. The packaging material for preserving the freshness of fruits and vegetables according to claim 1, wherein the through holes in the low rigidity portion have an average pore size of 30 to 1000 μm.

4. 4. The packaging material for preserving the freshness of fruits and vegetables according to claim 1, wherein the tensile modulus of the low rigidity portion obtained when a tensile test is conducted in accordance with JIS K7128 at 23°C and a load speed of 2 mm / min is 50 MPa or more and 1600 MPa or less at 23°C.

5. The packaging material for preserving the freshness of fruits and vegetables according to any one of claims 1 to 4, wherein the low rigidity portion comprises a film containing one or more resins selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, and / or a stretched version of said film.

6. 6. The packaging material for preserving the freshness of fruits and vegetables according to claim 1, wherein the thickness (μm) of the low stiffness portion relative to the thickness (μm) of the high stiffness portion is 0.1 to 0.

4.

7. The basis weight of the high stiffness portion is 20 to 150 g / m ２ The packaging material for preserving the freshness of fruits and vegetables according to any one of claims 1 to 6,

8. 8. The packaging material for preserving the freshness of fruit or vegetable according to claim 1, wherein at least a portion of the high stiffness portion extends from one end to the other end of the packaging material for preserving the freshness of fruit or vegetable.

9. 9. The packaging material for preserving the freshness of fruit or vegetable according to claim 1, wherein at least a portion of the high stiffness portion extends from one side end to the other side end of the packaging material for preserving the freshness of fruit or vegetable.

10. The packaging material for preserving the freshness of fruits and vegetables according to claim 1 , which is a bag for containing fruits and vegetables therein.

11. The freshness-preserving packaging material for fruits and vegetables according to claim 1 , which is a lid for a container body that contains fruits and vegetables.

12. A package containing fruit or vegetables, the package being produced by packaging fruit or vegetables with the packaging material for preserving the freshness of fruit or vegetables according to any one of claims 1 to 11.

13. The total open area of ​​the package containing fruits and vegetables is 0.001 to 100 mm per 100 g of fruits and vegetables. ２ The package containing fruits and vegetables according to claim 12,

14. The inner surface area of ​​the package containing fruits and vegetables per 100 g of fruits and vegetables is 100 to 5000 cm ２ The fruit or vegetable package according to claim 12 or 13, wherein:

15. A method for packaging fruits and vegetables, comprising packaging the fruits and vegetables with the packaging material for preserving the freshness of the fruits and vegetables according to any one of claims 1 to 11.

16. A preparation step of preparing a synthetic resin layer having a paper layer partially laminated thereon; a perforation step of forming holes in a portion of the synthetic resin layer where the paper layer is not laminated; a sawing process for producing a freshness-preserving packaging material for fruits and vegetables using the synthetic resin layer having the holes; Including, The packaging material for maintaining the freshness of fruits and vegetables has a high rigidity section consisting of a laminate of a part of the synthetic resin layer and the paper layer, which is arranged so as to support a low rigidity section consisting of the synthetic resin layer, and the area of ​​the high rigidity section is 50 to 95% of the total area of ​​the high rigidity section and the low rigidity section (however, this does not include a method for manufacturing a packaging material for maintaining the freshness of fruits and vegetables that is used while being contained in an outer casing).

17. a perforation step of providing holes in the synthetic resin layer; laminating a paper layer on the portion of the synthetic resin layer in which the holes are provided; a sawing process for producing a freshness-preserving packaging material for fruits and vegetables using the synthetic resin layer on which the paper layer is laminated; Including, The packaging material for maintaining the freshness of fruits and vegetables has holes in the parts of the synthetic resin layer where the paper layer is not laminated, and a high rigidity section consisting of a laminate of a part of the synthetic resin layer and the paper layer is arranged so as to support a low rigidity section consisting of the synthetic resin layer, and the area of ​​the high rigidity section is 50 to 95% of the total area of ​​the high rigidity section and the low rigidity section (however, this does not include a method for manufacturing a packaging material for maintaining the freshness of fruits and vegetables that is used while being contained in an outer casing).

18. The method for producing a freshness-preserving packaging material for fruits and vegetables according to claim 16 or 17, wherein in the perforation step, the holes are provided by laser irradiation or a hot needle.

19. The method for producing a freshness-preserving packaging material for fruits and vegetables according to claim 17, wherein the perforation step includes a step of irradiating the synthetic resin layer, which is transported at a substantially constant speed, with a laser.

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