JP2022048507A - Vegetables and fruits freshness holding bag, vegetables and fruits package, and vegetables and fruits freshness holding method - Google Patents

Abstract

To provide a vegetables and fruits freshness holding bag which can acquire a favorable freshness holding effect when it is closed by a back sealing tape.SOLUTION: A vegetables and fruits freshness holding bag is formed using a resin film, and when subjected to a tensile test in a direction in parallel with a bottom side of the vegetables and fruits freshness holding bag, under conditions of 23°C and speed of 2 mm/minutes, configured to: (1) have a yield point at an elongation of 10-50%; (2) have a tensile modulus of elasticity of 300-2000 Mpa; and cause a back sealing tape to close an opening part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fruit and vegetable freshness-maintaining bag, a fruit and vegetable package, and a method for maintaining the freshness of fruits and vegetables. More specifically, the present invention relates to a fruit and vegetable freshness-maintaining bag, a package containing fruits and vegetables in which fruits and vegetables are wrapped in the bag, and a method for maintaining the freshness of fruits and vegetables using the bag.

Traditionally, many fruits and vegetables such as vegetables and fruits are packed in bags, and most of them are sold with openings bound so that the fruits and vegetables do not pop out. As a method of binding the opening of such a package packed with fruits and vegetables, for example, it is known to use a bag sealing tape having adhesiveness, a rubber band, or the like for binding.

On the other hand, fruits and vegetables such as vegetables and fruits maintain their respiratory action even after being harvested. Therefore, during storage, distribution or storage after harvesting, the respiration of the fruits and vegetables themselves consumes energy and causes deterioration of freshness. Therefore, as a method for maintaining the freshness of fruits and vegetables, a method of appropriately suppressing the respiration of fruits and vegetables to maintain the freshness is known. The packaging bag used for maintaining the freshness of such fruits and vegetables is known as MA (Modified Atmosphere) packaging.

For example, Patent Document 1 discloses a packaging bag for maintaining freshness, which can store fruits and vegetables simply by twisting the opening of the bag without using tape or the like. Specifically, the flexural rigidity of the packaging bag disclosed in Patent Document 1 is 0.02 gf · cm ² / cm or more and 0.18 gf · cm ² / cm or less in both the vertical direction and the horizontal direction.

Japanese Unexamined Patent Publication No. 2018-177243

However, when the opening of the freshness-preserving packaging bag disclosed in Patent Document 1 is back-sealed, it has been found that there is room for improvement in terms of the freshness-preserving effect. Therefore, the present inventors have newly focused on the development of a freshness-preserving packaging bag for back sealing tape, and obtained the finding that it is effective to appropriately control the rigidity of the resin film constituting the freshness-preserving packaging bag. .. As a result of further examination, the freshness-preserving packaging bag has a yield point at an appropriate elongation rate in the tensile test, and by specifying the tensile elastic modulus, the gap in the back seal portion becomes too large and the outside air is inside the packaging bag. As a result, it was found that a good freshness-maintaining effect (MA effect) utilizing the MA packaging function can be obtained, and the present invention has been completed.

According to the present invention
A fruit and vegetable freshness-preserving bag formed using a resin film.
When a tensile test was conducted at 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness retention bag,
(1) It has a yield point at an elongation rate of 10 to 50% and has a yield point.
(2) The tensile elastic modulus is 300 to 2000 MPa, and the tensile elastic modulus is 300 to 2000 MPa.
A fruit and vegetable freshness-retaining bag is provided in which the opening is configured to be closed by a back sealing tape.

Further, according to the present invention,
A fruit and vegetable package is provided in which fruits and vegetables are stored inside from the above-mentioned fruit and vegetable freshness-retaining bag, and the opening of the fruit and vegetable freshness-retaining bag is closed with a back sealing tape.

Further, according to the present invention,
A method for preserving the freshness of fruits and vegetables is provided, in which the fruits and vegetables are housed inside the above-mentioned fruit and vegetable freshness-retaining bag, and the opening of the fruit and vegetable freshness-retaining bag is closed with a back sealing tape to store the fruits and vegetables.

According to the present invention, there is provided a fruit and vegetable freshness-retaining bag that can obtain a good freshness-retaining effect when closed by a back sealing tape.

It is a figure which shows the tensile test result of the fruit and vegetable freshness maintenance bag of Example 1. It is a figure which shows the tensile test result of the fruit and vegetable freshness maintenance bag of the comparative example 2.

Hereinafter, embodiments of the present invention will be described in detail.

In the present specification, the term "abbreviation" means to include a range in consideration of manufacturing tolerances, assembly variations, etc., unless otherwise specified.
In the present specification, the notation "XY" in the description of the numerical range indicates X or more and Y or less unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".

<Freshness retention bag for fruits and vegetables>
The fruit and vegetable freshness-retaining bag of the present embodiment is formed by using a resin film, and when a tensile test is performed at 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness-retaining bag,
(1) It has a yield point at an elongation rate of 10 to 50% and has a yield point.
(2) The tensile elastic modulus is 300 to 2000 MPa.
Further, the fruit and vegetable freshness-retaining bag of the present embodiment is configured so that the opening thereof is twisted horizontally by about 540 degrees and then closed by a back sealing tape. As a result, the opening of the fruit and vegetable freshness-retaining bag can be appropriately closed by the back sealing, and a good freshness-retaining effect can be obtained. In addition, the fruit and vegetable freshness-retaining bag of the present embodiment has appropriate strength against stresses such as twisting and tension during back sealing, so that the opening can be closed with strong strength and the freshness-maintaining effect is stable. Can be obtained.
The opening of the freshness-retaining bag for fruits and vegetables is a so-called bag opening, which is intended to be an opening for putting in and taking out fruits and vegetables, and is different from the through hole described later.

In general, one side of the back sealing tape is an adhesive surface, and both ends of the tape in the length direction are fixed to each other by the adhesive surfaces, and the bag mouth is bound by the adhesive surface in the area other than both ends of the tape. It is used to seal the opening of the bag by doing this (pasting the gassho). Examples of the material of the back sealing tape include those made of polypropylene film and cellophane. As the fruit and vegetable freshness-retaining bag of the present embodiment, a known back sealing tape can be used.

[Tensile test]
The fruit and vegetable freshness-retaining bag of the present embodiment satisfies the following (1) and (2) when subjected to a tensile test under the conditions of 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness-retaining bag.
(1) It has a yield point at an elongation rate of 10 to 50%.
(2) The tensile elastic modulus is 300 to 2000 MPa.
That is, the fruit and vegetable freshness-retaining bag of the present embodiment has a stress-strain curve (SS curve) between the elongation rates of 10 to 50% in the above tensile test. In other words, during the elongation rate of 10 to 50%, the stress drops sharply with strain (yield), or a phenomenon occurs in which the yield does not occur and the tilt decreases, resulting in a yield point, but even after yielding. , No breakage occurs, and the stress has the property of increasing or changing at an almost constant value. As a result, good durability can be obtained while flexibly deforming against the tensile load at the time of back sealing, and since it is properly back-sealed, the freshness-preserving effect of the freshness-preserving packaging bag of the present embodiment is stable. It is presumed that it will be able to be demonstrated effectively and effectively.

The tensile test is performed on a JIS K 7127 No. 1 dumbbell test piece using a mechanical strength measuring instrument for the dumbbell test piece at 23 ° C. and a tensile speed of 2 mm / min.
In addition, the direction parallel to the bottom is parallel to the lower side or the area including the side (bottom surface) when the opening (bag mouth) of the fruit and vegetable freshness holding bag is directed upward, and is usually the horizontal direction. Become.

In the above (1), the yield point is preferably at an elongation rate of 12 to 48%, more preferably at an elongation rate of 14 to 46%, and further preferably at an elongation rate of 15 to 30%.
In the above (2), the tensile elastic modulus is preferably 320 to 1800 MPa, more preferably 340 to 1500 MPa, and further preferably 400 to 1000 MPa.
As a result, the freshness-maintaining effect can be stably obtained, and at the time of back sealing, it has an appropriate strength against stresses such as torsion and tension, and the bag-breaking resistance can be improved.

Further, the fruit and vegetable freshness-retaining bag of the present embodiment preferably satisfies the following (3) in the tensile test.
(3) The yield point stress is 12 to 100 MPa.
As a result, the balance between the extensibility and the rigidity of the fruit and vegetable freshness-retaining bag is improved, and the freshness-retaining effect can be further easily obtained.
In the above (3), the yield point stress is preferably in the range of 15 to 95 MPa, more preferably in the range of 18 to 90 MPa. As a result, a space (gap) is created in the closed opening due to twisting back over time after back sealing, and it is possible to suppress the inflow of outside air (oxygen).

In order for the fruit and vegetable freshness-retaining bag of the present embodiment to satisfy the above (1) to (3), the selection of the resin film material, the combination of the layer structures, and the method of producing the resin film according to the material are devised. It can be realized by doing so. For example, the resin film may be stretched.

Further, the fruit and vegetable freshness-preserving bag of the present embodiment preferably has an oxygen concentration (%) in the bag less than 20% after 24 hours when stored at 20 ° C. after accommodating and back-sealing the fruits and vegetables. , 19% or less, more preferably 18% or less.
As a result, the respiration of fruits and vegetables is suppressed to a low level, and a good freshness-maintaining effect can be obtained.

[Resin film]
(raw materials)
The resin film is preferably transparent or translucent, and more preferably transparent, from the viewpoint that fruits and vegetables can be visually recognized from the outside. Further, it may be printed for the purpose of identifying fruits and vegetables.

The synthetic resin constituting the resin film is not particularly limited as long as it can be used for packaging fruits and vegetables, and known ones can be used.
Examples thereof include various polyethylene and ethylene copolymers, polypropylene, polyamide resins, polyvinyl chlorides, polystyrenes, acrylic resins, polyethylene terephthalates and polyester resins such as polylactic acid. These may be homopolymers, two or more kinds of copolymers, and may contain two or more kinds of these homopolymers and copolymers.

Specific examples of the above-mentioned various polyethylenes and ethylene copolymers include ethylene / vinyl alcohol copolymers, high-density polyethylenes, medium-density polyethylenes, low-density polyethylenes, linear low-density polyethylenes, and metallocene-linear low-density polyethylenes. Examples thereof include copolymers such as polyethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, polyethylene-α-olefin copolymer, and ionomers. These may contain one kind or two or more kinds, or may be a mixture of these and other resins.

Examples of the polyamide resin include nylon. Nylon is Nylon 6, Nylon 11, Nylon 12, Nylon 66, Nylon 6/10, Nylon 6/12, Nylon 6 / T, Nylon 6 / I, Nylon 9T, Nylon M5T, Polymethoxylylen adipamide (MXD nylon) ), Etc. can be used alone or in combination of two or more. Among these, nylon 6, nylon 11, nylon 12 and nylon 66 alone or in combination of two or more are preferable, and nylon 6 and nylon 66 alone or in combination of two or more are more preferable.

Linear low density polyethylene (L-LDPE) is usually a copolymer of ethylene and a small amount of α-olefin. The type of α-olefin is not particularly limited. Typical α-olefins include α-olefins having 3 to 10 carbon atoms, such as 1-butene, 1-hexene, 4-methylpentene-1, and 1-octene.

For example, when the fruits and vegetables packaged in the fruit and vegetable freshness preservation bag are heavy, polyethylene is dry-laminated, extruded, and co-extruded with respect to a film such as unstretched polypropylene, stretched polypropylene, unstretched nylon, stretched nylon, and stretched polyester. It is preferable to use a multilayer film.
Further, the synthetic resin film may be subjected to stretching treatment, annealing, or the like, and may be further provided with a sealant layer. In particular, the stretching treatment can improve the rigidity, pinhole resistance, water vapor / oxygen barrier property, and appearance of the synthetic resin film. For example, stretched nylon, stretched polylactic acid, and stretched polystyrene are preferable.

Resin films include anti-fog agents, anti-blocking agents, heat stabilizers, lubricants, impact-resistant improvers, processing aids, anti-static agents, UV absorbers, antioxidants, and weather-resistant antioxidants, as required. Additives such as fillers and pigments may be contained within a range that does not impair the performance of the resin film.

Specific examples of the anti-fog agent include glycerin laurate, diglycerin laurate, decaglycerin laurate, glycerin monostearate, sorbitan stearate and the like.

Examples of the anti-blocking agent include fine particle inorganic compounds such as silica, alumina, alumina silicate, and diatomaceous earth; and fine particle organic compounds such as polyethylene, cross-linked polyethylene, polymethyl methacrylate, and cross-linked polymethyl methacrylate. Among them, fine particle inorganic compounds are preferable, and silica is more preferable, from the viewpoint of maintaining the freshness-retaining effect.

The method for obtaining the resin film is not particularly limited. Examples of the method for obtaining the resin film include known methods such as extrusion, inflation, and calendar ring.

The resin film may be a single layer or a multilayer of two or more layers.

(Multilayer film)
From the viewpoint of enhancing the functionality of the resin film, it is preferable to have multiple layers. By making the number of layers, it is possible to add functions such as slipperiness to the surface layer of the resin film, which improves the handleability of the resin film and provides a fruit and vegetable freshness-retaining bag with an excellent balance between extensibility and rigidity. It will be possible to obtain it stably. As a result, it becomes easy to obtain a packaging bag in which a good freshness-preserving effect can be obtained even by back sealing. Further, for example, slipperiness can be obtained by forming the resin film into a two-layer or three-layer structure and using a layer containing an antiblocking agent as at least one surface layer.
When the resin film has multiple layers, the resin that is the base of each layer may be the same or different from each other. From the viewpoint of obtaining good adhesion between layers, it is preferable to use the same resin for each layer.

When the resin film has multiple layers, the thickness of each layer may be the same as or different from each other. For example, in the case of a three-layer structure, the thickness of the intermediate layer may be the highest and the thickness of the surface layer may be the lowest. The surface layer is preferably 10 to 20%, more preferably 12 to 17%, based on the total thickness of the resin film. This provides a good balance between flexibility and rigidity and provides good MA packaging for back sealing.

As a method for obtaining the multilayer film, known methods such as dry lamination, extrusion lamination, coextrusion, and coating can be appropriately used. From the viewpoint of improving the adhesion between layers and controlling the layer thickness, coextrusion is preferable.

(Humidity permeability)
The moisture permeability of the resin film at 40 ° C. and 90% RH is preferably 50 to 400 g / ( ^m 2.24 h), more preferably 100 to 350 g / ( ^m 2.24 h), and 120 to 320 g /. It is more preferably (m ^2.24h ).
By setting the moisture permeability of the resin film to the above lower limit value or more, it becomes easy to suppress the generation of mold.
On the other hand, by setting the moisture permeability of the resin film to the above upper limit value or more, it becomes easy to suppress wilting, discoloration, and germination of fruits and vegetables.
"Withering" means a state in which dents and wrinkles are formed on the surface of fruits and vegetables.

Moisture permeability can be measured by a method compliant with JIS Z0208 (cup method).

In the present invention, the moisture permeability of the resin film can be adjusted by controlling the selection of the material of the resin film, the method of manufacturing the film, the layer structure of the film, the presence or absence of through holes, the average diameter of through holes, and the like. ..

(Oxygen permeation amount)
The oxygen permeation amount of the resin film at 23 ° C. and 60% RH is preferably 5 cc / m ² · day · atm or more, more preferably 10 cc / m, from the viewpoint of maintaining the respiration of fruits and vegetables and improving the taste. It is ² · day · atm or more, and more preferably 30 cc / m ² · day · atm or more.
On the other hand, the oxygen permeation amount of the resin film at 23 ° C. and 60% RH is preferably 2000 cc / m ² · day · atm or less, more preferably 1000 cc / m ² ·, from the viewpoint of suppressing wilting and discoloration of fruits and vegetables. It is day · atm or less, and more preferably 500 cc / m ² · day · atm or less.

For the oxygen permeation amount, for example, the oxygen concentration in the packaging bag is measured for each of the packaging bag immediately after being filled with nitrogen and the packaging bag after being left for a certain period of time after being filled with nitrogen, and the oxygen concentration gradient thereof is measured. It can be calculated from.

Further, in the present invention, the oxygen permeation amount of the resin film is adjusted by controlling the selection of the material of the resin film, the film manufacturing method, the layer structure of the film, the presence or absence of through holes, the average diameter of through holes, and the like. be able to.

The fruit and vegetable freshness-preserving bag of the present invention can further enhance the effect of suppressing the occurrence of mold and wilting and the effect of preserving freshness by further satisfying the following requirements.

[Thickness]
The thickness of the fruit and vegetable freshness-retaining bag is preferably 10 to 70 μm, more preferably 15 to 50 μm, and even more preferably 18 to 45 μm. By setting the thickness of the fruit and vegetable freshness-retaining bag to the above lower limit or more, it is easy to increase the strength of the fruit and vegetable freshness-retaining bag. By setting the thickness of the fruit and vegetable freshness holding bag to the above upper limit value or more, the flexibility (suppleness) of the fruit and vegetable freshness holding bag can be maintained, and good sealing property can be easily obtained.

[Through hole]
The fruit and vegetable freshness-retaining bag may have through holes. This makes it possible to easily adjust the moisture permeability and the amount of oxygen permeation. This makes it possible to suppress the growth of mold, wilting, and discoloration while effectively maintaining the freshness of fruits and vegetables.

The planar shape of the through hole may be, for example, a circle, a polygon, or a slit. The circular shape is not limited to a perfect circle, but includes a substantially circular shape. In addition to the circular shape, it may be semi-circular or crescent-shaped. The polygon may be a shape surrounded by three or more line segments such as a triangle, a quadrangle, and a pentagon. The slit is a notch or a gap penetrating the synthetic resin film constituting the fruit and vegetable freshness-retaining bag, and may be a straight line, a curved line, an L-shape, an X mark, or the like, and its length or the like is particularly important. Not limited.

The average diameter of the through holes is preferably 10 μm to 200 μm, more preferably 20 to 100 μm, and even more preferably 40 to 80 μm. By setting it to the above lower limit value or more, the moisture permeability and the oxygen permeation amount are improved, and it becomes easy to suppress the generation of mold. On the other hand, when the value is not more than the above upper limit, the MA effect can be maintained while preventing the invasion of foreign substances, and the wilting and shaft wilting of fruits and vegetables can be suppressed.
The average diameter of the through hole is calculated from the opening area of the through hole with the through hole as a perfect circle.

When the fruit and vegetable freshness retention bag has a plurality of holes, it is preferable that the diameters of all the through holes are within the above numerical range from the viewpoint of ease of manufacture, but the diameters of some of the through holes are 10. It may be outside the range of about 200 μm.

The method for forming the through hole is not particularly limited, and a known method can be adopted. Examples of such known methods include a laser processing method, a needle processing method including a hot needle, a method using a mold such as a roll cutter, and the like.

The total perforated area per 1 kg of fruits and vegetables in the fruit and vegetable freshness retention bag is preferably 0.1 mm ² / kg or more, 5.4 × 10 ² mm ² / kg or less, and 0.2 mm ² / kg or more. More preferably, it is 2.0 × 10 ² mm ² / kg or less. By setting it to the above lower limit value or more, it is possible to suppress the generation of mold and the generation of dew condensation. On the other hand, when the value is not more than the above upper limit, the freshness of fruits and vegetables can be kept good and the occurrence of wilting and shaft withering can be suppressed.
The total opening area does not include the area of the opening for putting in and taking out fruits and vegetables in the fruit and vegetable freshness maintenance bag.

[size]
The fruit and vegetable freshness-preserving bag of the present embodiment is typically a quadrangular (rectangular, square, etc.) bag. Further, it may have a gusset at the bottom.
As an example, the size of the fruit and vegetable freshness-retaining bag can be about 100 mm × 100 mm to 250 mm × 350 mm for packaging of fruits and vegetables for general consumers.

In addition, the inner surface area of the fruit and vegetable freshness-retaining bag in the present embodiment can be appropriately set according to the shape, size, handleability, and the like of the fruit and vegetable to be packaged. For example, the internal surface area of the fruit and vegetable freshness-retaining bag per 100 g of fruits and vegetables may be 100 cm ² or more and 5000 cm ² or less, or 300 cm ² or more and 700 cm ² or less.

[Fruits and vegetables]
The fruits and vegetables to be packaged are not particularly limited. The fruits and vegetables can be, for example, at least one selected from the group consisting of cauliflowers, fruit vegetables, stem vegetables, root vegetables and leaf vegetables.
Specific examples of flower vegetables include broccoli, cauliflower, edible chrysanthemum, fukinoto, Japanese ginger, and oilseed rape (rape blossoms).
Specific examples of fruit vegetables include eggplant, tomato, pepper, paprika, capsicum, shishito pepper, pumpkin, zucchini, cucumber, horned melon (kiwano), white pepper, horned melon (bitter gourd, horned melon), wax gourd, calabash, and okura. Can be mentioned.
Specific examples of stem vegetables include asparagus, udo, kohlrabi, zha cai, bamboo shoots, water spinach, and rhubarb.
Specifically, as root vegetables, cubs, radishes, hatsuka radishes, kwai, gobo, yacon, Chinese artichoke, ginger, persnip, celeriac, carrots, lentils, beets, lily roots, sweet potatoes, sweet potatoes, potatoes, yams, yams. And so on.
Specific examples of leafy vegetables include ice plant, endive (kikujisha), mustard greens, Dutch chard (creson), cabbage, mecabbage, kale (hagoromokanran), komatsuna, coriander (pakuchi), saishin, shimatsunaso (moroheiya), shungiku, and seri. , Celoli, Taasai, Takana, Bok Choy, Tsurumurasaki, Nozawana, Chinese cabbage, parsley (Dutch jelly), Swiss chard (Swiss chard), Spinach, Mizuna, Mibuna, Mitsuba, Luccola, Lettuce (Chisha), Asatsuki, Eshalot, Onion, Chaibu Examples include Chinese cabbage, garlic, onion, mustard greens, liki, and cabbage.
Among them, fruit vegetables, root vegetables and leaf vegetables are preferable, and sweet potatoes, potatoes, tomatoes, Satsuma mandarin, shiitake mushrooms, onions and carrots are more preferable.

<Fruit and fruit packaging and how to maintain the freshness of fruits and vegetables>
By packaging fruits and vegetables using the above-mentioned fruit and vegetable freshness-preserving bag, a fruit and vegetable package can be obtained. Further, by packaging the fruits and vegetables using the above-mentioned fruit and vegetable freshness holding bag, deterioration of the freshness of the fruits and vegetables can be suppressed.
Fruits and vegetables are wrapped with back sealing tape. The back seal can be done using a suitable back sealing device.

The amount of fruits and vegetables contained in the bag may vary depending on the size of the bag, the type of fruits and vegetables, and the like. For fruits and vegetables for general consumers, an example is 50 to 1000 g, preferably 100 to 800 g.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.

Embodiments of the present invention will be described in detail based on Examples and Comparative Examples. As a reminder, the invention is not limited to examples.

<Example 1>
As raw materials for the first and third layers, 95 parts by weight of nylon 6 resin ("UBE Nylon 1030B2" manufactured by Ube Kosan Co., Ltd.) and 5 parts by weight of anti-blocking agent (silica-containing nylon 6 resin, manufactured by Ube Kosan Co., Ltd.) , "UBE Nylon 1015FDM1") was used in a dry blend.
Nylon 6 resin (“UBE Nylon 1030B2” manufactured by Ube Kosan Co., Ltd.) was used as a raw material for the second layer.
Using each of the raw materials of the first layer to the third layer, a multilayer resin film having the thickness shown in Table 1 was obtained by a T-die coextrusion film forming method.

<Example 2>
A multilayer resin film was obtained in the same manner as in Example 1 except that the layer ratio (total thickness) shown in Table 1 was adjusted.

<Example 3>
A multilayer resin film was obtained in the same manner as in Example 1 except that the layer ratio (total thickness) shown in Table 1 was adjusted.

<Example 4>
As raw materials for the first layer, 95 parts by weight of nylon 6 resin (manufactured by Ube Kosan Co., Ltd., "UBE Nylon 1030B2") and 5 parts by weight of anti-blocking agent (silica-containing nylon 6 resin, manufactured by Ube Kosan Co., Ltd., "UBE Nylon") A dry blend of 1015FDM1 ”) was used.
Nylon 6 resin (“UBE Nylon 1030B2” manufactured by Ube Kosan Co., Ltd.) was used as a raw material for the second layer.
As a raw material for the third layer, 100 parts by weight of an ethylene-vinyl alcohol copolymer (“E173B” manufactured by Kuraray Co., Ltd.) was used.
Using each of the raw materials of the first layer to the third layer, a multilayer resin film having the thickness shown in Table 1 was obtained by a T-die coextrusion film forming method.

<Comparative Example 1>
As a raw material for the first layer and the second layer, a polypropylene film (homotype, "Novatec pp FB3B" manufactured by Japan Polypropylene Corporation) was used.
As a raw material for the third layer, a polypropylene film (random type, "Wintech WFX4TA" manufactured by Japan Polypropylene Corporation) was used.
Using each of the raw materials of the first layer to the third layer, a multilayer resin film having the thickness shown in Table 1 was obtained by a T-die coextrusion film forming method.

<Comparative Example 2>
A stretched polypropylene film (“AF-642” manufactured by Futamura Chemical Co., Ltd.) was prepared as the first layer, and a resin film having the thickness shown in Table 1 was obtained.

<Comparative Example 3>
As the first layer, a stretched nylon film (manufactured by Unitika Ltd., "emblem ON") was prepared.
As the second layer, an ethylene-vinyl alcohol resin (Nippon Synthetic Chem Industry Co., Ltd., "Soanol 16DX" (solid content 16%)) was prepared.
An adhesive layer (one-component water-based polybutadiene adhesive, manufactured by Nippon Soda Co., Ltd., Titabond "T180E") is applied on the first layer with a dry film thickness of 0.03 μm (gravure coat: drying temperature 100 ° C., drying time 10 seconds). Then, the second layer was coated with a dry film thickness of 0.8 μm (gravure coat: drying temperature 100 ° C., drying time 10 seconds) to obtain a multilayer resin film having the thickness shown in Table 1.

<Comparative Example 4>
A stretched polypropylene film (“AF-642” manufactured by Futamura Chemical Co., Ltd.) was prepared as the first layer, and eight punch holes (diameter 5 mm) were provided to obtain a resin film having the thickness shown in Table 1.

<Manufacturing of fruit and vegetable freshness preservation bags>
The fruit and vegetable freshness-preserving bags of each example and each comparative example were produced by the following procedure.
Two resin films cut to the same size were prepared and stacked so that the four corners matched. Next, using an impulse sealer, heat-sealing was performed on three sides (both sides and bottom) to obtain a fruit and vegetable freshness-retaining bag (200 mm × 300 mm).
As the impulse sealer, P-300 manufactured by Fuji Impulse Co., Ltd. was used. The heat sealing process was performed under the conditions of the fusing sealing method and the maximum scale. As a result, a fusing seal portion was formed.
The fruit and vegetable freshness-preserving bag using the resin film of Comparative Example 4 was made so as to have eight punch holes.

<Evaluation / Measurement>
The following evaluations and measurements were performed on each of the obtained resin films or fruit and vegetable freshness-retaining bags. The results are shown in Table 1.

[Tensile test]
A tensile test was conducted at 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness retention bag. Specifically, a JIS K 7127 No. 1 dumbbell test piece was prepared from a fruit and vegetable freshness preservation bag, and the dumbbell test piece was used as a mechanical strength measuring instrument (A & D Co., Ltd., Tencilon universal material testing machine RTF-1250). It was used at 23 ° C. and a pulling speed of 2 mm / min.
From the tensile test results, (1) elongation rate (%) at the yield point, (2) tensile elastic modulus (MPa), and (3) yield point stress (MPa) were determined. The stress at the yield point is from the maximum value of the stress before and after the yield point is clear from the SS curve, and from the point before and after the inflection point in the SS curve when the yield point is unclear. It was calculated from the intersection of the two tangents drawn.
Further, FIG. 1 shows a tensile curve obtained in the tensile test of Example 1, and FIG. 2 shows a tensile curve obtained in the tensile test of Comparative Example 2.
The elongation rate (%) was determined based on the length of elongation starting from 40 mm between the marked lines.

[Humidity g / (m ^2.24h ) at 40 ° C. and 90% RH]
Measurements were made according to JIS Z 0208 (40 ° C., 90% RH) using a resin film.

[Oxygen permeation amount at 23 ° C. and 60% RH (cc / m ² · day · atm)]
(1) Filling with nitrogen gas A bag was formed using a resin film, the bag was sealed with a heat seal or the like, and then the bag was degassed using an aspirator or the like. Deaeration was carried out until both sides of the bag stuck. Next, this bag was filled with nitrogen gas (purity of 99.9% or more) using a white hard syringe. The amount of nitrogen gas to be injected should be adjusted to the size of the bag, and the film that constitutes the bag should not be tensioned by the injected nitrogen gas. Was measured. The nitrogen gas was degassed and injected, for example, by inserting an injection needle into the bag. When piercing the injection needle, a double-sided tape was attached to the film constituting the bag, and an adhesive tape made of polypropylene film (hereinafter referred to as "PP tape") was further attached on the double-sided tape. After pulling out the injection needle, the needle hole was immediately closed with PP tape. The tape to be attached to the bag was designed to fit in an area of 4.5 cm ² or less.
When the film constituting the bag is a fine pore film, the fine pores are not blocked with tape.
(2) Measurement of initial oxygen concentration The initial oxygen concentration (C0) in the bag immediately after filling with nitrogen gas (t = 0) was measured. 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 work was redone. The sampling gas for measuring the oxygen concentration was 10 cc or less. When injecting into gas chromatography, a fixed amount of about 1 cc was injected. In addition, the measurement of the standard gas (two or more points containing about 1% and about 10% oxygen) was also performed by injecting the same amount of gas, and a calibration curve was prepared.
(3) Storage of bags The bags whose initial oxygen concentration was measured were stored at 23 ° C. and 60% RH (constant temperature and humidity chamber). At this time, the bag was left standing so that no object would be placed on the bag or the wind from the fan of the constant temperature and humidity chamber would hit the bag directly.
(4) Measurement of oxygen concentration in the bag during storage and calculation of oxygen permeation rate Measurement of oxygen concentration in the bag is performed within the range of 1% or more and 7% or less of oxygen concentration immediately after filling with nitrogen gas and after 3 hours or more. It is necessary to measure a total of 3 to 5 points above the points and establish a proportional relationship (correlation coefficient of 0.98 or more) between the elapsed time t (hr) and the oxygen concentration in the bag. If the correlation coefficient did not hold, a retest was performed. If the oxygen permeation rate of the film constituting the bag is too high and the oxygen concentration in the bag rises too quickly to meet this condition, it is known that a part of the film is smaller than the film whose oxygen permeation rate is measured. You can make a bag by laminating it with a film of the same material and do the same. At this time, the surface area of the bag was the oxygen permeation rate of the measurement film obtained by subtracting the oxygen permeation rate of the known film part from the obtained oxygen permeation rate, excluding the portion bonded to another known film.
For the oxygen permeation rate, the following formula (1) was calculated using the value having the longer elapsed time.
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 filled nitrogen gas (cc)
t: Elapsed time (hr) from the time of gas filling

<Evaluation>
The following evaluations were made for each of the obtained fruit and vegetable freshness-retaining bags. The results are shown in Table 2.

[Freshness retention]
1) The holes shown in Table 3 were provided in each fruit and vegetable freshness preservation bag by laser processing. Put sweet potatoes, potatoes, tomatoes, oranges, shiitake mushrooms, onions, and carrots in the prepared bags by the weight (g) shown in Table 3, and seal the openings with back sealing tape (10 bags each prepared). ). This was subjected to a storage test at the storage temperature and storage period shown in Table 3. In addition, after sealing the vegetables in a bag, the oxygen concentration (%) in the bag was measured 24 hours later, and the results are shown in Table 2. The oxygen concentration in the bag was measured using a Check Point manufactured by MOCON Europe (formerly Dansensol).
-As shown in Table 2, the oxygen concentration (%) in the bag of each fruit and vegetable freshness-retaining bag of the example was controlled within the range in which the MA effect could be normally exhibited. On the other hand, in each of the fruits and vegetables freshness-retaining bags of the comparative example, the oxygen concentration (%) in the bag was not sufficiently controlled, and the oxygen concentration (%) in the bag was slightly close to (high) the outside air. The fruit and vegetable freshness-retaining bag of Comparative Example 4 was not subject to MA packaging because it had punch holes. Therefore, the numerical value of the oxygen concentration (%) in the bag shown in Table 2 showed the same oxygen concentration as the outside air.
2) After the storage test, each of sweet potato, potato, tomato, Satsuma mandarin, shiitake mushroom, onion, and carrot was evaluated by a skilled engineer according to the following evaluation criteria for mold incidence, wilting, discoloration, and germination. The results show the average value of 10 bags.
-Mold occurrence rate: Bag (number) rate (%) where moldy vegetables were found
・ Withering: 4-step sensory evaluation (4: No withering (fresh) 3: Slight withering (purchasing limit) 2: Conspicuous withering (consumption limit) 1: Corruption)
・ Discoloration: 4-step sensory evaluation (4: No discoloration (fresh) 3: Slight discoloration (purchase limit) 2: Conspicuous discoloration (consumption limit) 1: Corruption)
・ Germination: 4-step sensory evaluation (4: No germination (fresh) 3: Slight germination (purchase limit) 2: Conspicuous germination (consumption limit) 1: Corruption)

[Bag resistance]
First, 100 mL of nitrogen gas was sealed in each bag of each Example and Comparative Example, and the opening was heat-sealed to prepare a bag containing nitrogen gas. The conditions for heat sealing were the same for each bag.
After that, the evaluator pushed the inflated bag containing nitrogen gas by hand and evaluated whether it could be easily opened.
Ten bags containing nitrogen gas were prepared in each Example and Comparative Example, and were evaluated by 10 skilled engineers. If less than 2 people answered that the package was easily opened, it was evaluated as 〇 (good), and if there were 2 or more people, it was evaluated as × (bad).

According to the present invention
A fruit and vegetable freshness-preserving bag made of a resin film.
When a tensile test was conducted at 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness retention bag,
(1) It has a yield point at an elongation rate of 15 to 30 % and has a yield point.
(2) The tensile elastic modulus is 400 to 1000 MPa, and the tensile elastic modulus is 400 to 1000 MPa.
The resin film has a film containing a polyamide resin and has a film.
The oxygen permeation amount of the fruit and vegetable freshness-retaining bag in an atmosphere of 23 ° C. and 60% RH is 2 cc / m ² · day · atm or more and 1000 cc / m ² · day · atm or less.
A fruit and vegetable freshness-retaining bag is provided in which the opening is configured to be closed by a back sealing tape.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the reference embodiment of the present invention will be shown.
[1]
A fruit and vegetable freshness-preserving bag formed using a resin film.
When a tensile test was conducted at 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness retention bag,
(1) It has a yield point at an elongation rate of 10 to 50% and has a yield point.
(2) The tensile elastic modulus is 300 to 2000 MPa, and the tensile elastic modulus is 300 to 2000 MPa.
A fruit and vegetable freshness-retaining bag configured so that the opening is closed with back sealing tape.
[2]
In the tensile test,
(3) The fruit and vegetable freshness-retaining bag according to [1], wherein the yield point stress is 12 to 100 MPa.
[3]
The fruit and vegetable freshness-retaining bag according to [1] or [2], wherein the fruit and vegetable freshness-retaining bag has a moisture permeability of 50 to 350 g / (m 2.24 h) at ⁴⁰ ° C. and 90% RH .
[4]
The fruit and vegetable freshness-retaining bag according to any one of [1] to [3], wherein the thickness of the resin film is 10 to 50 μm.
[5]
The resin film is a film containing one or more selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, and / or stretched. The fruit and vegetable freshness-retaining bag according to any one of [1] to [4], comprising the film.
[6]
The oxygen permeation amount of the fruit and vegetable freshness-retaining bag in an atmosphere of 23 ° C. and 60% RH is 2 cc / m ² · day · atm or more and 50,000 cc / m ² · day · atm or less, any of [1] to [5]. The fruit and vegetable freshness retention bag listed in one.
[7]
The fruit and vegetable freshness-retaining bag according to any one of [1] to [5], wherein the resin film has a multi-layer structure.
[8]
A fruit and vegetable package in which fruits and vegetables are stored inside from the fruit and vegetable freshness-retaining bag according to any one of [1] to [7], and the opening of the fruit and vegetable freshness-retaining bag is closed with a back sealing tape.
[9]
The fruit and vegetable package according to [8], wherein the fruit and vegetable is one or more selected from the group consisting of flower vegetables, fruit vegetables, stem vegetables, root vegetables and leaf vegetables.
[10]
The fruits and vegetables are stored in the fruit and vegetable freshness-retaining bag according to any one of [1] to [7], and the opening of the fruit and vegetable freshness-retaining bag is closed with a back sealing tape to store the fruits and vegetables. Method.

Claims (10)

A fruit and vegetable freshness-preserving bag formed using a resin film.
When a tensile test was conducted at 23 ° C. and a speed of 2 mm / min in a direction parallel to the bottom of the fruit and vegetable freshness retention bag,
(1) It has a yield point at an elongation rate of 10 to 50%.
(2) The tensile elastic modulus is 300 to 2000 MPa, and the tensile elastic modulus is 300 to 2000 MPa.
A fruit and vegetable freshness-retaining bag configured so that the opening is closed with back sealing tape. In the tensile test,
(3) The fruit and vegetable freshness-retaining bag according to claim 1, wherein the yield point stress is 12 to 100 MPa. The fruit and vegetable freshness-retaining bag according to claim 1 or 2, wherein the fruit and vegetable freshness-retaining bag has a moisture permeability of 50 to 350 g / ( ^m 2.24 h) at 40 ° C. and 90% RH. The fruit and vegetable freshness-retaining bag according to any one of claims 1 to 3, wherein the thickness of the resin film is 10 to 50 μm. The resin film is a film containing one or more selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, and / or stretched. The fruit and vegetable freshness-retaining bag according to any one of claims 1 to 4, comprising the film. Any one of claims 1 to 5, wherein the oxygen permeation amount of the fruit and vegetable freshness-retaining bag in an atmosphere of 23 ° C. and 60% RH is 2 cc / m ² · day · atm or more and 50,000 cc / m ² · day · atm or less. Fruit and vegetable freshness retention bag described in the section. The fruit and vegetable freshness-retaining bag according to any one of claims 1 to 5, wherein the resin film has a multi-layer structure. A fruit and vegetable package in which fruits and vegetables are stored inside from the fruit and vegetable freshness-retaining bag according to any one of claims 1 to 7, and the opening of the fruit and vegetable freshness-retaining bag is closed with a back sealing tape. The fruit and vegetable package according to claim 8, wherein the fruit and vegetable is one or more selected from the group consisting of flower vegetables, fruit vegetables, stem vegetables, root vegetables and leaf vegetables. A method for preserving freshness of fruits and vegetables, wherein the fruits and vegetables are housed in the fruit and vegetable freshness holding bag according to any one of claims 1 to 7, and the opening of the fruit and vegetable freshness holding bag is closed with a back sealing tape to store the fruits and vegetables.

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