Freshness preservation bags for fruits and vegetables, packaging for fruits and vegetables, and method for preserving the freshness of fruits and vegetables.

Abstract

This technology provides stable and reliable opening and closing performance. [Solution] The fresh produce preservation bag 100 of the present invention comprises a bag body 10 made of synthetic resin film with an opening at the top, an openable and closable zipper portion 20 parallel to the width direction of the bag body 10, a strip-shaped sealing portion 30 forming the side of the bag body 10, and fixing portions 40 that fix both ends of the zipper portion 20 in the area including the side of the bag body 10, wherein the sealing portion 30 has a recess 50 on the side of the bag body 10 opposite to the aforementioned side, and the depth (mm) of the recess 50 is 0.5 or more relative to the width (mm) of the sealing portion 30.

Description

[Technical Field]

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

[0002] Vegetables, fruits, and other fresh produce continue to respire even after harvesting. Therefore, during storage, distribution, or preservation after harvest, the produce consumes energy through its own respiration, leading to deterioration of freshness. To maintain the freshness of fresh produce, methods are known that moderately suppress respiration. Packaging bags used for this purpose are known as MA (Modified Atmosphere) packaging.

[0003] In recent years, zippered bags have become known as containers for fruits and vegetables (for example, Patent Documents 1 to 3). For example, Patent Document 1 discloses a zippered packaging bag in which the outer film is welded and cut to form the side edges of the inner film, and the ends of the zipper are heat-pressed to form a fused section 2 to 10 mm wide, thereby integrally fusing and fixing the ends of a pair of zippers. Patent Document 2 also discloses a zippered packaging bag formed by a back seal. Patent Document 3 also discloses a zippered packaging bag in which the sides of the bag body are welded or cut, but the area where the ends of the zipper are located is an unwelded section. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2000-118542 [Patent Document 2] Japanese Patent Publication No. 2009-51522 [Patent Document 3] International Publication No. 2005 / 0190522 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the conventional packaging bags described in Patent Documents 1 to 3 had room for improvement in terms of maintaining good opening and closing performance of the zipper while also improving the freshness preservation effect. In other words, the zippered packaging bag described in Patent Document 1 has both ends of the bag formed by heat sealing, which can cause gaps at the zipper ends. Furthermore, because the zipper ends are difficult to move, they can be pulled too hard, resulting in gaps and other problems. Similarly, the zippered bag described in Patent Document 2 also had the problem of gaps forming. Therefore, the conventional zippered packaging bags described in Patent Documents 1 and 2 did not have sufficient airtightness and there was room for improvement in terms of enhancing the freshness preservation effect. Furthermore, the zippered packaging bag described in Patent Document 3 has both ends of the bag welded, but there is no welded part at the zipper end, and both ends of the opening at the top of the bag body are open, so it was not intended to obtain a freshness preservation effect.

[0006] The inventors of this invention conducted research to improve the freshness preservation effect of zippered packaging bags and focused on providing a strip-shaped sealing portion on the side of the bag body. Upon investigation, they found that while providing a strip-shaped sealing portion can suppress gas leakage from the zipper end, even when the packaging bag is opened, the rigidity of the zipper makes it difficult to maintain the open state, and the bag tends to close immediately. Further investigation revealed that in a zippered packaging bag configured to have a strip-shaped sealing portion on the side, having a constriction, or narrower area, in a part of the sealing portion provides appropriate flexibility to the sealing portion. By controlling the degree of constriction in the sealing portion, the packaging bag becomes locally flexible, resulting in good opening retention while suppressing gas leakage from the zipper end and enhancing the freshness preservation effect. In other words, the object of the present invention is to provide a zippered freshness-preserving packaging bag that can improve freshness preservation while maintaining good opening and closing performance of the zipper. [Means for solving the problem]

[0007] In other words, the present invention provides the following technology relating to fresh produce preservation bags.

[0008] [1] A bag body made of synthetic resin film with an opening at the top, The bag body has a zipper section that can be opened and closed, which is parallel to the width direction, The bag body has a strip-shaped sealing portion that forms the side edge, A first fixing portion is provided in the area including the side edge of the bag body, which fixes both ends of the zipper portion. A fresh produce freshness preservation bag comprising: The sealing portion has a recess on the side of the bag body opposite to the side edge, A fresh produce preservation bag in which the depth (mm) of the recess (mm) relative to the width (mm) of the sealing portion is 0.5 or more. [2] [1] A fresh produce freshness preservation bag as described above, A fresh produce preservation bag in which the depth of the recess is 0.9 to 2.8 mm. [3] A fresh produce preservation bag as described in [1] or [2], The first fixing part is a freshness-preserving bag for fruits and vegetables, which is located inside the recess. [4] A fresh produce preservation bag described in any one of [1] to [3], A fresh produce preservation bag in which the maximum length (mm) of the first fixing portion in the width direction of the bag body is longer than the depth (mm) of the recess. [5] A fresh produce preservation bag described in any one of [1] to [4], A fresh produce preservation bag in which at least one side of the recess is curved inward. [6] A fresh produce preservation bag described in any one of [1] to [5], A fresh produce preservation bag in which at least one side of the recess is stepped. [7] [3] A fresh produce preservation bag as described above, The maximum value of the distance between the first fixing part and the strip-shaped sealing part in the direction parallel to the side of the bag body is 0.7 to 4 mm, and the fresh fruit and vegetable freshness-keeping bag. [8] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to [7], The fresh fruit and vegetable freshness-keeping bag in which the opening width of the concave part is 9.0 to 15 mm. [9] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to [8], The fresh fruit and vegetable freshness-keeping bag in which the maximum thickness of the first fixing part is 0.3 to 1.3 mm.

[10] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to [9], The fresh fruit and vegetable freshness-keeping bag in which the total light transmittance (%) of the bag body with respect to the total light transmittance (%) of the sealing part is 0.90 to 1.00.

[11] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to

[10] , The fresh fruit and vegetable freshness-keeping bag in which the contact angle of the inner surface of the bag body with respect to water is 3 to 60°.

[12] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to

[11] , The fresh fruit and vegetable freshness-keeping bag in which the average length RSm of the roughness curve elements defined by JIS B 0601 on the surface of the sealing part is 80 to 550 μm.

[13] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to

[12] , The fresh fruit and vegetable freshness-keeping bag further having a second fixing part on at least one of the lower side corners of the bag body.

[14] The fresh fruit and vegetable freshness-keeping bag according to any one of [1] to

[13] , The fresh fruit and vegetable freshness-keeping bag in which the lower side of the bag body is formed by folding back the synthetic resin film.

[15] A package containing fresh fruits and vegetables, which contains fresh fruits and vegetables in the fresh fruit and vegetable freshness-keeping bag according to any one of [1] to

[14] .

[16] A method for maintaining the freshness of fresh fruits and vegetables, which includes the step of containing fresh fruits and vegetables in the fresh fruit and vegetable freshness-keeping bag according to any one of [1] to

[14] .

Advantages of the Invention

[0009] According to the present invention, a freshness-preserving packaging bag with a zipper can be provided that improves the freshness-preserving effect while maintaining good opening and closing performance of the zipper. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view of a packaging bag. [Figure 2] This is a magnified view of a portion of the packaging bag (around the indented area). [Figure 3] This is an enlarged view showing a modified example of a part of the packaging bag (around the indented area). [Figure 4] This is an enlarged view showing a modified example of a part of the packaging bag (around the indented area). [Figure 5] This is an enlarged view showing a modified example of a part of the packaging bag (around the indented area). [Figure 6] This is an enlarged view showing a modified example of a part of the packaging bag (around the indented area). [Figure 7] This is a schematic diagram showing an example of a packaging bag manufacturing method. [Modes for carrying out the invention]

[0011] In this specification, the notation "a~b" in descriptions of numerical ranges means a or more and b or less, unless otherwise specified. For example, "1~5 mass%" means "1 mass% or more and 5 mass% or less." Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower and upper limits of other numerical ranges. Unless otherwise specified, each component and material exemplified herein may be used alone or in combination of two or more.

[0012] In this specification, "top" refers to the direction in which the opening of the fresh produce preservation bag is located, and "bottom" refers to the direction opposite to the opening of the fresh produce preservation bag, i.e., the direction in which the bottom of the fresh produce preservation bag is located. Furthermore, in this specification, fresh produce preservation bags will also be referred to and described as "packaging bags."

[0013] Embodiments of the present invention will be described below.

[0014] <Freshness-preserving bags for fruits and vegetables> Figure 1 is a schematic perspective view showing one aspect of the fresh produce preservation bag 100 of this embodiment. As shown in Figure 1, the fresh produce preservation bag 100 comprises a bag body 10 made of synthetic resin film with an opening at the top, an openable and closable zipper portion 20 parallel to the width direction of the bag body 10, a strip-shaped sealing portion 30 that forms the side edge 11 of the bag body 10, and a first fixing portion 40 that fixes both ends of the zipper portion 20 to the area including the side edge 11 of the bag body 10, wherein the sealing portion 30 has a recess 50 on the side 12 opposite to the side edge 11 of the bag body 10.

[0015] The strip-shaped sealing portion 30 constitutes the side edge 11 of the bag body 10 and is used to maintain the strength of the bag body 10 while suppressing the formation of gaps at both ends of the zipper portion 20, thereby improving the freshness preservation effect. As shown in Figure 2, the width (mm) of the seal portion 30 is the distance from the side edge 11 to the opposite side 12 of the seal portion 30, and is represented by L1 (mm). The depth (mm) of the recess is the length from the imaginary line extending from the opposite side 12 of the seal portion 30 toward the side edge 11 of the seal portion 30 in the area where the seal portion 30 is not formed, and is represented by L2 (mm).

[0016] In this embodiment, the depth (mm) (L2) (L2 / L1) of the recess 50 relative to the width (mm) (L1) of the seal portion 30 is 0.50 or more, preferably 0.60 or more, and more preferably 0.75 or more. By setting L2 / L1 to be above the lower limit value, good opening and closing performance can be maintained. In other words, the recess 50 is intended to be a region where the width of the sealing portion 30 narrows. This makes the area around both ends of the zipper portion 20 moderately flexible, reducing the likelihood of the opening closing immediately due to the rigidity of the zipper portion 20. Furthermore, the moderate play at the ends of the zipper portion 20 makes opening and closing easier, and as a result, it is easier to achieve airtightness, further improving the freshness preservation effect. In addition, moderately fixing both ends of the zipper portion 20 improves durability against repeated opening and closing. For example, Figure 3 shows the case where (L2 / L1) is about 0.50. Furthermore, (L2 / L1) may be set to 0.85 or higher, or to 0.86 or higher, in order to maintain good opening and closing performance while improving the ability to hold the opening. On the other hand, the upper limit of L2 / L1 is not particularly limited, but it may be set to 0.99 or less.

[0017] Furthermore, in this embodiment, the bag body 10 has additional second fixing parts 41 at both lower corners. The second fixing parts 41 improve the strength of the bag body 10, resulting in better durability and freshness preservation. The size and shape of the second fixing parts 41 are not particularly limited and can be appropriately designed within the scope of the function and purpose of the fresh produce freshness preservation bag 100. In this embodiment, an example is described in which the second fixing portion 41 is provided on both of the lower corners, but the second fixing portion 41 may be provided on at least one of the lower corners of the bag body 10.

[0018] The depth (mm)(L2) of the recess 50 is preferably 0.9 mm or more, and more preferably 1.0 mm or more. By setting the depth (mm)(L2) of the recess 50 to be greater than or equal to the lower limit above, a constricted shape can be given to the seal portion 30, improving the ability to hold the opening and providing good opening and closing performance. As a result, the airtightness can also be improved, which enhances the freshness preservation effect. On the other hand, the depth (mm) (L2) of the recess 50 is preferably 2.8 mm or less, and more preferably 2.6 mm or less. By setting the depth (mm) (L2) of the recess 50 to or below the above upper limit, it is possible to improve the sealing strength of the sealing portion 30 while obtaining good opening retention.

[0019] Furthermore, in Figure 2, the opening width (mm) of the recess 50 is the distance between the start and end points of the constriction on the imaginary line extending the side 12 of the seal portion 30, and is represented as L5 (mm). The opening width (mm) (L5) of the recess 50 is preferably 9 mm or more, and more preferably 9.5 mm or more. By making the opening width (mm) (L5) of the recess 50 equal to or greater than the above lower limit, a constricted shape can be given to the sealing portion 30, thereby improving the opening and closing performance. On the other hand, the opening width (mm) (L5) of the recess 50 is preferably 15 mm or less, and more preferably 14.5 mm or less. By setting the opening width (mm) (L5) of the recess 50 to be below the above upper limit, the sealing strength of the sealing portion 30 can be improved while obtaining good opening and closing performance.

[0020] The first fixing part 40 secures both ends of the zipper part 20 in an area including the side edge of the bag body 10, thereby reducing the gap at the end of the zipper part 20 and improving the freshness preservation effect. In addition, the rigidity of the end of the zipper part 20 is increased, making it easier to open and close. Furthermore, even if the zipper part 20 is opened and closed repeatedly, damage to the bag body 10 and deformation of the zipper part 20 are suppressed, improving durability. In this embodiment, the first fixing portion 40 is positioned inside the recess 50. In other words, the first fixing portion 40 is formed to divide the recess 50. As a result, constrictions (recesses) are positioned between the first fixing portion 40 and the sealing portion 30. Furthermore, by setting (L2 / L1) to the above value around the first fixing portion 40, the synergistic effect of the first fixing portion 40 and the recess 50 makes it easier to maintain the open state of the fresh produce freshness preservation bag 100, and makes it easier to put in and take out the contents. In addition, by obtaining good opening and closing properties and durability, good freshness preservation can be maintained.

[0021] As shown in Figure 2, recesses 50a and 50b are arranged on both sides of the first fixing portion 40 by dividing the recess 50. In this case, the opening width (mm) of recesses 50a and 50b is preferably 0.7 to 4 mm, and more preferably 0.8 to 3.5 mm or more. The opening width (mm) of recesses 50a and 50b is the distance between the start and end points of the constriction on a virtual line extending the side 12 of the sealing portion 30.

[0022] Furthermore, in Figure 2, the maximum distance between the first fixing portion 40 and the strip-shaped sealing portion 30 in a direction parallel to the side edge 11 of the bag body 10 is the distance from the end of the side 12 of the strip-shaped sealing portion 30 on a virtual line extending the side 12 of the strip-shaped sealing portion 30 to the intersection point where the virtual line and the first fixing portion 40 intersect, and is represented as L4 (mm). L4 is the greater of the distance between the strip-shaped sealing portion 30 on one side of the first fixing portion 40 and the strip-shaped sealing portion 30 on the other side of the first fixing portion 40. In this embodiment, the maximum distance (L4) between the first fixing portion 40 and the strip-shaped sealing portion 30 in a direction parallel to the side edge 11 of the bag body 10 is preferably 0.7 to 4 mm. This ensures that good opening retention is stably achieved.

[0023] L4 is preferably 0.7 mm or more, and more preferably 0.8 mm or more. By setting L4 to be above the lower limit, a constricted shape can be given to the seal portion 30, improving the opening retention and opening / closing performance. On the other hand, L4 is preferably 4 mm or less, and more preferably 3.5 mm or less. By setting L4 to be below the above upper limit, the sealing strength of the sealing portion 30 can be improved while obtaining good opening and closing performance.

[0024] Furthermore, in Figure 2, the maximum length (mm) of the first fixing portion 40 in the width direction of the bag body 10 is the maximum length extending from the side edge 11 of the sealing portion 30 to the side opposite to the side edge 11 of the first fixing portion 40, and is represented as L3 (mm). The maximum length (mm) (L3) of the first fixing portion 40 in the width direction of the bag body 10 is preferably 4.0 to 8.0 mm, and more preferably 4.5 to 7.5 mm. This ensures that good opening retention is stably achieved.

[0025] In this embodiment, it is preferable that the maximum length (mm) (L3) of the first fixing portion 40 in the width direction of the bag body 10 is longer than the depth (mm) (L2) of the recess 50. In other words, the apex of the first fixing portion 40 protrudes inward from the bag body 10 beyond the sealing portion 30. This improves durability while providing good opening and closing and good opening retention.

[0026] On the other hand, as shown in Figure 4, the maximum length (mm) (L3) of the first fixing portion 40 in the width direction of the bag body 10 may be shorter than the depth (mm) (L2) of the recess 50. This makes it possible to improve the opening retention while obtaining good opening and closing performance.

[0027] The parameters relating to the first fixing portion 40, recess 50, and sealing portion 30 in this embodiment can be achieved by selecting the synthetic resin film that constitutes the bag body 10 and by devising the manufacturing method of the fresh produce preservation bag 100. For example, this can be achieved by controlling the procedure for making the bag from a roll of synthetic resin film, or the conditions for heat sealing of the first fixing portion 40 and the sealing portion 30. Further details will be explained in the manufacturing method of the fresh produce preservation bag 100.

[0028] The details of each component of the fresh produce preservation bag 100 of this embodiment will be described below.

[0029] [Bag body 10] The bag body 10 is a bag portion made of synthetic resin film and has an opening at the top for putting in and taking out fruits and vegetables. The sides 11 of the bag body 10 are heat-sealed. Furthermore, the inner surfaces of the bag body 10 are sealed together by a strip-shaped sealing portion 30 that extends inward from the sides 11 of the bag body 10. The bottom edge of the bag body 10 is formed by the folding of the synthetic resin film. In other words, the bottom edge of the bag body 10 is the folded portion of the synthetic resin film.

[0030] (Synthetic resin film) The bag body 10 is made of a synthetic resin film, which allows for appropriate respiration of fruits and vegetables while achieving the MA effect. In addition, a good appearance can be obtained for the packaged fruits and vegetables.

[0031] The synthetic resin film is preferably transparent or semi-transparent, and more preferably transparent, from the viewpoint of allowing the fruits and vegetables to be visible from the outside. It may also be printed with information for purposes such as identifying the fruits and vegetables.

[0032] The resin that makes up the synthetic resin film is not particularly limited as long as it can be used for packaging fruits and vegetables, etc., and any known resin can be used. For example, the synthetic resin film is preferably one or more selected from the group consisting of polyethylene, ethylene copolymers such as ethylene-vinyl alcohol copolymer, polyester resins such as polypropylene, polyvinyl chloride, polystyrene, (meth)acrylic resin, and polylactic acid, and polyamide resins such as nylon. In particular, polyethylene, ethylene-vinyl alcohol copolymer, polypropylene, polylactic acid, and nylon are preferred from the viewpoint of being able to appropriately control the water vapor permeability and oxygen permeability described later.

[0033] The method for molding the synthetic resin film is not particularly limited, but methods such as extrusion, inflation, and calendering can be used. When molding the resin film, additives such as antifogging agents may be mixed in as needed, and one or more types of resins may be blended. Furthermore, the synthetic resin film may be subjected to stretching or annealing, and a sealant layer may be provided to give it heat-sealing properties.

[0034] The thickness of the synthetic resin film is preferably 20 to 200 μm, more preferably 20 to 100 μm, and even more preferably 20 to 50 μm.

[0035] The synthetic resin film may be used as a single layer or as a multilayer structure of two or more layers.

[0036] The contact angle of the inner surface of the bag body 10 with respect to water is preferably 3 to 60°, and more preferably 4 to 58°. This suppresses the occurrence of condensation when fruits and vegetables are placed inside, thereby improving the freshness preservation effect. The contact angle with water can be determined, for example, by using a commercially available contact angle meter (such as the DROPMASTER-501 manufactured by Kyowa Interface Science Co., Ltd.) and measuring the water contact angle after 7 seconds by dropping 2 μL of purified water onto the surface to be measured using the droplet method. Furthermore, the contact angle can be adjusted by adjusting the materials of the synthetic resin film, such as anti-fogging agents and anti-condensation agents, or by surface treatment of the synthetic resin film.

[0037] The oxygen permeability of the synthetic resin film constituting the bag body 10 at 23°C and 60% RH is preferably 200 cc / (m³) from the viewpoint of maintaining the respiration of fruits and vegetables and preserving their freshness. 2 (day·atm) or more, more preferably 500cc / (m 2 (day·atm) or more, and even better is 800cc / (m 2 (day·atm) or more, and especially preferably 1000cc / (m 2 (This is the total value for days and hours.) On the other hand, the oxygen permeability of the synthetic resin film at 23°C and 60% RH is preferably 10,000 cc / (m²) from the viewpoint of maintaining the quality and freshness of fruits and vegetables. 2 (day·atm) or less, more preferably 7000cc / (m 2 It is less than or equal to (day·atm), and more preferably 4000cc / (m 2 It is less than or equal to (day·atm), and more preferably 3000cc / (m 2 (•day•atm) is less than or equal to the following:

[0038] The water vapor permeability of the synthetic resin film constituting the bag body 10 at 40°C is preferably 1 g / (m 2 ·day) or more, more preferably 3 g / (m 2 ·day) or more, from the viewpoint of releasing water vapor due to the respiration of fresh fruits and vegetables. On the other hand, the water vapor permeability of the synthetic resin film at 40°C is preferably 300 g / (m 2 ·day) or less, more preferably 100 g / (m 2 ·day) or less, still more preferably 50 g / (m 2 ·day) or less, and even more preferably 10 g / (m 2 ·day) or less, from the viewpoint of suppressing the respiration of fresh fruits and vegetables.

[0039] The water vapor permeability can be measured by a method conforming to JIS Z 0208 (cup method).

[0040] Note that the bag body 10 of the present embodiment may have through-holes formed therein, or may not have through-holes. The presence or absence of through-holes enables further adjustment of the water vapor permeability and the oxygen permeability.

[0041] The planar shape of the through-hole may be, for example, circular, polygonal, or slit. A slit is a cut or gap penetrating through the synthetic resin sheet constituting the packaging material, and may be linear, curved, L-shaped, cross-shaped, etc., and its length and the like are not particularly limited.

[0042] The average diameter of the through-hole is preferably 10 μm to 800 μm, more preferably 20 μm to 500 μm, and still more preferably 50 μm to 200 μm. In this case, the average diameter of the through-hole is calculated assuming the through-hole is a perfect circle from the opening area of the through-hole.

[0043] The above through-holes can be provided in at least one of the stages before and after forming the synthetic resin film into a bag shape.

[0044] [Recess 50] The recess 50 is a region formed in the strip-shaped sealing portion 30 that constitutes the side edge 11 of the bag body 10, where the sealing portion 30 has a constriction, recess, curved portion, or stepped portion in a part of the side 12 opposite to the side edge 11 of the bag body 10. In this embodiment, the recess 50 has a taper on part of both sides that gradually narrows towards the side 11, and is partially rounded. Note that the recess 50 does not need to be symmetrical left to right or up to down.

[0045] The recess 50 is preferably located within the edge 12 of the seal portion 30, encompassing the first fixing portion 40. Since the first fixing portion 40 secures the end of the zipper portion 20, the recess 50 is preferably located at or around the end of the zipper portion 20. This improves the ability to maintain the opening.

[0046] The recess 50 in this embodiment can be realized by selecting a synthetic resin film for the bag body 10 and by devising a method for manufacturing the fresh produce preservation bag 100.

[0047] (A modified form of the recess) In Figures 1 and 2, an example is shown where the recess 50 has approximately straight edges on both sides and a taper towards the side edge 11 of the bag body 10, but the shape of the recess 50 is not limited to this. For example, at least one side of the recess 50 may be stepped (Figure 5). In this case, the number of steps is not particularly limited and may be one step or two or more steps. Also, the steps may differ in size, height, and shape from one another. Furthermore, the vertices of the steps are not limited to right angles, but may be acute angles, obtuse angles, or rounded angles. Furthermore, for example, both sides of the recess 50 may be curved inward (Figure 6). As shown in Figure 6, the sides of the recess 50 protrude in the center and widen towards the side 11 in the vicinity of the side 11. In other words, the shape of the recess 50 may be round. In this case, the maximum distance (L4) between the first fixing part 40 and the strip-shaped sealing part 30 in a direction parallel to the side of the bag body 10 is the distance between the apex of the curved part of the recess 50 and the first fixing part 40, as shown in Figure 6.

[0048] [Seal part 30] The sealing portion 30 constitutes the side edge 11 of the bag body 10 and is an adhesive area where the inner surfaces of the bag body 10 are bonded together. The width of the sealing portion 30 is substantially constant, except for the area having the recess 50.

[0049] The sealing portion 30 can be formed when the synthetic resin film constituting the bag body 10 is cut by heat. Furthermore, the sealing portion 30 can improve the strength of the bag body 10.

[0050] The total light transmittance (%) of the bag body 10 relative to the total light transmittance (%) of the seal portion 30 is preferably 0.8 to 1.2, and more preferably 0.9 to 1.0. In other words, while a high total light transmittance (%) of the bag body 10 is desirable in order to make the fruits and vegetables easier to see, it is preferable that the total light transmittance of the seal portion 30 be lower than the total light transmittance (%) of the bag body 10 in order to improve the strength of the sides of the bag body 10 and obtain durability. The total light transmittance of the seal portion 30 can be controlled by controlling the sealing conditions or surface treatment conditions.

[0051] Furthermore, the average length RSm of the roughness curve elements defined in JIS B 0601 on the surface of the seal portion 30 is preferably 80 to 550 μm, and more preferably 90 to 520 μm. This suppresses the occurrence of condensation inside the fresh produce freshness preservation bag 100 and improves the freshness preservation effect. The RSm of the seal portion 30 can be controlled by controlling the sealing conditions or surface treatment conditions, etc.

[0052] [First fixed part 40] The first fixing portion 40 secures both ends of the zipper portion 20 to the area including the side edge 11 of the bag body 10. In other words, the first fixing portion 40 is a sealing portion that prevents the side edge 11 of the bag body 10 from tearing when the zipper portion 20 is opened. The first fixing portion 40 can be formed in the manufacturing process of the fresh produce preservation bag 100 by heat-sealing the convex and concave ridges that will become the zipper portion 20. The first fixing portion 40 is a resin ball formed by the heat melting and hardening of a synthetic resin film.

[0053] The shape of the first fixing part 40 in plan view is not particularly limited, but examples include mountain-shaped, circular, fan-shaped, triangular, and polygonal shapes.

[0054] Furthermore, the first fixing portion 40 can be flat or plate-shaped. The maximum thickness of the first fixing portion 40 is preferably 0.3 to 1.2 mm, more preferably 0.4 to 1.1 mm, even more preferably 0.5 to 1.1 mm, and especially preferably 0.6 to 1.1 mm. It is preferable that the thickness of the first fixing portion 40 is greater than the total thickness when two synthetic resin films are stacked together. This allows the zipper portion 20 to be fixed more firmly and improves ease of opening. The maximum thickness of the first fixing part 40 can be measured using a micrometer or the like.

[0055] [Second fixed part 41] The second fixing portion 41 is provided at the lower corner of the bag body 10 and improves the strength of the bag body 10. As a result, the occurrence of pinholes and other defects at the lower corner of the bag body 10 can be suppressed, and a stable freshness preservation effect can be obtained. The second fixing portion 41 is formed by heat sealing the synthetic resin film that constitutes the bag body 10.

[0056] The shape of the second fixing part 41 in plan view is not particularly limited, but examples include mountain-shaped, circular, fan-shaped, triangular, and polygonal shapes.

[0057] [Zipper section 20] The zipper section 20 is located parallel to the width direction of the bag body 10, allowing the bag to be opened and closed freely. The zipper portion 20 consists of a pair of concave and convex ridges, and both ends are welded together by the first fixing portion 40. The zipper portion 20 is formed from one side 11 to the other side 11 of the bag body 10. Known materials can be used for the zipper portion 20, and its size, arrangement, etc., are designed according to the application.

[0058] <Method for manufacturing a fresh produce preservation bag 100> Next, an example of a manufacturing method for the fresh produce preservation bag 100 will be described. Figure 7 shows a schematic diagram illustrating an example of a manufacturing method for the fresh produce preservation bag 100 of this embodiment. First, long convex strips 21 and long concave strips 22, which will later become the zipper portion 20, are heat-pressed onto the roll-shaped synthetic resin film 10p at symmetrical positions above and below it (Figure 7(a)). The convex strips 21 and concave strips 22 are made of resin and known materials can be used. The heat-pressing conditions are not particularly limited, but for example, conditions such as continuous lamination with a heated roll at 120 to 170°C and 0.05 to 0.50 MPa can be mentioned.

[0059] Next, as shown in Figure 7(b), the synthetic resin film 10p is folded in half so that its upper and lower ends meet, and the convex ridge 21 and concave ridge 22 are interlocked to obtain a pre-zipper portion 20p which will later become the zipper portion 20. Subsequently, a small heat plate for point sealing is used to heat-seal a portion of the interlocked convex ridge 21 and concave ridge 22 (pre-zipper portion 20p) and then solidify the resin to form a fixed portion 40p that has become a solid mass. The fixed portion 40p becomes the first fixed portion 40 after the bag is made. The conditions for heat-sealing the fixing portion 40p are not particularly limited, but for example, they can be 130-200°C, 0.1-2.5 seconds, and 0.5-1.5 MPa. The shape and size of the small heating plate are not particularly limited, but it is preferable that it is wide enough to cover the width of the zipper. By adjusting the heat-sealing conditions of the fixing part 40p and the shape and size of the small heating plate, the size, shape, and position of the fixing part 40p can be adjusted, and the depth of the recess 50, the width of the sealing part 30, and the shape of the fixing part 40 can be controlled.

[0060] Similarly, a small heat plate for point sealing is used to heat-seal a portion of the folded synthetic resin film, bonding the synthetic resin films together to form a fixed portion 41p. The fixed portion 41q becomes the second fixed portion 41 after the bag is made. The conditions for heat-sealing the fixing part 41p are not particularly limited, but for example, they can be 120-170°C, 0.05-1.0 seconds, and 0.05-0.5 MPa. The small heating plate for forming the fixing portion 41p may be the same as or different from the small heating plate for forming the fixing portion 41p, and its shape and size are not particularly limited. From the standpoint of improving the strength of the bag body 10 and improving freshness preservation, it is preferable that the small heating plate for forming the fixing portion 41p be cylindrical with a radius of about 2 to 10 mm.

[0061] Subsequently, as shown in Figure 7(c), heat fusion is performed in a strip shape using a strip-shaped hot plate 80, including the fixing parts 40p and 41p, to form the seal part 30p and flatten the fixing part 40p (Figure 7(d)). The seal part 30p becomes part of the seal part 30 after the bag is made. The conditions for heat-sealing the sealing portion 30p are not particularly limited, but for example, they can be 120-170°C, 0.05-1.0 seconds, and 0.05-1 MPa. The size of the strip-shaped heat plate is preferably greater than or equal to the length of the side of the later bag body 10 and has a width of about 2-8 mm.

[0062] Furthermore, by adjusting the width of the strip-shaped sealing portion 30 formed by the heating plate 80 and the heat-sealing conditions, the depth of the recess 50, the opening width, the width of the sealing portion 30, the shape of the fixing portion 40, its maximum thickness, and length can be controlled. In addition, the degree of deformation of the first fixing portion is controlled by the heat-sealing conditions of the heating plate 80. For example, if the sealing portion 30 is sealed with the heating plate 80 in a way that increases its width, the depth of the recess 50 can be increased.

[0063] As shown in Figure 7(e), the synthetic resin film 10p is then cut with the cutting blade 82 in the region including the sealing portion 30p, and the cut portion is heat-sealed (heat-sealed) to obtain the fresh produce preservation bag 100 of this embodiment.

[0064] <Package> The packaging of this embodiment contains fresh produce in the fresh produce preservation bag 100 described above. Preferably, the packaging has a zipper portion 20 that seals the opening of the fresh produce preservation bag 100.

[0065] Furthermore, in this embodiment, the inner surface area of ​​the packaging per 100g of fresh produce is 100 to 5000 cm². 2 Preferably, it is 200-1000cm 2 More preferably, 250-800cm 2 More preferably, 300-600cm 2 That is especially preferable.

[0066] Furthermore, in this embodiment, the packaging is preferably stored at an ambient temperature of 2 to 25°C. However, temperature fluctuations are acceptable depending on the application, distribution conditions, etc.

[0067] [Fruits and vegetables] The packaging of this embodiment contains fresh produce in a fresh produce preservation bag 100. While not particularly limited to fresh produce, examples include: perilla, spinach, komatsuna, mizuna, mibuna, asparagus, water spinach, lettuce, thyme, sage, parsley, Italian parsley, rosemary, oregano, lemon balm, chives, lavender, salad burnet, lamb's ear, arugula, dandelion, nasturtium, basil, arugula, watercress, molokhia, celery, kale, leeks, cabbage, Chinese cabbage, garland chrysanthemum, and salad greens. Examples include lettuce, butterbur, rapeseed, bok choy, Japanese parsley, water dropwort, Brussels sprouts, broccoli, cauliflower, Japanese ginger, daikon radish, carrot, burdock, radish, turnip, sweet potato, potato, nagaimo yam, yamaimo yam, taro, jinenjo yam, yamatoimo yam, bell pepper, paprika, shishito pepper, cucumber, eggplant, tomato, cherry tomato, pumpkin, bitter melon, okra, sweet corn, edamame, snow peas, green beans, broad beans, and mushrooms. Fruits such as citrus fruits, apples, pears, grapes, blueberries, persimmons, and strawberries, as well as cut flowers, are also effective. Cut vegetables and cut fruits are also effective. Cut vegetables refer to uncooked vegetables from which non-edible parts, such as roots, stems, or flowers, have been removed after harvesting from fields, and which have been cut using known methods to improve their ease of eating and appearance.

[0068] <Methods for maintaining freshness> The freshness preservation method of this embodiment is a method of preserving the freshness of fruits and vegetables by placing them in the freshness preservation bag 100 described above. After placing the fruits and vegetables inside, it is preferable that the opening of the freshness preservation bag 100 be sealed.

[0069] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. [Examples]

[0070] Next, the present invention will be described in detail with reference to examples, but the content of the present invention is not limited to these examples.

[0071] (1) Preparation of freshness preservation bags for fruits and vegetables <Example 1> Zippered bags were manufactured using synthetic resin film under the process conditions shown in Table 2, to create the freshness-preserving bags for fruits and vegetables shown in Table 1. The storage bag of Example 1 will be described in detail below. (procedure) First, a roll of synthetic resin film (biaxially oriented polypropylene film, 40 μm thick) with a width of 460 mm was heat-pressed to the top and bottom, respectively, at symmetrical positions. Next, the synthetic resin film was folded in half so that the upper and lower edges were aligned, and with the convex and concave stripes interlocked, a small heating plate for the first point seal (a rectangle measuring 5 mm x 10 mm) was used to heat-seal a portion of the interlocked convex and concave stripes (first fixing part). The heat-sealing conditions were 150°C, 1.0 second, and 1.0 MPa (Table 1, Condition A). Subsequently, a cylindrical object for the second point seal was used to heat-seal a portion of the folded synthetic resin film (second fixing part). The heat-sealing conditions were 150°C, 1.0 second, and 1.0 MPa (Table 2, Condition A). Next, a heat-sealed strip of a predetermined width was used to connect the first and second fixing parts, sealing them in a strip shape and flattening the first fixing part. The heat-sealing conditions were 150°C, 0.5 seconds, and 0.5 MPa (Table 1, Condition B). Subsequently, the strip-shaped seal was heat-sealed to divide it in half horizontally, thereby sealing the cut edges of the synthetic resin film and obtaining the fresh produce preservation bags (bag size: 160 mm wide x 230 mm high) shown in Table 1. The zipper was located 30 mm from the top edge of the bag. Furthermore, the obtained fresh produce preservation bag had a band-shaped sealing portion that formed the side of the bag body, with a recess on the side opposite to the side of the bag body, and the first fixing portion was located inside this recess. The shape of the recess was also observed, and the results are shown in Table 1.

[0072] Examples 2-9 and Comparative Examples 1-3 Except for the changes made to the process conditions shown in Table 2, the freshness-preserving bags for each type of fruit and vegetable shown in Table 1 were obtained using the same procedure as in Example 1.

[0073] (2) Measurement The following measurements were performed on each of the fresh produce preservation bags obtained. The results are shown in Table 1. • Measurement of the maximum thickness of the first fixing part The maximum thickness was measured using a micrometer.

[0074] ·Light transmittance (%) The light transmittance (%) of the seal portion (i) and the bag body portion (ii) of each fresh produce freshness preservation bag was measured in accordance with JIS K7361-1 (1999).

[0075] ·Contact angle (°) The contact angle (°) of the inner surface of each fresh produce preservation bag with water was determined using the droplet method with "DROPMASTER-501" manufactured by Kyowa Interface Science Co., Ltd. 2 μL of purified water was dropped onto the surface of the sample, and the water contact angle was measured after 7 seconds.

[0076] • Average length RSm of roughness curve elements as defined in JIS B 0601 The average length RSm (μm) of the surface of the seal portion of each fresh produce preservation bag was measured.

[0077] (3) Evaluation The following evaluations were conducted by technicians familiar with fresh produce preservation bags, using the obtained fresh produce preservation bags. (i) Opening and closing properties The zipper portion of the fresh produce preservation bag was manually opened and closed five times, and its ease of opening and closing was evaluated according to the following criteria. ·standard A: It opens and closes without any problems (no malfunctions occurred out of 5 attempts). B: Some issues (1 malfunction occurred out of 5 attempts) C: Problem found (2-3 malfunctions occurred out of 5 attempts) D: Difficulty opening and closing (failure occurred 4 or more times out of 5 attempts)

[0078] (ii) Aperture retention The zipper of the fresh produce preservation bag was manually closed once, and then manually opened wide for 5 seconds. After that, while holding the bottom of the bag by hand, the ability to maintain the open position was evaluated according to the following criteria. ·standard A: Able to maintain an opening of 1 cm or more for 1 minute or more. B: Able to maintain an open mouth of 1 cm or more for 20 seconds or more but less than 1 minute. C: Able to maintain an opening of 1 cm or more for 5 seconds or more but less than 20 seconds. D: The bag closes the moment you release your hand from the zipper (less than 5 seconds).

[0079] (iii) Durability The zipper portion of the fresh produce preservation bag was manually opened and closed 50 times. The appearance of the bag was observed during and after opening and closing, and its durability was evaluated according to the following criteria. ·standard A: No problem even after opening and closing it more than 30 times. B: The pack is damaged after being opened and closed more than 10 times but less than 30 times. C: The pack is damaged after being opened and closed 3 to 10 times. D: The pack was damaged after being opened and closed less than 3 times.

[0080] (iv) Freshness retention 200g of fresh edamame was placed in a fresh produce preservation bag and sealed by closing the zipper. This was then stored for 5 days at 20°C and 50% RH. Based on a comprehensive assessment of the deterioration of edamame after storage (yellowing, browning, spoilage, odor development, and deterioration of taste), the freshness retention was evaluated according to the following criteria. ·standard A: No loss of freshness B: Slightly less fresh. C: Clearly shows a decrease in freshness. D: Significant deterioration in freshness

[0081] [Table 1]

[0082] [Table 2] [Explanation of Symbols]

[0083] 10 bags (main body) 10p Synthetic resin film 11 Sides 12 sides 20 Zipper section 20p Pre-zipper section 21 Convex Strip 22 Concave line 30 Seal part 30p seal section 40 1st fixed part 40p fixed part 41 Second fixed part 41p fixed part 50 recesses 50a recess 50b recess 80 hot plate 82 Cutting blades 100 Fresh Produce Preservation Bags

Claims

1. A bag body made of synthetic resin film with an opening at the top, The bag body has a zipper section that can be opened and closed, which is parallel to the width direction, The bag body has a strip-shaped sealing portion that forms the side edge, A first fixing portion is provided in the region including the side edge of the bag body, which fixes both ends of the zipper portion. A fresh produce freshness preservation bag comprising: The sealing portion has a recess on the side of the bag body opposite to the side edge, A fresh produce preservation bag in which the depth (mm) of the recess (mm) relative to the width (mm) of the sealing portion is 0.5 or more.

2. A fresh produce preservation bag according to claim 1, A fresh produce preservation bag in which the depth of the recess is 0.9 to 2.8 mm.

3. A fresh produce preservation bag according to claim 1 or 2, The first fixing part is a freshness-preserving bag for fruits and vegetables, which is located inside the recess.

4. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag in which the maximum length (mm) of the first fixing portion in the width direction of the bag body is longer than the depth (mm) of the recess.

5. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag in which at least one side of the recess is curved inward.

6. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag in which at least one side of the recess is stepped.

7. A fresh produce preservation bag according to claim 3, A fresh produce freshness preservation bag, wherein the maximum distance between the first fixing portion and the strip-shaped sealing portion in a direction parallel to the side edge of the bag body is 0.7 to 4 mm.

8. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag in which the opening width of the recess is 9.0 to 15 mm.

9. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag in which the maximum thickness of the first fixing portion is 0.3 to 1.3 mm.

10. A fresh produce preservation bag according to claim 1 or 2, A fresh produce freshness preservation bag in which the total light transmittance (%) of the bag body is 0.90 to 1.00 relative to the total light transmittance (%) of the sealed portion.

11. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag in which the contact angle of the inner surface of the bag body with respect to water is 3 to 60°.

12. A fresh produce preservation bag according to claim 1 or 2, A fresh produce preservation bag wherein the average length RSm of the roughness curve elements defined in JIS B 0601 on the surface of the sealing portion is 80 to 550 μm.

13. A fresh produce preservation bag according to claim 1 or 2, A fresh produce freshness preservation bag, further having a second fixing portion at at least one of the lower corners of the bag body.

14. A fresh produce preservation bag according to claim 1 or 2, A fresh produce freshness preservation bag, wherein the lower edge of the bag body is formed by folding over the synthetic resin film.

15. A package containing fresh produce, wherein fresh produce is contained in a fresh produce preservation bag according to claim 1 or 2.

16. A method for preserving the freshness of fruits and vegetables, A method for preserving the freshness of fruits and vegetables, comprising the step of placing the fruits and vegetables in a freshness-preserving bag for fruits and vegetables described in claim 1 or 2.

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