Packaging bag, freshness preservation bag for fruits and vegetables, package containing fruits and vegetables, and method for preserving freshness of fruits and vegetables

Abstract

To provide a technology relating to a packaging bag that can suppress deformation of a through slit (S). [Solution] The packaging bag 100 of the present invention has a main body 10 that contains the contents and an opening 20 through which the contents are put in and taken out, the main body 10 being made of a synthetic resin film, the main body 20 having a through slit (S), and when the direction in which the opening 20 widens is the horizontal direction and the direction perpendicular to the horizontal direction is the vertical direction, the through slit (S) has both a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction (however, the through slit (Sa) and the through slit (Sb) may be the same or different).

Description

[Technical Field]

[0001] The present invention relates to a packaging bag, 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] Fruits and vegetables continue to respire even after they are harvested. Therefore, during storage, distribution, or preservation after harvest, the fruits and vegetables consume energy through their own respiration, causing a deterioration in freshness. Therefore, a known method for preserving the freshness of fruits and vegetables is to moderately suppress their respiration. Such packaging bags used to preserve the freshness of fruits and vegetables are known as modified atmosphere (MA) packaging.

[0003] For example, Patent Document 1 discloses a freshness-preserving bag that uses a rotating tool equipped with a perforation needle of a predetermined shape and a roller that transports a polyolefin film, and the perforation needle is pierced through the transported polyolefin film by the rotation of the rotating tool, creating a perforation section in the shape of a predetermined through slit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2022-134939 Summary of the Invention [Problem to be solved by the invention]

[0005] However, packaging bags made of conventional synthetic film resin with a through slit as described in Patent Document 1 had the problem that the weight of the contents was added to the bag body due to tension generated when the contents were placed inside, and vibrations during storage and transportation, causing the through slit in the bag body to deform. [Means for solving the problem]

[0006] The inventor conducted extensive research into suppressing changes in the shape of the through slits in packaging bags made of synthetic resin film and discovered that controlling the direction and shape of the through slits is effective, leading to the completion of the present invention. According to the present invention, the following packaging bag and related techniques are provided.

[0007] [1] A main body for accommodating contents; An opening for putting in and taking out the contents; A packaging bag having a main body made of a synthetic resin film, The main body portion has a through slit (S), When the direction in which the opening portion widens is defined as a horizontal direction and the direction perpendicular to the horizontal direction is defined as a vertical direction, The through slits (S) include a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction (however, the through slits (Sa) and the through slits (Sb) may be the same as each other or may be different). [2] The packaging bag according to [1], The maximum length (X) of the through slit (S) is 100 μm or more and 1000 μm or less. [3] The packaging bag according to [1] or [2], The packaging bag, wherein the through slit (S) has a bent or curved portion. [4] A packaging bag according to any one of [1] to [3], A packaging bag, wherein the maximum length (X) (μm) of the through slit (S) and the line segment (Y) (μm) connecting one end of the through slit (S) to the other end at the maximum length (X) satisfy 1.02≦X / Y≦1.70. [5] A packaging bag according to any one of [1] to [4], A packaging bag in which the smaller of the angles θ formed by a line segment (Y) connecting one end of the through slit (S) to the other end of the through slit (S) over its maximum length (X) and the vertical direction or the horizontal direction is 2°≦θ≦90°. [6] A packaging bag according to any one of [1] to [5], The through slit (S) is A packaging bag having a through slit (Sab) in which the through slit (Sa) and the through slit (Sb) are identical to each other. [7] A packaging bag according to any one of [1] to [6], The packaging bag has a ratio of the through slits (Sa) and the through slits (Sb) to the total through slits (S) of 30% or more and 100% or less. [8] A packaging bag according to any one of [1] to [7], The through slit (S) is The packaging bag separately includes a through slit (Sa) that is not parallel to the longitudinal direction and a through slit (Sb) that is not parallel to the transverse direction. [9] A packaging bag according to any one of [1] to [8], The packaging bag has a through slit (Sc) consisting of a first through slit and a second through slit intersecting the first through slit.

[10] A packaging bag according to any one of [1] to [9], The packaging bag has 1 or more and 500 or less through slits (S).

[11] A packaging bag according to any one of [1] to

[10] , The packaging bag has line segments (Y) connecting one end to the other end of the plurality of through slits (S) over the maximum length (X) thereof that are not parallel to each other.

[12] A packaging bag according to any one of [1] to

[11] , The packaging bag, wherein the synthetic resin film contains polyolefin.

[13] A packaging bag according to any one of [1] to

[12] , The packaging bag, wherein the synthetic resin film has a thickness of 10 μm to 200 μm.

[14] A freshness-keeping bag for fruits and vegetables, using the packaging bag described in any one of [1] to

[13] to keep fruits and vegetables fresh.

[15] A package containing fruits and vegetables, in which the fruits and vegetables are sealed in the fruit and vegetable freshness-keeping bag described in

[14] .

[16] A method for preserving the freshness of fruits and vegetables, comprising the steps of placing fruits and vegetables inside the fruit and vegetable freshness preservation bag described in

[14] and then sealing the fruit and vegetable freshness preservation bag. [Effects of the Invention]

[0008] According to the present invention, a technology is provided relating to a packaging bag made of a synthetic resin film that can suppress changes in the shape of a through slit. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic plan view showing a packaging bag of a first embodiment. [Figure 2] 1 is a schematic diagram for explaining the maximum length (X) and line segment (Y) of a through slit (S1). FIG. [Figure 3] FIG. 10 is a schematic diagram for explaining the angle θ of the through slit (S1). [Figure 4] FIG. 10 is a schematic plan view showing a modified example of the through slit (S1) of the first embodiment. [Figure 5] FIG. 10 is a schematic plan view showing a packaging bag of a second embodiment. [Figure 6] FIG. 10 is a schematic plan view showing a modified example of the through slit (S2). [Figure 7] 2 is a schematic diagram showing each through slit (S) of the packaging bag of the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and explanations thereof will be omitted where appropriate. Furthermore, all drawings are for illustrative purposes only. The shapes and dimensional ratios of each component in the drawings do not necessarily correspond to the actual products.

[0011] In this specification, unless otherwise specified, the expression "a to b" in the description of a numerical range means from a to b. For example, "1 to 5 mass %" means "1 mass % to 5 mass %."

[0012] In this specification, MD direction refers to the machine direction and indicates the direction in which a resin or sheet flows, and TD direction refers to the transverse direction and indicates the direction perpendicular to the flow direction.

[0013] In this specification, the through slit (S) refers to a fine linear gap having a width of less than 25 μm. The shape of the through slit (S) is not particularly limited, and examples thereof include a straight line, a curved line, a straight line with a bent portion, a straight line with a bent portion, and combinations thereof.

[0014] Furthermore, when there are multiple through slits (S), the through slits (S) may be the same as each other in shape, length, size, position, orientation, etc., or at least one of them may be different. Specifically, the line segments (Y) connecting one end to the other end of the multiple through slits (S) may not be parallel to each other.

[0015] Regarding the through slit (S), in the following first embodiment, an example will be described in which a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction are identical to each other, forming a through slit (Sab). In the second embodiment, an example will be described in which the through slits (Sa) that are not parallel to the vertical direction and the through slits (Sb) that are not parallel to the horizontal direction are different from each other. However, the through slit (S) may have all of the through slit (Sab), the through slit (Sa) and the through slit (Sb), or may have the through slit (Sab) and the through slit (Sa) but not the through slit (Sb), or may have the through slit (Sab) and the through slit (Sb) but not the through slit (Sa).

[0016] The maximum length (X) of the through slit (S), the length of the line segment (Y), and the angle θ, which will be described later, are all average values.

[0017] In the drawings, the direction in which the opening 20 of the packaging bag 100 and the packaging bag 200 widens is the horizontal direction (W direction), and the direction perpendicular to the horizontal direction is the vertical direction (H direction).

[0018] In addition, the position of the through slit (S) in the main body 10 in the drawing is an example and is not limited to that shown in the drawing.

[0019] First Embodiment FIG. 1 is a schematic plan view showing a packaging bag 100 of the present embodiment. 1, the packaging bag 100 has a main body 10 for accommodating contents and an opening 20 for putting in and taking out the contents, and the main body 10 is made of a synthetic resin film and has a plurality of through slits (S1). In this embodiment, the packaging bag 100 is made of a synthetic resin film.

[0020] In the first embodiment, the through slit (S1) has both a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction, and the through slit (Sa) and the through slit (Sb) are the same. In the following description, the slit where the through slit (Sa) and the through slit (Sb) are the same will be referred to as the through slit (Sab).

[0021] By having the through slit (Sab), the packaging bag 100 can suppress deformation of the through slit (S1). In other words, even if stress is applied to the bag body 10 due to the weight or movement of the contents, the stress applied to the through slit (S1) can be dispersed, and expansion, elongation, cracks, etc. of the through slit (S1) can be suppressed. Furthermore, since synthetic resin films generally have an MD direction and a TD direction, packaging bags 100 made therefrom tend to be easily deformed in the horizontal or vertical direction. Therefore, by having the through slit (S1) of this embodiment have a through slit (Sab) that is not parallel to either the vertical or horizontal direction, deformation of the through slit (S1) can be effectively suppressed.

[0022] In addition, when fruits and vegetables are packaged, deformation of the through slit (S) can be suppressed to a high level during transportation and storage of the package containing the fruits and vegetables, thereby reducing even slight fluctuations in the breathability and moisture permeability of the packaging bag 100, thereby improving the freshness-preserving effect of the fruits and vegetables.

[0023] 1 shows an example in which the main body 10 has nine through slits (S1), the number of through slits (S1) may be one or more. The position of the through slits (S1) in the main body 10 is not limited.

[0024] The through slit (S1) of the packaging bag 100 will be described in detail below.

[0025] [Through slit (S1) / Through slit (Sab)] The through slit (Sab) in the first embodiment has a curved portion, is substantially arc-shaped, and is not parallel to either the vertical direction (H direction) or the horizontal direction (W direction). That is, the through slit (Sab) is not parallel to either the vertical direction or the horizontal direction of the packaging bag 100.

[0026] In the first embodiment, the through slit (Sab) is described as being approximately arc-shaped, but the through slit (Sab) that is not parallel to either the vertical or horizontal direction of the packaging bag 100 is not limited to this, and may be, for example, as shown in Figure 4, a diagonal straight line (Figure 4(a)), a cross (Figure 4(b)), a straight line with a bend (Figure 4(c)), a wavy shape (Figure 4(d)), a combination of a curve and a straight line (Figure 4(e)), etc.

[0027] (Maximum length) The maximum length (X) of the through slit (S1) is preferably 100 μm or more, more preferably 150 μm or more, and even more preferably 200 μm or more, which can improve the breathability while suppressing deformation of the through slit (S1). On the other hand, the maximum length (X) of the through slit (S1) is preferably 1000 μm or less, more preferably 800 μm or less, and even more preferably 500 μm or less, which makes it easier to suppress the drying of the contents and the respiration of fruits and vegetables while suppressing deformation of the through slit (S1).

[0028] (Quantity) The number of through slits (S1) in the main body 10 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. This can improve breathability while suppressing deformation of the through slits (S1). On the other hand, the number of through slits (S1) in the main body 10 is preferably 500 or less, more preferably 300 or less, and even more preferably 200 or less. This makes it easier to suppress deformation of the through slits (S1), while also suppressing drying of the contents and suppressing respiration of fruits and vegetables.

[0029] (Flexibility / bending) As shown in FIG. 2, the maximum length (X) (μm) of the through slit (S1) and the line segment (Y) (μm) connecting one end of the through slit (S1) to the other end at the maximum length (X) preferably satisfy 1.02≦X / Y≦1.70, and more preferably satisfy 1.02≦X / Y≦1.50. Setting X / Y to be equal to or greater than the above-mentioned lower limit means that X is longer than Y, and the through slit (S1) is intended to be bent or curved. Therefore, by setting X / Y to be equal to or greater than the above-mentioned lower limit, deformation of the through slit (S1) can be more easily suppressed. On the other hand, setting X / Y to the above upper limit or less means that X is not too long compared to Y and the degree of bending / curving is gentle. Therefore, by setting X / Y to the above upper limit or less, it is possible to prevent stress from being applied to a portion of the through slit (S1) and making it prone to deformation. Specifically, for example, it is possible to prevent the through slit (S1) from deforming and connecting both ends of the through slit (S1), or from distorting the through slit (S1) and widening the opening.

[0030] For example, as shown in FIG. 3(a), even if the through slit (S1) has a slit that intersects with the arc-shaped slit, X can be set by focusing on the maximum length of the through slit (S1), and X / Y can be calculated by defining the line segment connecting one end of the set X to the other end as Y.

[0031] (non-parallelism) Furthermore, as shown in Figure 2, it is preferable that the smaller angle θ between the line segment (Y) connecting one end of the through slit (S1) to the other end at the maximum length (X) of the through slit (S1) and the vertical direction (H direction) or horizontal direction (W direction) of the packaging bag 100 is 2°≦θ≦90°. Setting the angle θ to the above-mentioned lower limit or more intends that the line segment (Y) is not parallel to the vertical direction (H direction) and the horizontal direction (W direction) but is tilted. Therefore, by setting the angle θ to the above-mentioned lower limit or more, the line segment (Y) is no longer parallel to the vertical direction (H direction) and the horizontal direction (W direction), which makes it easier to distribute stress and therefore makes it easier to suppress deformation of the through slit (S1). On the other hand, when the angle θ is the upper limit value (90°), the line segment (Y) is intended to be parallel to the vertical direction (H direction) or the horizontal direction (W direction). However, in this embodiment, since the through slit (S1) is curved, deformation of the through slit (S1) can be easily suppressed in this case as well (see Figure 3(c)).

[0032] 2, the angle θ formed by the line segment (Y) and the vertical direction (H direction) of the packaging bag 100 has been described, but when the angle formed by the line segment (Y) and the horizontal direction (W direction) of the packaging bag 100 is smaller, it is preferable that the angle formed by the line segment (Y) and the horizontal direction (W direction) of the packaging bag 100 is 2°≦θ≦90°. For example, FIG. 3(b) shows a case where the angle formed by the line segment (Y) and the horizontal direction (W direction) of the packaging bag 100 is smaller.

[0033] On the other hand, the through slit (S1) with an angle θ greater than 0° and less than 2° intends that the line segment (Y) is parallel to the vertical or horizontal direction.

[0034] (Through hole) The through slit (S1) may further have a through hole. The through hole is integral with the through slit (S1), is wider than the through slit (S1), and is a substantially circular opening. The diameter of the through hole is preferably 25 μm to 50 μm, more preferably 30 μm to 45 μm, and even more preferably 32 μm to 40 μm. For example, FIG. 1 shows a through slit (Sabd) having a through hole.

[0035] The through-holes can be formed by known methods such as laser processing and needle processing including hot needles.

[0036] (interval) When there are multiple through slits (Sab), in order to more effectively suppress deformation of the through slits (Sab), the distance between adjacent through slits (Sab) is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 8 mm or more.

[0037] (ratio) In the first embodiment, 100% of the through slits (S1) are through slits (Sab). That is, out of nine through slits (S1), nine are through slits (Sab). However, the proportion of through slits (Sab) is not limited to this. For example, the proportion of the through slits (Sab) to the total of the through slits (S1) may be 30% or more, 50% or more, or 70% or more. Specifically, for example, if there are four through slits (S1) and one out of the four is a through slit (Sab), the proportion of the through slits (Sab) is 25%. In particular, from the viewpoint of suppressing deformation and enhancing the freshness preservation effect, it is preferable that the ratio of the through slits (Sab) is 30% or more of the entire through slits (S1).

[0038] (Formation means / method) The above-mentioned through slit (S1) may be provided in the synthetic resin film in advance when manufacturing the packaging bag 100, or may be provided after the synthetic resin film is formed into a bag shape, or may be provided before or after the synthetic resin film is formed into a bag shape.

[0039] The method for forming the through slit (S1) is not particularly limited, and any known method can be used. Examples of such known methods include a needle processing method including a hot needle, a method using a mold such as a roll cutter, and a laser processing method. Details are described below.

[0040] Needles include sewing needles, injection needles, and acupuncture needles, and come in a variety of thicknesses and tip shapes to suit their respective uses, but there are no restrictions on the type of needle used. When using needles, the angle and curvature of the slit can be changed by adjusting the type, tip shape, angle, thickness, the angle at which the needle itself is placed, the depth of penetration, the direction and speed of needle and film movement, and the tension of the film. Needle shapes can be broadly divided into those that taper uniformly toward the tip, like sewing needles, and those with a tip shaped like a rod cut at an angle, like injection needles. Using the latter type of anisotropic needle makes it easier to create curved slits.

[0041] There are various types of blades, such as spring blades, carving blades, and etching blades, each of which has different thickness, shape, durability, etc., but there is no limit to the type of blade to be used. When a blade is used, it is possible to control the shape and direction of the slit by changing the shape and direction of the blade. The tip of the blade can be a blade with a reduced shape of a carving knife, flat knife, round knife, or triangular knife. Using a tiny round knife or triangular knife, it is possible to create a slit with a controlled shape and a high degree of curvature.

[0042] Although there are no particular limitations on the type of laser, a high-power carbon dioxide laser is preferably used. By moving the laser head or film during laser irradiation, slits with controlled angles and shapes can be continuously created. The method for creating multiple slits simultaneously or continuously is not limited, but an example is a method in which a roll or board equipped with multiple needles or blades is pressed against the film. Examples of methods for creating such a roll or board include a method in which multiple needles or blades are individually attached and fixed to a roll or board, as well as a method in which a flexible die is attached to a roll or board using photolithography technology to create multiple etching needles or etching blades simultaneously. Using a flexible die makes it easy to arrange blades of various shapes in random positions and directions.

[0043] Another example of a method using a perforation blade is a blade with a structure in which many tiny blades are continuously arranged in the width direction of the blade. Since perforation blades are generally used for the purpose of cutting processed paper or film along the perforations, ordinary perforation blades are not effective for this application. This is due to the fact that the spacing between the blades is too close. In this embodiment, when using perforation blades, it is preferable to use perforation blades with a spacing between the blades of several mm, preferably 5 mm or more.

[0044] There are no restrictions on the material of the needle or blade, but the durability of the needle or blade can be improved by treating the surface with a DLC coating or the like.

[0045] (Checking and measuring method) The method for measuring the dimensions of the through slit (S1) is not particularly limited, but examples include taking an enlarged image of the through slit (S1), actually measuring the printed photograph, and calculating the dimensions from the magnification of the photograph, or measuring using a digital microscope. Examples of digital microscopes include HRX-01 and RX-100 manufactured by Hirox Corporation, VHX series manufactured by Keyence Corporation, and DSX1000 manufactured by Olympus Corporation.

[0046] Second Embodiment Next, the configuration and operation of the packaging bag 200 of the second embodiment that differ from those of the packaging bag 100 of the first embodiment will be described.

[0047] FIG. 5 is a schematic plan view showing a packaging bag 200 of the second embodiment. As shown in FIG. 5, the packaging bag 200 has a main body 10 for accommodating contents and an opening 20 for putting in and taking out the contents, and the main body 10 is made of a synthetic resin film and has a plurality of through slits (S2).

[0048] In the second embodiment, the through slit (S2) has both a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction, and the through slit (Sa) and the through slit (Sb) are different.

[0049] By having the through slit (Sa) and the through slit (Sb), the packaging bag 200 can suppress deformation of the through slit (S2). That is, even if stress is applied to the bag body 10 due to the weight or movement of the contents, the stress applied to the through slit (S2) can be dispersed, and expansion, elongation, cracks, etc. of the through slit (S2) can be suppressed. Furthermore, since synthetic resin films generally have an MD direction and a TD direction, packaging bags 200 using such films tend to be easily deformed in the horizontal or vertical direction. Therefore, by having the through slits (S2) of this embodiment include both the through slits (Sa) that are not parallel to the vertical direction and the through slits (Sb) that are not parallel to the horizontal direction, even if one of them is easily deformed, the other is less likely to deform, and therefore deformation of the through slits (S2) can be suppressed for the entire packaging bag 200.

[0050] In addition, when fruits and vegetables are packaged, fluctuations in the air permeability and moisture permeability of the packaging bag 200 can be reduced, improving the freshness preservation effect of the fruits and vegetables.

[0051] 5 shows an example in which the main body 10 has nine through slits (S2), four through slits (Sa), and five through slits (Sb), but the numbers of through slits (S2), (Sa), and (Sb) are not limited to this. In addition, the positions of the through slits (S2) in the main body 10 are not limited.

[0052] The through slit (S2) of the packaging bag 200 will be described in detail below.

[0053] [Through slit (S2) / Through slit (Sa) / Through slit (Sb)] The through slit (Sa) in the second embodiment is not parallel to the vertical direction, but is a straight line parallel to the horizontal direction. The through slit (Sb) is not parallel to the horizontal direction, but is a straight line parallel to the vertical direction.

[0054] In the second embodiment, an example is given in which the through slits (Sa) and (Sb) are both straight lines, but the through slits (Sa) and (Sb) are not limited to this and may be, for example, T-shaped (Figure 6(a)), L-shaped (Figure 4(b)), cross-shaped (Figure 6(c)), U-shaped (Figure 6(d)), S-shaped (Figure 6(e)), etc., as shown in Figure 6. The through slit (S1) may have a through slit (Sc) consisting of a first through slit and a second through slit intersecting the first through slit. In this case, the lengths and shapes of the first through slit and the second through slit are not particularly limited, and the position where they intersect is also not particularly limited.

[0055] (ratio) In the second embodiment, the proportion of the through slits (Sa) relative to the total through slits (S2) is 0% or more, and from the viewpoint of suppressing deformation and enhancing the freshness-retaining effect, it is preferably 30% or more, more preferably 50% or more, even more preferably 70% or more, and even more preferably 100%. The proportion of the through slits (Sb) relative to the total through slits (S2) is 0% or more, and from the viewpoint of suppressing deformation and enhancing the freshness-retaining effect, it is preferably 30% or more, more preferably 50% or more, even more preferably 70% or more, and even more preferably 100%.

[0056] Other configurations and functions of the through slit (S2) are the same as those of the through slit (S1) described in the first embodiment.

[0057] The following describes the configuration, operation, etc. common to the packaging bag 100 and the packaging bag 200.

[0058] [Main body] The main body 10 is a bag-shaped body for accommodating contents. The main body 10 is made of synthetic resin.

[0059] (synthetic resin) The synthetic resin can be appropriately selected depending on the application from the viewpoints of mechanical strength, handling, processability, etc., but is preferably one or more selected from the group consisting of polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, (meth)acrylic resin; polyester resins such as polyethylene terephthalate and polylactic acid; and polyamide resins such as nylon.

[0060] The polyethylene mentioned above includes various polyethylenes and ethylene copolymers, and specific examples include copolymers such as high-density polyethylene (HDPE), medium-density polyethylene, low-density polyethylene, linear low-density polyethylene (LLDPE), metallocene-linear low-density polyethylene, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-α-olefin copolymer, as well as ionomers. The linear low-density polyethylene is usually a copolymer of ethylene and a small amount of an 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-propylene, 1-butene, 1-hexene, 4-methylpentene-1, and 1-octene. Of these, 1-propylene is preferred. The ethylene content of the ethylene-propylene copolymer is typically 4.5% or less.

[0061] The polypropylene may be a homopolymer, a random copolymer, or a block copolymer. More specifically, the homopolymer may be an isotactic polypropylene, a syndiotactic polypropylene, an atactic polypropylene, or the like, and the random copolymer may be an ethylene-propylene copolymer, a propylene-1-butene copolymer, a propylene-octene copolymer, or the like. Of these, the random copolymer is preferred.

[0062] Examples of the polyamide resin include nylon. Nylon includes nylon 6, nylon 11, nylon 12, nylon 66, nylon 6·10, nylon 6·12, nylon 6·T, nylon 6·I, nylon 9T, nylon M5T, and polymetaxylylene adipamide (MXD nylon), which can be used alone or in combination of two or more. Among these, nylon 6, nylon 11, nylon 12, and nylon 66, either alone or in combination of two or more, are preferred, and nylon 6 and nylon 66, either alone or in combination, are more preferred.

[0063] The synthetic resin film may contain additives such as anti-fogging agents, anti-blocking agents, heat stabilizers, lubricants, impact modifiers, processing aids, anti-static agents, ultraviolet absorbers, antioxidants, weather-resistant agents, fillers, and pigments, as needed, within the range that does not impair the performance of the synthetic resin film.

[0064] (film manufacturing method) The method for obtaining the synthetic resin film is not particularly limited, and examples of the method for obtaining the synthetic resin film include known methods such as extrusion, inflation, and calendering. The synthetic resin film may be stretched or annealed, or may be left unstretched. When stretched, the stretching ratio is not particularly limited, but may be, for example, about 2 to 5 times in both the MD and TD directions. The synthetic resin film may also be subjected to stretching or annealing.

[0065] (Thickness) The thickness of the synthetic resin film is preferably 10 to 200 μm, more preferably 15 to 100 μm, and even more preferably 20 to 50 μm.

[0066] (Layer composition) The synthetic resin film may be a single layer or a multi-layer film having two or more layers.

[0067] By making the synthetic resin film multilayered, it is possible to enhance the desired functionality. For example, by adding a function such as slipperiness to the surface layer of the synthetic resin film, the handling and heat-sealing properties of the synthetic resin film can be improved, and packaging bags with an excellent balance of elongation and rigidity can be consistently obtained. Furthermore, for example, by making the synthetic resin film into a two-layer or three-layer structure and using a layer containing an antiblocking agent as at least one of the surface layers, slipperiness can be obtained. Furthermore, for example, a sealant layer may be further provided to impart heat-sealing properties.

[0068] When the synthetic resin film is multilayered, the base resins of the layers may be the same or different from each other, but from the viewpoint of obtaining good adhesion between the layers, it is preferable that the same resin is used for each layer.

[0069] As a method for obtaining a multilayer film, known methods such as dry lamination, extrusion lamination, coextrusion, coating, etc. can be appropriately used. From the viewpoint of improving adhesion between layers and controlling layer thickness, coextrusion is preferred.

[0070] (oxygen permeability) The oxygen permeability of the synthetic resin film at 23°C and 60% RH is preferably 200 cc / (m) from the viewpoint of preserving the breathing of the fruit and vegetables and preserving their freshness, particularly when packaging fruit and vegetables. 2 ·day·atm) or more, and more preferably 500cc / (m 2 ·day·atm) or more, and more preferably 800cc / (m 2·day·atm) or more, and particularly preferably 1000cc / (m 2 ·day·atm) or more. On the other hand, the oxygen permeability of the synthetic resin film at 23°C and 60% RH is preferably 1,000,000 cc / (m) from the viewpoint of preserving the quality and freshness of fruits and vegetables, particularly when packaging fruits and vegetables. 2 ·day·atm) or less, and more preferably 300000cc / (m 2 ·day·atm) or less, and more preferably 100,000cc / (m 2 ·day·atm) or less, and particularly preferably 50000cc / (m 2 ·day·atm).

[0071] (Water vapor permeability) The water vapor permeability of the synthetic resin film at 40°C is preferably 1 g / (m) from the viewpoint of releasing water vapor due to respiration of the fruit and vegetables, particularly when the fruit and vegetables are packaged. 2 ·day) or more, and more preferably 3g / (m 2 ·day) or more. On the other hand, the water vapor permeability of the synthetic resin film at 40°C is preferably 300 g / (m) from the viewpoint of suppressing respiration of the fruits and vegetables, particularly when the fruits and vegetables are packaged. 2 ·day) or less, and more preferably 100g / (m 2 ·day) or less, and more preferably 50 g / (m 2 ·day) or less, and particularly preferably 10 g / (m 2 ·day) or less.

[0072] The water vapor permeability can be measured by a method in accordance with JIS Z 0208 (cup method).

[0073] Opening The opening 20 is located on the upper side of the packaging bag 100 and the packaging bag 200, and is an opening for putting in and taking out the contents. The opening 20 is sealed by using a member such as a heat seal process, back sealing tape, a cable tie, a rubber band, or crimping. Also, the main body 10 may be provided with a zipper or the like to allow the opening 20 to be easily opened and closed.

[0074] [Bag shape] The shapes of the packaging bag 100 and packaging bag 200 of this embodiment are not particularly limited, and can be any known bag shape such as a two-sided bag, a three-sided bag, a U-shaped bag, a back-sealed bag (a palm-shaped bag), a pouch, or a gusset bag. For example, the two-sided bag mentioned above is a bag made by folding a synthetic resin film in half and sealing both sides with the folded part as the bottom. The three-sided bag is a bag made by sealing the bottom and both sides of two overlapping layers of synthetic resin film. The U-shaped bag is a bag with the bottom of the bag crimped into a U shape. The seal can be a fusion-cut seal obtained by fusion-cutting a synthetic resin film. Fusion cutting is a method of cutting the synthetic resin film with heat using a hot wire, while melting and adhering the synthetic resin film at the cut portion.

[0075] The size (length and width) of the packaging bag 100 and packaging bag 200 of this embodiment can be designed appropriately depending on the application and contents, but for example, when used to package fruits and vegetables for general consumers, the size can be approximately 40 mm x 40 mm to 350 mm x 400 mm.

[0076] [Applications, packaged items] The contents are not particularly limited as long as they are suitable for moderate breathability, but examples include one or more items selected from the group consisting of fruits and vegetables, processed foods (fermented foods), medical supplies, and air fresheners. Specifically, when storing lactic acid bacteria-fermented foods such as kimchi, the generated gas can be released to the outside through the through slit (S), preventing the packaging bag 100 and the packaging bag 200 from bursting or breaking. Furthermore, when storing fragrances, for example, a certain amount of fragrance can be stably released through the through slit (S), making them suitable for use as air fresheners. Furthermore, after storing medical supplies, for example, sterilizing gas can be sealed inside through the through slit (S), improving the hygiene and safety of the medical supplies. In particular, packaging fruits and vegetables is more effective because slight deformation of the through slit (S) can prevent fluctuations in breathability and moisture permeability. The following describes the case where fruits and vegetables are stored.

[0077] (Fruits and vegetables) Fruits and vegetables refer to vegetables that have been grown in soil or hydroponically, from which inedible parts such as roots, skin, core, stem, seeds, and flowers have been removed, and the edible parts of the vegetables are left uncooked, taking into consideration ease of eating and cooking.

[0078] Examples of fruits and vegetables include, but are not limited to, semi-heading and heading vegetables such as cabbage, Chinese cabbage, lettuce (lettuce, leaf lettuce, cos lettuce, sunny lettuce, salad lettuce, and lettuce), and Brussels sprouts; spinach, komatsuna, mizuna, bok choy, turnip (kakina), non-heading lettuce (romaine lettuce, sunny lettuce, and the like); non-heading leafy vegetables such as chrysanthemum, kukitachina, shinobu-na, santona, rapeseed, chijirena, kousai-tai, urui, field wasabi, flower wasabi, watercress, arugula, shepherd's purse, petit vert, ice plant, and leaf radish; root vegetables such as sweet potato, potato, nagaimo (Japanese yam), yam, taro, jinenjo (Japanese yam), daikon radish, carrot, burdock, turnip, and ginger; leek, tuna, and the like. Examples of suitable vegetables include Allium vegetables such as onions and chives; Brassicaceae flower buds such as broccoli and cauliflower; Cucurbitaceae fruit vegetables such as cucumbers and pumpkins; Solanaceae fruit vegetables such as eggplant, tomato, cherry tomato, bell pepper, and paprika; okra, bitter melon, zucchini, bitter gourd, and sweet corn; immature beans such as edamame, snow peas, green beans, and broad beans; stem vegetables such as celery, asparagus, and wasabi; herbs such as myoga (ginger), myoba (Japanese parsley), Japanese water dropwort, mitsuba (Japanese parsley), and herbs (thyme, sage, parsley, Italian parsley, rosemary, oregano, lemon balm, chives, lavender, salad burnet, lamb's ear, rocket, dandelion, and nasturtium); and fungi and mushrooms. These may be packaged singly or in a mixture of two or more types.

[0079] Fruits and vegetables may be appropriately cut in consideration of purchase and consumption, and may be roughly divided into 1 / 8 to 1 / 2 in the case of cabbage, Chinese cabbage, pumpkin, etc. Furthermore, they may be cut into bite-sized pieces or shredded for eating raw in salads or for cooking in stir-fries.

[0080] <Packaging containing fruits and vegetables> The package containing fruits and vegetables of this embodiment (hereinafter also referred to as "package") contains fruits and vegetables in the above-described packaging bag 100 and packaging bag 200. This can improve the freshness-preserving effect of the fruits and vegetables.

[0081] The package preferably has a sealed opening 20 . The sealing can be achieved by a known method, such as heat sealing the opening 20 of the bag, or using a back-sealing tape (back seal), a cable tie, a rubber band, or a crimping member. In the case of a bag with a zipper, the opening 20 can be closed with the zipper.

[0082] The amount of fruit or vegetable contained in packaging bag 100 and packaging bag 200 may vary depending on the size of the container, the type of fruit or vegetable, the purpose of the package, etc. For fruit or vegetable intended for general consumers, the amount is preferably 50 to 1000 g, more preferably 100 to 800 g, from the viewpoint of ease of consumption immediately after opening and convenient carry-out and handling.

[0083] <How to maintain freshness> The freshness preservation method of this embodiment includes a step of storing fruits and vegetables in the above-described package containing the fruits and vegetables. Storage can be carried out by known methods, but it is preferable to store the package at an ambient temperature of 2 to 20°C. The ambient temperature refers to, for example, the temperature setting of a refrigerator or refrigerated room in which the package is stored, or the temperature setting of a showcase in which the package is displayed in a store, etc. It does not refer to a strict measurement of the temperature around the package. Furthermore, the average ambient temperature should be 2 to 20°C, and temporary temperatures of around 10°C are acceptable due to unavoidable circumstances such as the opening and closing of doors during transport of the package.

[0084] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0085] The present invention will be described in detail below with reference to examples and comparative examples. However, it should be noted that the present invention is not limited to the examples.

[0086] (1) Making packaging bags The synthetic resin films prepared were made from the following materials and used for each packaging bag. Tables 1 to 4 show the materials and thicknesses of each synthetic resin film. (material) OPP: Biaxially oriented polypropylene LLDPE: Linear low density polyethylene HDPE: High density polyethylene Next, using the synthetic resin film, fusion-cut bags, fusion-cut bags with zippers, U-shaped bags (bags with the bottom crimped into a U shape), and back-sealed bags were made by known methods to have the bag sizes (length x width) shown in Tables 1 to 4. For the fusion-cut bags, fusion-cut bags with zippers, and U-shaped bags, the lengthwise direction of the bag was the TD direction of the synthetic resin film, and for the back-sealed bags, the lengthwise direction of the bag was the MD direction of the synthetic resin film. Further, through slits (S) shown in Tables 1 to 4 and FIG. 7 were formed in each packaging bag by a known method.

[0087] (2) Observation of the through slit (S) The through slit (S) was observed using a digital microscope (RX-100 manufactured by Hirox Co., Ltd.) The results are shown in Tables 1 to 4.

[0088] (3) Evaluation method Fruits and vegetables (types, contents) shown in Table 1 were placed in each of the obtained packaging bags and sealed using the sealing method shown in Table 1 to obtain packages containing fruits and vegetables. Next, the fruits and vegetables were stored in the packaging under the following conditions 1 and 2, after which the fruits and vegetables were removed and evaluated according to the following evaluation criteria. The evaluation was carried out by an engineer familiar with fruit and vegetable freshness-keeping bags. The maximum length (X) of the through slit (S) of the packaging bag was also measured and the average value was calculated. Here, the maximum length of the through slit (S) after storage under condition 1 was designated X1, and the maximum length of the through slit (S) after storage under condition 2 was designated X2. These results are shown in Tables 1 to 4.

[0089] (Condition 1) After obtaining the packages containing the fruits and vegetables, they were stored as they were at the temperatures and for the number of days shown in Tables 1 to 4. (Condition 2) After obtaining the package containing the fruits and vegetables, a vibration test was carried out for 30 minutes under the conditions specified in JIS Z0232, and then the package was stored at the temperatures and for the number of days shown in Tables 1 to 4. The vibration test was carried out using a transport packaging vibration tester (FT-02K / 100) manufactured by EMIC Corporation. (Evaluation criteria) ◎5: No deterioration in freshness in appearance 〇4: There is a slight decrease in freshness in appearance. △3: Appearance shows moderate deterioration in freshness ×2: There is a clear decrease in freshness in appearance. ××1: Significant decrease in freshness in appearance

[0090] Even when the freshness of the fruits and vegetables deteriorated due to the vibration test under condition 2, the relative change in appearance (decrease in freshness) before and after storage was evaluated based on the state after the vibration test.

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] [Table 4]

[0095] Each packaging bag of the Examples had a through slit that was not parallel to the length and width of the bag, whereas Comparative Examples 1 to 4 had a straight through slit that was parallel to the length, and Comparative Examples 5 and 6 had a straight through slit that was parallel to the width. As a result, the Examples had a lower rate of change in the length of the through slit (X2 / X) before and after the test under Condition 2 than the Comparative Examples, and the through slit was prevented from tearing and elongating due to stress, or from deforming and widening. Furthermore, when used to package fruits and vegetables, the packaging bags of the Examples had better freshness-preserving effect than the Comparative Examples.

Claims

1. a main body portion for accommodating contents; An opening for putting in and taking out the contents; A packaging bag having a main body made of a synthetic resin film, The main body portion has a through slit (S), When the direction in which the opening portion widens is defined as a horizontal direction and the direction perpendicular to the horizontal direction is defined as a vertical direction, The through slits (S) have a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction, and the through slits (Sab) are identical to each other, The maximum length (X) (μm) of the through slit (S) and the line segment (Y) (μm) connecting one end of the through slit (S) to the other end at the maximum length (X) satisfy 1.02≦X / Y≦1.70, The packaging bag has line segments (Y) connecting one end to the other end of the plurality of through slits (S) over the maximum length (X) thereof that are not parallel to each other.

2. a main body portion for accommodating contents; An opening for putting in and taking out the contents; A packaging bag having a main body made of a synthetic resin film, The main body portion has a through slit (S), When the direction in which the opening portion widens is defined as a horizontal direction and the direction perpendicular to the horizontal direction is defined as a vertical direction, The through slits (S) have a through slit (Sa) that is not parallel to the vertical direction and a through slit (Sb) that is not parallel to the horizontal direction, and the through slits (Sab) are identical to each other, The packaging bag has line segments (Y) connecting one end to the other end of the plurality of through slits (S) over the maximum length (X) thereof that are not parallel to each other.

3. The packaging bag according to claim 1 or 2, The packaging bag, wherein the maximum length (X) of the through slit (S) is 100 μm or more and 1000 μm or less.

4. The packaging bag according to claim 1 or 2, The packaging bag, wherein the through slit (S) has a bent or curved portion.

5. The packaging bag according to claim 2, The maximum length (X) (μm) of the through slit (S) and the line segment (Y) (μm) connecting one end of the through slit (S) to the other end at the maximum length (X) satisfy 1.02≦X / Y≦1.

70.

6. The packaging bag according to claim 1 or 2, A packaging bag, wherein the smaller of the angles θ formed by a line segment (Y) connecting one end of the through slit (S) to the other end of the through slit (S) over its maximum length (X) and the vertical direction or the horizontal direction is 2°≦θ≦90°.

7. The packaging bag according to claim 1 or 2, A packaging bag in which the proportion of the through slits (Sa) and the through slits (Sb) is 30% or more and 100% or less of the total through slits (S).

8. The packaging bag according to claim 1 or 2, The through slit (S) is The packaging bag comprises a through slit (Sa) that is not parallel to the longitudinal direction and a through slit (Sb) that is not parallel to the transverse direction, separately.

9. The packaging bag according to claim 1 or 2, The packaging bag has a through slit (Sc) consisting of a first through slit and a second through slit intersecting the first through slit.

10. The packaging bag according to claim 1 or 2, The packaging bag has 1 or more and 500 or less through slits (S).

11. The packaging bag according to claim 1 or 2, The packaging bag, wherein the synthetic resin film contains polyolefin.

12. The packaging bag according to claim 1 or 2, The synthetic resin film has a thickness of 10 μm to 200 μm.

13. The packaging bag according to claim 1 or 2, The packaging bag, wherein the synthetic resin film is a single layer.

14. A freshness-keeping bag for fruits and vegetables, which uses the packaging bag according to claim 1 or 2 for preserving the freshness of fruits and vegetables.

15. A package containing fruits and vegetables, wherein the fruits and vegetables are sealed in the fruit and vegetable freshness-keeping bag according to claim 14.

16. A method for keeping fruits and vegetables fresh, comprising the step of placing fruits and vegetables inside the fruit and vegetable freshness-keeping bag according to claim 14, and then sealing the fruit and vegetable freshness-keeping bag.

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