JP2018016403A - Packaging bag excellent in gas permeability and anti-fogging property preferable for holding freshness of garden stuff and package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging bag capable of suppressing efficiently, growth of saprophyte, suitable for holding freshness of a content containing a large amount of moisture such as garden stuff, and capable of being produced with a simple and high yield method.SOLUTION: There is provided a packaging bag including a polymeric film, in which oxygen permeation degree at 22°C and 40%RH is 500-50000 cc/m/day/atm, in which a heat seal part is provided on at least one side, and a notch is provided on at least a part of the heat seal part.SELECTED DRAWING: Figure 2

Description

The present invention relates to a packaging bag comprising a polymer film in which permeability of oxygen or the like is in a specific range and a surface of a compound having a specific amount of a specific surface activity exists.
The packaging bag is excellent in anti-fogging property and productivity, is suitable for maintaining the freshness of fruits and vegetables, and is particularly suitable for maintaining the freshness of cut vegetables and the like.

A gas permeable film that is provided with a gas permeable portion on a polymer film substrate and allows gas such as oxygen, carbon dioxide, and water vapor to pass through the gas permeable portion is used in the field of foods, particularly for fresh vegetables such as fruits and vegetables. It is suitably used as a packaging material. Using such a gas permeable film, for example, when packaging vegetables, fruits, etc., the oxygen concentration suitable for maintaining the freshness of the vegetables, fruits, etc., for example, an oxygen concentration of about 1 to 4% is maintained. It is known that contents can be stored while maintaining freshness over a relatively long period of time.
For example, in Patent Document 1, in a package containing fruits and vegetables made of a polymer film in which fruits and vegetables are sealed, the package is composed of (A) a porous polymer film and (B) a nonporous polymer film, The water vapor transmission rate measured under the conditions where the film characteristics of at least one of (A) and (B) are 25 ° C. and the relative humidity is 75% is 50 to 800 gm ⁻² d ^{−1 based} on the effective surface area of the package. There is described a packaged product with fruits and vegetables characterized in that the open area ratio of (A) is 3 × 10 ^{−6 to} 7 × 10 ⁻⁴ % with respect to the effective surface area of the package. Specifically, (A) a porous polymer film made of stretched polypropylene having a thickness of 35 μm, having 95 holes with an average pore diameter of 30 μm, 9 holes with an average pore diameter of 60 μm, etc. It is used.

  As another method, Patent Document 2 discloses a package for maintaining the freshness of fruits and vegetables characterized by adjusting the gas permeation amount by providing an opening in the package, and the opening is provided using a hollow tube. Is listed. More specifically, a fluororesin tube having an outer diameter of 3 mm, an inner diameter of 1 mm, and a length of 5 cm is used as the hollow tube.

  Furthermore, as another method, the thermoplastic resin film is led to the outside of the filling cylinder to form a cylinder, and one end surface of the cylinder-shaped film is heat-sealed to form a cylindrical bag. An unheat-sealed portion having a width of 1 to 20 mm is provided in all four corners of the packaging bag at a ratio of 3 to 50% of the area of the heat-sealed zone in the seal portion zone, and the inside of the bag is formed by the non-heat seal portion. A packaging bag containing fruits and vegetables characterized by a bag structure that can be ventilated to the outside has been proposed (see, for example, Patent Document 3).

In this way, a package capable of maintaining a specific oxygen concentration is generally produced using a polymer film having low oxygen permeability. Since a polymer film with low oxygen permeability usually has low water vapor permeability, even if an opening is provided, the humidity in the package tends to increase and condensation tends to occur. Since fruits and vegetables contain a lot of moisture, a package containing the fruits and vegetables or the like is particularly susceptible to condensation.
During condensation, various germs and the like are likely to propagate, and there is a risk of causing bad odor and content to decay. Therefore, it has been proposed to blend and apply a predetermined amount of a compound having a predetermined surface activity to the polymer film constituting the package in order to prevent condensation (see, for example, Patent Document 4).

  The demand for cut vegetables has increased in recent years because it can be easily used for meals, and has high economic value. On the other hand, when vegetables are cut, the respiratory action and metabolic reaction are activated, and the quality tends to decrease rapidly. Moreover, since it has a comparatively wide cut surface, it is easily affected by bacteria and spoilage. Furthermore, when organic components and the like are eluted from the cut surface during condensation, remarkable breeding of germs and the like using this as a nutrient often occurs.

JP-A-5-168400 Japanese Unexamined Patent Publication No. 2000-4780 JP 2002-308293 A International Publication No. 2014/142218 A1 Pamphlet

The present invention is a packaging bag capable of realizing MA packaging in which a part of the heat-sealing part is provided with a non-sealing part, which can extremely effectively suppress propagation of germs and the like, and contains a large amount of moisture such as fruits and vegetables. It is an object of the present invention to provide a packaging bag suitable for maintaining the freshness of contents, particularly contents that are easily affected by bacteria such as cut vegetables, and that can be manufactured by a simple and high-yield method.
As a result of intensive studies, the inventor focused on the heat seal part formed by processing when making a packaging bag from a polymer film, and provided a notch in the heat seal part, thereby opening an opening for precision ventilation. It has been found that the above problems can be solved by providing the present invention, and the present invention has been completed.

That is, the present invention
[1]
A packaging bag comprising a polymer film, wherein the oxygen permeability at 22 ° C. and 40% RH is 500 to 50000 cc / m ² / day / atm, and has a heat seal part on at least one side thereof, A packaging bag having a notch in at least a part of the heat seal portion.

Hereinafter, [2] to [16] are each one of the preferred embodiments of the present invention.
[2]
The polymer film constituting the packaging bag is selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerin monolaurate and diglycerin monolaurate on at least a part of the surface located on the inner side of the packaging bag. The packaging bag according to [1], wherein 0.002 to 0.5 g / m ² of at least one compound is present.
[3]
The packaging bag according to [1] or [2], wherein the polymer film contains 0.001 to 3% by mass of the compound in total.
[4]
[1] to [3], wherein the polymer film contains the compound in a range of 50 to 90% of the total thickness from the inner side surface of the packaging bag in the thickness direction. ] The packaging bag as described in any one of.
[5]
The packaging bag according to any one of [1] to [4], wherein the polymer film includes two or more layers, and the compound is contained only in a layer located on the inner side of the packaging bag.
[6]
The packaging bag according to any one of [1] to [5], wherein the polymer film includes at least one of myristyl diethanolamine monostearate and stearyl diethanolamine monostearate.
[7]
The packaging bag according to any one of [1] to [6], wherein a wetting index of at least one surface of the polymer film is 35 dyn or more.
[8]
The packaging bag according to any one of [1] to [7], wherein the cutout has a length of 1 to 10 mm.
[9]
The packaging bag according to any one of [1] to [8], wherein the notch is an unfused portion of the heat seal portion.
[10]
The packaging bag according to any one of [1] to [8], wherein the notch is a part of the polymer film cut out in the heat seal portion.
[11]
The packaging bag according to any one of [1] to [10], wherein the polymer film includes a polyethylene film layer.
[12]
The packaging bag according to [11], wherein the density of the polyethylene film layer increases from the inner surface of the packaging bag in the thickness direction.
[13]
The packaging bag according to any one of [1] to [10], wherein the polymer film is a stretched polypropylene film or a laminate of a stretched film and a polyethylene film.
[14]
The packaging bag according to any one of [1] to [13], which is used for maintaining freshness of fruits and vegetables.
[15]
A package for maintaining freshness of fruits and vegetables, wherein the fruits and vegetables are stored in the packaging bag according to any one of [1] to [14].
[16]
A method for producing a packaging bag comprising a polymer film, having a heat seal part on at least one side thereof, and having a notch in at least a part of the heat seal part,
a) heat sealing one side of the polymer film to form a cylindrical bag;
b) storing the contents in the cylindrical bag; and c) heat-sealing the cylindrical bag to form a packaging bag,
The said manufacturing method with which the notch of this heat seal part is formed simultaneously with the heat seal in process a) or c).

According to the present invention, it is possible to extremely effectively suppress the propagation of various germs, etc., and to maintain the freshness of the content that contains a large amount of moisture such as fruits and vegetables, particularly the content that is easily affected by germs such as cut vegetables. Provided is a suitable packaging bag that has a high practical value that cannot be realized by the prior art, and can be manufactured by a simple and high-yield method.
By storing fruits and vegetables in the packaging bag of the present invention, it is possible to provide a fruit and vegetable freshness-keeping package having a high freshness-keeping function that could not be realized by the prior art with high productivity and economy.

It is a top view which shows the packaging bag of a prior art. It is a top view which shows one Embodiment of the packaging bag of this invention. It is a top view which shows other one Embodiment of the packaging bag of this invention. It is a schematic diagram which shows the structure of the packaging bag of one Example of this invention. It is a schematic diagram which shows the structure of the packaging bag of the other Example of this invention. It is a schematic diagram which shows the structure of the packaging bag of one comparative example. It is a schematic diagram which shows the structure of the packaging bag of another comparative example.

Hereinafter, modes for carrying out the present invention will be described.
The present invention is a packaging bag comprising a polymer film, wherein the oxygen permeability at 22 ° C. and 40% RH is 500 to 50000 cc / m ² / day / atm, and a heat seal portion is provided on at least one side thereof. It is the said packaging bag which has and has a notch in at least one part of this heat seal part.

Here, the method for measuring oxygen permeability in the present invention is as follows.
First, a bag having an inner size of 220 mm × 240 mm is formed by the following method.
One film is folded almost equally into two, approximately 5 mm wide, and heat sealing is performed with an impulse sealer (manufactured by Fuji Impulse Co., product number Fi-200-10WK) with the heating condition scale set to 3, and the heat sealing is performed. Heat seal the whole of one side that is almost perpendicular to the heat seal side so that the side is almost in the center, except the end of about 2 cm that is one communicating part of the other side, and the inner dimension is 220 mm × A 240 mm bag is formed.
Next, nitrogen gas is injected from the communication portion, and when the inside of the bag becomes saturated, almost all the gas in the bag is discharged from the communication portion. After repeating this operation five times, nitrogen gas is injected to saturate the inside of the bag with nitrogen gas, and the communicating portion is heat-sealed with the impulse sealer under the same conditions. The bag saturated with nitrogen gas is left in a room at 22 ° C. and 40% relative humidity in air (1 atm, oxygen concentration: 21%, nitrogen concentration: 79%) for 6 hours.
Next, about 20 cc is sampled with a sampling needle tube, and the oxygen concentration in the bag is measured with a food packaging zirconia oxygen concentration meter (model number LC-750F, manufactured by Toray Engineering Co., Ltd.). Furthermore, the volume of the gas in the bag is measured, and the oxygen permeability is calculated from the following formula.

(Expression) Oxygen permeability = change in internal oxygen concentration (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (1232 cm ² ) /0.21 (partial pressure of oxygen )

In addition, “comprising a polymer film” as used herein means that when the entire packaging bag is made of a polymer film and when a part of the packaging bag is made of a polymer film, It is intended to include both.
Therefore, the packaging bag may be a flexible polymer packaging bag whose whole or main part is composed of a flexible polymer film, such as a flexible polymer film and coated paper. It may be a flexible packaging bag in which other flexible members are combined.

In one embodiment of the packaging bag of the present invention, for example, in a state in which two polymer films are overlapped with each other, or in a state in which one polymer film is folded, three or two sides are heat-sealed. A packaging bag can be formed by, for example, fusing. The remaining one side can be sealed by arranging the contents such as fruits and vegetables in the packaging bag and then similarly fusing by heat sealing.
Such a packaging bag may have a circular shape, a triangular shape, a quadrangular shape, or a polygonal shape equal to or more than a quadrangular shape in a plan view, but is preferably rectangular from the viewpoint of processability and ease of handling.
In one embodiment of the packaging bag of the present invention, for example, a polymer film is rolled into a cylindrical shape, and one end surface of the cylindrical film is heat-sealed to form a cylindrical bag. After filling a certain amount into the bag, the other end face of the cylindrical bag can be heat sealed.

(Heat seal part)
The packaging bag of the present invention has a heat seal portion on at least one side thereof. As described above, in a state where two polymer films are overlapped with each other, three sides are heat sealed to form a packaging bag, and after the contents are placed in the packaging bag, the remaining one side is heat sealed. The package may be completed, and in a state where one polymer film is folded, two sides are heat-sealed to form a packaging bag, and after the contents are placed in the packaging bag, the remaining 1 The package may be completed by heat-sealing the sides. In addition, the polymer film is rolled up into a cylindrical shape, one end face of the cylindrical film is heat sealed to form a cylindrical bag, and then the content is filled into the cylindrical bag after a certain amount, You may complete a package by heat-sealing the other end surface of a cylindrical bag.
As a practically preferable embodiment, a so-called pillow-type packaging machine can be used to produce a packaging bag and a package having a heat seal portion. In a pillow type packaging machine, first, a polymer film supplied from a roll or the like is back-sealed (center-sealed) to form a tube (tube-like), and a top-bottom seal (end-seal) is filled and filled with contents. Can be sealed. The end seal may be one that cuts simultaneously (cut seal).
From the viewpoint of productivity and the like, the polymer films in the packaging bag of the present invention, or the junction between the polymer film and other members are preferably all heat-sealed, but by other methods. You may have a junction. For example, bonding with an adhesive or mechanical bonding may be used in combination.
When performing heat sealing, a polymer film having excellent heat sealability may be selected and the polymer film itself may be heat sealed, or the polymer film may be used as a laminated film to form a heat seal layer (sealant layer). ) May be provided. When the heat seal layer is provided, it may be provided on the entire surface of the film, or may be provided only on a part of the film, particularly on the part (and its periphery) where heat sealing is performed.

Heat sealing may be performed by a hot plate method, an impulse method, a band method, a high frequency method, an ultrasonic method, etc. that have been conventionally adopted in the technical field, and there is no particular limitation on the method, but from the viewpoint of productivity. Is preferably performed by a hot plate method. In implementing the hot plate method, it is desirable to use a seal bar which is a rod-like member having a built-in heating element. The seal bar may be provided with a cutter or without a cutter, but is preferably provided with a cutter from the viewpoint of productivity. By controlling the heating element, the temperature of the seal bar is controlled to an appropriate temperature, and by pressing the superposed polymer film with the seal bar, the polymer film can be heat sealed. The temperature of the seal bar may be appropriately set in consideration of the melting point, thickness, production rate, etc. of the polymer film (or its sealant layer). For example, low-density polyethylene films having a thickness of about 30 to 50 μm are heat-sealed. In some cases, the temperature is preferably about 110 to 140 ° C.
When the polymer films are sufficiently fused together by heat sealing, the air-tightness of the heat sealing portion is maintained. That is, when each side is sufficiently heat-sealed, the oxygen permeability of the packaging bag substantially matches that calculated from the oxygen permeability and area of the polymer film itself.

(Notch)
The heat seal part in the packaging bag of this invention has a notch in at least one part. Here, the notch means a portion that is present in a continuous heat seal portion and is not heat-sealed or insufficient. The notch is a portion that has air permeability because the polymer films that are overlaid due to not being heat-sealed or insufficient are not fused together and there are voids between the polymer films. is there. The gap between the polymer films in the notch varies depending on the type of polymer, the thickness of the polymer film, the width of the heat seal part, the length of the notch, etc., but is usually 0.1 μm to 100 μm. More preferably, it is 0.5 μm to 5 mm.
Although there is no particular limitation on the method of providing the notch, for example, the notch can be provided by not partially heat-sealing by devising the shape of the seal bar etc. Notches can also be provided by separating the gaps. Moreover, you may provide by removing the inclusion provided between both polymer films in the case of heat sealing, and you may provide by cutting off the heat seal part of both polymer films partially.
Since the packaging bag of the present invention has a notch in at least a part of the heat seal portion, the oxygen permeability at 22 ° C. and 40% RH is 500 to 50000 cc / m ² / day / atm. The oxygen permeability is more preferably in the range of 1000 to 5000 cc / m ² / day / atm. In the present invention, a notch is provided in the heat seal portion in this way, and therefore it is possible to provide a notch together at the time of heat sealing processing. By adjusting the number and length of the cutouts in the seal portion, that is, the length in the direction perpendicular to the direction communicating with the outside air, a packaging bag having a desired oxygen permeability can be manufactured simply and with a high yield. Furthermore, in the notch of the heat seal part, the size of the communication port facing the outside air and the size of the communication port facing the inside of the package body can be respectively adjusted, or from the communication port facing the outside air to the communication port facing the inside of the package body By adjusting the length of MA, more accurate MA packaging becomes possible.

The oxygen permeability can be adjusted as appropriate by changing the number of cutouts, the length, and the like, and it is desirable to adjust the oxygen permeability so that an environment such as an oxygen concentration suitable for storage of contents is obtained. The notch is preferably 1% to 10% of the heat seal area from the viewpoint of preventing entry of foreign matter. The length, number, etc. of the cutouts can be determined by a heat sealing device.For example, when heat sealing is performed using a seal bar, a groove corresponding to the length of the cutout portion is formed in the seal bar. By providing the number corresponding to the number of notches, it is possible to provide notches with a desired length and number.
The length of the notch is preferably 1 to 20 mm, and particularly preferably 3 to 10 mm.
Although the number of notches is not particularly limited, for example, it is preferable to have 1 to 20 notches per packaging bag because a wide range of oxygen permeability can be obtained as required.
The notch interval is not particularly limited because it depends on the number of notches required, but it is preferably 1 to 10% of the heat seal area from the viewpoint of manufacturing efficiency and the strength of the film. .
The size and shape of each notch need not be the same, and the size, shape and number of notches can be set and changed as appropriate as long as the oxygen permeability of the entire packaging bag is appropriate. In that case, the ratio of the notch to the effective area of the polymer film serves as a guideline. For example, when a notch with a length of 5 mm and a gap of 1 μm between films is provided, there is an effect of increasing the oxygen permeability of about 1000 cc / m ² / day / atm for every 200 mm × 200 mm packaging bag. It is preferable to determine the number of notches from the oxygen permeability of the entire packaging bag required based on such knowledge.

(Slit opening)
In the packaging bag of this invention, since predetermined | prescribed oxygen permeability is implement | achieved by the notch provided in the heat seal part, it is not necessary to provide an opening part in the said polymer film itself. From the viewpoint of productivity, it is often preferable not to provide an opening in the polymer film itself.
However, the polymer film itself may have an opening as long as the object of the present invention is not violated. For example, as described later, when the gas permeability is changed nonlinearly with respect to the pressure difference between the inside of the packaging bag and the outside of the packaging bag, the notch provided in the heat seal portion and the polymer film itself are provided. You may use together a slit-shaped opening part.
In an embodiment in which the polymer film itself has an opening, the polymer film has at least one opening, and the opening has one or more slit-like shapes having a length of 0.5 to 7 mm. It is preferable to have a portion. That is, it is preferable that a portion having a width of less than 10 μm exists over at least 0.5 mm of the length of the opening. From the viewpoint of preventing entry of foreign matters and the like from the outside, the width is preferably less than 10 μm over the entire length of the opening. The opening is preferably composed of 1 or more and 5 or less slit-shaped parts from the viewpoint of preventing entry of foreign substances, productivity, and handling properties, and is composed of 1 or more and 3 or less slit-shaped parts. More preferably, it is more preferably composed of one or two slit-like shapes.
When the opening is composed of one slit-shaped part and two or more openings are provided, the length directions of the slit-shaped parts are, for example, perpendicular to each other. However, it is preferable to provide the slit-shaped portions so that the length directions of the slit-shaped portions are substantially parallel to each other.
In addition, when the opening is configured by combining two or more slit-shaped portions, each slit-shaped portion is, for example, two slit-shaped portions are “ten” or “ “X” may be provided so as to cross each other, or three or more slit-shaped portions may be provided so as to cross each other at one point. Further, for example, the slit-shaped portions such as “T” may be provided so as to be continuous in different length directions without crossing each other. By using such slit-shaped openings in combination, while realizing the desired oxygen permeability, floating foreign substances such as fine inorganic substances, pollen, germs, germs, etc. are packaged. It becomes much easier to effectively prevent the bag from entering the bag. Furthermore, by making the width of the slit-shaped part forming the opening less than 10 μm, it becomes easier to prevent intrusion of foreign matters in the air having a maximum diameter of 10 μm or more.
From the viewpoint of ensuring air permeability, the maximum length of the continuous substantially linear portion of the slit-like shape forming the slit-like opening is preferably 0.5 to 7 mm, more preferably 0. It is 7-7 mm, More preferably, it is 0.8-5 mm, Especially preferably, it is 1.0-3.0 mm, More preferably, it is 1.0-2.0 mm. On the other hand, the width of the slit-shaped opening is preferably less than 10 μm, more preferably 7 μm or less, and even more preferably 5 μm or less, from the viewpoint of preventing the entry of foreign matter from the outside. Preferably it is 3 micrometers or less. If the length of the slit-shaped opening is less than 0.5 mm, the required gas permeability may not be sufficiently contributed, and if it is 7 mm or more, foreign matter in the air may enter.
The lower limit of the width of the slit-shaped opening is not particularly limited as long as the oxygen permeability at 22 ° C. and 40% RH can be maintained within the range of 500 to 50000 cc / m ² / day / atm.

When the pressure difference between the inside of the packaging bag and the outside of the packaging bag is small, the slit-shaped opening in the polymer film transmits oxygen within the range of 500 to 50000 cc / m ² / day / atm. It has a relatively small gas permeability as typified by, but when the pressure difference between the inside of the packaging bag and the outside of the packaging bag is large, the pressure inside the packaging bag is reduced by, for example, being transported by airplane and the outside air pressure is lowered. When it becomes significantly higher than the outside of the packaging bag, the gas permeability is remarkably increased by increasing the width of the central portion of the slit. That is, the gas permeability changes nonlinearly with respect to the pressure difference between the inside of the packaging bag and the outside of the packaging bag. For this reason, even if the pressure inside the packaging bag rises due to the pressure difference between the inside of the packaging bag and the outside of the packaging bag, such as when transported by airplane as described above, the packaging bag is damaged by the pressure. Can be effectively prevented. On the other hand, when the pressure inside the packaging bag is low and the pressure outside the packaging bag is high, air can be allowed to flow in from the slit-shaped opening provided in the polymer film, so the contents are damaged by the pressure from the outside. Can be prevented. At this time, since the width of the slit-shaped opening is very small, foreign matter or the like from the outside does not flow in.

  The number of slit-shaped openings is not particularly limited, but the relationship between the number, shape, size, and oxygen permeability of the entire packaging bag is the same as that described above for the notch. It can design so that it may become a packaging bag which has desired oxygen permeability combined with oxygen permeability by notch.

(Polymer film)
The thickness of the polymer film is not particularly limited. From the viewpoints of accuracy and ease when forming the cutout, flexibility, strength, transparency, economy, and the like when forming the packaging bag, the polymer film What is necessary is just to select a suitable thickness suitably in relation to the material which forms a film. Typically, the thickness of the polymer film is preferably 10 to 100 μm, more preferably 20 to 80 μm, and particularly preferably 30 to 50 μm.

As described above, the oxygen permeability of the packaging bag of the present invention is in the range of 500 to 50000 cc / m ² / day / atm, and is suitable for storage conditions such as the amount, type and temperature of contents. The transparency can be selected.
When the oxygen permeability of the packaging bag is in the above range, the oxygen concentration inside the freshness-maintaining package that contains fruits and vegetables in the packaging bag depends on the conditions of the fruits and vegetables to be stored, For vegetable products, 0.5 to 5% by volume is preferable because it is suitable for maintaining the freshness of fruits and vegetables. Generally, if the oxygen concentration is less than 0.5% by volume, an alcohol odor is generated in the vegetable, and if it is 5% by volume or more, browning is considered to be large.

The polymer film constituting the packaging bag of the present invention has at least one compound selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerin monolaurate and diglycerin monolaurate on the surface located inside the bag (Hereinafter, also referred to as “specific compound”) is preferably 0.002 to 0.5 g / m ² .
The presence of 0.002 to 0.5 g / m ^{2 of the} specific compound on at least one surface of the polymer film suppresses the growth of germs due to condensation on the surface of the polymer film, and has high antibacterial properties. Since a polymer film is obtained, it is preferable. It is more preferable that the polymer film contains 0.001 to 3% by mass of the specific compound from the viewpoint of antibacterial properties. In addition, from the viewpoint of antibacterial properties, the polymer film is subjected to an antibacterial test according to JISZ2801, using Escherichia coli, under conditions where wiping with alcohol is not performed in order to maintain the surface state of the polymer film. It is preferable that the viable cell count on at least one surface of the polymer film after 24 hours is 1/100 times or less.

In the packaging bag of this preferred embodiment, at least a part of the heat seal portion at at least one end of the packaging bag has a notch, and the polymer film has a specific oxygen permeability by the notch or the like. A specific amount of a specific compound present on at least a part of the inner surface of the packaging bag, more specifically, 0.002 to 0.5 g / at least on the inner surface of the polymer film packaging bag. Maintaining high freshness that could not be achieved by the prior art by combining at least one compound selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerin monolaurate and diglycerin monolaurate present in m ² Function can be realized.
The mechanism that achieves a high freshness maintaining function by combining a notch provided in such a heat seal portion with a specific amount of a specific compound is not necessarily clear, but in addition to the freshness retention effect by MA packaging, the heat seal portion The specific compound is also present on the surface of the communication part formed by the notch provided in the bag, so that the invasion of bacteria and the like into the packaging bag is suppressed, and the specific compound prevents bacteria from growing in the bag. It is presumed to prevent effectively.

  As a specific compound preferably used in the present invention, palmityl diethanolamine, stearyl diethanolamine, glycerin monolaurate, or diglycerin monolaurate may be used alone, or a mixture thereof may be used. Palmityldiethanolamine is an alkyldiethanolamine having a palmityl group which is a long-chain alkyl group having 16 carbon atoms. Stearyl diethanolamine is an alkyl diethanolamine having a stearyl group having 18 carbon atoms. Glycerol monolaurate is a monoester of lauric acid (carbon number 12) and glycerin. Diglycerin monolaurate is a monoester of lauric acid (carbon number 12) and diglycerin.

  Stearyl diethanolamine and palmityl diethanolamine have a relatively high melting point compared to myristyl diethanolamine and lauryl diethanolamine. For this reason, when melt-molding a polymer film, stearyl diethanolamine and palmityl diethanolamine are relatively difficult to volatilize, particularly in heat setting when the polymer film is a stretched film. Stearyl diethanolamine and palmityl diethanolamine are excellent in antibacterial properties and freshness retention. Furthermore, when a polymer film is used for a packaging bag, the transfer to the contents is relatively slow, the food safety is excellent, and the performance can be sustained.

(Alkyldiethanolamine; carbon number of long chain alkyl group; melting point)
Stearyl diethanolamine; 18; 51 ° C
Palmityl diethanolamine; 16; 28 ° C
Myristyl diethanolamine; 14; 22-23 ° C
Lauryl diethanolamine; 12; liquid at room temperature.

  The specific compound preferably used in the present invention may individually contain a similar compound. Palmityl diethanolamine (16 carbon atoms) may include, for example, a small amount of myristyl diethanolamine (14 carbon atoms) or alkyldiethanolamine having an alkyl group having 12 to 20 carbon atoms such as stearyl diethanolamine (18 carbon atoms). Stearyl diethanolamine (carbon number 18) may contain a small amount of alkyldiethanol having an alkyl group having 16 to 20 carbon atoms, for example. Further, the specific compound may contain a small amount of a compound in which a part of amines of the similar compounds of palmityl diethanolamine and stearyl diethanolamine forms an ester with an aliphatic carboxylic acid. Further, the glycerin monolaurate may contain a small amount of a monoester of a higher linear aliphatic carboxylic acid having 10 or 14 carbon atoms and glycerin. The diglycerin monolaurate may contain a small amount of a monoester of a higher aliphatic carboxylic acid having 10 or 14 carbon atoms and diglycerin. The (di) glycerin monoester may contain a small amount of a similar compound such as (di) glycerin diester, (di) glycerin triester, or a similar compound in which the glycerin part is diglycerin and the diglycerin part is triglycerin. Good. Similar compounds of these specific compounds are generally synthesized at the same time or difficult to separate in steps such as synthesis and separation of the specific compounds. Moreover, the said similar compound may be contained 50 mass parts or less with respect to 100 mass parts of specific compounds, may be contained 40 mass parts or less, and it is preferable that it is not contained.

  Furthermore, the polymer film used in the present invention may contain other additives such as antistatic agents, antifogging agents (excluding specific compounds) and lubricants as necessary, in addition to the specific compounds as described later. Can be included. The total of these other additives and the similar compound may be contained in an amount of 50 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less, with respect to 100 parts by mass of the specific compound. May be.

In the polymer film constituting the packaging bag of the present invention, the specific compound is preferably present in an amount of 0.002 to 0.5 g / m ^{2 on} at least a part of the inner surface of the packaging bag. The polymer film is more preferably a specific compound to at least a portion of said surface 0.004~0.4g / ^{m 2} is present, more preferably in 0.01 to 0.3 g / ^{m 2} is present, It is particularly preferable that 0.02 to 0.2 g / m ^{2 is} present. The specific compound is preferably present at 0.002 to 0.5 g / m ^{2 on} at least a part of the surface in contact with the contents of the polymer film, that is, the inner surface of the packaging bag, but also on the outer surface. May be present. Examples of the method for causing the specific compound to exist on the surface of the polymer film include a coating method in which the specific compound is sprayed on the surface, or a solution, suspension, or the like containing the specific compound is applied to the surface. Moreover, you may make a surface layer and intermediate | middle layer containing the surface which contact | connects the content of a polymer film contain a specific compound. The content of the specific compound in the polymer film is preferably 0.001 to 3% by mass, more preferably 0.01 to 3% by mass, from the viewpoint of allowing the specific compound to bleed out in the above range on the surface. 0.1 to 2% by mass is more preferable.

<Method for quantifying a specific compound on the surface of a polymer film>
The amount of the specific compound on the surface of the polymer film is a value calculated from the coating amount of the specific compound when the specific compound is applied to the surface by a coating method. When the specific compound is blended in the polymer film, the amount of the specific compound on the surface of the polymer film is determined by washing the surface of the polymer film with dichloromethane, collecting the washing liquid, and concentrating. This is a value determined after silylation and gas chromatography / mass spectrometry (GC / MS) after constant volume.

  The polymer film constituting the packaging bag of the present invention preferably has a wetness index of at least one surface of 35 dyn or more from the viewpoint of further improving anti-fogging and drip-proof properties. The wetting index is more preferably 36 dyn or more, further preferably 37 dyn or more, and particularly preferably 38 dyn or more. The upper limit of the wetting index is not particularly limited, but can be, for example, 50 dyn or less. Moreover, it is preferable that the wetting index of the surface layer of the polymer film in contact with the contents is 35 dyn or more. The wetting index is a value confirmed using a mixed liquid for wet tension test manufactured by Wako Pure Chemical Industries, Ltd. As a method of setting the wetting index of the surface of the polymer film to 35 dyn or more, a method of performing corona treatment on the surface is preferable.

  The polymer film constituting the packaging bag of the present invention has a range of 50 to 90% of the total thickness from the surface in contact with the contents, that is, usually the inner surface of the packaging bag, in the thickness direction. It is preferable that a specific compound is contained in. That is, assuming that the thickness of the entire film is 100%, the position of the surface in contact with the contents to be packaged is 0%, and the position of the surface opposite to the surface in contact with the contents is 100%. When the specific compound is contained in the range of 50 to 90%. When the specific compound is included in the range, the specific compound bleeds out appropriately on the surface that comes into contact with the contents, and can exhibit antibacterial properties and accompanying it, freshness retention. The range is more preferably 65 to 90%, still more preferably 80 to 90%.

  The polymer film constituting the packaging bag of the present invention is composed of two or more layers, and it is preferable that the specific compound is contained only in the surface in contact with the contents, that is, usually the layer located inside the packaging bag. That is, the specific compound is preferably contained only in the surface layer in direct contact with the contents. Since the specific compound is included only in the surface layer, the specific compound can be easily bleed out to the surface in contact with the contents, so that it exhibits high antibacterial properties and contains the specific compound as a whole film. The amount can be reduced. In addition, when the specific compound is provided to the surface of the surface layer, it corresponds to the case where the specific compound is included only in the surface layer.

  Although there is no restriction | limiting in particular in the material of the said polymer film, The polymer used for the film for conventional fruit and vegetables packaging can be used suitably. Examples thereof include polyethylene, polypropylene, polyethylene terephthalate, polystyrene, nylon (polyamide), ethylene vinyl acetate copolymer (EVA), polybutylene succinate, polybutylene succinate adipate, and polylactic acid. Further, for example, natural polymers such as cellophane can be used. Further, any one of these materials may be used alone, or a plurality of these materials may be blended and / or laminated.

  From the viewpoint of ease of processing and cost, the polymer film is preferably made of a thermoplastic resin. Examples of the thermoplastic resin include homopolymers or copolymers of α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl / 1-pentene, and 1-octene. Specifically, ethylene polymers such as high pressure method low density polyethylene, linear low density polyethylene (LLDPE), high density polyethylene, propylene homopolymer, propylene / α-olefin random copolymer, propylene block copolymer. And propylene-based polymers such as poly 1-butene and poly 4-methyl / 1-pentene. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyamides such as nylon-6, nylon-66, and polymetaxylene adipamide, polyvinyl chloride, polyimide, and ethylene / acetic acid. Examples thereof include a vinyl copolymer or a saponified product thereof, polyvinyl alcohol, polyacrylonitrile, polycarbonate, polystyrene, ionomer, polylactic acid, polybutylene succinate and the like, or a mixture thereof. These thermoplastic resins may be used alone or in combination of two or more. Among these, as the thermoplastic resin, polyolefin, polyester, polyamide and the like are preferable because they are excellent in rigidity and transparency. As the thermoplastic resin, an ethylene polymer and a propylene polymer are more preferable because they are lightweight and excellent in film processability, and a propylene polymer is more preferable from the viewpoint of flexibility and transparency.

<Propylene polymer>
Examples of the propylene polymer include a propylene homopolymer (also referred to as homo PP) manufactured and sold under the name of polypropylene, and a propylene / α-olefin random copolymer (also referred to as random PP). And crystalline polymers mainly composed of propylene such as a mixture of propylene homopolymer and low crystalline or amorphous propylene / ethylene random copolymer (also called block PP). . Further, the propylene-based polymer may be a mixture of propylene homopolymers having different molecular weights, and is composed of a propylene homopolymer and a random copolymer of propylene and ethylene or an α-olefin having 4 to 10 carbon atoms. It may be a mixture.

  Specific examples of the propylene polymer include polypropylene, propylene / ethylene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 1-butene copolymer, and propylene / 1-pentene copolymer. Copolymer of propylene such as propylene / 1-hexene copolymer and propylene / 1-octene copolymer as a main monomer and at least one selected from ethylene and α-olefin having 4 to 10 carbon atoms Coalescence is mentioned. These may use 1 type and may use 2 or more types together.

The density of the propylene-based polymer is preferably 0.890 to 0.930 g / cm ³ , and more preferably 0.900 to 0.920 g / cm ³ . The propylene-based polymer MFR (ASTM D1238 load 2160 g, temperature 230 ° C.) is preferably 0.5 to 60 g / 10 minutes, more preferably 0.5 to 10 g / 10 minutes, and more preferably 1 to 5 g / 10 minutes. Is more preferable.

<Stretched polypropylene film>
The stretched polypropylene film of the present invention may be composed of a film stretched in at least one direction, or the stretched polypropylene film itself may be stretched in at least one direction. Moreover, when obtaining a biaxially stretched film as a stretched polypropylene film, it can also be easily manufactured by, for example, sequential or simultaneous biaxial stretching. When a biaxially stretched film is obtained as the stretched polypropylene film of the present invention, it is usually stretched 5 to 8 times in the longitudinal direction, and then stretched 8 to 10 times in the transverse direction using a tenter mechanism, and the thickness of the film Is finally made 20 to 40 μm or stretched 5 to 10 times (25 to 100 times in terms of surface magnification) in the longitudinal and transverse directions, respectively.

<Ethylene polymer>
Examples of the ethylene polymer include a homopolymer of ethylene, a copolymer of ethylene as a main monomer and at least one α-olefin having 3 to 8 carbon atoms, an ethylene / vinyl acetate copolymer, Saponifications and ionomers are mentioned. Specifically, polyethylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-pentene copolymer, ethylene / 1-hexene copolymer, ethylene / 4-methyl-1-pentene Examples thereof include copolymers of ethylene as a main monomer, such as a copolymer and an ethylene / 1-octene copolymer, and at least one kind of an α-olefin having 3 to 8 carbon atoms. The proportion of α-olefin in these copolymers is preferably 1 to 15 mol%.

  Examples of the ethylene polymer include ethylene polymers manufactured and sold under the name of polyethylene. Specifically, high pressure method low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE) are preferable, and LLDPE is more preferable. LLDPE is a copolymer of ethylene and a small amount of propylene, butene-1, heptene-1, hexene-1, octene-1, 4-methyl-pentene-1, and the like. The ethylene polymer may be an ethylene homopolymer or a polymer mainly composed of ethylene such as LLDPE.

Density of the ethylene polymer is preferably ^{0.910~0.940g / cm 3, 0.920~0.930g / cm} 3 is more preferable. When the density is 0.910 g / cm ³ or more, heat sealability is improved. Moreover, when the density is 0.940 g / cm ³ or less, workability and transparency are improved.

  The blend and / or laminate may be a blend and / or laminate of any of the above polymers, and any of the above polymers and a material other than the polymer. Blends and / or laminates. That is, the polymer film is a material other than a polymer, such as a heat stabilizer (antioxidant), a weather stabilizer, an ultraviolet absorber, a lubricant, a slip agent, a nucleating agent, an antiblocking agent, an antistatic agent, an antifogging agent. In addition to pigments and dyes, various fillers such as talc, silica, and diatomaceous earth may be included, or a laminate of a polymer film and metal foil, paper, nonwoven fabric, or the like may be used.

<Polyethylene film>
The polyethylene film suitably used in the present invention is a film containing the ethylene polymer. Various known molding methods can be used for the polyethylene film of the present invention, but cast molding by extrusion using an extruder is preferred from the viewpoint of production efficiency.

  When the polymer film constituting the packaging bag of the present invention is a polyethylene film, the polyethylene (ethylene polymer) is directed from the surface in contact with the contents (usually the inner surface of the packaging bag) in the thickness direction. ) Is preferably increased. That is, in a polymer film containing an ethylene polymer, the resin density of the ethylene polymer increases from the surface in contact with the content to the surface opposite to the surface in contact with the content. preferable. By having such a resin density gradient, the specific compound existing in the polymer film tends to bleed out to the surface side in contact with the contents, and the content of the specific compound in the polymer film is reduced. In addition, the amount of the specific compound present on the surface in contact with the contents can be within the scope of the present invention, and high antibacterial properties are obtained. The density of the ethylene-based polymer may increase continuously in the thickness direction or may increase stepwise. For example, when the polymer-supported film is composed of three layers, the density of the ethylene polymer contained in the intermediate layer and the back layer is preferably higher than the density of the ethylene polymer contained in the surface layer. Moreover, the density of the ethylene polymer contained in the back surface layer may be higher than the density of the ethylene polymer contained in the surface layer and the intermediate layer. Moreover, the density of the ethylene-type polymer contained in the order of a surface layer, an intermediate | middle layer, and a back surface layer may become high. Further, it is preferable that at least the density of the ethylene polymer contained in the intermediate layer is higher than the density of the ethylene polymer contained in the surface layer.

<Stretched film>
Polyamide film made of nylon 6, nylon 66, etc., film made of polyester represented by polyethylene terephthalate, polyethylene naphthalate, polycarbonate film, ethylene / vinyl alcohol copolymer film, polyvinyl alcohol film, polyvinyl chloride film, polyvinylidene chloride Films, polystyrene films, polyolefins such as polypropylene, and poly-L lactic acid, poly-D lactic acid, or uniaxial or biaxially stretched films composed of stereocomplex crystal polylactic acid in which poly-L lactic acid and poly-D lactic acid are coordinated precisely.

<Laminated body of stretched film and polyethylene film>
The laminate of the stretched film and the polyethylene film of the present invention is obtained by laminating the polyethylene film layer and the stretched film layer. The polyethylene film may be stretched in one or two directions, but is preferably an unstretched film from the viewpoint of the stability of the mechanical strength of the packaging bag.
Dry lamination is performed by adhering a stretched film and a polyethylene film prepared in advance with an adhesive. From the viewpoint of adhesion stability, the surface of the stretched film to which the adhesive is applied should be corona treated. preferable. Specifically, the surface tension of the film surface after the corona treatment is preferably 35 mN / m or more, more preferably 40 mN / m or more, from the viewpoint of adhesion stability.

  These polymer films may be stretched or printed and coated with inorganic antibacterial agents such as silver and copper and organic antibacterial agents such as chitin, chitosan and allylisothiocyanate. These may be used, or these may be kneaded in the film.

From the viewpoints of transparency, flexibility, cost, etc., it is particularly preferable to use a stretched polypropylene film or a laminate of a stretched polypropylene film and a polyethylene film that has been widely used in the art as a polymer film. . Since these films are generally excellent in heat sealability, productivity is good in the production of packaging bags.
In this case, when the stretched propylene film is used alone, the thickness is preferably 10 to 100 μm, and when the laminate of the stretched polypropylene film and the polyethylene film is used, the former thickness is 10 to 50 μm. The latter thickness is preferably 10 to 120 μm.

  When a polymer film that is not necessarily suitable for heat sealing is used, it may be formed by laminating or coating a sealant layer on all or part of the polymer film. Examples thereof include a cellophane film coated with an acrylic resin and a film obtained by laminating polyethylene terephthalate (PET) with linear low density polyethylene (LLDPE) polystyrene and EVA, and these can be used as suitable polymer films.

The packaging bag of the present invention has a specific range of oxygen permeability, and thereby can control the oxygen concentration in the packaging bag and suppress the propagation of various germs, etc. It is preferably used for maintaining the freshness of the contained contents, particularly for maintaining the freshness of fruits and vegetables.
In this embodiment, the fruits and vegetables stored in the packaging bag and kept fresh are not particularly limited, for example, fruits such as banana, mango, ume, apple, strawberry, mandarin, grape, Japanese pear, pear, radish, Root vegetables such as carrot, Chinese yam, burdock, tomato, cucumber, eggplant, peppers, green beans, fruit vegetables such as okra, green beans sprout, soy bean sprout, sprout such as cypress, shiitake, shimeji, eringi, maitake, Examples include fungi (mushrooms) such as matsutake, broccoli, spinach, komatsuna, ginger rhinoceros, cabbage, lettuce, leafy vegetables such as asparagus, chrysanthemum, lilies, carnations and seedlings.

In this embodiment, there is no particular limitation on the form of the fruits and vegetables stored in the packaging bag and kept fresh, but the freshness is controlled by controlling the oxygen concentration and thereby controlling the respiration of fruits and vegetables while suppressing the propagation of germs and the like. From the action of the present embodiment of maintaining the water content, it is particularly effective for maintaining the freshness of the fruits and vegetables in the form of containing a lot of water and substantially breathing.
Therefore, the fruits and vegetables may be as-harvested, so-called pre-treated after removing outer leaves or the like, or so-called cut vegetables that have been cut. In addition, the fruits and vegetables may be those that have been subjected to any or all of the treatments such as washing, cooling, and dehydration, and may be those that do not perform any of these treatments.

  The demand for cut vegetables has increased in recent years because it can be easily used for meals, and has high economic value. On the other hand, when vegetables are cut, the respiratory action and metabolic reaction are rapidly activated, and the quality tends to decrease rapidly. Moreover, since it has a comparatively wide cut surface, it is easily affected by bacteria and spoilage. Furthermore, when organic components and the like are eluted from the cut surface during condensation, remarkable breeding of germs and the like using this as a nutrient often occurs. Since this embodiment can be used effectively for maintaining the freshness of such cut vegetables, it has a particularly high economic value.

  Depending on the type and form of fruits and vegetables, the preferred oxygen concentration for maintaining freshness varies to some extent, and accordingly, the preferred oxygen permeability, as well as the preferred size (length) of the notch in the heat seal part that gives such oxygen permeability, Although the shape and the number are different, by setting these appropriately, the freshness can be effectively maintained by the packaging bag within the scope of the present invention for any of the above fruits and vegetables.

By storing the fruits and vegetables in the packaging bag of the present invention, it is possible to produce a package for maintaining the freshness of fruits and vegetables that is one embodiment of the present invention.
Hereinafter, the manufacturing method of the packaging body for fruit and vegetable freshness maintenance of this embodiment is demonstrated to the example of the packaging body for freshness maintenance of cut vegetables.

  First, in the pretreatment process, the outer leaves are manually removed, divided into 2 to 4 parts, and the vegetables removed from the core are supplied to the conveyor. Vegetables transported by the conveyor are cut by a slicer, washed in a washing tank filled with cold water and also cooled, and then drained by a centrifugal dehydrator or the like after draining. The dehydrated cut vegetables are rolled into a cylindrical shape by rounding the polymer film, and one end surface of the cylindrical film is heat-sealed and filled into a cylindrical bag. Subsequently, the cylindrical bag is heat-sealed and cut at two places above and below the place where the vegetables are filled with a seal bar with a cutter, and a package for maintaining the freshness of the cut vegetables is manufactured. At the time of heat sealing at the two upper and lower positions, a notch is formed in the heat seal portion by, for example, a groove provided in the seal bar.

From the viewpoint of maintaining the freshness of the cut vegetables, it is preferable to use a sharp blade and reduce the number of scratches on the cut surface.
In addition, as the cut width is narrower, the cutting area increases and it becomes more difficult to maintain freshness. From the viewpoint of maintaining freshness, it is preferable that the cut width is wider as long as it matches the form of demand.
Furthermore, since it is more difficult to maintain freshness when a lot of bacteria are attached to the cut vegetables from the beginning, it is preferable to reduce the adhesion of bacteria as much as possible by washing the cut vegetables well. Washing is particularly effective for maintaining freshness because it not only reduces the adhesion of various bacteria, but also has the effect of removing cell fluids and the like that contain highly active enzymes and the like and can cause discoloration.
In addition, it is important for maintaining the freshness to sufficiently remove moisture adhering to the cut vegetable surface after washing. Even if the water is drained by standing after washing, it is often effective to remove water using a centrifugal dehydrator or the like because much water is still attached to the cut vegetable surface.

In addition, you may deaerate the package for fruit and vegetable freshness preservation | save of this embodiment after storage of fruit and vegetables and sealing of a packaging bag. By performing deaeration, it becomes possible to quickly reach a desired oxygen concentration designed as an equilibrium state between the oxygen permeability of the packaging bag and the respiration rate of the fruits and vegetables, which is advantageous in maintaining freshness.
Moreover, it is preferable to deaerate after sealing a packaging bag also from a viewpoint of the efficiency improvement in the process of distribution, space saving, exclusion of specific gas, etc.
In particular, in the case where an opening having a slit-like cross-sectional shape is provided in the polymer film constituting the packaging bag of the present invention, a relatively simple means such as applying mechanical pressure can be used for the central portion of the slit. The gas permeability can be remarkably increased by widening the width, which makes it possible to deaerate the package relatively easily and in a short time.

In the packaging body for maintaining freshness of fruits and vegetables of the present embodiment, only fruits and vegetables may be accommodated in the packaging bag of the present invention, or other members may be accommodated.
For example, in addition to fruits and vegetables, a hygroscopic agent and / or an antibacterial agent may be stored in the packaging bag.
There is no limitation in particular in a moisture absorbent, The well-known or commercially available material which has a moisture absorption effect or a humidity control effect can be used. Suitable examples of the hygroscopic agent include activated carbon, silica gel, alumina gel, silica alumina gel, anhydrous magnesium sulfate, zeolite, synthetic zeolite, calcium oxide, calcium chloride, and calcined alum, or a mixture thereof. For example, but not limited to.
Among these, it is particularly preferable to use activated carbon which has relatively little concern about the influence on fruits and vegetables and the use of fruits and vegetables near foods. The activated carbon can be either powdered or granular, and the raw material can be anything from coconut husk, sawdust, charcoal, bamboo charcoal, lignite, peat, diamond, and petroleum pitch. The activated carbon is preferably wrapped in non-woven fabric, cellophane, paper, etc. for each unit used, but the activated carbon itself may be in the form of a fiber. The activated carbon packaging material is preferably a heat-sealable material such as a non-woven fabric made of a synthetic resin. However, any material such as paper or natural fiber can be used as long as it has water vapor permeability and does not spill activated carbon. no problem.

  There is no particular limitation on the antibacterial agent, and a substance having an antibacterial action can be used as appropriate, but a natural antibacterial agent with relatively little concern about the effect on fruits and vegetables and use in the vicinity of fruits and vegetables as foods. It can be preferably used. More specifically, natural antibacterial agents such as chitosan, allyl isothiocyanate, hinokitiol, limonene and the like can be stored in a packaging bag.

Hereinafter, the present invention will be described in more detail with reference to Examples / Comparative Examples.
In the following description, “parts” means “parts by mass” and “%” means “mass%” unless otherwise specified.
It should be noted that the present invention is not limited in any way by the following examples.

(1) Antibacterial test An antibacterial test according to JISZ2801 was performed using Escherichia coli.
However, wiping with alcohol was not performed to keep the surface of the freshness-preserving film.
Put a specified quantity of Escherichia coli in 1/500 normal bouillon medium, drop it onto a 4cm square film surface and sandwich it with PE film. Were collected, and the number of bacteria was measured using a normal agar medium.
That is, since it is difficult to count bacteria one by one under a microscope, colonies were measured and used as the viable cell count CFU (colony forming unit).
Moreover, the sample pinched | interposed between PE films was set as Control, and it compared with the experimental result.
The result showed the average value of n = 3.

(2) Preparation of a freshness-keeping film (1) Propylene polymer (1-1) Intermediate layer Propylene homopolymer: melting point (Tm) = 160 ° C., MFR = 3 g / 10 minutes (manufactured by Prime Polymer Co., Ltd.) Using.
(1-2) Back layer and surface layer Propylene / ethylene random copolymer: Melting point (Tm) = 138 ° C., MFR = 7 g / 10 min (manufactured by Prime Polymer Co., Ltd.) was used.
(3) Fatty acid ester of glycerol Stearyl diethanolamine monostearate: 6%
Stearyl diethanolamine: 1.9%
Stearyl monoglyceride: 2.0%
In each case, the reagents from Riken Vitamin Co., Ltd. (product name Riquemar series) are dissolved in isopropyl alcohol at the above-mentioned predetermined concentrations, and the propylene homopolymer is sprayed, dried, pelletized, and containing fatty acid ester of glycerin. A master batch was obtained so that the amount of the antifogging agent was 10%.
(4) Molding of freshness-preserving film (biaxially stretched film) A fatty acid ester of glycerin is formulated in the intermediate layer as shown in Table 1, and the back layer / intermediate layer / surface layer three-layer film is continuously formed by a biaxial stretcher. The freshness-keeping films A, A2, and B made of a multilayer stretched film were produced.
The stretching temperature of the freshness-keeping film was longitudinal stretching: 100 ° C. and lateral stretching: 180 ° C. The heat setting temperature was 180 ° C. and the setting time was 10 seconds.


As apparent from Table 1, film A2 in which only stearyldiethanolamine was added in the same amount as film A compared to film A compared to film A in which stearyldiethanolamine, stearyldiethanolamine monostearate, and glycerin monoglyceride were mixed in a predetermined amount in the intermediate layer The antibacterial property was remarkably low, and the number of bacteria was larger than 1/100 compared with control. Since film B did not contain any components, it naturally did not have antibacterial properties.
The following freshness-keeping tests were conducted on film A (with antibacterial properties) and film B (without antibacterial properties).

(3) Oxygen permeability First, a bag having an inner size of 220 mm × 240 mm was formed by the following method.
One film is folded almost equally into two, approximately 5 mm wide, and heat sealing is performed with an impulse sealer (manufactured by Fuji Impulse Co., product number Fi-200-10WK) with the heating condition scale set to 3, and the heat sealing is performed. Heat seal the whole of the side that is almost perpendicular to the heat seal side so that the side is almost in the center, and the whole part except for the end of about 2 cm that is one communicating part of the other side. A 240 mm bag was formed.
Next, nitrogen gas was injected from the communication portion, and after the bag was saturated, almost all the gas in the bag was discharged from the communication portion. After repeating this operation five times, nitrogen gas was injected to saturate the inside of the bag with nitrogen gas, and the communicating portion was heat sealed with the impulse sealer under the same conditions. The bag saturated with nitrogen gas was left in a room at 22 ° C. and 40% relative humidity in air (1 atm, oxygen concentration: 21%, nitrogen concentration: 79%) for 6 hours.
Next, about 20 cc of the gas in the bag was sampled with a sampling needle tube, and the oxygen concentration in the bag was measured with a food packaging zirconia oxygen concentration meter (model number LC-750F, manufactured by Toray Engineering Co., Ltd.). Furthermore, the volume of the gas in the bag was measured, and the oxygen permeability was calculated from the following formula.
(Expression) Oxygen permeability = change in internal oxygen concentration (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (1232 cm ² ) /0.21 (partial pressure of oxygen )

(4) Abundance of specific compound The surface of the polymer film is washed with dichloromethane, and the washing solution is collected, concentrated and fixed, then silylated, and gas chromatograph mass spectrometry (GC / MS) is used. Quantified.
(5) Odor test and test method When the package was opened, the face was brought close to it and the inner odor was smelled, and sensory evaluation was performed at n = 3.
・ Evaluation criteria Judgment criteria are as follows.
5: Does not smell.
4: Smell a little 3: Smell 2: Smell very smell 1: Smell very much (6) Bottom leakage / test method A hand was placed on the front of the bottom of the test sample, and the presence or absence of leakage was confirmed by touch.
・ Evaluation criteria ○: Drops do not adhere to the hand, and leakage cannot be confirmed by touch.
×: Drops adhere to the hand and leakage can be confirmed by touch.
(7) Freshness maintenance test Here, a freshness maintenance test was conducted using film A (with antibacterial properties) and film B (without antibacterial properties).
Broccoli and cauliflower were cut into bite sizes (about 5 cm square) and immersed in 250 ppm aqueous hypochlorous acid solution for 10 minutes to sterilize miscellaneous bacteria.
Also, using film A (with antibacterial properties) and film B (without antibacterial properties), FIG. 4 (Example 1), FIG. 5 (Example 2), FIG. 6 (Comparative Example 1), and FIG. 2) Make a bag with a size of 220mm x 240mm and a thickness of 30μm on the seal part with the size shown in Tables 2 and 3, and put 30g of broccoli or cauliflower sterilized as above into each bag. A change with time was confirmed. The experiment was performed at n = 3, and the averages are shown in Table-2 and Table-3.
Since broccoli and cauliflower both have large respiration rates, in Comparative Example 2 (when film B was used), the oxygen concentration was 1.0% or less on the fifth day. As a result, the odor suddenly deteriorated. This is presumed to be due to anaerobic breathing and discharge of substances such as alcohol. In Comparative Example 1 in which a notch was also provided at the bottom, there was leakage of liquid (flocculated water) from the bottom. Furthermore, when the difference between film A (with antibacterial properties) and film B (without antibacterial properties) was compared in each system, film A (with antibacterial properties) tended to suppress odor.

  The packaging bag of the present invention can extremely effectively suppress the propagation of germs and the like, and maintains the freshness of the content that contains a lot of moisture such as fruits and vegetables, especially the content that is susceptible to germs such as cut vegetables. Since the packaging bag is suitable for manufacturing and can be manufactured by a simple and high-yield method, it has high applicability in various fields of industries such as food processing, distribution, and dining out.

Claims (16)

A packaging bag comprising a polymer film, wherein the oxygen permeability at 22 ° C. and 40% RH is 500 to 50000 cc / m ² / day / atm, and has a heat seal part on at least one side thereof, The packaging bag which has a notch in at least one part of a heat seal part. The polymer film constituting the packaging bag is selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerin monolaurate and diglycerin monolaurate on at least a part of the surface located on the inner side of the packaging bag. The packaging bag according to claim 1, wherein at least one compound is present in an amount of 0.002 to 0.5 g / m ² .   The packaging bag according to claim 1 or 2, wherein the polymer film contains 0.001 to 3 mass% of the compound in total.   4. The polymer film according to claim 1, wherein the polymer film contains the compound in a range of 50 to 90% with respect to the total thickness from the inner surface of the packaging bag in the thickness direction. The packaging bag as described in any one of Claims.   The packaging bag according to any one of claims 1 to 4, wherein the polymer film is composed of two or more layers, and the compound is contained only in a layer located on the inner side of the packaging bag.   The packaging bag according to any one of claims 1 to 5, wherein the polymer film contains at least one of myristyl diethanolamine monostearate and stearyl diethanolamine monostearate.   The packaging bag according to any one of claims 1 to 6, wherein a wetting index of at least one surface of the polymer film is 35 dyn or more.   The packaging bag as described in any one of Claim 1 to 7 whose length of the said notch is 1-10 mm.   The packaging bag according to any one of claims 1 to 8, wherein the notch is an unfused portion of the heat seal portion.   The packaging bag according to any one of claims 1 to 8, wherein the notch is a part of the polymer film cut out in the heat seal portion.   The packaging bag according to any one of claims 1 to 10, wherein the polymer film includes a polyethylene film layer.   The packaging bag according to claim 11, wherein the density of the polyethylene film layer increases from the inner surface of the packaging bag in the thickness direction.   The packaging bag according to any one of claims 1 to 10, wherein the polymer film is a stretched polypropylene film or a laminate of a stretched film and a polyethylene film.   The packaging bag according to any one of claims 1 to 13, which is used for maintaining freshness of fruits and vegetables.   A package for maintaining freshness of fruits and vegetables, wherein the fruits and vegetables are stored in the packaging bag according to any one of claims 1 to 14. A method for producing a packaging bag comprising a polymer film, having a heat seal part on at least one side thereof, and having a notch in at least a part of the heat seal part,
a) heat sealing one side of the polymer film to form a cylindrical bag;
b) storing the contents in the cylindrical bag; and c) heat-sealing the cylindrical bag to form a packaging bag,
The said manufacturing method with which the notch of this heat seal part is formed simultaneously with the heat seal in process a) or c).