JP7547785B2 - Antibacterial Films and Packaging Materials - Google Patents

Description

The present invention relates to an antibacterial film and a packaging material formed using the same.

Antibacterial films containing isothiocyanate esters have been proposed to form packaging materials that enable spatial sterilization (see Patent Document 1).

However, the isothiocyanate esters used as antibacterial agents are the same spicy ingredients found in mustard and wasabi, and have a strong, irritating odor. As a result, the irritating odor is felt during film processing and storage, leaving room for improvement in terms of the working environment. In addition, because the isothiocyanates are highly volatile, it is difficult to retain the ingredients, and there is also the problem that their effectiveness is not maintained for long periods of time.

An antibacterial film has been proposed that maintains its effectiveness for a long period of time by incorporating a portion of the isothiocyanate ester in cyclodextrin (see Patent Document 2).

However, only a portion of the isothiocyanate ester is included in the cyclodextrin, and the remainder is simply kneaded into the resin, so there is still an irritating odor that can be felt during film processing, etc., and problems remain in the work environment.

An antibacterial film has been proposed that contains an isothiocyanate ester in a water-soluble film-forming agent, which prevents the isothiocyanate ester from being released under low humidity conditions and maintains its effectiveness for a long period of time (see Patent Document 3).

However, this method of encapsulating in so-called microcapsules requires that the layer in which the capsules are dispersed be thickened due to the large size of the capsules. This leads to increased manufacturing costs and limitations on the applications of the material.

Patent Application No. 1-291552 Patent Application No. 2007-523388 Patent Application No. 2004-546438

In consideration of the above problems, the objective of the present invention is to provide an antibacterial film that suppresses irritating odors during film processing and storage, can maintain antibacterial effects for a long period of time, and has no particular limitations on the film thickness of the layer that contains the antibacterial agent.

In order to solve the above problems, the present invention proposes the following configuration.
[1] An antibacterial film comprising a substrate, an adhesive layer containing an antibacterial agent, and a heat-sealable resin layer having a water vapor transmission rate of 1 to 50 g/ ^m2 ·24h, wherein the antibacterial agent contains two types of agents selected from the group consisting of aldehydes or alcohols having a molecular weight of 200 or less, and the antibacterial agent is encapsulated in cyclodextrin.
[2] The antibacterial film according to [1], characterized in that the antibacterial agent is one agent selected from cinnamaldehyde, citral, carvacrol, and eugenol, and one agent selected from hexanal, trans-2-hexenal, and 2-nonanol.
[3] The antibacterial film according to either [1] or [2], wherein the cyclodextrin is γ-cyclodextrin.
[4] The antibacterial film described in any one of [1] to [3], characterized in that the water vapor permeability of the heat-sealable resin layer is 10 to 40 g / m ² · 24 h.
[5] A packaging material comprising the antibacterial film according to any one of [1] to [4].

By adopting the above-mentioned configuration, the antibacterial film and packaging material according to the present invention can suppress irritating odors during film processing and storage, and can maintain the antibacterial effect for a long period of time.
This is because the inclusion of the cyclodextrin clathrate of the antibacterial agent in the film makes it possible to reduce the volatility of the antibacterial agent under low humidity conditions, and furthermore, the use of two types of agents makes it possible to volatilize the antibacterial agent in stages as the moisture content increases. In addition, since the outer diameter of cyclodextrin is about 1.3 nm, which is less than 1/1000 of the microcapsule, it is possible to prepare the antibacterial film of the present invention without any particular restrictions on the film thickness of the layer containing the antibacterial agent.

1 is a schematic cross-sectional view showing a layer structure of an antibacterial film according to the present invention.

(First embodiment: antibacterial film)
The antibacterial film of the first embodiment of the present invention comprises a substrate, an adhesive layer, and a heat-sealable resin layer, and the adhesive layer contains two types of antibacterial agents selected from the group consisting of aldehyde or alcohol compounds having a molecular weight of 200 or less, and the antibacterial agents are encapsulated in cyclodextrin.

Figure 1 shows a schematic cross-sectional view of the layer structure of the antibacterial film of this embodiment. The antibacterial film in Figure 1 is composed of a substrate 10, an adhesive layer 20, and a heat-sealable resin layer 30 laminated together.

(Substrate)
The substrate 10 is desirably a substrate that can be formed into a film having sufficient mechanical strength and heat resistance to be used as a packaging material.
In addition, it is preferable that the substrate 10 is made of a material with low water vapor permeability in order to prevent the antibacterial component contained in the film from escaping to the outside of the package.

Non-limiting examples of materials for forming the substrate 10 include synthetic resins selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), and polyamides (PA), such as nylon (registered trademark).

The substrate 10 may be a single layer, or may have a laminated structure of multiple layers.
The substrate 10 preferably has a thickness of 10 μm to 50 μm. By having the substrate 10 have a thickness within this range, good processability and handling properties can be obtained.

If necessary, the substrate 10 may contain any additives known in the art, such as plasticizers, antioxidants, colorants, fillers, UV absorbers, antistatic agents, antiblocking agents, flame retardants, thickeners, etc.

(Adhesive Layer)
The adhesive layer 20 contains an antibacterial agent and an adhesive. The adhesive layer 20 has a function of storing and releasing the antibacterial agent, and a function of bonding the substrate 10 and the heat-sealable resin layer 30. Non-limiting examples of adhesives that can be used include polyester-based adhesives, polyurethane-based adhesives, polyether-based adhesives, acrylic-based adhesives, epoxy-based adhesives, ethylene-vinyl acetate-based adhesives, vinyl chloride-based adhesives, silicone-based adhesives, and rubber-based adhesives.

The adhesive layer 20 contains two types of antibacterial agents. The antibacterial agents contained in the adhesive layer 20 are aldehyde or alcohol compounds having a molecular weight of 200 or less, preferably 60 or more and 200 or less, and more preferably 90 or more and 200 or less.
If the molecular weight is 200 or more, the volatility of the antibacterial agent is low, and therefore favorable spatial antibacterial properties cannot be obtained. Non-limiting examples of aldehyde or alcohol compounds that can be used include trans-2-hexenal (molecular weight 98.14), hexanal (molecular weight 100.16), benzaldehyde (molecular weight 106.12), octanal (molecular weight 128.21), cinnamaldehyde (molecular weight 132.16), anisaldehyde (molecular weight 136.15), piperonal (molecular weight 150.13), perillaldehyde (molecular weight 150.22), vanillin (molecular weight 152.15), citral ( 3,7-dimethyl-2,6-octadienal) (molecular weight 152.23), citronellal (molecular weight 154.25), decanal (molecular weight 156.27), hydroxycitronellal (molecular weight 172.26), 2-nonanol (molecular weight 144.26), eugenol (molecular weight 164.20), carvacrol (molecular weight 150.22), linalool (molecular weight 154.25), 2-phenylethanol (molecular weight 122.16), and 2-phenoxyethanol (molecular weight 138.17).
More preferably, one agent selected from cinnamaldehyde, citral, carvacrol, and eugenol is combined with one agent selected from hexanal, trans-2-hexenal, and 2-nonanol.

The two types of antibacterial agents contained in the adhesive layer 20 are both encapsulated in cyclodextrin. Cyclodextrin is a cyclic oligosaccharide made of glucose, and by encapsulating a compound in the cavity within the ring, it is possible to reduce odor during processing with the antibacterial agent and maintain the antibacterial effect for a long period of time. In particular, the inside of the cyclodextrin ring is hydrophobic, making it easy to encapsulate hydrophobic compounds.

Cyclodextrins include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, and the inner diameters of their cavities are 0.5-0.6 nm, 0.7-0.8 nm, and 0.9-1.0 nm, respectively. The structures and sizes of compounds that are easily encapsulated vary depending on the inner diameter of the cavity, so by using these in different ways, it is possible to encapsulate a variety of compounds. Cyclodextrins also have the function of sustained release of encapsulated compounds. This sustained release function changes depending on the size of the compound encapsulated with cyclodextrin and the amount of water in the space.

In the present invention, it is preferable to encapsulate an antibacterial agent in γ-cyclodextrin. γ-cyclodextrin exhibits high sustained release ability for the above-mentioned cinnamaldehyde, citral, carvacrol, and eugenol under high humidity conditions, and can exhibit spatial antibacterial properties, but has low sustained release ability under low humidity conditions and does not exhibit spatial antibacterial properties. Furthermore, γ-cyclodextrin exhibits high sustained release ability for the above-mentioned hexanal, trans-2-hexenal, and 2-nonanol under low to medium humidity conditions, and can therefore exhibit spatial antibacterial properties even under low to medium humidity conditions.

Therefore, by combining and encapsulating antibacterial drugs with different sustained release abilities in γ-cyclodextrin, it is possible to shift the timing of release of the antibacterial drug depending on the moisture content (two-stage sustained release), making it possible to maintain the effect for a longer period of time.

On the other hand, α- and β-cyclodextrins are more likely to release the seven antibacterial drugs mentioned above under low humidity conditions than γ-cyclodextrins, and have inferior antibacterial durability. The difference in the release ability of antibacterial drugs in various cyclodextrins is presumed to be due to the inner diameter of the cyclodextrin and the molecular size and bulkiness of the molecular structure of the antibacterial drug.
The larger the inner diameter of the cavity of cyclodextrin, the larger the three-dimensional structure that is easy to include. Therefore, it can be predicted that γ-cyclodextrin will easily take in compounds that have bulky hydrophobic sites such as branched alkyl chains and benzene rings, but will not easily release them. In addition, since the size of cyclodextrin is on the order of nanometers, there is no restriction on the film thickness of the adhesive layer 20 as in the case of microcapsules.

The adhesive layer 20 preferably has a thickness of 1 μm to 10 μm. By having a thickness within this range, the adhesive strength between the substrate 10 and the heat-sealed resin layer 30 (hereinafter sometimes referred to as "lamination strength") can be made sufficiently high, and peeling (delamination) of the substrate 10 and/or the heat-sealed resin layer 30 during use or distribution can be prevented. At the same time, the processability when forming the adhesive layer 20 is improved.

More preferably, the adhesive layer 20 has a thickness of 2 μm to 7 μm. By having a thickness within this range, the laminate strength can be further increased, and it is possible to shorten the drying time when forming the adhesive layer 20 and prevent insufficient drying. If necessary, the adhesive layer 20 may contain any additive known in the art, such as a colorant, a filler, an ultraviolet absorber, or a thickener.

(Heat-sealing resin layer)
It is desirable that the thermal adhesive resin layer 30 exhibits excellent adhesion to the adherend when heated. The thermal adhesive resin layer 30 may be a self-supporting film or a non-self-supporting layer formed by coating or the like. The thermal adhesive resin layer 30 may be selected according to the required antibacterial effect and the permeation amount of the antibacterial agent to be used.

Non-limiting examples of materials for forming the thermally adhesive resin layer 30 include synthetic resins selected from the group consisting of PE, PP, and ethylene-vinyl acetate copolymer (EVA). The thermally adhesive resin layer 30 may be a single layer or may have a laminated structure of multiple layers.
The thermal adhesive resin layer 30 preferably has a thickness of 10 μm to 100 μm. By having a thickness within the above range, good processability, handling properties, ease of opening, and thermal adhesiveness can be obtained.

If necessary, the heat-sealable resin layer 30 may contain any additive known in the art, such as an adhesion promoter, a plasticizer, an antioxidant, a colorant, a filler, an ultraviolet absorber, an antistatic agent, an antiblocking agent, a flame retardant, a thickener, an antifogging agent, or a slip agent.

(Water vapor transmission rate of heat-sealing layer)
The heat-sealing resin layer 30 has a water vapor transmission rate of 1 to 50 g/ ^m2 ·24 h measured according to JIS Z 0208. If the water vapor transmission rate is less than 1 g/ ^m2 ·24 h, the amount of moisture that permeates is small, making it difficult to gradually release the antibacterial agent. If it is more than 50 g/ ^m2 ·24 h, the antibacterial agent is released too quickly, making it difficult to maintain the effect for a long period of time. The preferred range is 10 to 40 g/ ^m2 ·24 h. By having a water vapor transmission rate within this range, stronger antifungal properties can be maintained for a longer period of time.

The water vapor permeability of the heat-sealing resin layer 30 may be controlled using known techniques. For example, a method may be used in which fine holes are drilled in the base film and the area density (opening ratio) of the holes is controlled, or a method may be used in which the material of the heat-sealing resin layer 30 is changed to a material having the desired water vapor permeability.

In the antibacterial film of this embodiment, the desired spatial antibacterial effect depends on the amount of volatilization of the antibacterial agent. The amount of volatilization of the antibacterial agent can be controlled by the type of antibacterial agent and the content of the cyclodextrin inclusion complex of the antibacterial agent, the material and film thickness of the substrate 10, the type of adhesive contained in the adhesive layer 20, the film thickness of the adhesive layer 20, the material, film thickness and water vapor transmission rate of the heat-sealed resin layer 30, etc.

The antibacterial film of this embodiment can be manufactured by applying a composition containing an adhesive and an antibacterial agent onto a substrate 10 to form an adhesive layer 20, and then forming a heat-sealed resin layer 30 on the adhesive layer 20. There are no particular limitations on the method for forming the heat-sealed resin layer 30, but it can be performed by any technique known in the art, such as extrusion lamination of a heat-sealed resin or dry lamination of a heat-sealed film.

The antibacterial film of this embodiment may also include an additional layer having a desired function on the surface of the substrate 10 opposite the adhesive layer 20, between the substrate 10 and the adhesive layer 20, between the adhesive layer 20 and the heat-sealable resin layer 30, or on the surface of the heat-sealable resin layer 30 opposite the adhesive layer 2. Non-limiting examples of the additional layer include a colored layer, a light-shielding layer, a gas barrier layer, a water vapor permeable layer, a UV absorbing layer, a fragrance-retaining layer, a heat-shielding layer, etc.

(Second embodiment: packaging material)
A packaging material according to a second embodiment of the present invention is characterized in that it contains the antibacterial film according to the first embodiment. Specifically, at least a part of the packaging material is formed from the antibacterial film according to the first embodiment.

Non-limiting examples of the packaging material of this embodiment include bags (MA packaging material, bags with zippers, etc.), lid materials (top materials), sheets, cover films, and interior cardboard.
The bag-shaped packaging material can be formed by bonding the antibacterial film of the first embodiment and a second film by heating the peripheral portions with the heat-sealable resin layer 30 disposed on the inside. The second film can be formed using any material known in the art, such as PE, PET, PEN, PP, or PA, provided that the second film can be bonded by the heated heat-sealable resin layer 30.

Alternatively, the bag-shaped packaging material may be formed by bonding together two sheets of the antibacterial film of the first embodiment by heating the peripheral portions with the heat-sealable resin layer disposed on the inside.
Furthermore, a third film may be interposed around the periphery where the lamination is performed to form a bag with a so-called "gusset". The bag-shaped packaging material may have any shape including a rectangle, a circle, or a triangle. The bag with a zipper is formed by mechanically forming an openable and closable fitting at the opening of the bag-shaped packaging material.

The lid material of this embodiment is adhered to the opening of a container made of various materials such as glass, metal, and polymer by heat fusing the heat-sealable resin layer 30 of the antibacterial film of the first embodiment.

The cover film according to this embodiment is useful for covering an article placed on a support. The cover film is used by heat fusing the heat-sealable resin layer 30 of the antibacterial film of the first embodiment to the support around the article.

The interior cardboard of this embodiment can be formed by bonding cardboard and the base material 10 of the antibacterial film of the first embodiment together so that the heat-sealable resin layer 30 of the antibacterial film becomes the inner surface when the final package is formed. The bonding may be performed using any adhesive known in the art.

Below are examples and comparative examples of the packaging bag of the present invention.

Example 1
First, cinnamaldehyde (molecular weight 132.16) was added as antibacterial agent 1 to a saturated aqueous solution of γ-cyclodextrin, and the mixture was shaken for a while to obtain a precipitate of a γ-cyclodextrin inclusion complex of cinnamaldehyde.
The resulting precipitate was filtered under reduced pressure, washed with acetone, and dried under reduced pressure to obtain a dry powder of a cyclodextrin inclusion complex. Similarly, a dry powder of a γ-cyclodextrin inclusion complex of citronellal (molecular weight 154.25) was obtained as antibacterial drug 2.

Next, a coating composition containing the two types of γ-cyclodextrin inclusion complexes and a urethane adhesive was prepared. The coating composition was applied to a substrate 10 made of PET (E5100 manufactured by Toyobo Co., Ltd.) having a thickness of 12 μm, and dried at a temperature of 80° C. to form an adhesive layer 20.
Finally, a PE film (LL-XMTD manufactured by Futamura Chemical Co., Ltd.) having a thickness of 30 μm was laminated onto the adhesive layer 20 to form a heat-sealable resin layer 30, thereby obtaining an antibacterial film.

The water vapor permeation rate was measured in accordance with JIS Z 0208. The water vapor permeation rate of the gas permeable film of this example was 30 g/m ² ·24 h.

Next, a film was cut out from the obtained antibacterial film and laminated so that the heat-sealable resin layers 30 faced each other to obtain a pouch having an inner dimension of 10 cm x 10 cm. Three cherry tomatoes were placed in the obtained pouch and stored in a thermostatic chamber at 25°C for 10 days.
The condition of mold growth was checked after 3 days and 10 days, and the results were rated as follows: "○" if no mold growth was observed visually, "△" if growth was observed visually on 1/3 or less of the surface area, and "×" if growth was observed visually on an area wider than 1/3 of the surface area. ○ and △ are within the acceptable range.

Furthermore, the odor of the obtained film was evaluated sensorily. If the odor of the antibacterial agent not encapsulated in gamma-cyclodextrin was barely detectable, it was rated as "Good", if the odor of the antibacterial agent was slightly detectable, it was rated as "Good", and if the odor of the antibacterial agent was detectable, it was rated as "Poor". Good and Good were within the acceptable range.

The evaluation results of the resulting packaging bags are shown in Table 1 below.

Example 2
A packaging bag was formed by repeating the procedure of Example 1, except that the antibacterial agent 2 was changed from citronellal to hexanal (molecular weight 100.16). The evaluation results of the obtained packaging bag are shown in Table 1.

Example 3
A packaging bag was formed by repeating the procedure of Example 1, except that the antibacterial agent 2 was changed from citronellal to trans-2-hexenal (molecular weight 98.14). The evaluation results of the obtained packaging bag are shown in Table 1.

Example 4
A packaging bag was formed by repeating the procedure of Example 1, except that the antibacterial agent 2 was changed from citronellal to 2-nonanol (molecular weight 144.26). The evaluation results of the obtained packaging bag are shown in Table 1.

Example 5
A packaging bag was formed by repeating the procedure of Example 2, except that the antibacterial agent 1 was changed from cinnamaldehyde to citral (molecular weight 152.24). The evaluation results of the obtained packaging bag are shown in Table 1.

Example 6
A packaging bag was formed by repeating the procedure of Example 2, except that the antibacterial agent 1 was changed from cinnamaldehyde to carvacrol (molecular weight 150.22). The evaluation results of the obtained packaging bag are shown in Table 1.

(Example 7)
A packaging bag was formed by repeating the procedure of Example 2, except that the antibacterial agent 1 was changed from cinnamaldehyde to eugenol (molecular weight 164.20). The evaluation results of the obtained packaging bag are shown in Table 1.

(Example 8)
A packaging bag was formed by repeating the procedure of Example 2, except that the cyclodextrin to be included was changed from γ-cyclodextrin to α-cyclodextrin. The evaluation results of the obtained packaging bag are shown in Table 1.

Example 9
A packaging bag was formed by repeating the procedure of Example 2, except that the cyclodextrin to be included was changed from γ-cyclodextrin to β-cyclodextrin. The evaluation results of the obtained packaging bag are shown in Table 1.

Example 10
A packaging bag was formed by repeating the procedure of Example 2, except that the water vapor transmission rate of the heat-sealable resin layer 30 was changed to 1 g/ ^m2 ·24 h. The evaluation results of the obtained packaging bag are shown in Table 1.

(Example 11)
A packaging bag was formed by repeating the procedure of Example 2, except that the water vapor transmission rate of the heat-sealable resin layer 30 was changed to 10 g/m ² ·24 h. The evaluation results of the obtained packaging bag are shown in Table 1.

Example 12
A packaging bag was formed by repeating the procedure of Example 2, except that the water vapor transmission rate of the heat-sealable resin layer 30 was changed to 40 g/m ² ·24 h. The evaluation results of the obtained packaging bag are shown in Table 1.

(Example 13)
A packaging bag was formed by repeating the procedure of Example 2, except that the water vapor transmission rate of the heat-sealable resin layer 30 was changed to 50 g/m ² ·24 h. The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 1)
A packaging bag was formed by repeating the procedure of Example 1, except that the antibacterial agent 2 was changed from citronellal to hexylcinnamaldehyde (molecular weight 216.32). The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 2)
A packaging bag was formed by repeating the procedure of Example 2, except that the antibacterial agents 1 and 2 were not encapsulated with γ-cyclodextrin. The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 3)
A packaging bag was formed by repeating the procedure of Example 2, except that the antibacterial drug 2, hexanal, was not included in γ-cyclodextrin. The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 4)
A packaging bag was formed by repeating the procedure of Example 2, except that the cinnamaldehyde of the antibacterial drug 1 was not encapsulated with γ-cyclodextrin. The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 5)
A packaging bag was formed by repeating the procedure of Example 2, except that the antibacterial agent was changed to only one type, hexanal. The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 6)
A packaging bag was formed by repeating the procedure of Example 2, except that the water vapor transmission rate of the heat-sealable resin layer 30 was changed to 0.5 g/ ^m2 ·24 h. The evaluation results of the obtained packaging bag are shown in Table 1.

(Comparative Example 7)
A packaging bag was formed by repeating the procedure of Example 2, except that the water vapor transmission rate of the heat-sealable resin layer 30 was changed to 60 g/m ² ·24 h. The evaluation results of the obtained packaging bag are shown in Table 1.

As can be seen from Table 1, in Example 1, antifungal properties were obtained using an antibacterial agent having a molecular weight of 200 or less, and the odor was also good. In Examples 2 to 7, all of the evaluations were good.
In Examples 8 and 9, when α- or β-cyclodextrin was used, antifungal properties were obtained that were not as long-lasting as those of γ-cyclodextrin, and the odor evaluation was also favorable.
In Example 10, a heat-sealable resin layer with a slightly low water vapor permeability was used, while in Example 13, a slightly high water vapor permeability was used. The moisture content was not optimal for two-stage sustained release, but the anti-mold durability was within an acceptable range.
In Examples 11 and 12, the water vapor transmission rate of the heat-sealing layer was set to 10 and 40 g/m ² ·24 h, respectively, and both of them were excellent in terms of antifungal durability evaluation and odor evaluation.

On the other hand, in Comparative Example 1, an aldehyde compound having a molecular weight of more than 200 was used as the antibacterial agent, which volatilized, and too little of the antibacterial agent penetrated the heat-sealable resin layer, resulting in no sustained antifungal effect.
From Comparative Examples 2 to 4, when one or two of the antibacterial agents were not encapsulated in γ-cyclodextrin, the antibacterial agents did not have a sustained release property, and long-term antifungal properties were not obtained. In addition, the volatility was too high, resulting in a strong odor.
In Comparative Example 5, when only one kind of agent was used, two-stage sustained release was not obtained, and antifungal durability was not obtained. In Comparative Examples 6 and 7, when the water vapor transmission rate was too small, the antibacterial agent was not sustainedly released, and antifungal properties were not obtained, and when the water vapor transmission rate was too large, the antibacterial agent was released too quickly, and the evaluation of the sustained antifungal property and the evaluation of the odor were not satisfactory.
The invention as originally claimed is set forth below.
[1]
An antibacterial film comprising a substrate, an adhesive layer containing an antibacterial agent, and a heat-sealable resin layer having a water vapor transmission rate of 1 to 50 g/m2 ^· 24 h,
The antibacterial film is characterized in that the antibacterial agent contains two types of agents selected from the group consisting of aldehydes and alcohols having a molecular weight of 200 or less, and the antibacterial agent is encapsulated in cyclodextrin.
[2]
Item 2. The antibacterial film according to item 1, wherein the antibacterial agent is one selected from the group consisting of cinnamaldehyde, citral, carvacrol, and eugenol, and one selected from the group consisting of hexanal, trans-2-hexenal, and 2-nonanol.
[3]
3. The antibacterial film according to claim 1, wherein the cyclodextrin is γ-cyclodextrin.
[4]
4. The antibacterial film according to any one of items 1 to 3, wherein the heat-sealable resin layer has a water vapor permeability of 10 to 40 g/m2 ^· 24 h.
[5]
Item 5. A packaging material comprising the antibacterial film according to any one of Items 1 to 4.

10 Base material 20 Adhesive layer 30 Heat fusion resin layer

Claims (4)

An antibacterial film comprising a substrate, an adhesive layer containing an antibacterial agent, and a heat-sealable resin layer having a water vapor transmission rate of 1 to 50 g/ ^m2 ·24 h,
the antibacterial agent contains two types of agents selected from the group consisting of aldehydes and alcohols having a molecular weight of 200 or less, and the antibacterial agent is included in cyclodextrin;
The antibacterial film is characterized in that the antibacterial agent is one agent selected from cinnamaldehyde, citral, carvacrol, and eugenol, and one agent selected from hexanal, trans-2-hexenal, and 2-nonanol (however, excluding antibacterial films containing citral, hexanal, and linalool as the antibacterial agent) . The antibacterial film according to claim 1, characterized in that the cyclodextrin is γ-cyclodextrin. 3. The antibacterial film according to claim 1, wherein the heat-sealable resin layer has a water vapor permeability of 10 to 40 g/ ^m2 ·24 h. A packaging material comprising the antibacterial film according to any one of claims 1 to 3.

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