Resin film, packaging material, building material, method for producing resin film, method for imparting antimicrobial activity, method for recycling resin film, and adhesive

Abstract

To provide a resin film capable of easily adjusting the concentration of a chemical agent on the surface.SOLUTION: A resin film includes a hydrophilic resin layer that is drug-permeable and hydrophilic and a drug layer, in which the hydrophilic resin layer is hydrophilic, a drug that is an organic acid having 1 to 10 carbon atoms permeates the resin layer, the drug is present on a first surface of the hydrophilic resin layer, the drug layer is provided on a second surface of the hydrophilic resin layer, and the drug layer contains the drug and any one or both of agar and gelatin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin film, a packaging material, a building material, a method for producing a resin film, a method for imparting antimicrobial activity, a method for recycling a resin film, and a pressure-sensitive adhesive. [Background technology]

[0002] Resin films having antimicrobial activity, such as antibacterial activity, are used, for example, in food packaging films and the like. Food waste has become a major social issue in recent years. It is expected that food waste can be reduced if food packaging films with antimicrobial activity can be used to extend the shelf life of food.

[0003] Known examples of resin films with antimicrobial activity include laminated resin films in which an antibacterial layer is formed on one side of a substrate layer (Patent Documents 1 and 2). Such resin films are typically obtained by applying a solution containing an agent with antibacterial effect to one side of the substrate layer and drying it to form an antibacterial layer on one side of the substrate. In the resin film obtained in this manner, the side on the antibacterial layer side is the front side of the resin film, and the side on the substrate layer side is the back side of the resin film, and the front side of the resin film has antimicrobial activity.

[0004] On the other hand, in order to slowly release volatile fragrances, a film has been proposed that consists of a drug-containing film that contains a volatile drug and a sustained-release layer that suppresses gas permeation by adding a filler (Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2008-545761 [Patent Document 2] US Patent Application Publication No. 2005 / 0129937 [Patent Document 3] Japanese Patent Application Publication No. 2019-069581 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the case of the resin films described in Patent Documents 1 and 2, the concentration of the agent in the antibacterial layer is determined during the manufacturing process of the resin film, i.e., when a solution containing the agent is applied to one side of the base layer. Therefore, if the concentration of the agent in the antibacterial layer is low, the antibacterial effect cannot be maintained for a long period of time. In order to maintain the antibacterial effect, the concentration of the agent in the antibacterial layer can be increased, but since the antibacterial layer is easily touched by human hands, depending on the type of agent, it may be irritating to the skin. As such, it has been difficult to adjust the concentration of the agent on the surface of the resin film. Furthermore, the film described in Patent Document 3 is intended to slowly release synthetic fragrances, and has not been investigated as a resin film having antimicrobial activity.

[0007] The present invention aims to provide a resin film that allows for easy adjustment of the concentration of a chemical on its surface, a packaging material and a building material that use the same, a method for manufacturing a resin film, a method for imparting antimicrobial activity, a method for recycling a resin film, and a pressure-sensitive adhesive. [Means for solving the problem]

[0008] The present invention includes the following aspects. [1] A resin film having a hydrophilic resin layer that is drug-permeable and hydrophilic and a drug layer, a drug which is an organic acid having 1 to 10 carbon atoms permeates the hydrophilic resin layer and is present on the first surface of the hydrophilic resin layer; the drug layer is provided on a second surface of the hydrophilic resin layer; The drug layer is a resin film containing the drug and either or both of agar and gelatin. [2] The resin film according to [1], wherein the hydrophilic resin layer contains at least one resin selected from the group consisting of polyamide, cellulose resin, and polyurethane. [3] The resin film according to [2], wherein the hydrophilic resin layer contains polyamide, and the polyamide contains either or both of nylon 6 and nylon 66. [4] The resin film according to any one of [1] to [3], wherein the thickness of the hydrophilic resin layer is 10 μm or more. [5] The resin film according to any one of [1] to [4], wherein a resin layer is provided on the drug layer on the side opposite to the hydrophilic resin layer. [6] A packaging material comprising the resin film according to any one of [1] to [5]. [7] A building material comprising the resin film according to any one of [1] to [5]. [8] A method for producing a resin film according to any one of [1] to [5], A method for producing a resin film, comprising contacting a composition containing the drug and either or both of agar and gelatin with the second surface of the hydrophilic resin layer for 5 seconds or more, thereby allowing at least a portion of the drug to penetrate to the first surface of the hydrophilic resin layer and imparting antimicrobial activity to the first surface of the hydrophilic resin layer. [9] A method for imparting antimicrobial activity, comprising: applying a composition containing a drug, which is an organic acid having 1 to 10 carbon atoms, and either or both of agar and gelatin, to a second surface of a hydrophilic resin layer that is drug-permeable and hydrophilic; and allowing at least a portion of the drug to penetrate to a first surface of the hydrophilic resin layer, thereby imparting antimicrobial activity to the first surface of the hydrophilic resin layer.

[10] A method for recycling a resin film, comprising separating the hydrophilic resin layer and the drug layer from the resin film according to any one of [1] to [5] in a solvent, recovering at least one of the separated hydrophilic resin layer and the drug, and using the recovered hydrophilic resin layer to manufacture the resin film.

[11] A method for recycling a resin film according to

[10] , comprising recovering the drug separated in water together with a solvent, concentrating the recovered mixture of the drug and solvent, contacting the concentrate with the second surface of the hydrophilic resin layer for 5 seconds or more, and allowing at least a portion of the recovered drug to penetrate to the first surface of the hydrophilic resin layer, thereby imparting antimicrobial activity to the first surface of the hydrophilic resin layer.

[12] An adhesive comprising an organic acid having 1 to 10 carbon atoms and agar. [Effects of the Invention]

[0009] According to the present invention, there are provided a resin film in which the concentration of a drug on the surface can be easily adjusted, a packaging material, a building material, a method for manufacturing a resin film using the same, a method for imparting antimicrobial activity, a method for recycling a resin film, and a pressure-sensitive adhesive. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a resin film according to the present invention. [Figure 2] 1 is a cross-sectional view schematically illustrating an example of a method for producing a resin film according to the present invention. [Figure 3] 1 is a cross-sectional view schematically illustrating an example of a resin film according to the present invention. [Figure 4] 1 is a graph showing the viable cell count (initial value, 24 hours after the start of the test) of each test piece subjected to the antibacterial test in Example 3, with the vertical axis on a common logarithmic scale. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the resin film etc. according to the present invention will be described in detail below with reference to FIG. 1 as appropriate. It should be noted that a numerical range expressed using "~" includes the numerical values ​​on both ends of the "~". In addition, the drawings used in the following explanation may show characteristic parts enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may differ from the actual ones.

[0012] [Resin film] First Embodiment FIG. 1 is a cross-sectional view schematically illustrating an example of a resin film according to the first embodiment. The resin film 10 of the first embodiment includes a hydrophilic resin layer 11 and a drug layer 12 provided on the second surface 11b of the hydrophilic resin layer 11. A drug M is permeated into the hydrophilic resin layer 11, and the drug M is present on the first surface 11a of the hydrophilic resin layer 11. The drug layer 12 contains the drug M and either or both of agar and gelatin. 1, the drug M is merely shown schematically, and the drug M does not necessarily exist in particulate form. The same applies to the other figures.

[0013] In the first embodiment, the first surface 11a of the hydrophilic resin layer 11 is the surface 10a of the resin film 10. The surface 10a of the resin film 10 is the surface that comes into contact with microorganisms. In the first embodiment, the surface of resin film 10 opposite to front surface 10a is referred to as back surface 10b of resin film 10. In the case of the example of resin film 10 shown in FIG. 1, second surface 12b, which is the surface of drug layer 12 opposite to hydrophilic resin layer 11, is back surface 10b of resin film 10. In the first embodiment, first surface 11a of hydrophilic resin layer 11 is also referred to as the front surface of hydrophilic resin layer 11, and second surface 11b of hydrophilic resin layer 11 is also referred to as the back surface of hydrophilic resin layer 11. In addition, first surface 12a, which is the surface of drug layer 12 facing hydrophilic resin layer 11, is also referred to as the front surface of drug layer 12, and second surface 12b of drug layer 12 is also referred to as the back surface of drug layer 12.

[0014] <Drugs> The drug M imparts antimicrobial activity to the first surface 11a of the hydrophilic resin layer 11, that is, the surface 10a of the resin film 10. The drug M is an organic acid having a carbon number of 1 to 10. The drug M may be used alone or in combination of two or more kinds.

[0015] Examples of organic acids having 1 to 10 carbon atoms include oxalic acid, glycolic acid, lactic acid, tartaric acid, succinic acid, fumaric acid, malic acid, orotic acid, citric acid, gluconic acid, salicylic acid, quinic acid, coumaric acid, caffeic acid, ferulic acid, malonic acid, glutaric acid, isophthalic acid, suberic acid, adipic acid, and azelaic acid. Furthermore, as the organic acid having 1 to 10 carbon atoms, a carboxylic acid having 1 to 10 carbon atoms can also be used. Examples of the carboxylic acid having 1 to 8 carbon atoms include formic acid (CHO), acetic acid (CHO), propionic acid (CHO), butyric acid (CHO), isobutyric acid (CHO), and valeric acid (CHO). 10 O2), caproic acid (C6H 12 O2), enanthic acid (C7H 14 O2), caprylic acid (C8H 16 O2) and other fatty acids. The carboxylic acid having 1 to 10 carbon atoms is preferably at least one selected from the group consisting of these exemplified carboxylic acids having 1 to 10 carbon atoms, and more preferably at least one selected from the group consisting of carboxylic acids having 2 to 6 carbon atoms. The organic acids having 1 to 10 carbon atoms may be used alone or in combination of two or more.

[0016] <Hydrophilic resin layer> The hydrophilic resin layer 11 is a film that has drug permeability and hydrophilicity. In the present invention, "drug permeability" refers to the property of a drug attached to the surface or back surface of the hydrophilic resin layer 11 penetrating into the interior of the hydrophilic resin layer 11, and also of a drug that has penetrated into the interior of the hydrophilic resin layer 11 seeping out to the surface or back surface of the hydrophilic resin layer 11. The hydrophilicity of a resin can be expressed, for example, by the water absorption rate measured by the ASTM D570 method. In the present invention, "hydrophilic" means that the water absorption rate of the resin is 0.5 or more. In order to facilitate the permeability of the drug M and the adjustment of the drug M concentration, the water absorption rate of the resin is preferably 0.75 or more, and more preferably 1.0 or more.

[0017] The hydrophilic resin layer 11 is permeated with a drug M. It is preferable that the drug M penetrates from the second surface 11b to the first surface 11a of the hydrophilic resin layer 11. By penetrating the drug M from the second surface 11b to the first surface 11a of the hydrophilic resin layer 11, stickiness of the surface 10a of the resin film 10 caused by the drug M can be suppressed.

[0018] A drug M is present on the first surface 11a of the hydrophilic resin layer 11. The presence of the drug M on the first surface 11a of the hydrophilic resin layer 11 imparts antimicrobial activity to the first surface 11a of the hydrophilic resin layer 11, i.e., the surface 10a of the resin film 10. Moreover, since the drug M has permeated the hydrophilic resin layer 11, even if the drug M present on the first surface 11a of the hydrophilic resin layer 11 is consumed and reduced, at least a portion of the drug M that has permeated the hydrophilic resin layer 11 gradually seeps out to the first surface 11a of the hydrophilic resin layer 11, so that antimicrobial activity can be maintained for a long period of time.

[0019] The antimicrobial activity is preferably at least one selected from the group consisting of antibacterial activity, antifungal activity and antiviral activity. Antibacterial activity is evaluated, for example, according to the test method of JIS Z 2801:2012 (antibacterial processed products - antibacterial test method, antibacterial effect). The antifungal activity is evaluated, for example, by the test method of JIS Z 2911:2018 (fungal resistance test method). Antiviral activity is evaluated, for example, using the test method ISO 21702:2019 (Determination of antiviral activity of plastics and other non-porous surfaces).

[0020] When antibacterial activity is imparted to the first surface 11a of the hydrophilic resin layer 11, it is preferable that the resin film 10 has antibacterial activity against at least one species selected from the group consisting of gram-negative bacteria other than Escherichia coli, such as Salmonella, Enterobacter, Pseudomonas, Moraxella, Helicobacer, Bdellovibrio, Acetobacter, and Legionella. Furthermore, it is preferable that the resin film 10 has antibacterial activity against at least one species selected from the group consisting of gram-positive bacteria other than Staphylococcus aureus, for example, Firmicutes such as Bacillus, Lactobacillus, Clostridium, Thermoanaerobacter, Haloanaerobium, Natraanaerobius, and Erysipelotrichus, and actinomycetes such as Actinomyces, Streptomyces, and Bifidobacterium.

[0021] When antifungal activity is imparted to the first surface 11a of the hydrophilic resin layer 11, it is preferable that the resin film 10 has antifungal activity against at least one species selected from the group consisting of molds and yeasts other than Aspergillus and Cladosporium, such as Penicillium, Trichoderma, Fusarium, Neurospora, Aureobasidium, Saccharomyces, Candida, Cryptococcus, and Schizosaccharomyces.

[0022] When antiviral activity is imparted to the first surface 11a of the hydrophilic resin layer 11, it is preferable that the resin film 10 has antiviral activity against at least one type selected from the group consisting of enveloped viruses, such as varicella-zoster virus, smallpox virus, hepatitis B virus, hepatitis C virus, Japanese encephalitis virus, Zika virus, rubella virus, SARS coronavirus, MERS coronavirus, COVID19 virus, hepatitis D virus, measles virus, human respiratory syncytial virus, rabies virus, Crimean-Congo hemorrhagic fever virus, Ebola virus, Marburg virus, human immunodeficiency virus, influenza A virus (H1N1, H3N2, etc.), and adult T-cell leukemia virus. Furthermore, it is preferable that the resin film 10 has antiviral activity against at least one non-enveloped virus selected from the group consisting of feline calicivirus, adenovirus, human papillomavirus, poliovirus, hepatitis A virus, norovirus, enterovirus, and rotavirus. Furthermore, the resin film 10 preferably has antiviral activity against the new coronavirus.

[0023] The resin constituting the hydrophilic resin layer 11 is not particularly limited as long as it has drug permeability and hydrophilicity, and examples thereof include polyamide, cellulose resin, and polyurethane. The resin constituting the hydrophilic resin layer 11 preferably contains at least one resin selected from the group consisting of polyamide, cellulose resin, and polyurethane, and polyamide is particularly preferred because it is particularly excellent in drug permeability and concentration adjustment. The resins constituting the hydrophilic resin layer 11 may be used singly or in combination of two or more.

[0024] The hydrophilic resin layer 11 may be a single layer film or a laminated film in which a plurality of single layer films are laminated. When the hydrophilic resin layer 11 is a laminated film, the resins constituting the respective single layer films may be the same or different, but it is preferable that at least one single layer film contains polyamide.

[0025] Examples of the polyamide include nylons such as nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, nylon 6T, nylon 9T, nylon M5T, and nylon 612. In view of the excellent tensile strength and burst strength when made into a film, the polyamide preferably contains either or both of nylon 6 and nylon 66, and more preferably contains nylon 6. Examples of the cellulose resin include nitrocellulose and acetylcellulose. Examples of the polyurethane include polyester-based thermoplastic polyurethane, polyether-based thermoplastic polyurethane, and polycarbonate-based thermoplastic polyurethane.

[0026] The thickness of the hydrophilic resin layer 11 is preferably 0.01 μm or more, more preferably 0.1 μm or more, even more preferably 10 μm or more, even more preferably 20 μm or more, particularly preferably 30 μm or more, and most preferably 50 μm or more. The thickness of the hydrophilic resin layer 11 is preferably 5000 μm or less, more preferably 2500 μm or less, even more preferably 1000 μm or less, particularly preferably 500 μm or less, and most preferably 300 μm or less. When the thickness of the hydrophilic resin layer 11 is equal to or greater than the lower limit, damage to the resin film 10 during use tends to be prevented and the sustained release period of the drug M tends to be maintained. When the thickness of the hydrophilic resin layer 11 is equal to or less than the upper limit, the flexibility of the resin film 10 is easily maintained, allowing the resin film 10 to be applied to various locations, such as curved surfaces. Furthermore, the drug M does not reach the surface of the resin layer for too long, which tends to facilitate use. The preferred lower and upper limits of the thickness of the hydrophilic resin layer 11 can be arbitrarily combined, and are, for example, preferably 0.01 to 5000 μm, more preferably 0.1 to 2500 μm, even more preferably 10 to 1000 μm, even more preferably 20 to 1000 μm, particularly preferably 30 to 500 μm, and most preferably 50 to 300 μm.

[0027] <Drug layer> The drug layer 12 is a layer containing the drug M and either or both of agar and gelatin, and is provided on the second surface 11b of the hydrophilic resin layer 11. In the case of the example resin film 10 shown in Figure 1, at least a portion of the drug M contained in the drug layer 12 penetrates from the second surface 11b of the hydrophilic resin layer 11 to the first surface 11a and seeps out onto the first surface 11a.

[0028] Drug layer 12 may contain ingredients other than drug M, agar, and gelatin (hereinafter also referred to as "other ingredients"). Drug layer 12 contains at least one of agar and gelatin, which gives drug layer 12 adhesiveness.

[0029] The other component preferably has affinity and adhesiveness for the hydrophilic resin layer. The other component may migrate to the surface of the hydrophilic resin layer, similar to the drug M, or may remain in the drug layer. Examples of the other components include (meth)acrylic polymers, such as homopolymers of alkyl (meth)acrylates and copolymers obtained by copolymerizing alkyl (meth)acrylates with monomer components copolymerizable therewith. In terms of imparting adhesiveness to drug layer 12, a copolymer obtained by copolymerizing an alkyl(meth)acrylate with at least one monomer component selected from the group consisting of a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, an amide group-containing monomer, and other vinyl monomers copolymerizable therewith is preferred. That is, the copolymer contains alkyl(meth)acrylate units and units derived from a monomer component copolymerizable with alkyl(meth)acrylate, and preferably contains alkyl(meth)acrylate units and units derived from at least one monomer component selected from the group consisting of a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, an amide group-containing monomer, and other vinyl monomers. The other components may be used alone or in combination of two or more.

[0030] The content of drug M in drug layer 12 is not particularly limited, and the content of drug M may be determined within the range that drug layer 12 can contain, depending on the location where resin film 10 is provided.

[0031] The content of drug M in drug layer 12 is preferably 1 ppm by mass or more, more preferably 100 ppm by mass or more, and even more preferably 1% by mass or more, based on the entire drug layer 12. Furthermore, the content of drug M in drug layer 12 is preferably 99% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, based on the entire drug layer 12. If the content of drug M is equal to or greater than the lower limit, sufficient antimicrobial activity is exerted. If the content of drug M is equal to or less than the upper limit, the components do not separate within the drug layer, allowing for uniform adhesion and uniform antimicrobial activity.

[0032] The total content of agar and gelatin in drug layer 12 is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on the total amount of drug layer 12. Furthermore, the total content of agar and gelatin in drug layer 12 is preferably 99% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less, based on the total amount of drug layer 12. If the total content of agar and gelatin is equal to or greater than the lower limit, sufficiently strong adhesion can be achieved. If the total content of agar and gelatin is equal to or less than the upper limit, softness can be maintained without solidifying.

[0033] The thickness of drug layer 12 is preferably 0.005 μm or more, more preferably 0.5 μm or more, even more preferably 5 μm or more, and particularly preferably 50 μm or more. Furthermore, the thickness of drug layer 12 is preferably 50,000 μm or less, more preferably 500 μm or less, and particularly preferably 500 μm or less. If the thickness of drug layer 12 is equal to or greater than the lower limit, the total amount of drug M contained in resin film 10 increases, allowing antimicrobial activity to be maintained for a longer period of time. If the thickness of drug layer 12 is equal to or less than the upper limit, the flexibility of resin film 10 is more easily maintained, allowing resin film 10 to be installed in various locations.

[0034] The hydrophilic resin layer and the drug layer are preferably composed of different resins. This is because the roles played by each layer are different. That is, the hydrophilic resin layer is directly exposed to the external environment, so it is preferable that it has abrasion resistance and water resistance, while the drug layer is preferably composed of a soft resin so as to control the concentration of drug M and not hinder the movement of drug M. From this point of view, a combination is preferred in which the resin constituting the hydrophilic resin layer is polyamide, and the drug layer contains, as other components, a copolymer containing units derived from alkyl (meth)acrylate and units derived from at least one monomer component selected from the group consisting of carboxyl group-containing monomers copolymerizable therewith, amide group-containing monomers, and other vinyl monomers other than these.

[0035] The amount of the drug M present on the surface 10a of the resin film 10 is not particularly limited as long as it is an amount that can exhibit antimicrobial activity. For example, if the drug M is present in an amount that can be identified by a pH test, the drug M can have antimicrobial activity. For example, if the amount of the drug M is 5.5×10 per square centimeter of the resin film surface, -10 Preferably, at least 1.0 x 10 moles of drug M are present, more preferably at least 1.0 x 10 moles. -9 mol or more, more preferably 2.5 × 10 -9 Preferably, more than 1 molar of drug M is present.

[0036] It is preferable that the pH of the surface 10a of the resin film 10 be less than 7 due to the chemical M. The pH of the surface 10a of the resin film 10 is measured as follows. A piece of pH test paper (pH 1-14 test paper) cut to a length of 1.5 cm is placed on the surface 10a of the resin film 10. A drop of water with a pH of 7 is dropped onto the pH test paper, and after 5 minutes, the color change of the pH test paper is visually observed. The color of the pH test paper is compared with the color chart to obtain a pH measurement value.

[0037] <Manufacturing method> The resin film 10 can be obtained, for example, by contacting a composition containing a drug M and either or both of agar and gelatin (hereinafter also referred to as "composition (C)") with the second surface 11b of the hydrophilic resin layer 11 for 5 seconds or more, allowing at least a portion of the drug M to penetrate to the first surface 11a of the hydrophilic resin layer 11, and imparting antimicrobial activity to the first surface 11a of the hydrophilic resin layer 11. 2, for example, the drug M attached to the back surface (i.e., second surface 11b) of the hydrophilic resin layer 11 penetrates into the hydrophilic resin layer 11, and further, the drug M that has penetrated into the hydrophilic resin layer 11 seeps out onto the surface (i.e., first surface 11a) of the hydrophilic resin layer 11. Therefore, even if the composition (C) is not applied from the surface side of the hydrophilic resin layer 11, the drug M is present on the first surface 11a of the hydrophilic resin layer 11, and antimicrobial activity can be exhibited.

[0038] Composition (C) contains Agent M and either or both of agar and gelatin. Composition (C) may contain, instead of drug M, a component from which drug M is derived. The component from which drug M is derived is a component that produces drug M by decomposition or the like. Composition (C) may contain other components, such as those exemplified above in the description of drug layer 12. One type of the other components may be used alone, or two or more types may be used in combination.

[0039] The composition (C) may contain a solvent other than the drug M. Examples of the solvent include water, and organic solvents such as methanol, ethanol, isopropyl alcohol, hexane, heptane, toluene, and xylene. The solvents may be used alone or in combination of two or more.

[0040] The method for contacting the composition (C) with the second surface 11b of the hydrophilic resin layer 11 is not particularly limited, but examples include methods for contacting the composition (C) with the second surface 11b of the hydrophilic resin layer 11 by spray coating, roller coating, flow coating, roller coating, pouring into a mold, etc.

[0041] The contact time when the composition (C) is brought into contact with the second surface 11b of the hydrophilic resin layer 11 is 5 seconds or more, preferably 10 seconds or more, more preferably 1 minute or more, and even more preferably 5 minutes or more. The contact time may be 20 minutes or more, but sufficient antimicrobial activity is usually obtained with 20 minutes of contact.

[0042] The contact temperature when the composition (C) is brought into contact with the second surface 11b of the hydrophilic resin layer 11 is not particularly limited, but is preferably 0 to 50°C, more preferably 5 to 35°C.

[0043] When the composition (C) is brought into contact with the second surface 11b of the hydrophilic resin layer 11 by the method described above, it is preferable to dry the second surface 11b and, if necessary, the first surface 11a of the hydrophilic resin layer 11 after the contact. The hydrophilic resin layer 11 is preferably air-dried at, for example, 0 to 50°C, and more preferably air-dried at 5 to 35°C.

[0044] It is preferable to surface-treat second surface 11b of hydrophilic resin layer 11 before contacting composition (C) with second surface 11b of hydrophilic resin layer 11. By surface-treating second surface 11b of hydrophilic resin layer 11, the adhesiveness of composition (C) is further increased, and as a result, the adhesiveness of drug layer 12 to hydrophilic resin layer 11 is increased. Examples of surface treatments include surface oxidation treatments such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, and ozone / ultraviolet treatment, as well as sandblasting, etc. Among these, from the viewpoints of the effect of the surface treatment, productivity, and production costs, surface oxidation treatments are preferred, and corona treatment is particularly preferred.

[0045] <Applications of resin film> Resin film 10 can be widely used in locations where it is desired to reduce microbial activity. Specifically, by providing resin film 10 in locations where it is desired to reduce microbial activity, such as the surface of a desk, building wall materials, wallpaper, ceiling materials, floor materials, doorknobs, doors, straps, handrails, and other building materials, interior materials for vehicles such as automobiles, trains, ships, and airplanes, building materials and equipment in medical facilities, and packaging materials for medical instruments, microbial activity can be reduced.

[0046] When the resin film 10 is provided in these locations, the resin film 10 is provided so that the first surface 11a of the hydrophilic resin layer 11, that is, the surface 10a of the resin film 10, comes into contact with the microorganisms. Drug layer 12 has adhesiveness due to the inclusion of either or both of agar and gelatin, and therefore resin film 10 can be attached so that second surface 12b of drug layer 12 comes into contact with a predetermined location. Alternatively, resin film 10 may be attached to the predetermined location using a separate adhesive or bonding agent.

[0047] The resin film 10 is useful for construction and building material applications. When used as a building material, it is preferable that the resin film 10 be easily bendable, and it is required to have a bending strength that does not cause cracks or breakage when bent. The bending strength measured by ASTM D790 method is used as an index, and it is 300 kg / cm 2 More than 400 kg / cm is preferable. 2 More preferably, 500 kg / cm 2 More preferably, it is 2000 kg / cm or more. 2 Preferably less than 1500 kg / cm 2 Less than 1000kg / cm is more preferable. 2 The following is even more preferred: It is also preferable that the material has a strength that can withstand external scratches. As an index of this, Rockwell hardness measured by ASTM D785 method is used, and R50 or more is preferable, R75 or more is preferable, and R100 or more is more preferable. Furthermore, R200 or less is preferable, R150 or less is preferable, and R125 or less is more preferable.

[0048] When adhesive is used to attach to a wall or the like, the softer the material, the easier it is to handle, so the glass transition temperature is preferably 0°C or lower. It is more preferably -10°C or lower, and even more preferably -20°C or lower. It is also preferable that the material has the property of easily adhering to the object to which it is attached, i.e., tackiness, and it is preferable that the material has tackiness at temperatures from -5°C to 20°C.

[0049] The resin film 10 is useful as a packaging material. When the resin film 10 is used as a packaging material, in order to ensure sufficient strength, the thickness of the hydrophilic resin layer 11 is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and particularly preferably 50 μm or more.

[0050] <Action and effect> The resin film 10 of the first embodiment can exhibit antimicrobial activity because the drug M permeates the hydrophilic resin layer 11 and is present on the first surface 11a of the hydrophilic resin layer 11, i.e., the surface 10a of the resin film 10. Moreover, because the drug M permeates the hydrophilic resin layer 11, even if the drug M present on the first surface 11a of the hydrophilic resin layer 11 is consumed and reduced, at least a portion of the drug M that has permeated the hydrophilic resin layer 11 gradually seeps out to the first surface 11a of the hydrophilic resin layer 11, so the antimicrobial activity can be maintained for a long period of time. Furthermore, because the resin film 10 of the first embodiment includes the drug layer 12, at least a portion of the drug M contained in the drug layer 12 gradually permeates from the second surface 11b to the first surface 11a of the hydrophilic resin layer 11 and seeps out onto the first surface 11a, thereby maintaining antimicrobial activity for a longer period of time. Note that when the concentration of the drug M reaches equilibrium, the drug M does not seep out any further from the inside of the hydrophilic resin layer 11 and from the drug layer 12 onto the first surface 11a of the hydrophilic resin layer 11, making it easier to maintain a constant amount of the drug M present on the first surface 11a of the hydrophilic resin layer 11.

[0051] In this way, in resin film 10 of the present embodiment, drug M seeps out from back surface 10b toward front surface 10a, making it easy to adjust the concentration of drug M on front surface 10a of resin film 10. In particular, since the concentration of drug M in drug layer 12 can be easily adjusted by adjusting the thickness of drug layer 12, the duration of antimicrobial activity can be easily controlled. In addition, the drug layer 12 contains, in addition to the drug M, either agar or gelatin or both, and is adhesive, so that the resin film 10 can be easily attached to the object to which antimicrobial activity is to be imparted.

[0052] Second Embodiment FIG. 3 is a cross-sectional view schematically illustrating an example of a resin film according to the second embodiment. Resin film 20 of the second embodiment includes hydrophilic resin layer 11, drug layer 12 provided on second surface 11b of hydrophilic resin layer 11, and resin layer 13 provided on second surface 12b of drug layer 12 opposite to hydrophilic resin layer 11. That is, in resin film 20 of the second embodiment, hydrophilic resin layer 11 and resin layer 13 are provided on both surfaces of drug layer 12. Drug M permeates hydrophilic resin layer 11, and drug M is present on first surface 11a of hydrophilic resin layer 11 opposite to drug layer 12. In the second embodiment, the first surface 11a of the hydrophilic resin layer 11 is the surface that comes into contact with microorganisms, and the first surface 13a of the resin layer 13 may also be the surface that comes into contact with microorganisms.

[0053] The same parts of the resin film 20 as those of the resin film 10 are denoted by the same reference numerals and will not be described.

[0054] <Resin layer> The resin layer 13 is typically a film. The resin layer 13 may or may not have hydrophilic properties. When the resin layer 13 has hydrophilic properties, the resin layer 13 has drug permeability. The hydrophilic resin layer 13 may be formed in the same manner as that described for the hydrophilic resin layer 11, and the preferred embodiments are also the same.

[0055] When the resin layer 13 is hydrophilic, the drug M preferably permeates from the second surface 13b to the first surface 13a of the resin layer 13. By allowing the drug M to permeate from the second surface 13b to the first surface 13a of the resin layer 13, stickiness of the first surface 13a of the resin layer 13 caused by the drug M can be suppressed. Furthermore, when the resin layer 13 is hydrophilic, it is preferable that a drug M be present on the first surface 13a of the resin layer 13. The presence of the drug M on the first surface 13a of the resin layer 13 imparts antimicrobial activity to the first surface 13a of the resin layer 13. Moreover, since the drug M has permeated the resin layer 13, even if the drug M present on the first surface 13a of the resin layer 13 is consumed and reduced, at least a portion of the drug M that has permeated the resin layer 13 gradually seeps out to the first surface 13a of the resin layer 13, and therefore the antimicrobial activity can be maintained for a long period of time.

[0056] The antimicrobial activity imparted to the first surface 13a of the resin layer 13 may be the same as the antimicrobial activity imparted to the first surface 11a of the hydrophilic resin layer 11, and is preferably at least one selected from the group consisting of antibacterial activity, antifungal activity, and antiviral activity.

[0057] When the resin layer 13 is hydrophilic, the resin constituting the resin layer 13 may be the same as those listed as the resin constituting the hydrophilic resin layer 11, and preferably contains at least one resin selected from the group consisting of polyamide, cellulose resin, and polyurethane, with polyamide being particularly preferred because of its excellent drug permeability and concentration adjustment. The resin constituting the hydrophilic resin layer 13 may be one type used alone or two or more types used in combination.

[0058] If the resin layer 13 does not have hydrophilicity, the resin layer 13 also does not have drug permeability and is not permeated by the drug M. Furthermore, the drug M is not present on the first surface 13a of the resin layer 13, and therefore antimicrobial activity is not imparted. Examples of resins that can be used to form the non-hydrophilic resin layer 13 include polyolefins. The resin that can be used to form the non-hydrophilic resin layer 13 preferably contains at least one resin selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polymethyl methacrylate, and polyvinyl chloride, as these resins are versatile, readily available, and inexpensive, with polyethylene, polypropylene, and polymethyl methacrylate being particularly preferred. The resin constituting the non-hydrophilic resin layer 13 may be one type used alone or two or more types used in combination.

[0059] The resin layer 13 may be a single layer film or a laminated film in which a plurality of single layer films are laminated. When the resin layer 13 is a laminated film, the resins constituting the respective single layer films may be the same or different, but it is preferable that at least one single layer film contains polyamide.

[0060] For the same reasons as for the hydrophilic resin layer 11, the thickness of the resin layer 13 is preferably 0.01 μm or more, more preferably 0.1 μm or more, even more preferably 10 μm or more, even more preferably 20 μm or more, particularly preferably 30 μm or more, and most preferably 50 μm or more, and is preferably 5000 μm or less, more preferably 2500 μm or less, even more preferably 1000 μm or less, particularly preferably 500 μm or less, and most preferably 300 μm or less. The preferred upper and lower limits of the thickness of the resin layer 13 can be arbitrarily combined, and are, for example, preferably 0.01 to 5000 μm, more preferably 0.1 to 2500 μm, more preferably 10 to 1000 μm, even more preferably 20 to 1000 μm, particularly preferably 30 to 500 μm, and most preferably 50 to 300 μm.

[0061] The amount of the drug M present on the first surface 11a of the hydrophilic resin layer 11 is not particularly limited as long as it is an amount that can exhibit antimicrobial activity. For example, if the drug M is present to an extent that can be identified by the surface analysis or pH test in the Examples, it can have antimicrobial activity. For example, 5.5×10 per square centimeter of the resin film surface -10 Preferably, at least 1.0 x 10 moles of drug M are present, more preferably at least 1.0 x 10 moles. -9 mol or more, more preferably 2.5 × 10 -9 Preferably, more than 1 molar of drug M is present. The same applies to the amount of the drug M when it is present on the first surface 13a of the resin layer 13.

[0062] The pH of the first surface 11a of the hydrophilic resin layer 11 is preferably made less than 7 by the drug M. Similarly, the pH of the first surface 13a of the hydrophilic resin layer 13 is preferably made less than 7 by the drug M. The method for measuring pH is as explained in the first embodiment.

[0063] The various configurations of the resin layer 13, such as the resin that constitutes the resin layer 13, the type of drug M that can be penetrated, its thickness, whether it is a single-layer film or a laminated film, etc., may be the same as or different from those of the hydrophilic resin layer 11.

[0064] <Manufacturing method> The resin film 20 can be obtained, for example, by contacting the composition (C) with the second surface 11b of the hydrophilic resin layer 11 and the second surface 13b of the resin layer 13 for 5 seconds or more, and allowing at least a portion of the drug M to penetrate to the first surface 11a of the hydrophilic resin layer 11, thereby imparting antimicrobial activity to the first surface 11a of the hydrophilic resin layer 11. When the resin layer 13 is hydrophilic, at least a portion of the drug M penetrates into the resin layer 13 as well as to the first surface 13a, and the first surface 13a of the resin layer 13 is also imparted with antimicrobial activity. Because the hydrophilic resin layer 11 has drug permeability, the drug M that has soaked into the hydrophilic resin layer 11 seeps out onto the first surface 11a of the hydrophilic resin layer 11. Therefore, even without applying the composition (C) to the first surface 11a of the hydrophilic resin layer 11, the drug M is present on the first surface 11a of the hydrophilic resin layer 11, and antimicrobial activity can be exhibited. Similarly, when the resin layer 13 has hydrophilic properties, even without applying the composition (C) to the first surface 13a of the resin layer 13, the drug M is present on the first surface 13a of the resin layer 13, and antimicrobial activity can be exhibited.

[0065] The method for contacting the composition (C) with the second surface 11b of the hydrophilic resin layer 11 and the second surface 13b of the resin layer 13 is not particularly limited, but examples include a method in which the composition (C) is applied to each of the second surface 11b of the hydrophilic resin layer 11 and the second surface 13b of the resin layer 13 by spray coating, roller coating, flow coating, roller coating, pouring into a mold, etc., to bring them into contact, and then the second surface 11b of the hydrophilic resin layer 11 and the second surface 13b of the resin layer 13 are bonded together so that they face each other.

[0066] The contact time when the composition (C) is brought into contact with the second surface 11b of the hydrophilic resin layer 11 and the second surface 13b of the resin layer 13 is 5 seconds or more, preferably 10 seconds or more, more preferably 1 minute or more, and even more preferably 5 minutes or more. The contact time may be 20 minutes or more, but sufficient antimicrobial activity is usually obtained with 20 minutes of contact.

[0067] The contact temperature when the composition (C) is brought into contact with the second surface 11b of the hydrophilic resin layer 11 and the second surface 13b of the resin layer 13 is not particularly limited, but is preferably 0 to 50°C, more preferably 5 to 35°C.

[0068] Before contacting composition (C) with second surface 11b of hydrophilic resin layer 11 and second surface 13b of resin layer 13, it is preferable to surface-treat second surface 11b of hydrophilic resin layer 11 and second surface 13b of resin layer 13. This further enhances the adhesiveness of composition (C) to second surface 11b of hydrophilic resin layer 11 and second surface 13b of resin layer 13, thereby enhancing the adhesiveness of drug layer 12 to hydrophilic resin layer 11 and resin layer 13.

[0069] <Applications of resin film> Like the resin film 10, the resin film 20 of the second embodiment can be used for building materials, interior materials for mobile bodies, packaging materials, etc., and is particularly useful as a packaging material.

[0070] <Action and effect> Similar to the first embodiment, the resin film 20 of the second embodiment exhibits antimicrobial activity because the drug M penetrates the hydrophilic resin layer 11 and is present on the first surface 11a of the hydrophilic resin layer 11. Moreover, because the drug M penetrates the hydrophilic resin layer 11, even if the drug M present on the first surface 11a of the hydrophilic resin layer 11 is consumed and reduced, at least a portion of the drug M that has penetrated the hydrophilic resin layer 11 gradually seeps out to the first surface 11a of the hydrophilic resin layer 11, thereby maintaining antimicrobial activity for a long period of time. Furthermore, because the resin film 20 of the second embodiment includes the drug layer 12, at least a portion of the drug M contained in the drug layer 12 also gradually penetrates and seeps out to the first surface 11a of the hydrophilic resin layer 11, thereby maintaining antimicrobial activity for a longer period of time. For the same reason, if the resin layer 13 is hydrophilic, the first surface 13a of the resin layer 13 can also exhibit antimicrobial activity, and the antimicrobial activity can be maintained for a long period of time. Furthermore, drug layer 12 contains either agar or gelatin or both in addition to drug M and has adhesive properties, so that hydrophilic resin layer 11 and resin layer 13 can be easily attached to each other.

[0071] Other Embodiments The resin film of the present invention is not limited to the above-described embodiments. For example, a peelable coating layer (not shown) may be provided on the second surface of the drug layer in the first embodiment. Because the drug layer has adhesive properties, it is preferable that the coating layer be provided until just before use of the resin film, and the coating layer may be peeled off from the drug layer just before use of the resin film. The covering layer may be, for example, a film that has been subjected to a release treatment by applying a release agent to one surface of a base film. Examples of the substrate film include films of polyethylene terephthalate (PET), polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylic resin, and the like. The release agent may be, for example, a silicone resin.

[0072] [Method for imparting antimicrobial activity] The method for imparting antimicrobial activity according to the embodiment is a method for imparting antimicrobial activity to the first surface of a hydrophilic, drug-permeable hydrophilic resin layer by contacting the second surface with a composition (C) containing a drug, which is an organic acid having 1 to 10 carbon atoms, and either or both of agar and gelatin, and allowing at least a portion of the drug to penetrate to the first surface of the hydrophilic resin layer.

[0073] Examples of the hydrophilic resin layer to which antimicrobial activity is imparted include the hydrophilic resin layers exemplified above in the description of the resin film. The hydrophilic resin layer may also be a product (e.g., curtain, sponge, etc.) made of, for example, polyamide, cellulose resin, polyurethane, etc. Examples of the composition (C) include the drug and composition (C) exemplified above in the description of the resin film. The method for bringing the composition (C) into contact with the second surface of the hydrophilic resin layer includes the methods exemplified above in the description of the resin film.

[0074] The contact time when the composition (C) is brought into contact with the second surface of the hydrophilic resin layer is preferably 5 seconds or more, more preferably 10 seconds or more, even more preferably 1 minute or more, and particularly preferably 5 minutes or more. The contact time may be 20 minutes or more, but sufficient antimicrobial activity is usually obtained with 20 minutes of contact. The contact temperature when the composition (C) is brought into contact with the second surface of the hydrophilic resin layer is not particularly limited, but is preferably from 0 to 50°C, and more preferably from 5 to 35°C, for example.

[0075] When the composition (C) is brought into contact with the second surface of the hydrophilic resin layer, it is preferable to dry the second surface of the hydrophilic resin layer, and optionally the first surface, after the contact. The hydrophilic resin layer is preferably air-dried at, for example, 0 to 50°C, more preferably 5 to 35°C. Before the composition (C) is brought into contact with the second surface of the hydrophilic resin layer, the second surface of the hydrophilic resin layer is preferably subjected to a corona treatment.

[0076] Antimicrobial activity may be imparted to the first surface of the hydrophilic resin layer by contacting composition (C) with the first surface of the hydrophilic resin layer and allowing the drug to penetrate to the second surface of the hydrophilic resin layer. Alternatively, antimicrobial activity may be imparted to the first surface of the hydrophilic resin layer by immersing the first surface of the hydrophilic resin layer or the entire hydrophilic resin layer in composition (C) to bring composition (C) into contact with at least the first surface of the hydrophilic resin layer and allowing the drug to penetrate into the hydrophilic resin layer. If a drug layer is formed on the first surface of the hydrophilic resin layer, this drug layer is peeled off.

[0077] [Recycling methods for resin films] The method for recycling a resin film according to this embodiment is a method for recycling the resin film according to the first and second embodiments described above after use. The resin film recycling method according to the embodiment is a method of separating a hydrophilic resin layer and a drug layer from a resin film in a solvent, recovering at least one of the separated hydrophilic resin layer and the drug, and using the recovered hydrophilic resin layer to manufacture the resin film of the first or second embodiment. In the recycling method according to the embodiment, only the separated hydrophilic resin layer may be recycled, only the drug may be recycled, or both the separated hydrophilic resin layer and the drug may be recycled. Furthermore, when the resin film has a resin layer on the opposite side of the drug layer from the hydrophilic resin layer, the resin layer may be recovered and recycled.

[0078] When recycling the drug, the drug separated in the solvent is recovered together with the solvent, the recovered mixture of drug and solvent is concentrated, and the concentrate is brought into contact with the second surface of the hydrophilic resin layer for 5 seconds or more, allowing at least a portion of the recovered drug to penetrate to the first surface of the hydrophilic resin layer, thereby imparting antimicrobial activity to the first surface of the hydrophilic resin layer. The hydrophilic resin layer with which the concentrate is brought into contact may be the recovered hydrophilic resin layer or a new hydrophilic resin layer.

[0079] When the recovered hydrophilic resin layer is recycled, the composition (C) may be brought into contact with the second surface of the recovered hydrophilic resin layer for 5 seconds or more, and at least a portion of the drug may be allowed to penetrate to the first surface of the hydrophilic resin layer, thereby imparting antimicrobial activity to the first surface of the hydrophilic resin layer. Furthermore, the recovered hydrophilic resin layer may be melted once to produce a film, and the film may be used as the hydrophilic resin for material recycling.

[0080] The resin film can be separated into the hydrophilic resin layer and the drug by immersing it in a solvent. In this separation operation, it is preferable to immerse the resin film in water and stir it, as this facilitates separation of the hydrophilic resin layer and the drug. As the solvent, in addition to water, organic solvents such as alcohols can be used, with water being preferred.

[0081] The temperature of the solvent when separating the resin film into the hydrophilic resin layer and the drug is preferably 1 to 100°C, more preferably 10 to 50°C. If the temperature of the solvent is equal to or higher than the lower limit, the resin film is sufficiently soft and stirring becomes effective. If the temperature of the solvent is equal to or lower than the upper limit, the resin film does not shrink or deform due to heat, making it easy to handle thereafter.

[0082] The method for concentrating the mixture of the drug and the solvent is not particularly limited, and examples thereof include vacuum concentration. Heating vacuum concentration is preferred because it can shorten the concentration time.

[0083] Examples of methods for contacting the concentrate with the second surface of the hydrophilic resin layer include methods for contacting the concentrate with the second surface of the hydrophilic resin layer by spray coating, roller coating, flow coating, roller coating, pouring into a mold, etc., and methods for contacting the concentrate with the second surface of the hydrophilic resin layer by immersing the second surface of the hydrophilic resin layer in the concentrate.

[0084] The contact time when the concentrate is brought into contact with the second surface of the hydrophilic resin layer is 5 seconds or more, preferably 10 seconds or more, more preferably 1 minute or more, and even more preferably 5 minutes or more. The contact time may be 20 minutes or more, but sufficient antimicrobial activity is usually obtained with 20 minutes of contact.

[0085] The contact temperature when the concentrate is brought into contact with the second surface of the hydrophilic resin layer is not particularly limited, but is preferably 0 to 50°C, more preferably 5 to 35°C.

[0086] When the concentrate is brought into contact with the second surface of the hydrophilic resin layer, it is preferable to dry the second surface of the hydrophilic resin layer, and optionally the first surface, after the contact. The hydrophilic resin layer is preferably air-dried at, for example, 0 to 50°C, more preferably 5 to 35°C.

[0087] Before contacting the concentrate with the second surface of the hydrophilic resin layer, the second surface of the hydrophilic resin layer is preferably surface-treated, and more preferably corona-treated.

[0088] [Adhesive] The adhesive according to the embodiment contains an organic acid having 1 to 10 carbon atoms and agar. The adhesive according to the embodiment has adhesiveness due to the agar, and antimicrobial activity due to the organic acid having 1 to 10 carbon atoms. Examples of the organic acid having 1 to 10 carbon atoms include the same ones as those exemplified for the resin film described above, and the preferred embodiments are also the same. The organic acid having 1 to 10 carbon atoms contained in the pressure-sensitive adhesive may be one type or two or more types.

[0089] The adhesive according to the embodiment may contain any optional component other than the organic acid having 1 to 10 carbon atoms and agar. Examples of optional components include water, methanol, ethanol, and isopropyl alcohol. The optional components contained in the pressure-sensitive adhesive may be one type or two or more types.

[0090] The content of the C1-10 organic acid in the adhesive is preferably 1 ppm by mass or more, more preferably 100 ppm by mass or more, and even more preferably 1% by mass or more, based on the total amount of the organic acid, agar, and optional components. The content of the C1-10 organic acid in the adhesive is preferably 99% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, based on the total amount of the organic acid, agar, and optional components. When the content of the C1-10 organic acid is equal to or greater than the lower limit, the adhesive exhibits sufficiently high antimicrobial activity. When the content of the C1-10 organic acid is equal to or less than the upper limit, the organic acid does not precipitate or separate, and can be used stably.

[0091] The content of agar in the adhesive is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on the organic acid, agar, and optional ingredients. The content of agar in the adhesive is preferably 99% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less, based on the organic acid, agar, and optional ingredients. If the content of agar is equal to or greater than the lower limit, sufficiently strong adhesiveness can be achieved. If the content of agar is equal to or less than the upper limit, softness can be maintained without solidifying. [Example]

[0092] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following descriptions.

[0093] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The embodiments of the present invention can be modified in various ways as long as the gist of the present invention is not changed.

[0094] [Example 1] As the first hydrophilic resin layer, a nylon 6 film with one side corona-treated (manufactured by Mitsubishi Chemical Corporation, product name "Diamilon (registered trademark) C", 80 mm x 80 mm x 100 μm thick, single-layer film, water absorption (measured by ASTM D570 method): 1.6%) was used. Powdered agar (country of origin: Indonesia, Korea, Chile, distributor: Asahi Co., Ltd.) and citric acid (crystal) (processor: Kenei Pharmaceutical Co., Ltd.) were also used. One teaspoon (1.33 g) of powdered agar and two teaspoons (4.19 g) of citric acid as Agent M were added to 150 mL of water in a pot, and while stirring with a spoon, heating was started on an induction heater, boiled for 5 seconds, and then heating was stopped. After the bubbling caused by boiling had subsided, the liquid was checked and found to be a transparent, homogeneous liquid with no residual residue. The mixture was allowed to cool to 43°C, yielding Composition (C-1). The first hydrophilic resin layer was placed on a table with the corona-treated surface facing up, and a square wooden frame measuring 6 cm in length and 4 cm in width was placed on top of it. A 10 mL pipette was preheated by pouring hot water at 50°C into and out of the pipette, and then 5 mL (5.29 g) of composition (C-1) was measured out. While holding the wooden frame with one hand, composition (C-1) was poured into the wooden frame so as to cover the entire surface of the first hydrophilic resin layer inside the wooden frame. After 1 hour, the agar had increased in viscosity, and the wooden frame was removed to form a square drug layer gel. After leaving it as is for 2 days, a transparent, adhesive drug layer was obtained. The drug layer weighed 0.29 g. The composition of this drug layer was 35% by mass water, 15% by mass agar, and 50% by mass citric acid. A nylon 6 film of the same shape as the first hydrophilic resin layer was prepared as the second hydrophilic resin layer, and the corona-treated surface was pressed against the drug layer with care to avoid air bubbles as much as possible, to obtain test piece 1.

[0095] [Example 2] Twenty days after obtaining test piece 1 in Example 1, composition (C-2) was prepared with the same composition as composition (C-1), except that citric acid manufactured by Kosakai Pharmaceutical Co., Ltd. was used as drug M. A drug layer was formed in the same manner as in Example 1, except that a round stainless steel metal frame with a diameter of 6 cm, a depth of 4 cm, and a thickness of 200 μm was used instead of the wooden mold. One hour after pouring composition (C-2), the agar did not solidify, but did not flow out. After leaving it as it was for three days, a transparent, adhesive drug layer was obtained. The composition of the drug layer was the same as in Example 1. A nylon 6 film of the same shape as the first hydrophilic resin layer was prepared as the second hydrophilic resin layer, and the corona-treated surface was pressed against the drug layer with care to avoid air bubbles as much as possible, to obtain test piece 2.

[0096] [Example 3] Thirty days after obtaining test piece 1 in Example 1, test pieces 1 and 2 were subjected to an antibacterial test using a method based on JIS Z 2801:2012. The test bacteria used were the following Escherichia coli. The test conditions were as follows: Escherichia coli (NBRC3972) <Test conditions> Test bacteria dilution: 1 / 500NB Inoculation volume of test bacteria: 0.4mL / sample Sterilization of test specimen: wipe with absolute ethanol Operating conditions: Dark place, 35°C, relative humidity above 90% Duration of action: 24 hours Adhesive film: Reinforced polyethylene (Stomacher 80 type, ORGANO), 40mm x 40mm x 0.09mm thick

[0097] 24 hours after the start of the antibacterial test, test pieces 1 and 2 were each placed in a sterilized stomacher bag, 10 mL of SCDLP bouillon medium was added, and the bacterial solution was thoroughly washed out to prepare a sample. 1 mL of the sample was cultured on a standard agar medium at 35°C for 48 hours, after which the viable bacterial count was measured and the antibacterial activity was evaluated based on the viable bacterial count in the washout. Separately, 0.4 mL of test bacterial solution was dropped onto the surface of two untreated films as comparative test pieces, and then a cling film was placed over them and pressed down so that the test bacterial solution was evenly distributed. The viable bacterial count was measured on one of the two comparative test pieces immediately afterwards (initial value for the comparative test piece), and on the other piece after 24 hours. The results are shown in Figure 4. The vertical axis in Figure 4 is a common logarithmic scale.

[0098] 4, it was revealed that the comparative test piece did not have antibacterial properties, but the viable bacterial counts of test pieces 1 and 2 obtained in Examples 1 and 2 were below the detection limit, and that they had high antibacterial properties. Furthermore, test piece 2 was measured 15 days after preparation, and test piece 1 was measured 30 days after preparation, indicating that high antibacterial properties were continuously maintained for one month.

[0099] [Example 4] Composition (C-1) was prepared as an adhesive in the same manner as in Example 1. The polyethylene label attached to a commercially available 500 mL bottle was removed, and the adhesive component was completely wiped off. The bottle was placed on a table with the backside of the label facing up, and a ruler was placed on the edge of the bottle to hold it down. Approximately 3 mL of composition (C-1) was then dropped onto the bottle and spread over the entire surface with a medicine spoon. After leaving the bottle to stand for two days, test piece 3 was obtained, on which a colorless and transparent adhesive layer had formed.

[0100] When the adhesive layer of test piece 3 was pressed against a glass wine bottle, test piece 3 firmly stuck to the bottle, demonstrating that composition (C-1) functions as an adhesive. Furthermore, when washed with hot water at 40°C, the label easily peeled off, showing that no adhesive components were attached to the label.

[0101] [Example 5] Two packets (10.0 g) of commercially available Morinaga Cook Gelatin and two teaspoons (4.19 g) of citric acid manufactured by Kosakai Pharmaceutical Co., Ltd. were added to 150 mL of water, heated to 100°C while stirring, and then cooled to 40°C to obtain a low-viscosity composition (C-3). A nylon 6 film (manufactured by Mitsubishi Chemical Corporation, trade name "Diamilon® C", 80 mm x 80 mm x 100 μm thick) with one side corona-treated was used as the first hydrophilic resin layer. It was placed on a table with the corona-treated side facing up, and a round stainless steel metal frame with a diameter of 6 cm, a depth of 4 cm, and a thickness of 200 μm was placed on top of it. A 10 mL pipette was preheated by pouring hot water at 50°C into and out of the pipette. 5 mL (5.29 g) of Composition (C-3) was then measured out. While holding the metal frame with one hand, Composition (C-3) was poured into the metal frame to cover the entire surface of the first hydrophilic resin layer. After 15 minutes, the metal frame was removed and the film was left to stand for 1 day. The surface was dry and non-sticky. A thin layer of 0.5 mL of water was applied to the surface, resulting in a drug layer that exhibited adhesiveness. The drug layer consisted of 54% water by mass, 32% gelatin by mass, and 14% citric acid by mass. A nylon 6 film of the same shape as the first hydrophilic resin layer was prepared as the second hydrophilic resin layer, and the corona-treated surface was pressed against the drug layer, taking care to avoid air bubbles as much as possible, to obtain test piece 4.

[0102] Test piece 4 and a piece of nylon 6 film used as a control were left in the room atmosphere for three days. Two standard agar plates manufactured by Shimadzu Diagnostics Co., Ltd. were pressed onto the surface of each of test piece 4 and the control piece, and after covering them, incubation was initiated in an incubator at 36°C. After one day, the food stamps were observed and bacterial colonies had grown on the surface of the control piece to a degree that they were difficult to count, occupying 30-40% of the total surface area. In contrast, only three small colonies had formed on test piece 4, demonstrating its antibacterial properties. [Explanation of symbols]

[0103] 10 Resin film 11 Hydrophilic resin layer 11a First side 11a 11b The Second Side 12 Drug Layer 13 Resin layer 13a First Side 13b Second Side 20 Resin film M drug

Claims

1. A resin film having a hydrophilic resin layer that is drug-permeable and hydrophilic and a drug layer, a drug which is an organic acid having 1 to 10 carbon atoms permeates the hydrophilic resin layer and is present on a first surface of the hydrophilic resin layer; the drug layer is provided on a second surface of the hydrophilic resin layer; The drug layer is a resin film containing the drug and either or both of agar and gelatin.

2. The resin film according to claim 1 , wherein the hydrophilic resin layer contains at least one resin selected from the group consisting of polyamides, cellulose resins, and polyurethanes.

3. The resin film according to claim 2 , wherein the hydrophilic resin layer contains polyamide, and the polyamide contains either or both of nylon 6 and nylon 66.

4. The resin film according to claim 1 or 2, wherein the hydrophilic resin layer has a thickness of 10 μm or more.

5. The resin film according to claim 1 or 2, wherein a resin layer is provided on the surface of the drug layer opposite to the hydrophilic resin layer.

6. A packaging material comprising the resin film according to claim 1 or 2.

7. A building material comprising the resin film according to claim 1 or 2.

8. The method for producing the resin film according to claim 1 or 2, A method for producing a resin film, comprising contacting a composition containing the drug and either or both of agar and gelatin with the second surface of the hydrophilic resin layer for 5 seconds or more, thereby allowing at least a portion of the drug to penetrate to the first surface of the hydrophilic resin layer, and imparting antimicrobial activity to the first surface of the hydrophilic resin layer.

9. A method for imparting antimicrobial activity, comprising: applying a composition containing a drug, which is an organic acid having 1 to 10 carbon atoms, and either or both of agar and gelatin, to a second surface of a hydrophilic resin layer that is drug-permeable and hydrophilic, and allowing at least a portion of the drug to penetrate to a first surface of the hydrophilic resin layer, thereby imparting antimicrobial activity to the first surface of the hydrophilic resin layer.

10. A method for recycling a resin film, comprising separating the hydrophilic resin layer and the drug layer from the resin film according to claim 1 or 2 in a solvent, recovering at least one of the separated hydrophilic resin layer and the drug, and using the recovered hydrophilic resin layer to manufacture the resin film.

11. 11. The method for recycling a resin film according to claim 10, wherein the drug separated in water is recovered together with a solvent, the recovered mixture of the drug and the solvent is concentrated, and the concentrate is brought into contact with the second surface of the hydrophilic resin layer for 5 seconds or more, thereby allowing at least a portion of the recovered drug to penetrate to the first surface of the hydrophilic resin layer, thereby imparting antimicrobial activity to the first surface of the hydrophilic resin layer.

12. An adhesive comprising an organic acid having 1 to 10 carbon atoms and agar.

Images