Resin film, laminate, and package or container

Abstract

To provide a laminate that can express sufficient antibacterial, sterilizing, and bactericidal properties, achieving high reliability.SOLUTION: A resin film contains a polyolefin resin, and a tannic acid derivative with at least some of hydroxy groups substituted with C1 to 18 chain hydrocarbon groups. The polyolefin resin is, for example, one or more selected from polyethylene resin, polypropylene resin, and polybutylene resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin film, a laminate, and a package or container having the laminate. [Background technology]

[0002] In the food packaging and pharmaceutical packaging industries, sterilization processes such as retort sterilization and aseptic filling have been studied and put into practical use to prevent infection by bacteria such as E. coli in order to maintain the safety of the contents. Meanwhile, with the recent spread of infectious diseases, consumers have become more conscious of hygiene, and safety of packaging materials is being demanded. While inorganic compounds, silver, copper, and other substances are known to have antibacterial and antiviral properties, there is still room for improvement in terms of cost and food safety when used in packaging materials that come into direct contact with food.

[0003] Tannin, a type of polyphenol, has long been used as a rust inhibitor and is known to form a stable coating on the surface of zinc, for example. However, tannin is hardly soluble in organic solvents, limiting its applications. However, by substituting at least a portion of the hydroxyl groups in the tannin molecule with alkyl ethers or alkyl esters to form water-insoluble tannic acid derivatives, its applications can be broadened (Patent Document 1).

[0004] However, the above-mentioned coating is believed to be formed by a film formed by the reaction of gallic acid, etc. in tannic acid with zinc, and then a film formed by the coagulation polymerization or associative polymerization of tannic acid, which is then layered on top of the film (Non-Patent Document 1). The hydroxyl groups of gallic acid, etc., contained in tannic acid, are involved in these reactions. Therefore, if these hydroxyl groups are converted to alkyl ethers, etc., it becomes difficult to form a coating, and there is a concern that the rust prevention effect will be reduced. Even in Patent Document 1, the evaluation is conducted exclusively in a solution state.

[0005] Therefore, a film-forming composition containing a tannic acid derivative in which the hydrogen atoms in at least some of the hydroxyl groups of tannic acid are substituted with a chain hydrocarbon group having 3 to 18 carbon atoms has been proposed (for example, Patent Document 2). This film-forming composition is said to have film-forming properties and to be capable of forming stable films on various substrates. This is thought to be because the tannic acid derivative molecules are aligned with each other so that their chain hydrocarbon groups are aligned, resulting in an orderly orientation. This orientation provides film stability that more than compensates for the loss of hydroxyl groups, and as a result, it is said to exhibit superior rust prevention, antibacterial, and bactericidal properties compared to a coagulated film of tannic acid. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-307362 [Patent Document 2] International Publication No. 2016 / 076311 [Non-patent literature]

[0007] [Non-Patent Document 1] Metal Surface Technology, Vol. 29, No. 1, pp. 38-42 and Fig. 10, 1978 Summary of the Invention [Problem to be solved by the invention]

[0008] However, while the conventional film-forming compositions containing tannic acid derivatives described above can reduce costs, their antibacterial reliability is not sufficient, and there is still room for improvement when used as packaging materials that come into direct contact with food, medical products, etc. In particular, packaging materials are provided with a sealing layer for attachment to containers or to other packaging materials, and in use cases where the contents come into direct contact with the sealing layer, it is necessary to prevent contamination of the contents due to, for example, elution of the antibacterial substance contained in the sealing layer. Furthermore, in recent years, with the diversification of lifestyles and the need for preserved food in emergencies, etc., the uses of food packaging materials have become more diverse, and there is a demand for food packaging materials that can exhibit sufficient rust prevention, antibacterial, and bactericidal properties in a variety of uses.

[0009] An object of the present invention is to provide a resin film, a laminate, and a package or container that exhibit sufficient antibacterial, sterilizing and disinfecting properties and can achieve high reliability. [Means for solving the problem]

[0010] In order to achieve the above object, the inventors conducted extensive research and found that by incorporating into a resin film a polyolefin resin and a tannic acid derivative in which at least some of the hydroxyl groups are substituted with a chain hydrocarbon group having 1 to 18 carbon atoms, the specific tannic acid derivative can be stably retained inside the resin or on the surface of the resin, resulting in sufficient antibacterial, sterilizing and disinfecting properties and achieving high reliability.

[0011] That is, the present invention provides the following configurations. [1] A resin film comprising a polyolefin resin and a tannic acid derivative in which at least a portion of a plurality of hydroxyl groups is substituted with a chain hydrocarbon group having 1 to 18 carbon atoms.

[0012] [2] The resin film according to [1] above, wherein the polyolefin resin is one or more selected from the group consisting of polyethylene-based resins, polypropylene-based resins, and polybutylene-based resins.

[0013] [3] The resin film according to the above [1] or [2], wherein the tannic acid derivative is present in an amount of 0.5% by mass or more and 30% by mass or less relative to the total amount of the resin film.

[0014] [4] A package or container in which the resin film according to any one of [1] to [3] above is used.

[0015] [5] A package or container comprising a container body and one or more of the resin films according to any one of [1] to [3] above attached to the container body.

[0016] [6] The packaging or container described in [5] above, wherein the resin film constitutes a lid material for the container body.

[0017] [7] The packaging or container described in [5] above, wherein the resin film is attached to the outer surface of the container body.

[0018] [8] A package or container comprising an exterior part formed by laminating one or more of the resin films according to any one of [1] to [3] above, and a storage part formed inside the exterior part.

[0019] [9] A laminated structure including the resin film according to any one of [1] to [3] above and a thermoplastic resin film, A laminate having the resin film as an outermost layer.

[0020]

[10] A package or container in which the laminate described in [9] above is used.

[0021]

[11] A packaging body or container comprising a container body and one or more of the laminates described in [9] above attached to the container body.

[0022]

[12] The packaging or container described in

[11] above, wherein the laminate constitutes a lid material for the container body.

[0023]

[13] The packaging or container described in

[11] above, wherein the laminate is attached to the outer surface of the container body.

[0024]

[14] A packaging body or container comprising an exterior part formed by bonding one or more of the laminates described in [9] above, and a storage part formed inside the exterior part. [Effects of the Invention]

[0025] According to the present invention, sufficient antibacterial, sterilizing and disinfecting properties can be exhibited, and high reliability can be achieved. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a chemical reaction flow diagram showing an example of derivatization of tannic acid. [Figure 2A] FIG. 2A is a cross-sectional view showing an example of a specific configuration of a laminate according to an embodiment of the present invention. [Figure 2B] FIG. 2B is a cross-sectional view showing an example of another specific configuration of the laminate according to this embodiment. [Figure 3] FIG. 3 is a perspective view showing an example of a specific configuration of a container using the laminate according to this embodiment. [Figure 4] FIG. 4 is a perspective view showing another example of a specific configuration of a package using the laminate according to this embodiment. [Figure 5A] FIG. 5A is a perspective view showing another example of a specific configuration of a package using the laminate according to this embodiment. [Figure 5B] FIG. 5B is a cross-sectional view taken along line II in FIG. 5A. [Figure 6] FIG. 6 is a perspective view showing another example of a specific configuration of a container using the laminate according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments. <Resin film> The resin film of this embodiment contains a polyolefin resin and a tannic acid derivative in which at least some of the hydroxyl groups have been substituted with a chain hydrocarbon group having 1 to 18 carbon atoms.

[0028] [Polyolefin resin] Specifically, the polyolefin resin used in this embodiment is preferably one or more types selected from polyethylene-based resins, polypropylene-based resins, and polybutylene-based resins, and more preferably a polyethylene-based resin or a polypropylene-based resin.

[0029] (Polyethylene resin) An example of the polyethylene resin for the resin film is linear polyethylene. Linear polyethylene is obtained by copolymerizing ethylene monomer as the main component with an α-olefin such as 1-butene, 1-hexene, 1-octene, or 4-methylpentene as a comonomer by low-pressure radical polymerization using a single-site catalyst. The comonomer content in the linear polyethylene is preferably in the range of 0.5 to 20 mol%, more preferably in the range of 1 to 18 mol%.

[0030] Examples of the single-site catalyst include various single-site catalysts, such as metallocene catalyst systems that combine a metallocene compound of a transition metal of Group IV or V of the periodic table with an organoaluminum compound and / or an ionic compound. Single-site catalysts have uniform active sites, and therefore, compared with multi-site catalysts with non-uniform active sites, the molecular weight distribution of the resulting resin is sharper. This results in less precipitation of low-molecular-weight components when the resin is formed into a film, and allows for the production of resins with excellent physical properties, such as stable seal strength and excellent blocking resistance.

[0031] The density of linear polyethylene is 0.900 to 0.945 g / cm 3 It is preferable that the density is 0.910 to 0.940 g / cm 3It is more preferable that the density is within this range. If the density is within this range, the film has appropriate rigidity and is excellent in mechanical strength such as heat seal strength and pinhole resistance, and the film formability and extrusion suitability are improved. The melting point of the linear polyethylene is generally preferably within the range of 60 to 130°C, more preferably 70 to 120°C. If the melting point is within this range, processing stability is improved and further flexibility is also achieved, resulting in good pinhole resistance. Furthermore, the MFR (190°C, 21.18N) of the ethylene resin is preferably 2 to 20 g / 10 min, more preferably 3 to 10 g / 10 min. If the MFR is within this range, the film extrusion moldability is improved.

[0032] The proportion of the linear polyethylene used in the resin film is preferably such that the resin is the main component, and is preferably contained in an amount of 70% by mass or more of the resin component, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0033] Furthermore, resins other than linear polyethylene may be used in combination in the resin film. As the types of resins that can be used in combination, polyethylene-based resins other than linear polyethylene, polypropylene-based resins, or the resins exemplified as resins that can be used in combination can be preferably used.

[0034] When these other resins are used, they preferably account for 30% by mass or less of the resin components contained in the resin film, more preferably 20% by mass or less, and even more preferably 10% by mass or less. There is no particular lower limit, but they may be used in an amount of 1% by mass or more depending on the desired properties.

[0035] (Polypropylene resin) Examples of polypropylene resins for the resin film include propylene homopolymers, propylene-ethylene copolymers, propylene-α-olefin random copolymers such as propylene-1-butene copolymers, ethylene-1-butene copolymers, and propylene-ethylene-1-butene terpolymers, and metallocene-catalyzed polypropylenes. These may be used alone or in combination of two or more.

[0036] The polypropylene resin preferably has an MFR (230°C) of 0.5 to 30.0 g / 10 min and a melting point of 110 to 165°C, and more preferably an MFR (230°C) of 2.0 to 15.0 g / 10 min and a melting point of 115 to 162°C. If the MFR and melting point are within these ranges, the processing stability, the processability when co-extrusion processed with other layers, and the film formability are improved.

[0037] When a resin film is primarily composed of a polypropylene resin, other resins may be used in combination to improve adhesion with adhesives or printing inks when laminating the film with an adhesive to another substrate or when printing. Examples of other resins that can be used in combination include linear polyethylenes such as linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE), branched polyethylenes, ethylene-vinyl acetate copolymers (EVA), ethylene-methyl methacrylate copolymers (EMMA), ethylene-ethyl acrylate copolymers (EEA), ethylene-methyl acrylate (EMA) copolymers, ethylene-ethyl acrylate-maleic anhydride copolymers (E-EA-MAH), ethylene-acrylic acid copolymers (EAA), and ethylene-methacrylic acid copolymers (EMAA); and ionomers of ethylene-acrylic acid copolymers, ionomers of ethylene-methacrylic acid copolymers, and copolymers of ethylene and other monomers having a cyclic olefin structure, such as norbornene-based monomers. These resins may be used alone or in combination.

[0038] When these other resins are used, the content is preferably 35% by mass or less, more preferably 20% by mass or less, based on the total amount of resin components forming the resin film. There is no particular lower limit, but the content may be 1% by mass or more depending on the desired properties.

[0039] [Tannic acid derivatives] Tannin is a general term for plant components that produce polyphenols upon hydrolysis. Tannins are broadly classified into hydrolyzable tannins, in which gallic acid or ellagic acid is ester-bonded to sugars such as glucose and is easily hydrolyzed by acids or enzymes, and condensed tannins, in which compounds with a flavanol skeleton are polymerized. Derivatization in the present disclosure is possible with either type of tannin or a mixture thereof, and it is believed that the effects of the present disclosure can be achieved. Hydrolyzable tannins are preferred, and for example, those containing tannic acid as the main component, as represented by the following formula (1), are derivatized.

[0040] [ka]

[0041] Tannic acid has multiple hydroxyl groups, and in the derivatives disclosed herein, the hydrogen atoms of at least some of the hydroxyl groups are substituted with linear hydrocarbon groups having 1 to 18 carbon atoms. The total number of hydroxyl groups in the starting tannic acid varies depending on the type. Preferably, 10% or more of the substituents are substituted, more preferably 20% or more, and particularly preferably 40% or more. For example, in the case of the above formula (1), the total number of hydroxyl groups is 25, and one of these is substituted, preferably 3 or more, more preferably 5 or more, and particularly preferably 10 or more.

[0042] The upper limit of the number of substituents varies depending on the type of substituent, the substrate to be applied, and the purpose of use. All hydroxyl groups may be substituted as long as the desired adhesion to the substrate to be used can be achieved. When applied to polar substrates such as metals and glass, it is preferable that 80% or less of the number of substituents are substituted, more preferably 60% or less. For example, in the case of the above formula (1), it is preferably 20 or less, more preferably 15 or less.

[0043] Examples of the chain hydrocarbon group having 1 to 18 carbon atoms include linear or branched alkyl, alkenyl, and alkynyl groups, which are bonded to the tannic acid skeleton via a bond containing an oxygen atom derived from a hydroxyl group. Specific examples of the chain hydrocarbon group include butyl, hexyl, heptyl, octyl, isooctyl, nonyl, isononyl, decyl, undecyl, dodecyl, hexadecyl, propylene, hexylene, hexadecenyl, and octadecenyl groups. The chain hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 4 to 18, and even more preferably 6 to 16. Examples of the bond containing an oxygen atom include an ether bond, an ester bond, and a urethane bond.

[0044] The content of the tannic acid derivative is preferably 0.5% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 25% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less, relative to the total amount of the resin film. When the content of the tannic acid derivative is 5% by mass or more and 15% by mass or less, the tannic acid derivative can be more stably retained in the resin and can exhibit more excellent antibacterial properties.

[0045] (Method of producing tannic acid derivatives) Tannic acid derivatives can be obtained by the Williamson ether synthesis, which is an alkylation reaction. Specifically, they can be produced by reacting tannic acid with an alkyl halide in a solvent such as tetrahydrofuran or dimethyl sulfoxide in the presence of a basic catalyst. The basic catalyst can be one or more catalysts selected from the group MH, M2CO3, and M (M: alkali metal). For example, K2CO3 converts an OH group to O - M + This can promote the nucleophilic reaction of the O-group to an alkyl halide (X-R1: X: halogen, R1: alkyl group). Examples of alkyl halides that can be used include alkyl iodides. Instead of alkyl halides, those having a sulfonyl group or the like as a leaving group can also be used. Alkylation reactions other than the Williamson ether synthesis method can also be used. Furthermore, dehydration condensation reactions with carboxylic acids using condensing agents such as N,N'-dicyclohexylcarbodiimide (DCC) and condensation reactions with isocyanates can also be used.

[0046] The reaction is carried out at a temperature between 70°C and 100°C for approximately 1 hour. Figure 1 shows an example of the derivatization of tannic acid of formula (1). Using K2CO3 as a basic catalyst, the reaction mixture is heated to 85°C in DMF to give a derivative (TA(C 10 ) 9) is shown. By changing the molar ratio of alkyl halide to tannic acid, the value of n, which is the number of alkyl groups introduced into tannic acid, can be set to the desired value.

[0047] [Other additives] The resin film of this embodiment may contain one or more of the following components, as long as they do not impair the object of the present invention: antistatic agents, heat stabilizers, nucleating agents, antioxidants, lubricants, antiblocking agents, release agents, UV absorbers, colorants, etc. In particular, to ensure processability during film formation and packaging suitability for filling machines, the coefficient of friction of the film surface is preferably 1.5 or less, and more preferably 1.0 or less. Therefore, it is preferable to appropriately contain a lubricant, antiblocking agent, and / or antistatic agent. The content of these additives in the resin film is preferably 5% by mass or less, more preferably 3% by mass or less. For this reason, the content of the resin component in the resin film (the total content of the resin component and the antifogging agent when an antifogging agent is contained) is preferably 95% by mass or more, more preferably 97% by mass or more.

[0048] <Method of manufacturing resin film> The method for producing the resin film of the present embodiment is not particularly limited, but for example, a masterbatch pellet obtained by melt-kneading a polyolefin resin and a tannic acid derivative in an extruder or the like can be obtained as is, or other additives can be added to polyolefin resin pellets and the film can be obtained by an extrusion method.

[0049] <Laminate> The laminate of this embodiment has a laminate structure including the above-mentioned resin film and thermoplastic resin film, with the resin film as the outermost layer. The total number of layers in the laminate is not particularly limited as long as it includes a resin film and a thermoplastic resin film, and may be composed of two layers of a resin film and a thermoplastic resin film, or may be composed of three layers of a resin film (surface layer), a thermoplastic resin film (sealing layer), and an intermediate film (intermediate layer) between the resin film and the thermoplastic resin film. The laminate may also be composed of four or more layers including a resin film and a thermoplastic resin film.

[0050] [Thermoplastic resin film] Specifically, the thermoplastic resin film is preferably one or two types selected from polyethylene-based resins and polypropylene-based resins, and more preferably a polyethylene-based resin or a polypropylene-based resin.

[0051] (Polyethylene resin) Examples of polyethylene resins for thermoplastic resin films include polyethylene resins such as very low-density polyethylene (VLDPE), linear low-density polyethylene (LLDPE), linear medium-density polyethylene (LMDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); ethylene copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers. These may be used alone or in combination. Among these, LLDPE, LMDPE, and HDPE are preferred from the viewpoints of tearability and the pinhole resistance and rigidity of multilayer films.

[0052] (Polypropylene resin) Examples of polypropylene-based resins for thermoplastic resin films include propylene homopolymers; propylene-ethylene copolymers; propylene-α-olefin random copolymers such as propylene-1-butene copolymers, ethylene-1-butene copolymers, and propylene-ethylene-1-butene terpolymers; and metallocene-catalyzed polypropylenes. These may be used alone or in combination. Among these, propylene-α-olefin random copolymers are preferred, with propylene-α-olefin random polymers polymerized using metallocene catalysts being particularly preferred. When these polypropylene-based resins are used as thermoplastic resin films, the film's heat resistance and softening temperature can be increased, making them suitable for use as laminating films for packaging materials with excellent steam and high-pressure heat sterilization properties, such as boiling or hot filling at temperatures below 100°C or retort sterilization at temperatures above 100°C.

[0053] The thermoplastic resin film obtained above may be used by laminating it with another substrate film. The other substrate film that can be used in this case is not particularly limited, but from the viewpoint of easily achieving the effects of the present invention, it is preferable to use a plastic substrate, particularly a biaxially stretched thermoplastic resin film. In addition, for applications that do not require transparency, aluminum foil can be used alone or in combination.

[0054] Examples of stretched thermoplastic resin films include biaxially oriented polyester (PET), biaxially oriented polypropylene (OPP), biaxially oriented polyamide (PA), coextruded biaxially oriented polypropylene with a central layer of ethylene-vinyl alcohol copolymer (EVOH), biaxially oriented ethylene-vinyl alcohol copolymer (EVOH), coextruded biaxially oriented polypropylene coated with polyvinylidene chloride (PVDC), etc. These may be used alone or in combination.

[0055] Assuming that the resin film is (F1) and the thermoplastic resin film is (F2), the laminate may have the following specific configurations, but is not limited to these. Resin film of polyethylene resin and tannic acid derivative (f1) / polypropylene resin (f2) Resin film of polyethylene resin and tannic acid derivative (f1) / polyethylene resin (f2) Resin film of polypropylene resin and tannic acid derivative (f1) / polypropylene resin (f2) Resin film of polypropylene resin and tannic acid derivative (f1) / polyethylene resin (f2) Resin film of polyester resin and tannic acid derivative (f1) / polyethylene resin (f2) Resin film of polyester resin and tannic acid derivative (f1) / polypropylene resin (f2) Resin film of polystyrene resin and tannic acid derivative (f1) / polyethylene resin (f2) Resin film of polystyrene resin and tannic acid derivative (f1) / polypropylene resin (f2)

[0056] <Method of manufacturing laminate> The method for producing the laminate of the present embodiment is not particularly limited, but the laminate can be produced by, for example, a coextrusion method in which a polyolefin resin and a tannic acid derivative are melt-kneaded in an extruder or the like to obtain masterbatch pellets, and then the masterbatch pellets and each resin or resin mixture used in the laminate are heated and melted in separate extruders, and laminated in a molten state while being heated and melted using a coextrusion multilayer die method, a feed block method, or the like, and then formed into a film by inflation, a T-die chill roll method, or the like.

[0057] [Specific configuration of laminate and packaging or container] The packaging or container according to this embodiment uses the above-mentioned resin film or the above-mentioned laminate, and the form thereof is not particularly limited. Hereinafter, a packaging or container using a laminate will be described as an example. A packaging or container using a resin film is similar to a packaging or container using a laminate, and therefore a description thereof will be omitted. 2A and 2B are cross-sectional views showing an example of a specific configuration of the laminate according to this embodiment. 2A, laminate 10 has a layered structure including resin film 11 and thermoplastic resin film 12, with resin film 11 being the outermost layer. Resin film 11 contains (1) a polyolefin resin and (2) a tannic acid derivative in which at least a portion of a plurality of hydroxyl groups has been substituted with a chain hydrocarbon group having 1 to 18 carbon atoms. This makes it possible to inhibit the proliferation of bacteria, viruses, etc. with a simplified layer structure.

[0058] Also, as shown in FIG. 2B, it may have a laminated structure including a resin film 11, a thermoplastic resin film 12, and an intermediate film 13 arranged between the resin film 11 and the thermoplastic resin film 12, with the resin film 11 being the outermost layer. The intermediate film 13 is not particularly limited, but is preferably a polyethylene-based resin or a polypropylene-based resin. Examples of the polyethylene-based resin for the intermediate film include polyethylene resins such as very low-density polyethylene (VLDPE), linear low-density polyethylene (LLDPE), linear medium-density polyethylene (LMDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers.

[0059] Examples of polypropylene resins for the intermediate film include propylene homopolymers; propylene-ethylene copolymers; propylene-α-olefin random copolymers such as propylene-1-butene copolymers, ethylene-1-butene copolymers, and propylene-ethylene-1-butene terpolymers; and metallocene-catalyzed polypropylenes.

[0060] FIG. 3 is a perspective view showing an example of a specific configuration of a container using the laminate 10 according to this embodiment. As shown in FIG. 3, the container 30 includes a container body 31 and a laminate 10 attached to the container body 31. The laminate 10 has a laminated structure including a resin film 11 and a thermoplastic resin film 12, with the resin film 11 being the outermost layer. The thermoplastic resin film 12 constitutes the innermost layer of the lid. In this embodiment, the laminate 10 constitutes the lid of a container body 31 and is attached to the container body 31 so as to close an opening 32 of the container body 31. At this time, the thermoplastic resin film 12 seals the internal space 33, isolating it from the outside, and the internal space 33 is maintained in a sealed or airtight state.

[0061] In this embodiment, the resin film 11 constitutes the outermost layer of the lid material, and the specific tannic acid derivative is held inside or on the surface of the resin of the resin film 11. As a result, the resin film 11 suppresses the growth of bacteria, viruses, and the like in the container 30.

[0062] FIG. 4 is a perspective view showing another example of a specific configuration of a package using the laminate 10 according to this embodiment. 4, packaging body 40 includes an exterior portion 41 formed by bonding together a plurality of laminates 10, and a storage portion 42 formed inside exterior portion 41. Laminate 10 has a laminated structure including resin film 11 and thermoplastic resin film 12, with resin film 11 as the outermost layer. Storage portion 42 is formed, for example, by bonding together laminate 10 located at the bottom and laminate 10 located at the outer periphery.

[0063] The thermoplastic resin film 12 is provided on a portion of the surface of the resin film 11, and is disposed in the opening 43 of the exterior part 41. After the contents are placed in the storage part 42 of the package 40, the opening 43 is closed and the thermoplastic resin films 12 are heat-sealed while abutting against each other, thereby isolating the storage part 42 from the outside and maintaining the storage part 42 in a sealed or airtight state.

[0064] In this embodiment, the resin film 11 constitutes the outermost layer of the package 40, and the specific tannic acid derivative is held inside or on the surface of the resin of the resin film 11. According to this configuration, the resin film 11 suppresses the growth of bacteria, viruses, and the like in the package 40.

[0065] FIG. 5A is a perspective view showing another example of a specific configuration of a package using the laminate 10 according to this embodiment, and FIG. 5B is a cross-sectional view taken along line II in FIG. 5A. 5A and 5B, the package 50 includes an exterior part 51 formed by bonding two sheets of the laminate 10 together, and a storage part 52 formed inside the exterior part 21. The storage part 52 can store contents C, such as food, medicine, etc. The storage part 52 may contain a gas such as air, or may be in a reduced pressure state such as a vacuum.

[0066] The laminate 10 has a laminate structure including a resin film 11 and a thermoplastic resin film 12, with the resin film 11 being the outermost layer.

[0067] The exterior part 51 is formed, for example, by bonding together two thermoplastic resin films 12 provided on two laminates 10. By sealing the thermoplastic resin films 12, the storage part 52 is isolated from the outside, and the storage part 52 is maintained in a sealed or airtight state.

[0068] In this embodiment, the resin film 11 constitutes the outermost layer of the package 50, and the specific tannic acid derivative is held inside or on the surface of the resin of the resin film 11. According to this configuration, the resin film 11 suppresses the growth of bacteria, viruses, etc. in the package 50. Furthermore, the layer configuration can be simplified, which allows for weight reduction and cost reduction of the package.

[0069] FIG. 6 is a perspective view showing another example of a specific configuration of a container using the laminate 10 according to this embodiment. As shown in FIG. 6, the container 60 includes a container body 61 and two laminates 10-1 and 10-2 attached to the container body 61.

[0070] The laminate 10-1 has a laminated structure including a resin film 11 and a thermoplastic resin film 12, with the resin film 11 as the outermost layer. The laminate 10-1 constitutes a lid for a container body 61, and is attached to the container body 61 so as to close an opening 62 of the container body 61. At this time, the thermoplastic resin film 12 seals the internal space 63, isolating it from the outside, and the internal space 63 is maintained in a sealed or airtight state.

[0071] The resin film 11 of the laminate 10-1 constitutes the outermost layer of the container 60, and the specific tannic acid derivative is held inside the resin of the resin film 11 or on the resin surface thereof.

[0072] Like the laminate 10-1, the laminate 10-2 has a laminate structure including a resin film 11 and a thermoplastic resin film 12, with the resin film 11 being the outermost layer. The laminate 10-2 is attached to the outer surface, for example, the outer peripheral surface, of the container body 61. The resin film 11 of the laminate 10-2 constitutes the outermost layer of the container 60, and the specific tannic acid derivative is held inside or on the resin surface of the resin film 11. With this configuration, the resin films 11, 11 of the laminates 10-1, 10-2 can suppress the growth of bacteria, viruses, and the like in the container 60. [Example]

[0073] Examples of the present invention will be described below. The present invention is not limited to the examples shown below. In the examples, "parts" means mass % unless otherwise specified.

[0074] (Synthesis of tannic acid derivatives) [Synthesis Example 1] 35 parts of tannic acid (Tokyo Chemical Industry Co., Ltd.) and 65 parts of n-methyl iodide were dissolved in N,N-dimethylformamide (hereinafter referred to as DMF), 63 parts of potassium carbonate was added, and the mixture was reacted for 10 hours at 85° C. After that, the DMF was distilled under reduced pressure, washed with water, and dried to obtain a tannic acid derivative (TA1-5) substituted with 5 equivalents (20% of the number of substituents) of alkyl groups having one carbon atom.

[0075] (Preparation of antibacterial masterbatch "Antibacterial MB(1)" based on propylene-ethylene copolymer) [Preparation Example 1] A propylene-ethylene copolymer (MFR (230°C) 7 g / 10 min, melting point 130°C) and a tannic acid derivative (TA1-5) were mixed in a mass ratio of 80 / 20, melted and kneaded in an extruder, and then the mixture was put into a granulator to obtain antibacterial masterbatch pellets (hereinafter referred to as antibacterial agent MB(1)).

[0076] (Preparation of antibacterial masterbatch "Antibacterial MB(2)" based on linear polyethylene) [Preparation Example 2] Linear polyethylene (MFR (190°C) 4 g / 10 min, density 0.905 g / cm3) and a tannic acid derivative (TA1-5) were mixed in a mass ratio of 80 / 20, melt-kneaded in an extruder, and then processed in a granulator to obtain antibacterial masterbatch pellets (hereinafter referred to as antibacterial agent MB(2)).

[0077] Example 1 The resin mixtures for the surface layer, intermediate layer, and seal layer were prepared using the following resins: These mixtures were fed into three extruders and co-extruded to form a 30-μm-thick laminate, with the average thicknesses of the surface layer, intermediate layer, and seal layer being 7 μm, 18 μm, and 5 μm, respectively.

[0078] Surface layer: Propylene-ethylene copolymer (ethylene-derived component content: 4.2%, density: 0.90 g / cm 3 15 parts by mass of propylene-ethylene-1-butene terpolymer (density: 0.90 g / cm 3 ), melt index (hereinafter referred to as MI): 6 g / 10 min, melting point: 140°C) 3 25 parts by mass of crystalline ethylene-1-butene copolymer (density: 0.88 g / cm , MFR: 5.4 g / 10 min (190 °C, 21.18 N)) 3 A mixture of 10 parts by mass of MI (4 g / 10 min) and 50 parts by mass of antibacterial agent MB (1) Middle layer: propylene homopolymer (density: 0.90 g / cm 3 , MFR: 7.5 g / 10 min) 75 parts by mass, and propylene-ethylene copolymer (ethylene content: 5.2%, density: 0.90 g / cm 3 , MFR: 5.4 g / 10 min) 10 parts by mass, and linear low-density polyethylene (density: 0.905 g / cm 3 , MFRI: 4.0 g / 10 min) 10 parts by mass of resin mixture Seal layer: propylene-ethylene copolymer (ethylene-derived component content: 5.0 mass%, density: 0.90 g / cm 3 , MFR (measurement temperature 230 °C): 7 g / 10 min) 70 parts by mass, and propylene-1-butene copolymer (density: 0.90 g / cm 3 , MFR (measurement temperature 230 ° C): 4 g / 10 minutes) 30 parts by mass of resin mixture

[0079] Example 2 The following resins were used as the resin components for the surface layer, intermediate layer, and seal layer to prepare resin mixtures for each layer. These mixtures were fed into three extruders and co-extruded so that the average thicknesses of the surface layer, intermediate layer, and seal layer laminate were 7 μm, 18 μm, and 5 μm, respectively, to form a 30 μm-thick laminate. The surface layer of the resulting laminate was then subjected to corona discharge treatment to achieve a surface energy of 35 mN / m, yielding a laminate.

[0080] Surface layer: propylene-ethylene block copolymer resin (propylene-derived component content: 90% by mass, density: 0.90 g / cm 3 , MFR (measurement temperature 230 ° C): 5 g / 10 min) 50 parts by mass and antibacterial agent MB (1) 50 parts by mass Intermediate layer: 50 parts by mass of propylene-ethylene block copolymer (density: 0.90 g / cm3, MI: 8 g / 10 min, melting point 160 °C) and 50 parts by mass of propylene-ethylene random copolymer (ethylene content: 5.2%, density: 0.90 g / cm 3 , MFR: 5.4 g / 10 min) 40 parts by mass, and linear low-density polyethylene (density: 0.905 g / cm 3 , MFRI: 4.0 g / 10 min) 10 parts by mass of resin mixture Seal layer: Propylene-ethylene random copolymer (ethylene-derived component content: 5.0 mass%, density: 0.90 g / cm 3 , MFR (measurement temperature 230 °C): 7 g / 10 min) 70 parts by mass, and propylene-1-butene copolymer (density: 0.90 g / cm 3 , MFR (measurement temperature 230 ° C): 4 g / 10 minutes) 30 parts by mass of resin mixture

[0081] Example 3 The following resins were used to prepare the resin mixtures for the surface layer, intermediate layer, and seal layer. These mixtures were fed into three extruders and co-extruded to form a 30-μm-thick laminate, with the average thicknesses of the surface layer, intermediate layer, and seal layer being 10 / 16 / 4 μm. The surface layer of the resulting laminate was then subjected to corona discharge treatment to achieve a surface energy of 39 mN / m. A 12-μm polyester film was then attached using Dikdry LX510 / KR90 adhesive to obtain a laminate.

[0082] Surface layer: (Laminate layer) resin is linear low-density polyethylene (density: 0.935 g / cm 3 , MFRI: 4.0 g / 10 minutes) 50 parts by mass and antibacterial agent MB (2) 50 parts by mass Middle layer: Linear low-density polyethylene (density 0.933 g / cm 3 , MFR5.0g / 10min) 100 parts by mass Heat seal layer: 100 parts by weight of propylene-ethylene copolymer [MFR (230°C) 7 g / 10 min, melting point 130°C]

[0083] As a result, it was confirmed that in all of Examples 1 to 3, when a surface layer was formed using a mixture in which a tannic acid derivative substituted with an alkyl group having one carbon atom was contained in a polyolefin resin, a resin film that stably retained tannic acid could be formed. Therefore, it is presumed that the resin film or a laminate having the resin film inhibits bacterial growth and exhibits sufficient antibacterial properties. [Explanation of symbols]

[0084] 10 Laminate 10-1 Laminate 10-2 Laminate 11 Resin film 12 Thermoplastic resin film 13 Intermediate Film 20 Packaging 21 Exterior part 22 Storage section 30 containers 31 Container body 32 Opening 33 Interior Space 40 Packaging 41 Exterior part 42 Storage section 43 Opening 50 Packaging 51 Exterior part 52 Storage section 60 containers 61 Container body 62 Opening 63 Interior Space

Claims

1. A resin film comprising a polyolefin resin and a tannic acid derivative in which at least a portion of a plurality of hydroxyl groups of tannic acid are substituted with a chain hydrocarbon group having 1 to 18 carbon atoms.

2. The resin film according to claim 1 , wherein the polyolefin resin is one or more selected from the group consisting of polyethylene-based resins, polypropylene-based resins, and polybutylene-based resins.

3. The resin film according to claim 1 or 2, wherein the tannic acid derivative is present in an amount of 0.5% by mass or more and 30% by mass or less relative to the total amount of the resin film.

4. A packaging body or container in which the resin film according to any one of claims 1 to 3 is used.

5. A packaging body or container comprising a container body and one or more resin films according to any one of claims 1 to 3 attached to the container body.

6. The packaging body or container according to claim 5 , wherein the resin film constitutes a lid material for the container body.

7. The packaging or container according to claim 5 , wherein the resin film is attached to the outer surface of the container body.

8. A package or container comprising an exterior part formed by laminating one or more resin films according to any one of claims 1 to 3, and a storage part formed inside the exterior part.

9. A laminated structure including the resin film according to any one of claims 1 to 3 and a thermoplastic resin film, A laminate having the resin film as an outermost layer.

10. A package or container in which the laminate according to claim 9 is used.

11. A package or container comprising a container body and one or more laminates according to claim 9 attached to the container body.

12. 12. The package or container according to claim 11, wherein the laminate constitutes a lid material for the container body.

13. 12. The package or container of claim 11, wherein the laminate is attached to an exterior surface of the container body.

14. A package or container comprising: an exterior part formed by laminating one or more of the laminates according to claim 9; and a storage part formed inside the exterior part.

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