Antimicrobial film and package

0001The present invention relates to antibacterial films and packaging. More specifically, it relates to an antibacterial film for vacuum packaging of food.

0002As an antibacterial film used for preserving food, a film containing an antibacterial agent is known.

0003For example, Japanese Patent Application Laid-Open No. 05-000074 (Patent Document 1) describes a food product in which at least a part or all of the inner surface in contact with the contents is filled with chitosan and sealed. The storage method of is described. This container uses a laminated body in which a plurality of thermoplastic resins are co-extruded by a co-extrusion method and laminated so that at least the layer containing chitosan is on the end side, and the layer containing chitosan in the laminated body is inside. The resin produced by vacuum forming type 1, pressure air forming, vacuum pressure air forming or heat sealing, and heat-melted resin by the extrusion coating method or the extrusion method is extruded from the T die and cooled by a cooling roll. In the meantime, the chitosan is sprayed on the extruded resin or on the cooling roll by the chitosan spraying means, cooled by the cooling roll, and then the chitosan is retained on the resin surface. Resin film, resin sheet or laminated resin film, laminated resin Any of the methods of vacuum forming, pressure forming, vacuum pressure forming or heat sealing using a sheet so that the surface of the resin film, resin sheet or laminated resin film, or laminated resin sheet having chitosan is on the inside. Manufactured in.

0004For example, according to International Publication No. 2008/139593 (Patent Document 2), a two-layer plastic sheet in which a polyethylene film containing an antioxidant and an antibacterial agent is laminated on the inner layer and a polyvinyl alcohol film having a high gas barrier property is laminated on the outer layer. A plastic sheet for a packaging container is disclosed, which comprises.

<p num="0005"><patcit num="1"><text>Japanese Unexamined Patent Publication No. 05-000074</text></patcit><patcit num="2"><text>International Publication No. 2008/139593 Pamphlet</text></patcit></p>

<p num="0006"> However, chitosan used in the container described in Japanese Patent Application Laid-Open No. 05-000074 is water-soluble. Therefore, although the film in which chitosan is held on the surface by the spraying means has a high antibacterial effect, it has a property of eluting chitosan into the food in contact with it. That is, the film in which chitosan is retained on the surface has a problem in that an additive that is unnecessary for food is added. On the other hand, when chitosan is included in the layer, there is a problem in antibacterial effect.</p><p num="0007"> The plastic sheet for packaging containers described in International Publication No. 2008/139593 has a problem in antibacterial effect because most of the antibacterial agents are contained in the polyethylene film.</p><p num="0008"> Therefore, an object of the present invention is to provide an antibacterial film and a package having high antibacterial properties and high safety against food.</p>

<p num="0009"> Such an object is achieved by the present invention described in the following (1) to (8).</p><p num="0010"> (1) At least a sealant layer and a support layer laminated in contact with the sealant layer are included, the sealant layer contains antibacterial particles, and a part of the surface of the antibacterial particles is the sealant layer. The resin film exposed from the surface opposite to the support layer, and the resin film was cut into a size of 5 cm × 5 cm and immersed in 50 mL of pure water at 25 ° C. for 24 hours. A resin film characterized in that the amount of metal ion extracted from the resin film to the pure water is 0.05 ppm / cm2 or more and 1.0 ppm / cm2 or less. (2) The antibacterial film according to claim 1, wherein the antibacterial particles are inorganic antibacterial agents.</p><p num="0011"> (3) The antibacterial film according to any one of (1) and (2), wherein the antibacterial particles have an average particle size of 2 μm or more and 10 μm or less.</p><p num="0012"> (4) The antibacterial film according to any one of (1) to (3), wherein the resin constituting the support layer and the resin constituting the sealant layer are polyolefin-based resins.</p><p num="0013"> (5) The antibacterial film according to (4), wherein the polyolefin-based resin is any one of a polyethylene-based resin, a polypropylene-based resin, and a mixed resin of a polyethylene-based resin and a polypropylene-based resin.</p><p num="0014"> (6) The antibacterial film according to any one of (1) to (5), wherein the sealant layer has a layer thickness of 50% or more and 300% or less of the average particle size of the antibacterial particles.</p><p num="0015"> (7) At least one of a pinhole resistant resin layer, an oxygen barrier resin layer, a glossy resin layer, a steam barrier resin layer, and a retort resistant resin layer is further laminated on the support layer. The antibacterial film according to any one of (1) to (6).</p><p num="0016"> (8) A package containing the antibacterial film according to any one of (1) to (7).</p>

<p num="0017"> According to the present invention, it is possible to provide an antibacterial film and a package having excellent safety, antibacterial properties and appearance.</p>

0018<figref num="1">It is a schematic cross-sectional view which shows an example of the antibacterial film which concerns on 1st Embodiment.</figref><figref num="2">It is a partially enlarged view of FIG.</figref><figref num="3">It is a schematic cross-sectional view which shows the other example of the antibacterial film which concerns on 1st Embodiment.</figref><figref num="4">It is a schematic cross-sectional view which shows the other example of the antibacterial film which concerns on 1st Embodiment.</figref><figref num="5">It is a schematic cross-sectional view which shows the other example of the antibacterial film which concerns on 1st Embodiment.</figref><figref num="6">It is a schematic cross-sectional view which shows the other example of the antibacterial film which concerns on 1st Embodiment.</figref><figref num="7">It is a schematic cross-sectional view which shows an example of the package | body which concerns on 2nd Embodiment.</figref>

0019Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same elements have the same reference numerals, and their names and functions are also the same. Therefore, the detailed description of them will not be repeated.

0020[First Embodiment] FIG. 1 is a schematic cross-sectional view showing an example of the antibacterial film according to the first embodiment. FIG. 2 is a partially enlarged view of FIG. In the following, for convenience of explanation, the upward direction of FIGS. 1 and 2 may be described as upward, and the downward direction may be described as downward, but these directions are absolute during manufacturing and use. Yes, it does not point in the direction.

0021[Antibacterial film] As shown in FIG. 1, the antibacterial film 100 includes a sealant layer 210, a support layer 220, antibacterial particles 230, an intermediate layer 300, an outer layer 400, and an adhesive layer 510,520.

0022The support layer 220 is provided in contact with the sealant layer 210. The intermediate layer 300 is provided on the support layer 220 via the adhesive layer 510. Further, the outer layer 400 is provided on the intermediate layer 300 via the adhesive layer 520.

0023As shown in FIG. 2, the sealant layer 210 is embedded with antibacterial particles 230. Further, a part 231 of the surface of the embedded antibacterial particles 230 protrudes from the surface 211 opposite to the support layer 220 and is exposed. The sum of the area of a part 231 (exposed area) of the surface of the exposed antibacterial particles 230 and the area of the surface 211 where the antibacterial particles 230 are not exposed is the sum of the area of the sealant layer 210 when the antibacterial particles 230 are not embedded. The area of the virtual surface 211V is 1.005 times, preferably 1.01 times. Since the antibacterial property reaches a plateau by securing the exposed area of the antibacterial particles 230 to some extent, the upper limit value within the range of the exposed area is not particularly limited. On the other hand, from the viewpoint of ensuring transparency, the upper limit within the range of the exposed area is, for example, 1.1 times.

0024The antibacterial film 100 is the amount of metal ions extracted from the antibacterial film into the pure water when the antibacterial film is cut into 5 cm × 5 cm and immersed in 50 mL of pure water for 24 hours at 25 ° C. However, it is 0.05 ppm / cm2 or more and 1.0 ppm / cm2 or less. As a result, the criterion of antibacterial effect "bacterial activity value 2.0 or more" defined in the antibacterial property test based on JIS Z2801 can be achieved. When the amount of metal ion extracted is 0.05 ppm / cm2 or more, excellent antibacterial performance is obtained, which is preferable. Further, when the amount of metal ion extracted is less than 1.0 ppm / cm2, good transparency is preferable, and when it is less than 0.5 ppm / cm2, further good transparency is preferable.

0025In the present invention, since the antibacterial particles 230 are exposed in the antibacterial film 100 as described above, the antibacterial film is cut into 5 cm × 5 cm and immersed in 50 mL of pure water at 25 ° C for 24 hours. The amount of metal ions extracted from the antibacterial film to the pure water can be 0.05 ppm / cm2 or more and 1.0 ppm / cm2 or less. Further, by appropriately changing the thickness, material, and additive of the sealant layer, the amount of metal ion extracted can be 0.05 ppm / cm2 or more and 1.0 ppm / cm2 or less.

0026The total thickness T4 of the antibacterial film 100 is 40 μm or more and 300 μm or less, for example, 100 μm. When the total thickness T4 of the antibacterial film 100 is in the above range, good moldability is obtained, which is preferable. The cloudiness of the antibacterial film 100 is 40% or less, preferably 30% or less. When the cloudiness is in the above range, good transparency is obtained, which is preferable.

0027[Sealant layer] The resin constituting the sealant layer 210 is often a thermoplastic transparent resin. A polyolefin-based resin is preferable. Examples of the polyolefin-based resin include homopolymers or copolymers of α-olefins having 2 or more and 12 or less carbon atoms, preferably 2 or more and 6 or less carbon atoms.

0028The sealant layer 210 has antibacterial performance and a heat sealing function.

0029In the case of a copolymer, the copolymerization mode may be alternating copolymerization, random copolymerization or block copolymerization. For example, random and / or block copolymers of ethylene monomers or propylene monomers with other α-olefin monomers, specifically polypropylene-ethylene copolymers, propylene-1-hexene copolymers, propylene-4- Examples thereof include a methyl-1 pentane copolymer, poly 4-methyl-1-pentene, and polybutene-1. These resins can be used alone or in combination of two or more.

0030In the present invention, the polyolefin-based resin is an ethylene homopolymer and copolymer (polyethylene-based resin), a propylene homopolymer and copolymer (polypropylene-based resin), and a polyethylene-based resin and a polypropylene-based resin. It is preferably selected from mixed resins. As a result, the antibacterial film 100 of the present invention is excellent in handleability during production. Handleability includes slipperiness, sealing property, and other ease of handling.

0031Among the polyethylene-based resins, the ethylene homopolymerized resin is a branched polyethylene composed substantially only of ethylene monomers. From the viewpoint of transparency, the density of the ethylene homopolymerized resin is preferably 910 kg / m3 or more and less than 930 kg / m3. A preferred example of such branched polyethylene is low density polyethylene (LDPE).

0032Among the polyethylene-based resins, the ethylene copolymer resin is a resin composed of an ethylene monomer and other comonomer. Preferably, it is a linear ethylene copolymer resin having a straight chain of polyethylene as a main chain and a side chain derived from a comonomer. Further, as the ethylene copolymer resin, the following resins may be used alone or in a mixed mode of a plurality of types.

0033Examples of the comonomer of the ethylene copolymer resin include at least one of an α-olefin, a vinyl compound, and an acrylamide compound.

0034The α-olefin as a comonomer has 3 or more and 20 or less carbon atoms, preferably 3 or more and 12 or less, and more preferably 4 or more and 8 or less. More specifically, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 4 -Methyl-1-hexene and the like can be mentioned. These α-olefins may be used alone or in combination of two or more.

0035More specific examples of the ethylene copolymer resin using α-olefin as a comonomer include linear low density polyethylene (L-LDPE), medium density polyethylene (MDPE) and high density polyethylene (HDPE).

0036The vinyl compound as a comonomer may be, for example, vinyl acetate, an unsaturated carboxylic acid such as methyl (meth) acrylate, an unsaturated ether such as methyl vinyl ether, ethyl vinyl ether, or butyl vinyl ether. These vinyl compounds may be used alone or in combination of two or more.

0037The acrylamide-based compound as the comonomer may be, for example, N-alkylacrylamide, N, N-dialkylacrylamide, N-alkylmethacrylamide, N, N-dialkylmethacrylamide and the like. These acrylamide compounds may be used alone or in combination of two or more.

0038The polypropylene-based resin may be a homopolypropylene-based resin. Further, the polypropylene-based resin may be a random and / or block copolymer of propylene and α-olefin which is a small amount of other comonomer. The α-olefin as a comonomer is ethylene or carbon number 4 or more and 20 or less, preferably 3 or more and 12 or less, and more preferably 4 or more and 8 or less. More specifically, for example, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 4- Examples thereof include methyl-1-hexene. These α-olefins may be used alone or in combination of two or more.

0039More specifically, propylene-ethylene copolymer, propylene-1-hexene copolymer, poly4-methyl-1-pentene, polybutene-1 and the like can be mentioned. These resins can be used alone or in combination of two or more.

0040The thickness T1 of the sealant layer 210 (see FIG. 1) is preferably designed to have a thickness close to the particle size of the antibacterial particles 230. Specifically, it is, for example, 50% or more and 300% or less of the average particle size of the antibacterial particles 230. Further, the range of the thickness T1 of the sealant layer 210 is set to any two numerical values of 60%, 70%, 80%, 90%, 100%, 110%, 150%, 200% and 250% as the upper and lower limits. It may be a range. More specifically, the range of the thickness T1 of the sealant layer 210 is, for example, 3 μm or more and 15 μm or less, preferably 3.5 μm or more and 12.5 μm or less.

0041When the thickness T1 is 50% or more of the average particle diameter of the antibacterial particles 230, the transparency is good, and when it is 300% or less, the antibacterial particles 230 are easily exposed and the antibacterial properties are easily ensured.

0042Here, in the present invention, the surface 211M and / or the surface 212M that define the thickness T1 of the sealant layer 210 shown in FIG. 1, the thickness T2 of the support layer 220 described later, and the total thickness T4 of the antibacterial film 100 are antibacterial particles 230. Is the surface averaged in consideration of the surface protruding from the surfaces 211 and 212 (see FIG. 2) of the sealant layer 210. Therefore, the thickness T1 of the sealant layer 210 shown in FIG. 1, the thickness T2 of the support layer 220 described later, and the total thickness T4 of the antibacterial film 100 mean the average thickness in consideration of the protrusion of the antibacterial particles 230.

0043Since the thickness T1 of the sealant layer 210 is composed of a thin thickness close to that of the antibacterial particles 230, as shown in FIG. 2, a part 232 of the other surface of the antibacterial particles 230 is formed from the surface 212 on the support layer 220 side. Some may stick out. Therefore, in this case, the surface 212 of the sealant layer 210 has poor surface smoothness. A support layer 220 is provided to buffer the surface non-smoothness of the surface 212 of the sealant layer 210. Specifically, a part 232 of the other surface of the antibacterial particles 230 protruding from the surface 212 of the sealant layer 210 is fitted into the support layer 220 to buffer the surface non-smoothness of the surface 212 of the sealant layer 210. To do. As a result, the surface 222 of the support layer 220 opposite to the sealant layer 210 becomes smooth.

0044[Antibacterial particles] The antibacterial particle 230 contains an antibacterial substance and a carrier carrying the antibacterial substance.

0045The antibacterial particle 230 in the present invention is a particle having an antibacterial substance. Preferably, the antibacterial substance is an inorganic antibacterial agent which is an inorganic antibacterial substance. Many inorganic antibacterial agents have high safety because the migration of antibacterial particles themselves is suppressed, and are particularly useful when the antibacterial film 100 is applied to food packaging.

0046As the inorganic antibacterial substance, those containing metal ions are preferable, and those containing silver, copper, and zinc ions are particularly mentioned. Among these, those containing silver ions are preferable from the viewpoint of antibacterial effect and safety. Examples of the compound containing silver ions include silver nitrate and the like. Examples of the carrier include silicate-based carriers such as zeolite (crystalline aluminosilicate), silica gel, and clay minerals, phosphate-based carriers such as zirconium phosphate and calcium phosphate, soluble glass, activated charcoal, metal carriers, and organic metals. Can be mentioned.

0047The average particle size of the antibacterial particles 230 is, for example, 2 μm or more and 10 μm or less, preferably 2.5 μm or more and 8 μm or less. When the average particle size is 2 μm or more, the antibacterial particles are easily exposed and the dispersion of light in the sealant layer can be suppressed. Moreover, since the average particle size is 10 μm or less, the film forming stability is excellent.

0048The average particle size means the particle size at an integrated value of 50% in the particle size distribution obtained by the laser diffraction / scattering method.

0049[Support layer] The support layer 220 is a layer that is substantially free of antibacterial particles 230. Substantially free of antibacterial particles 230, as described in FIG. 2, except for a portion of the other surface of the antibacterial particles 230 protruding from the surface 212 of the sealant layer 210, in which a portion 232 is fitted. It means that it does not contain antibacterial particles 230.

0050The support layer 220 has a function of improving pinhole resistance.

0051The resin constituting the support layer 220 is a transparent resin having flexibility. Preferably, the resin constituting the support layer 220 is a polyolefin-based resin. Examples of the polyolefin-based resin include those exemplified as the resin constituting the sealant layer 210.

0052The resin constituting the support layer 220 may be the same as or different from the resin constituting the sealant layer 210. The resin constituting the support layer 220 is preferably the same type as the resin constituting the sealant layer 210. When the resin constituting the support layer 220 and the resin constituting the total sealant 210 are of the same type, it is possible to suppress the generation of flow marks and the decrease in cloudiness due to the rough interface, and the appearance is excellent. In the present invention, when the resin constituting the support layer 220 is the same as the resin constituting the sealant layer 210, the sealant layer 210 and the support layer 220 are in contact with each other even if the boundary between the two layers is unclear. It is assumed that they are in a laminated state. In this case, the sum of the area of a part 231 (exposed area) of the surface of the exposed antibacterial particles 230 and the area of the surface 211 where the antibacterial particles 230 are not exposed is the sealant when the antibacterial particles 230 are not embedded. The area of the virtual surface 211V of layer 210 is 1.005 times, preferably 1.01 times, and the sum of the layer thicknesses of the sealant layer 210 and the support layer 220 (see FIG. 1) is 360% of the average particle size of the antibacterial particles 230. If it is more than 5000% or less, it can be judged that it is the constitution of the present invention.

0053The support layer 220 preferably has an internal haze of 10% or less in order to preferably ensure the transparency of the antibacterial film 100. Here, the internal haze of the support layer 220 is the degree of cloudiness due to the scattering that can be generated by the support layer 220. Specifically, when measuring film haze according to JIS-K-7105, a sample in which transparent tape is attached to both sides of the film in order to eliminate light scattering due to unevenness on the surface of the film (antibacterial film 100). Was prepared, the internal haze was measured using a haze meter, and only the light scattering inside the film (support layer 220) was extracted.

0054The thickness T2 of the support layer 220 can be, for example, 300% or more, preferably 400% or more, of the average particle diameter of the antibacterial particles 230 in order to secure the above-mentioned buffering function. Below the above range, the cushioning of the surface non-smoothness of the surface 212 of the sealant layer 210 becomes insufficient, which tends to adversely affect the appearance. The upper limit of the thickness within the range of T2 is not particularly limited, but is, for example, 4700%, preferably 4000%. If it exceeds the above range, it may be difficult to thin the entire antibacterial film 100.

0055[Middle layer and outer layer] The intermediate layer 300 and the outer layer 400 take into consideration the physical characteristics of the adjacent layer, the use of the antibacterial film 100, the manufacturing method, and / or the treatment at the time of manufacturing the package 700 (described later) (retort treatment such as high temperature heat treatment, low temperature boiling treatment, etc.). However, those skilled in the art can appropriately determine the function according to the desired function. The functions assigned to these layers include mechanical properties (eg rigidity, impact resistance, bending resistance and pinhole resistance), retort resistance, water resistance, antistatic resistance, chemical resistance, and fragrance retention. , Non-adsorption property, oxygen barrier property, water vapor barrier property, glossiness, label suitability (that is, the label can be attached following a curved surface and does not easily come off even after a long period of time from the time of application. ) Etc. can be mentioned.

0056For example, examples of the pinhole-resistant resin layer include a polyamide-based resin layer. Examples of the polyamide resin include polycapramid (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), polyundecaneamide (nylon-11), and poly. Lauryl lactam (nylon-12), polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6,6), poly Hexamethylene sebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), polydecamethylene adipamide (nylon-10) , 8), Caprolactam / lauryllactam copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer (nylon-6 / 9), caprolactam / hexamethylenediammon adipate copolymer Combined (nylon-6 / 6,6), lauryl lactam / hexamethylene diammonium adipate copolymer (nylon-12 / 6,6), ethylenediamine adipamide / hexamethylene diammonium adipate copolymer (nylon-2, 6 / 6,6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sevacate copolymer (nylon-6 / 6,6 / 6,12), ethyleneammonium adipate / hexamethylene diammonium adipate / hexamethylene Diammonium sevacate copolymer (nylon-6 / 6,6 / 6, Crystalline polyamides such as 10), etc., the main skeleton of which is a polymer of at least one of terephthalic acid and isophthalic acid and hexamethylenediamine, specifically, a polymer of hexamethylenediamine-isophthalic acid, hexamethylenediamine. -Acrystalline polyamide-based resins such as terephthalic acid polymers and hexamethylenediamine-terephthalic acid-hexamethylenediamine-isophthalic acid copolymers are used. These resins can be used alone or in combination of two or more.

0057Examples of the oxygen barrier resin layer include a layer of ethylene vinyl acetate copolymer saponified product (ethylene-vinyl alcohol copolymer; EVOH). The ethylene copolymerization ratio of EVOH is not particularly limited, but is preferably 24 mol% or more and 44 mol% or less. When the ethylene copolymerization ratio is 24 mol% or more, the workability of the antibacterial film 100 is excellent, and it is possible to satisfactorily suppress the deterioration of the oxygen barrier property due to the influence of heated water or steam. When the ethylene copolymerization ratio is 44 mol% or less, the oxygen barrier property is improved under a dry condition, and the contents are less likely to be deteriorated.

0058Examples of the water vapor barrier resin layer include a layer of high density polyethylene (HDPE) and a polypropylene resin.

0059High-density polyethylene (HDPE) is crystalline potiethylene with a density of 0.942 or higher, in which ethylene monomers are bonded substantially linearly.

0060Examples of the polypropylene-based resin include crystalline polypropylene-based resin. Specifically, the crystalline polypropylene-based resin includes at least one of a crystalline propylene homopolymer, a crystalline propylene-ethylene random copolymer, a crystalline propylene-α-olefin random copolymer, and ethylene and α-olefin. Examples thereof include a crystalline block copolymer with propylene. Examples of the α-olefin include α-olefins having 4 or more and 10 or less carbon atoms such as 1-butene, 1-pentene, 1-hexene, 1-octene and 1-decene. These α-olefins may be copolymerized at an arbitrary ratio.

0061Examples of the glossy resin layer include a polyester resin layer. As the polyester resin, for example, a divalent acid such as terephthalic acid as an acid component, or a derivative thereof having an ester-forming ability is used, and as a glycol component, a glycol having 2 to 10 carbon atoms, another divalent alcohol or the like is used. Examples thereof include saturated polyester resins obtained by using those derivatives having an ester-forming ability. Specific examples of the saturated polyester resin include polyalkylene terephthalate resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, polytetramethylene terephthalate resin, and polyhexamethylene terephthalate resin. These polyester-based resins can improve at least one of the appearance and texture of the antibacterial film 100.

0062Further, the polyester resin may be copolymerized with other components. As the component to be copolymerized, a known acid component, alcohol component, phenol component, these derivatives having an ester-forming ability, a polyalkylene glycol component and the like are used.

0063Examples of the acid component to be copolymerized include an aromatic carboxylic acid having a divalent or higher carbon number of 8 or more and 22 or less, an aliphatic carboxylic acid having a divalent or higher carbon number of 4 or more and 12 or less, and a divalent or higher carbon number of 8 or more. An alicyclic carboxylic acid of 15 or less, and these derivatives having an ester-forming ability are used. Specifically, as the acid component to be copolymerized, for example, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, bis (p-carbodiphenyl) methaneanthranedicarboxylic acid, 4,4'-diphenylcarboxylic acid, 1,2-bis (Phenoxy) Etan-4,4'-dicarboxylic acid, 5-sodium sulfoisophthalic acid, adipic acid, sebacic acid, azelaic acid, dodecandioic acid, maleic acid, trimesic acid, trimellitic acid, pyromellitic acid, 1,3 -Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and derivatives thereof having an ester-forming ability can be mentioned. These acid components can be used alone or in combination of two or more.

0064Examples of the alcohol component and the phenol component to be copolymerized include an aliphatic alcohol having a divalent value or more and a carbon number of 2 or more and 15 or less, an alicyclic alcohol having a divalent value or more and a carbon number of 6 to 20 or less, and a carbon number of 6 to 40. Examples thereof include dihydric or higher aromatic alcohols, divalent or higher phenols, and derivatives thereof having an ester-forming ability. Specifically, as the alcohol component and phenol component to be copolymerized, ethylene glycol, propanediol, butanediol, hexanediol, decanediol, neopentyl glycol, cyclohexanedimethanol, cyclohexanediol, 2,2'-bis (4-) Examples thereof include compounds such as hydroxyphenyl) propane, 2,2'-bis (4-hydroxycyclohexyl) propane, hydroquinone, glycerin, and pentaerythritol, and derivatives thereof having an ester-forming ability.

0065Examples of the polyalkylene glycol component to be copolymerized include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random or block copolymers thereof, and alkylene glycol of bisphenol compounds (polyethylene glycol, polypropylene glycol, polytetramethylene glycol, these. (Random or block copolymers, etc.) Modified polyoxyalkylene glycols such as adducts and the like.

0066Examples of the retort-resistant resin layer include a laminate of a polyamide-based resin layer and an oxygen barrier resin layer. More specifically, a polyamide resin layer, an oxygen barrier layer, and a polyamide resin layer are laminated in this order. By directly laminating the polyamide resin layer so as to be in contact with both sides of the oxygen barrier layer, the restoration of the oxygen barrier property deteriorated by the retort treatment is assisted. That is, the moisture absorbed by the retort treatment is retained in the oxygen barrier resin layer, and the polyamide resin layers are directly laminated on both sides of the oxygen barrier layer to form a polyolefin resin such as an adhesive layer. By not having a moisture-proof layer, the water absorbed by the oxygen barrier resin layer is quickly discharged. It is believed that this preferably helps restore the oxygen barrier property that is reduced by the retort treatment. However, in the present invention, the mechanism for exhibiting retort resistance is not limited to the above. Further, the oxygen barrier resin layer to be a constituent layer of the retort resistant resin layer may contain a resin composition containing a polyamide resin and an ethylene-vinyl alcohol copolymer (EVOH). Thereby, heat resistance barrier property can be imparted. This allows for faster recovery of the oxygen barrier properties reduced by the retort treatment.

0067When the oxygen barrier resin layer, which is a constituent layer of the retort-resistant resin layer, contains a polyamide resin, the content of the polyamide resin is preferably 5% by mass or more and 30% by mass or less, preferably 15% by mass. More preferably, it is% or more and 25% by mass or less. When the content of the polyamide resin is within the above range, it is possible to quickly recover the oxygen barrier property after the retort treatment while maintaining the good oxygen barrier property of EVOH.

0068The ethylene copolymerization ratio of the EVOH resin is not particularly limited, but is preferably 20 mol% or more and 60 mol% or less, and more preferably 25 mol% or more and 50 mol% or less. When the ethylene copolymerization ratio is 25 mol% or more, extrusion is easy, and when it is 50 mol% or less, the oxygen barrier property can be kept good.

0069Further, when the package after packaging the contents with the antibacterial film 100 is subjected to low-temperature boiling treatment, for example, heat sterilization treatment at 60 ° C or higher and 95 ° C or lower, polypropylene resin or polyamide resin having high heat resistance is applied. , A layer such as a polyester resin having a high melting point is preferable.

0070In addition, when the package after packaging the contents with the antibacterial film 100 is not heat-sterilized, the gloss or rigidity is good in order to improve at least one of the appearance of the package and the texture when it is picked up. It is preferably a polyester-based resin, an EVOH resin having good label suitability or rigidity, and the like.

0071[Adhesive layer] The resins constituting the adhesive layers 510 and 520 have the characteristics of the resins constituting the support layer 220, the intermediate layer 300, and the outer layer 400 (specifically, the adhesive strength between the layers, the strength of the resin forming the layers, and the pin resistance. It can be appropriately selected by those skilled in the art depending on the hole property, flexibility, moldability, etc.). The resins constituting the adhesive layers 510 and 520 are transparent resins, and known adhesive resins such as adhesive polyolefin resins are used. More specifically, a modified polyolefin resin modified with an unsaturated carboxylic acid or an acid derivative, and a polymer and a mixture of the modified polyolefin resin and the polyolefin resin can be mentioned. More specifically, ethylene-methacrylate-glycidyl acrylate ternary copolymer and various polyolefins such as polypropylene are grafted with monobasic unsaturated fatty acids, dibasic unsaturated fatty acids, or anhydrides thereof. Etc. are used. Examples of monobasic unsaturated fatty acids include acrylic acid and methacrylic acid. Examples of the dibasic unsaturated fatty acid include maleic acid, fumaric acid, itaconic acid and the like. Therefore, examples of the adhesive resin include a maleic acid grafted ethylene-vinyl acetate copolymer and a maleic acid grafted ethylene-α-olefin copolymer.

0072[Manufacturing of antibacterial film] The antibacterial film 100 is made of, for example, a sealant layer 210 film-forming resin composition in which antibacterial particles 230 are dispersed, a support layer 220 film-forming resin composition, an intermediate layer 300 film-forming resin composition, and an outer layer 400. The film-forming resin composition and the adhesive layer 510,520 film-forming resin composition can be formed into a film by using an air-cooled or water-cooled co-extrusion inflation method or a co-extrusion T-die method. When the coextrusion T-die method is used, the film can be formed by using an appropriate feed block and die. The coextrusion T-die method is preferable from the viewpoint of controlling the thickness of the antibacterial film 100 and the transparency.

0073Further, a film may be formed by the laminating method.

0074The amount of the antibacterial particles 230 dispersed in the sealant layer 210 film-forming resin composition is 0.2% or more and 25% or less, preferably 0.5% or more and 20% in the sealant layer 210 film-forming resin composition on a weight basis. It can be as follows. As a result, a part of the surface of the antibacterial particles 230 can be preferably exposed from the sealant layer 210 after the film formation.

0075In addition to the above, the sealant layer 210 in which the antibacterial particles 230 are dispersed, the support layer 220, the intermediate layer 300, and the outer layer 400 are separately formed in advance, and the adhesive layers 510 and 520 are used as film-forming resin compositions, respectively. The antibacterial film 100 may be produced by a method of joining the layers of the above to each other with a laminator or the like.

0076[Other examples] The present invention is not limited to the above-mentioned first embodiment, and any modification may be made as long as the desired antibacterial property and appearance are not impaired. 3 to 6 are schematic cross-sectional views showing another example of the antibacterial film according to the first embodiment.

0077In the first embodiment described above, the intermediate layer 300 and the outer layer 400 are further laminated on the support layer 220, but these are not essential configurations in the present invention. For example, the antibacterial film 100a shown in FIG. 3 does not have an outer layer 400. In this case, for example, a resin having both mechanical strength and other desired functionality can be used for the intermediate layer 300 itself. On the other hand, the antibacterial film 100b shown in FIG. 4 does not have the intermediate layer 300. In this case, a resin having both desired functionality and other mechanical strength can be used for the outer layer 400. In addition, it does not have to have both the intermediate layer 300 and the outer layer 400.

0078Further, in the above first embodiment, only one intermediate layer 300 is provided, but the intermediate layer 300 may be a plurality of layers. In the antibacterial film 100c shown in FIG. 5, the intermediate layer 300c is composed of a plurality of layers of the functional layer 310c and the functional layer 320c. The functional layer 310c and the functional layer 320c can each have different functions.

0079Further, as in the antibacterial film 100d shown in FIG. 6, the intermediate layer 300d may be a product in which a plurality of layers in which the functional layer 310d and the functional layer 320d are combined are repeatedly laminated.

0080In the first embodiment and other examples described above, the adhesive layers 510 and 520 are provided, but those skilled in the art can easily determine the necessity depending on the characteristics of the resin constituting each layer to be laminated. Can be decided on.

0081In addition, in the first embodiment and other examples, additives such as antioxidants, slip agents, anti-blocking agents, ultraviolet absorbers, resin modifiers, stabilizers, and impact resistance of fluororesins, silicone rubbers, etc. Additives such as an additive may be used as appropriate.

0082[Second Embodiment] FIG. 7 is a schematic cross-sectional view showing an example of the package according to the second embodiment.

0083The packaging body 700 shown in FIG. 7 is composed of a bottom material 710 and a lid material 720. An antibacterial film 100 is used for the bottom material 710, and the bottom material 710 is composed of a recess formed so that the sealant layer 210 side of the antibacterial film 100 is concave, and an unformed edge portion surrounding the recess. The recess is formed, for example, by deep drawing. Contents (not shown) such as foods, beverages, and pharmaceuticals are stored in the recesses.

0084In the present embodiment, the antibacterial film 100 is also used for the lid material 720. The lid material 720 covers the bottom material 710 so that the sealant layer 210 contacts the sealant layer 210 at the edge of the bottom material 710, and the sealant layers 210 that are in contact with each other are sealed from each other. As a result, the recess of the bottom material 710 is sealed. Preferably, the contents are hermetically sealed for vacuum packaging. By vacuum-packing the contents, the antibacterial effect of the antibacterial particles 230 (see FIG. 1) embedded in the sealant layer 210 can be efficiently obtained.

0085[Other examples] In the second embodiment described above, an example in which the antibacterial film 100 is used for both the bottom material 710 and the lid material 720 has been given, but the present invention is not limited to this embodiment. In the present invention, the antibacterial film 100 may be used for at least one of the bottom material 710 and the lid material 720. Therefore, a film other than the antibacterial film 100 may be used for either the bottom material 710 or the lid material 720.

0086When a film other than the antibacterial film 100 is used, it may be an antibacterial film having another configuration of the present invention, an antibacterial film other than the present invention, or another non-antibacterial film may be used. Of these, at least the layer that comes into contact with the inclusion is preferably the sealant layer 210 in which the antibacterial particles 230 are embedded, as in the antibacterial film 100.

0087As the lid material 720, for example, a biaxially stretched polypropylene film (OPP film), a biaxially stretched polyethylene terephthalate film (VM-PET film) on which a metal oxide is vapor-deposited, a film laminated with a polyethylene resin, or the like is used. May be good.

<p num="0088"> Examples will be shown below and the present invention will be described in more detail, but the present invention is not limited to the following examples.</p><p num="0089"> [Example 1] First, as a layer structure, an antibacterial film having an outer layer / adhesive layer / support layer / antibacterial particle-containing sealant layer having an oxygen barrier property was prepared.</p><p num="0090"> Specifically, a polyamide resin (manufactured by Ube Kosan Co., Ltd., trade name: 1030B2) is prepared as a resin constituting the outer layer having an oxygen barrier property, and an adhesive resin (Mitsui Chemicals Co., Ltd.) is prepared as a resin constituting the adhesive layer. A company-made product, product name: NF536) was prepared, and a low-density polyethylene resin (Ube-Maruzen Polyethylene Co., Ltd., product name: F222NH) was prepared as a resin constituting the support layer. As a resin constituting the sealant layer, a low-density polyethylene resin (manufactured by Ube-Maruzen Polyethylene Co., Ltd., trade name: F222NH) was prepared. As antibacterial particles, silver ion-based antibacterial particles (average particle diameter 5 μm, manufactured by Fuji Chemical Co., Ltd., trade name: BM-102TG) were prepared.</p><p num="0091"> 4% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer. The above-mentioned polyamide resin, adhesive resin, low-density polyethylene resin and resin composition for a sealant layer were co-extruded using a feed block and a die so as to be laminated in this order. As a result, an antibacterial film was created.</p><p num="0092"> The average thickness of the obtained antibacterial film was 100 μm, the average thickness of the sealant layer was 5 μm, the thickness of the support layer was 50 μm, and the thickness of the outer layer was 30 μm.</p><p num="0093"> The appearance (visual) of the obtained antibacterial film was transparent, and the cloudiness measured in accordance with JIS K7136 was 6%. For the degree of cloudiness, prepare a sample with pylon crystal tape (manufactured by Kyowa Co., Ltd.) attached to both sides of the antibacterial film, measure the internal haze using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH2000), and measure the internal haze. Only the light scattering of is extracted.</p><p num="0094"> &lt;Surface observation&gt; The surface of the sealant layer was observed on the obtained antibacterial film using a non-contact surface measuring device VertScan (manufactured by Ryoka System Co., Ltd.) using an optical interference method. Specifically, the ratio of the surface area of the actual sealant layer in which the antibacterial particles are embedded to the surface area of the sealant layer in the case where the antibacterial particles are not embedded, including the surface of the exposed antibacterial particles (hereinafter, the surface area ratio). To be described.) Was derived.</p><p num="0095"> &lt;Measurement of silver ion elution amount&gt; The obtained antibacterial film was cut into 5 cm × 5 cm with a utility knife. This was placed in a polypropylene screw cap bottle and fixed to the wall surface of the bottle with double-sided tape so that the antibacterial surface was in contact with water. 50 mL of ultrapure water was poured into this so that the film was completely immersed, and the film was stored at 25 ° C. for 24 hours to extract silver ions. The silver ion concentration of the obtained extract was measured. The silver ion concentration was measured with an IPC emission spectroscopic analyzer (ICPS-2000 manufactured by Shimadzu Corporation) under the conditions of a measurement wavelength of 328.068 nm and an internal standard element Y: 371.029 nm.</p><p num="0096"> &lt;Antibacterial test&gt; Separately, two types of bacterial solutions were prepared. One of the bacterial solutions contained Pseudomonas, which is an aerobic bacterium. The other bacterial solution contained lactic acid bacteria, which are facultative anaerobes. The reason for selecting the above two bacteria is that it was possible to identify the bacteria that cause putrefaction in the meat used in the storage test described below.</p><p num="0097"> An antibacterial test was conducted in accordance with JIS Z 2801. Specifically, the bacterial solution was dropped onto the surface of the test piece and inoculated, and the bacterial solution and the antibacterial film were brought into close contact with each other so that the sealant layer of the obtained antibacterial film was in contact with the bacterial solution at 35 ° C. The cells were cultured for 24 hours ± 1 hour in an environment of ± 1 ° C and a relative humidity of 90% or more. Then, the test piece was washed away, and the viable cell count per 1 cm2 of the test piece was measured.</p><p num="0098"> &lt;Meat preservation test&gt; Using the obtained antibacterial film, one slice of pork loin was wrapped in a three-way seal. In the three-way seal packaging, vacuum packaging is performed by degassing seal.</p><p num="0099"> The packaged meat was stored in a refrigerated showcase at 5 ° C and its appearance was monitored. The appearance was judged visually, and Pork Color Standard (PCS) was used as the judgment index.</p><p num="0100"> &lt;Transparency&gt; The transparency was judged by whether or not the contents could be confirmed in the above three-way seal packaging. The internal haze is preferably 10% or less in order to preferably ensure transparency. Here, the internal haze is the degree of fogging caused by the scattering that can occur inside the film. Specifically, when measuring film haze in accordance with JIS-K-7105, a sample in which transparent tape is attached to both sides of the film in order to eliminate light scattering due to unevenness on the surface of the film (antibacterial film 100). Was created, the internal haze was measured using a haze meter, and only the light scattering inside the film was extracted. [Example 2] Antibacterial films were prepared in the same manner as in Example 1 except that 8% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done. [Example 3] Antibacterial films were prepared in the same manner as in Example 1 except that 12% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done.</p><p num="0101"> [Example 4] The same as in Example 1 except that a resin composition for a sealant layer was prepared using silver ion-based antibacterial particles (average particle diameter 3 μm, manufactured by Fuji Chemical Co., Ltd., trade name: BM-103NA) as antibacterial particles. Antibacterial film was prepared and each test was performed. [Example 5] Antibacterial films were prepared in the same manner as in Example 4 except that 8% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done. [Example 6] Antibacterial films were prepared in the same manner as in Example 4 except that 12% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done. [Example 7] Antibacterial films were prepared in the same manner as in Example 4 except that 20% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done. [Example 8] Antibacterial films were prepared in the same manner as in Example 4 except that 30% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done. [Example 9] Antibacterial films were prepared in the same manner as in Example 4 except that 40% by mass of antibacterial particles were dispersed in the low-density polyethylene resin constituting the sealant layer to prepare a resin composition for the sealant layer, and each test was performed. Was done.</p><p num="0102"> [Comparative example 1] Antibacterial films were prepared in the same manner as in Example 1 except that a resin composition for a sealant layer was prepared without using antibacterial particles, and each test was carried out.</p><p num="0103"> [Comparative example 2] As the antibacterial particles, silver ion-based antibacterial particles (average particle diameter 0.9 μm, manufactured by Toa Synthetic Co., Ltd., trade name: Novalon) were used to prepare a resin composition for a sealant layer in the same manner as in Example 1. Antibacterial films were prepared and tested.</p><p num="0104"> &lt;Result&gt; Table 1 shows the results of surface observations according to Examples 1 to 9, Comparative Example 1 and Comparative Example 2.</p><p num="0105"><tables num="1"><img id="000003" he="39" wi="150" file="JP2016030406A_D0001.tif" img-format="tif" img-content="drawing" /></tables>As shown in Table 1, from Example 1, the sealant layer and the support layer laminated in contact with the sealant layer are included, and the antibacterial particles are embedded in the sealant layer and the antibacterial particles are embedded. A part of the surface of the sealant layer is an antibacterial film exposed from the surface opposite to the support layer, and the antibacterial film is cut into 5 cm × 5 cm and made into 50 mL of pure water. Because it is an antibacterial film characterized in that the amount of metal ion extracted from the antibacterial film to the pure water when immersed at 25 ° C for 24 hours is 0.05 ppm / cm2 or more and 1.0 ppm / cm2 or less. , Gram-negative bacteria (green pus bacteria) and Gram-positive bacteria (lactic acid bacteria) showed excellent antibacterial properties, and the effect of suppressing fading was confirmed. On the other hand, since Comparative Examples 1 and 2 were films that did not satisfy the above conditions, the antibacterial properties and the fading suppressing effect were insufficient.</p><p num="0106"> Preferred embodiments of the present invention are as described above, but the present invention is not limited thereto, and various other embodiments that do not deviate from the gist and scope of the present invention are made. Furthermore, the actions and effects described in this embodiment are examples and do not limit the present invention.</p>

0107100,100a, ~, 100d antibacterial film 210 sealant layer 211 Surface (opposite the support layer of the sealant layer) 211V Virtual surface (of sealant layer without antibacterial particles embedded) 220 Support layer 230 antibacterial particles 231 Part of the surface (of antibacterial particles) 300,300c, 300d intermediate layer 310c, 310d, 320c, 320d Functional layer 400 outer layer 510,520 Adhesive layer 700 packaging