Rust preventive film and rust preventive package

Abstract

To provide a rust-prevention film capable of preventing rust from generating to a content being packaged by a simple layer constitution without using a volatile rust-prevention agent.SOLUTION: A rust-prevention film includes a first layer and a second layer laminated on one side of the first layer. The first layer is composed of an olefin resin having heat sealability. The first layer includes, as additive, an antioxidizing agent, a neutralizer, an antiblocking agent and a slip agent. A content of the antioxidizing agent in the first layer is 50 to 100 ppm, a content of the neutralizer is 50 to 100 ppm, a content of the antiblocking agent is 50 to 100 ppm, and a content of the slip agent is 50 to 100 ppm.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a rust-preventive film that suppresses the occurrence of rust on packaged contents, and a rust-preventive package having the rust-preventive film.

Background Art

[0002] Packaging materials for the purpose of transporting and long-term storing articles having metals, such as metal articles made of metal materials and parts using metals, are being developed. There is a demand for a packaging material that has higher and more stable rust prevention properties and can be manufactured by a simple manufacturing process with a simple layer structure so as to maintain the functions and properties of the metal articles as the contents. For example, for the purpose of rust prevention of metal articles, packaging laminates in which a resin contains a highly volatile vaporizable rust preventive that volatilizes at normal temperature to exhibit a rust prevention effect are described in Patent Documents 1 to 3. However, in a rust-preventive film using a volatile rust preventive, when the sealing property of a package produced from this rust-preventive film is insufficient, there is a problem that almost no rust prevention effect is exhibited on the contents. In addition, volatile rust preventives may contain substances harmful to the human body (for example, carcinogenicity, etc.), and care is required in handling them. Therefore, a rust-preventive film that does not use a volatile rust preventive is desired.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure has been made in view of the above circumstances, and a main object thereof is to provide a rust preventive film that can suppress the occurrence of rust in the contents to be packaged with a simple layer structure without using a volatile rust preventive agent.

Means for Solving the Problems

[0005] The rust preventive film of the present disclosure has a first layer and a second layer laminated on one surface of the first layer. The first layer is composed of an olefin resin having heat sealability. The first layer has, as additives, an antioxidant, a neutralizing agent, an antiblocking agent, and a slip agent. The content of the antioxidant in the first layer is 50 ppm or more and 100 ppm or less, the content of the neutralizing agent in the first layer is 50 ppm or more and 100 ppm or less, the content of the antiblocking agent in the first layer is 50 ppm or more and 100 ppm or less, and the content of the slip agent in the first layer is 50 ppm or more and 100 ppm or less.

[0006] In the rust preventive film of the present disclosure, the second layer may be composed of an olefin resin, and the total content of the additives contained in the second layer may be more than the total content of the additives contained in the first layer.

[0007] The rust preventive film of the present disclosure may have a base material layer laminated on the second layer.

[0008] In the rust preventive film of the present disclosure, the base material layer may be a barrier base material layer.

[0009] In the rust preventive film of the present disclosure, the antioxidant may contain a phenolic antioxidant.

[0010] In the rust preventive film of the present disclosure, the neutralizing agent may contain calcium oxide.

[0011] In the rust preventive film of the present disclosure, the antiblocking agent may contain sodium aluminosilicate.

[0012] In the rust-preventive film of the present disclosure, the slip agent may contain stearic acid.

[0013] The rust-preventive package of the present disclosure is composed of the rust-preventive film and has the first layer on the inside.

[0014] The rust-preventive package of the present disclosure may be sealed at a pressure lower than atmospheric pressure inside the package.

Advantages of the Invention

[0015] According to the present disclosure, it is possible to provide a rust-preventive film that can suppress the generation of rust on the contents to be packaged with a simple layer structure without using a volatile rust preventive.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each figure, for ease of understanding, the size and ratio of the members may be changed or exaggerated. Also, for ease of viewing, parts that are not necessary for explanation and repeated reference numerals may be omitted. Although omitted in each figure, a functional layer such as an adhesive layer can also be provided between the layers. Furthermore, if necessary, in order to strengthen the adhesive strength (adhesion strength) between the layers, physical surface treatments such as corona discharge treatment, ozone treatment, plasma treatment, glow discharge treatment, sandblasting treatment, etc., and chemical surface treatments such as oxidation treatment using chemical agents can be performed in advance on the laminated surfaces of the layers.

[0018] (Rust preventive film) Fig. 1 is a schematic cross-sectional view showing an example of the layer structure of the rust preventive film of the present disclosure. The rust preventive film 1 shown in Fig. 1 has a first layer 11 and a second layer 12 laminated on one surface of the first layer 11. In the rust preventive film 1 shown in Fig. 1, a form in which the first layer 11 is a single layer is illustrated, but the first layer of the rust preventive film of the present disclosure may be composed of multiple layers. Similarly, in the rust preventive film 1 shown in Fig. 1, a form in which the second layer 12 is a single layer is illustrated, but the second layer of the rust preventive film of the present disclosure may be composed of multiple layers.

[0019] Fig. 2 is a schematic cross-sectional view showing another example of the layer structure of the rust preventive film of the present disclosure. The rust preventive film of the present disclosure may have a configuration in which a base material layer is laminated on the second layer. For example, the rust preventive film 2 shown in Fig. 2 has a second layer 12 laminated on the first layer 11, and further has a base material layer 13 laminated on the second layer 12. In the rust preventive film 2 shown in Fig. 2, a form in which the base material layer 13 is a single layer is illustrated, but the base material layer of the rust preventive film of the present disclosure may be composed of multiple layers.

[0020] Further, an adhesive layer may be provided between each layer of the rust preventive film 1 shown in Fig. 1 and the rust preventive film 2 shown in Fig. 2.

[0021] The thickness of the rust preventive film of the present disclosure is not particularly limited, but is preferably 25 μm or more and 200 μm or less. When the thickness of the rust preventive film is thinner than the above range, there are problems such as the rigidity of the rust preventive film being too low or the rust preventive film being easily torn. Also, it becomes difficult for the rust preventive film to exhibit sufficient supportability, rust preventive effect, heat sealability, etc. in a well-balanced manner. On the other hand, when the thickness of the rust preventive film is thicker than the above range, the rigidity of the rust preventive film is too strong, and the usability as a packaging material tends to deteriorate.

[0022] The rust preventive film is preferably transparent, and more preferably has a higher transparency. This is because a rust preventive package made from a rust preventive film with high transparency allows the contents to be easily visible. In the packaging of steel materials, the rust preventive film is usually used in combination with other packaging materials, and there is often a need to distinguish it from transparent general-purpose olefin films (polyethylene, polypropylene). Therefore, colorants such as blue, orange, yellow, and green are added and it is supplied as a lightly colored film, and it is manufactured with a transparency that allows the contents (steel materials) to be confirmed. Such a colored film has a light color and a small difference in color tone from a film without added colorant when it is alone, but the distinction from other packaging materials becomes clear in the wound state.

[0023] Note that "transparent" means having a transparency such that one side of the rust preventive film can be seen through from the other side through the rust preventive film. For example, it is desirable to have a visible light transmittance of 90% or more. The visible light transmittance is specified as the average value of the transmittances at each wavelength when measured in the wavelength range of 380 nm to 780 nm using a spectrophotometer ("UV-3100PC" manufactured by Shimadzu Corporation, compliant with JIS K 0115). Also, for this reason, the haze of the rust preventive film is set to be less than 20%. The haze value is measured in accordance with JIS K7136, for example, using a haze meter HM-150 type manufactured by Murakami Color Technology Research Institute Co., Ltd.

[0024] In the rust preventive film of the present disclosure, in order to avoid affecting the rust preventive effect of the first layer 11, no colorant is added to the first layer 11, and the colorant is added to the second layer 12 and the base material layer 13 formed on the first layer 11 for manufacturing. In particular, in the case of a configuration having a second layer 12 laminated on the first layer 11 and further having a base material layer 13 laminated on the second layer 12, such as the rust preventive film 2 shown in FIG. 2, by adding a colorant only to the second layer 12, even when the base material layer 13 comes into contact with the first layer 11 when the rust preventive film 2 is wound up, more specifically, even when the outer surface of the base material layer 13 comes into contact with the inner surface of the first layer 11 (that is, the surface of the first layer 11 that contacts the contents as a package), since no colorant is added to the base material layer 13, it is possible to avoid the colorant from affecting the rust prevention property of the first layer 11.

[0025] (First layer) The first layer 11 of the rust preventive film of the present disclosure is composed of an olefin resin having heat sealability and has a predetermined amount of an antioxidant, a neutralizing agent, an antiblocking agent, and a slip agent as additives, respectively. Specifically, the content of the antioxidant in the first layer 11 is 50 ppm or more and 100 ppm or less. Also, the content of the neutralizing agent in the first layer 11 is 50 ppm or more and 100 ppm or less. Also, the content of the antiblocking agent in the first layer 11 is 50 ppm or more and 100 ppm or less. Also, the content of the slip agent in the first layer 11 is 50 ppm or more and 100 ppm or less.

[0026] The first layer 11 of the rust preventive film of the present disclosure has a second layer 12 on one of its surfaces, but the surface opposite to the surface having the second layer 12 will come into contact with an article having a metal, which is the content to be packaged by the rust preventive film of the present disclosure, at least in part. For example, when the rust preventive film 1 shown in FIG. 1 is used as a package, the side of the first layer 11 becomes the inner layer of the package (that is, the inner layer), and the side of the second layer 12 becomes the outer layer of the package (that is, the outer layer). Also, when the rust preventive film 2 shown in FIG. 2 is used as a package, the side of the first layer 11 becomes the inner layer of the package (that is, the inner layer), and the side of the base material layer 13 becomes the outer layer of the package (that is, the outer layer).

[0027] And since each of the above additives contained in the first layer 11 of the rust-preventive film of the present disclosure is in the above-specified content, while ensuring stable film-forming properties during the production of the rust-preventive film of the present disclosure, it exerts a rust-preventive effect on the contents packaged with the rust-preventive film of the present disclosure.

[0028] The thickness of the first layer 11 of the rust-preventive film of the present disclosure can be appropriately set within the range of the thickness of the rust-preventive film, but is preferably 5 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and still more preferably 10 μm or more and 50 μm or less. When the thickness of the first layer 11 is within the above range, a sufficient rust-preventive effect can be exerted, and the rigidity of the entire rust-preventive film can be made to have an appropriate strength. On the other hand, when the thickness of the first layer 11 is thinner than the above range, there is a possibility that a sufficient rust-preventive effect cannot be exerted. Also, when the thickness of the first layer 11 is thicker than the above range, the rust-preventive effect does not improve much, and there is a possibility that the rigidity of the entire rust-preventive film becomes too strong and the usability as a packaging material deteriorates.

[0029] <Olefin resin> The olefin resin constituting the first layer 11 of the rust-preventive film of the present disclosure preferably has an affinity suitable for the dispersion of the rust preventive and is excellent in film-forming properties, and more preferably has heat-sealing properties. As the olefin resin, one or more selected from polyolefin-based polymers, that is, homopolymers of olefins and / or copolymers using olefins as monomers can be selected and used.

[0030] Examples of the olefin (olefin monomer) constituting the polyolefin-based polymer include ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, and the like. Therefore, examples of the polyolefin polymer include ethylene polymers, propylene polymers, 1-butene polymers, 1-hexene polymers, 4-methyl-1-pentene polymers, and the like. These polymers may be used alone or in combination of two or more. That is, the polyolefin polymer may be a mixture of various polymers.

[0031] Among the above, examples of the ethylene polymer include ethylene homopolymers (polyethylene) and copolymers of ethylene and other monomers (ethylene copolymers).

[0032] Examples of the ethylene homopolymer include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE).

[0033] Examples of the ethylene copolymer include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-4-methyl-1-pentene copolymer, and the like. Among these, linear low density polyethylene (LLDPE) polymerized by a metallocene catalyst and having a density of 0.89 g / cm 3 or more and 0.93 g / cm 3 or less is preferably used because of its excellent heat sealability, strength, touch, and flexibility. Note that the ethylene units (structural units derived from ethylene) contained in the ethylene copolymer only need to be more than 50% of the total number of structural units (usually 99.999% or less). For example, it can be 80% or more and 99.999% or less of the total number of structural units, or 90% or more and 99.995% or less, or further 99.0% or more and 99.990% or less.

[0034] In addition, examples of the propylene-based polymer include a propylene homopolymer (polypropylene) and a copolymer of propylene and another monomer (propylene copolymer). Examples of the propylene copolymer include a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-pentene copolymer, and a propylene-1-octene copolymer. Polypropylene is generally classified into a highly rigid homopolymer (homopolypropylene) obtained by polymerizing only propylene, a highly transparent and flexible random polymer (random polypropylene) obtained by copolymerizing a small amount of ethylene, and a high-impact block copolymer in which a rubber component (EPR) is uniformly and finely dispersed in the homo- and random polymers. Among these, homopolypropylene is excellent in odor barrier properties. The propylene units (structural units derived from propylene) contained in the propylene copolymer may be 50% or more (usually 99.999% or less) of the total number of structural units. For example, it can be 80% or more and 99.999% or less of the total number of structural units, or 90% or more and 99.995% or less, or further 99.0% or more and 99.990% or less.

[0035] The density of the polyolefin resin is preferably 0.880 g / cm 3 or more and 0.950 g / cm 3 or less from the viewpoint of processability.

[0036] Also, from the viewpoints of mechanical strength and processability, the melt flow rate (MFR) is preferably in the range of 1.0 g / 10 min or more and 10.0 g / 10 min or less. By having an appropriate viscosity during melt processing, it becomes possible to incorporate and coat particulate saturated fatty acids in the resin, and it becomes possible to prevent the saturated fatty acids from dropping off from the film.

[0037] <Additive> In the rust-preventive film of the present disclosure, since the content of each of the above additives in the first layer 11 is the above-specified content, while ensuring stable film-forming properties during the production of the rust-preventive film of the present disclosure, a rust-preventive effect is exerted on the contents packaged with the rust-preventive film of the present disclosure. Each additive contained in the first layer 11 of the rust-preventive film of the present disclosure is preferably uniformly dispersed on the surface of the first layer 11 (more specifically, the surface opposite to the side having the second layer 12). The above surface of the first layer 11 is the surface that contacts the contents packaged with the rust-preventive film of the present disclosure, and since each additive is uniformly dispersed on this surface, a uniform rust-preventive effect can be exerted on the contents. In addition, each additive contained in the first layer 11 of the rust-preventive film of the present disclosure only needs to be uniformly dispersed on the surface of the first layer 11 as described above. For example, in the thickness direction of the first layer 11, it may be dispersed with a concentration gradient. In other words, each additive contained in the first layer 11 of the rust-preventive film of the present disclosure may be dispersed with a concentration gradient in the thickness direction of the first layer 11, but is preferably uniformly dispersed in the plane direction of the first layer 11.

[0038] Each additive contained in the first layer 11 of the rust-preventive film of the present disclosure is preferably contained using a masterbatch in which each additive is melt-blended with an olefin resin at a high concentration. This is because it becomes easier to incorporate each additive into the first layer 11 of the rust-preventive film of the present disclosure in a state where the additives are uniformly dispersed. Each of the additives and olefin resin melt-blended into the masterbatch may be one type or two or more types. Also, one or two or more additives may be contained in one masterbatch. The olefin resin used for the masterbatch may be the same as or different from the main olefin resin constituting the first layer 11 of the rust-preventive film of the present disclosure.

[0039] The content of the above four types of additives (antioxidant, neutralizing agent, antiblocking agent, and slip agent) contained in the first layer 11 of the rust preventive film of the present disclosure is preferably in the range of 50 ppm or more and 100 ppm or less respectively. If the content of each additive is within this range, the rust preventive film of the present disclosure can exhibit a sufficient rust prevention effect while maintaining film forming properties and quality stability during long-term storage. On the other hand, when the content of each additive is less than 50 ppm, the film forming properties and quality stability during long-term storage tend to be inferior, which is not preferable. Also, when the content of each additive exceeds 100 ppm, it becomes difficult to exhibit a sufficient rust prevention effect, which is not preferable.

[0040] Here, the reason why it becomes difficult to exhibit a sufficient rust prevention effect when the content of each additive exceeds 100 ppm has not been elucidated in detail. However, as in the examples described later, this phenomenon has been confirmed in the evaluation test. For example, it is considered that the masterbatch used to uniformly disperse each additive contains corrosive substances that cause rust. However, it is difficult to identify the presence of such corrosive substances because the content is expected to be extremely small.

[0041] Therefore, in the rust preventive film of the present disclosure, by setting the content of each of the above additives to a predetermined content, while ensuring film forming properties and quality stability during long-term storage, corrosive substances and the like mixed in are reduced to the limit, and a rust prevention effect is exerted on the contents packaged with the rust preventive film of the present disclosure.

[0042] <Antioxidant> The additives contained in the first layer 11 of the rust preventive film of the present disclosure include an antioxidant. As the antioxidant, it is preferable to use a primary antioxidant that captures the generated radicals and a secondary antioxidant that decomposes the hydroperoxide generated from the radicals in combination. It is also possible to use an antioxidant having both the functions of the primary antioxidant and the secondary antioxidant. Examples of the primary antioxidants include phenolic antioxidants, amine antioxidants, and hindered amine antioxidants. Examples of the secondary antioxidants include phosphorus antioxidants and sulfur antioxidants. Examples of the antioxidants having both the functions of the primary antioxidant and the secondary antioxidant include hydroxylamine antioxidants. The antioxidant contained in the first layer of the rust-preventive film of the present disclosure is preferably a phenolic antioxidant, one containing a phenolic antioxidant and a phosphorus antioxidant, or a hydroxylamine antioxidant. Among these, those having a hydrophilic group and a hydrophobic group are more preferable. In addition, phosphorus antioxidants and hydroxylamine antioxidants also function to prevent the coloring of the polyethylene film.

[0043] Examples of the phenolic antioxidants include the following. Examples of the monophenolic antioxidants include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and the like. Examples of the bisphenolic antioxidants include 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(4-ethyl-6-tert-butylphenol), 4,4'-thiobis-(3-methyl-6-tert-butylphenol), 4,4'-butylidene-bis-(3-methyl-6-tert-butylphenol), 3,9-bis[{1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl}2,4,9,10-tetraoxaspiro]5,5-undecane, and the like. Examples of the polymer-type phenolic antioxidants include 1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis-{methylene-3-(3’,5’-di-tert-butyl-4’-hydroxyphenyl)propionate}methane, bis{(3,3’-bis-4’-hydroxy-3’-tert-butylphenyl)butyric acid} glycol ester, 1,3,5-tris(3’,5’-di-tert-butyl-4’-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, tocopherol (vitamin E), and the like. Among them, as the phenolic antioxidant, tetrakis-{methylene-3-(3’,5’-di-tert-butyl-4’-hydroxyphenyl)propionate}methane is particularly preferred.

[0044] Examples of the phosphorus-based antioxidants (also referred to as phosphite-based antioxidants) include the following. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, cyclic neopentanetetraylbis(octadecyl phosphite), tris(mono- and / or dinonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, cyclic neopentanetetraylbis(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis(2,6-di-tert-butylphenyl) phosphite, 2,2-methylenebis(4,6-tert-butylphenyl) octyl phosphite, 2,4,8,10-tetra-tert-butyl-6-(3-(3-methyl-4-hydroxy-5-tert-butylphenyl)propoxy)dibenz(d,f)(1,3,2)dioxaphosphepine, and the like can be mentioned. Among these, tris(2,4-di-tert-butylphenyl) phosphite is particularly preferable.

[0045] The content of the antioxidant in the first layer 11 of the rust-preventive film of the present disclosure is preferably in the range of 50 ppm or more and 100 ppm or less. If the content of the antioxidant is within this range, the rust-preventive film of the present disclosure can exhibit a sufficient rust-preventive effect while maintaining film-forming properties and quality stability during long-term storage. On the other hand, when the content of the antioxidant is less than 50 ppm, the film-forming properties and quality stability during long-term storage are likely to deteriorate, which is not preferable. Also, when the content of the antioxidant is greater than 100 ppm, it is difficult to exhibit a sufficient rust-preventive effect, which is not preferable. In addition, when adding two or more kinds of antioxidants, the total amount thereof shall be taken as the addition amount of the antioxidant. In other words, when two or more kinds of antioxidants are contained in the first layer 11 of the rust preventive film of the present disclosure, the total amount thereof shall be taken as the content of the antioxidant.

[0046] <Neutralizing agent> The additives contained in the first layer 11 of the rust preventive film of the present disclosure also include a neutralizing agent. The neutralizing agent is added for the purpose of incorporating chloride ions contained particularly in polyethylene polymerized by a Ziegler catalyst, and hydrotalcites, silicates, metal oxides, metal hydroxides, fatty acid metal salts, etc. are selected.

[0047] Examples of hydrotalcites include hydrated basic carbonates such as magnesium, calcium, zinc, aluminum, bismuth, etc. or those not containing crystal water, and natural products and synthetic products can be used. Examples of natural products include those having the structure of Mg6Al2(OH) 16 CO3·4H2O. Examples of synthetic products include Mg 0.7 Al 0.3 (OH)2(CO3) 0.15 ·0.54H2O, Mg 4.5 Al2(OH) 13 CO3·3.5H2O, Mg 4.2 Al2(OH) 12.4 CO3, Zn6Al2(OH) 16 CO3·4H2O, Ca6Al2(OH) 16 CO3·4H2O, Mg 14 Bi2(OH) 29.6 ·4.2H2O, etc.

[0048] Examples of silicates include aluminum silicate, calcium silicate, etc. Examples of the metals in metal oxides and metal hydroxides include metals of Group II of the periodic table, zinc, aluminum, tin, lead, etc. Among such metal oxides and metal hydroxides, magnesium oxide, calcium oxide, zinc oxide, aluminum oxide, calcium hydroxide, aluminum hydroxide, magnesium hydroxide, etc. are often used.

[0049] The content of the neutralizing agent in the first layer 11 of the rust-preventive film of the present disclosure is preferably in the range of 50 ppm or more and 100 ppm or less. If the content of the neutralizing agent is within this range, the rust-preventive film of the present disclosure can exhibit a sufficient rust-preventive effect while maintaining film-forming properties and quality stability during long-term storage. On the other hand, when the content of the neutralizing agent is less than 50 ppm, the film-forming properties and quality stability during long-term storage tend to deteriorate, which is not preferable. Also, when the content of the neutralizing agent is greater than 100 ppm, it becomes difficult to exhibit a sufficient rust-preventive effect, which is not preferable. In addition, when adding two or more kinds of neutralizing agents, the total amount thereof is taken as the addition amount of the neutralizing agent. In other words, the content of the neutralizing agent in the first layer 11 of the rust-preventive film of the present disclosure is the total amount thereof when two or more kinds of neutralizing agents are included.

[0050] <Anti-blocking agent> The additives contained in the first layer 11 of the rust-preventive film of the present disclosure also include an anti-blocking agent. The anti-blocking agent is added for the purpose of preventing adhesion between films. The anti-blocking agent has the effect of roughening the surface state of the film by adding inorganic fine particles, and various natural or artificial inorganic minerals such as silica, clay, talc, diatomaceous earth, feldspar, kaolin, zeolite, kaolinite, wollastonite, sericite, aluminosilicate, and calcium aluminosilicate are used. Among these, aluminosilicates such as sodium aluminosilicate are often used.

[0051] The content of the anti-blocking agent in the first layer 11 of the rust-preventive film of the present disclosure is preferably in the range of 50 ppm or more and 100 ppm or less. If the content of the anti-blocking agent is within this range, the rust-preventive film of the present disclosure can exhibit a sufficient rust-preventive effect while maintaining film-forming properties and quality stability during long-term storage. On the other hand, when the content of the antiblocking agent is less than 50 ppm, the film-forming property and the quality stability during long-term storage tend to be inferior, which is not preferable. Further, when the content of the antiblocking agent is greater than 100 ppm, it becomes difficult to exhibit a sufficient rust prevention effect, which is not preferable. In addition, when adding two or more kinds of antiblocking agents, the total amount thereof is taken as the addition amount of the antiblocking agent. In other words, the content of the antiblocking agent contained in the first layer 11 of the rust-preventive film of the present disclosure is the total amount thereof when two or more kinds of antiblocking agents are contained.

[0052] <Slip agent> The additives contained in the first layer 11 of the rust-preventive film of the present disclosure also include a slip agent. A slip agent (also called a lubricant) is added for the purpose of maintaining the physical stability of the material during processing, such as preventing adhesion to the metal surface of the processing apparatus, reducing friction with the metal surface, and improving the fluidity of the material when thermoplastic resin is subjected to heat molding processing. Fatty acids are used as the slip agent, and examples thereof include fatty acids, metal fatty acids, and fatty acid esters. Specific fatty acids include caproic acid, heptanoic acid, nonanoic acid, octanoic acid, decanoic acid, undecylic acid, lauric acid, stearic acid, nonadecanoic acid, arachidic acid, and the like.

[0053] Examples of the metal fatty acid include alkali metal salts and alkaline earth metal salts of the above fatty acids, and specific examples include calcium stearate, zinc stearate, magnesium stearate, and the like. It is known that these also function as the neutralizing agent described above. In the first layer of the rust-preventive film of the present disclosure, when a metal fatty acid is used as the slip agent, the metal fatty acid is not used as the neutralizing agent.

[0054] Examples of the fatty acid ester include alcohol esters such as the above-mentioned fatty acids and glycerin fatty acid esters. Glycerin fatty acid esters are preferably glycerin tri-fatty acid esters, more preferably glycerin fatty acid esters, and even more preferably glycerin tricaprylate.

[0055] The content of the slip agent in the first layer 11 of the rust preventive film of the present disclosure is preferably in the range of 50 ppm or more and 100 ppm or less. If the content of the slip agent is within this range, the rust preventive film of the present disclosure can exhibit a sufficient rust preventive effect while maintaining film formability and quality stability during long-term storage. On the other hand, when the content of the slip agent is less than 50 ppm, film formability and quality stability during long-term storage are likely to deteriorate, which is not preferable. Also, when the content of the slip agent is greater than 100 ppm, it becomes difficult to exhibit a sufficient rust preventive effect, which is not preferable. When adding two or more kinds of slip agents, the total amount thereof is taken as the addition amount of the slip agent. In other words, when the first layer 11 of the rust preventive film of the present disclosure contains two or more kinds of slip agents, the total amount thereof is taken as the content of the slip agent.

[0056] <Other Additives> The rust preventive film of the present disclosure may contain, for example, various plastic compounding agents and additives other than the above-mentioned antioxidant, neutralizing agent, antiblocking agent, and slip agent in extremely small amounts for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, releasability, flame retardancy, antifungal properties, electrical properties, strength, etc. However, the content thereof is limited to a range in which the rust preventive effect of the first layer of the rust preventive film of the present disclosure does not decrease. In the above, as general compounding agents, for example, crosslinking agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, etc. can be contained.

[0057] (Second Layer) As described above, when the rust-proof film of the present disclosure is used as a packaging material, the first layer 11 side becomes the inner layer (i.e., the inner layer) of the packaging material, and the second layer 12 side becomes the outer layer (i.e., the outer layer) of the packaging material relative to the first layer 11. More specifically, for example, when the rust-preventive film 1 shown in Fig. 1 is used as a package, the first layer 11 side becomes the inner layer (i.e., the inner layer) of the package, and the second layer 12 side becomes the outer layer (i.e., the outer layer) of the package. Also, when the rust-preventive film 2 shown in Fig. 2 is used as a package, the first layer 11 side becomes the inner layer (i.e., the inner layer) of the package, and the base layer 13 side becomes the outer layer (i.e., the outer layer) of the package. The second layer 12 of the rust-preventive film of the present disclosure may be a single layer or may be configured with multiple layers.

[0058] In the rust-preventive film of the present disclosure, the second layer 12 is composed of an olefin resin, and the total content of the additives contained in the second layer 12 is greater than the total content of the additives contained in the first layer 11. Therefore, even if the content of the above-mentioned four types of additives (antioxidant, neutralizer, antiblocking agent, and slip agent) in the first layer 11 of the rust-resistant film of the present disclosure is in the range of 50 ppm or more and 100 ppm or less, which is smaller than that of normal films, by making the rust-resistant film of the present disclosure have a laminated structure of the first layer 11 and the second layer 12 and making the content of the additives in the second layer 12 close to that of normal films, the film-forming properties of the rust-resistant film of the present disclosure and the quality stability during long-term storage can be further improved. In addition, in the rust-preventive film 1 shown in FIG. 1, the occurrence of pinholes due to friction during transportation can be suppressed by optimizing the content of the slip agent contained in the second layer 12.

[0059] Furthermore, as described above, in the case of a configuration having a base material layer 13 on the second layer 12, such as the rust-proofing film 2 shown in Figure 2, by adding a colorant only to the second layer 12, even if the base material layer 13 comes into contact with the first layer 11 when the rust-proofing film 2 is rolled up, more specifically, even if the outer surface of the base material layer 13 comes into contact with the inner surface of the first layer 11 (i.e., the surface of the first layer 11 that comes into contact with the contents as a package), it is possible to avoid the colorant affecting the rust-proofing properties of the first layer 11, because no colorant has been added to the base material layer 13.

[0060] The olefin resin constituting the second layer 12 of the rust-preventive film of the present disclosure may be one or more selected from polyolefin polymers, that is, olefin homopolymers and / or copolymers using olefin as a monomer, in the same manner as the olefin resin contained in the above-mentioned first layer 11. The olefin resin used in the second layer 12 may be the same as or different from the olefin resin constituting the first layer 11.

[0061] The thickness of the second layer 12 of the rust-preventive film of the present disclosure can be appropriately set within the range of the thickness of the rust-preventive film, but is preferably 10 μm or more and 100 μm or less. If the thickness of the second layer 12 is within the above range, there is little risk of a significant adverse effect on the heat sealability and film formability of the entire rust-preventive film.

[0062] (base material layer) The substrate layer 13 may be a layer that can impart various functions to the rust-preventive film of the present disclosure, such as mechanical, physical, and chemical functions, such as support, rigidity, flexibility, pinhole resistance, etc. For example, when a barrier substrate layer having a barrier property against water vapor is used as the substrate layer 13, the penetration of moisture into the interior of a package produced from the rust-preventive film of the present disclosure can be effectively prevented. The thickness of the base layer 13 can be set appropriately within the range of the thickness of the anti-rust film, but if the purpose is to impart appropriate strength and stiffness to the anti-rust film, it is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

[0063] <Barrier substrate layer> The barrier substrate layer has a resin layer and an inorganic oxide film provided on one surface of the resin layer. The resin layer functions as a support layer for the inorganic oxide film in the barrier substrate layer. As the resin layer, various resins having strength, heat resistance, etc. can be used. Specifically, resin films such as polyester resins, polyamide resins, polyaramid resins, polyolefin resins, polycarbonate resins, polystyrene resins, polyacetal resins, and fluorine resins can be used. In particular, polyethylene terephthalate (PET) films are preferably used for reasons such as printability, vapor deposition suitability, and antistatic properties of vapor deposition. The resin layer may be either an unstretched film or a uniaxially or biaxially stretched film.

[0064] Examples of materials for forming the inorganic oxide film include oxides such as silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. Among these, aluminum oxide, silicon oxide, and magnesium oxide are preferred in terms of barrier performance and production efficiency.

[0065] The inorganic oxide film may have a single layer structure formed by one deposition process, or a multilayer structure formed by repeating the deposition process multiple times. In the case of a multilayer structure, each layer may be made of the same material or different materials. In addition, each layer may be formed by the same formation method or different formation methods.

[0066] The thickness of the inorganic oxide film can be set in the range of 5 nm to 100 nm as the total thickness of the film. By setting the thickness of the inorganic oxide film in the above range, a barrier substrate layer having excellent flexibility and pinhole resistance can be obtained.

[0067] On the other hand, if the thickness of the inorganic oxide film exceeds 100 nm, the flexibility decreases, and there is a risk that the inorganic oxide film may crack due to external forces such as bending or pulling. Therefore, it becomes difficult to achieve sufficient barrier performance. In addition, the stress of the material itself increases, which is undesirable. In addition, the productivity is significantly reduced, and protrusions tend to form due to the growth of abnormal grains, which is also undesirable. Furthermore, if the thickness of the inorganic oxide film is less than 5 nm, the film covering property is poor and pinholes are likely to occur, making it difficult to achieve sufficient barrier performance.

[0068] Examples of methods for forming an inorganic oxide film include physical vapor deposition methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. In the present disclosure, the deposition method in the vacuum deposition method is preferable, and a resistance heating method, an induction heating method, an electron beam heating method, and the like can be appropriately selected and used as necessary.

[0069] In particular, in the present disclosure, it is preferable to provide an inorganic oxide film by a vacuum deposition method using a resistance heating method. In the vacuum deposition method using a resistance heating method, the deposition material is heated by Joule heat using an electric resistor, and compared to other heating methods, it is possible to form a uniform deposition film because the deposition material is heated overall. In addition, the line speed can be set high. In addition, the vacuum deposition method using a resistance heating method can suppress charging of the film. In the present disclosure, it is particularly preferable to provide an aluminum oxide vapor deposition film as the inorganic oxide film by a resistance heating type vacuum deposition method from the viewpoints of barrier performance, antistatic properties, cost, and the like.

[0070] (Method of manufacturing anti-rust film) The method for producing the rust-preventive film of the present disclosure will be described below. Note that the production method described below is only an example and does not limit the present disclosure. Each layer constituting the rust-preventive film of the present disclosure can be produced by any method such as a T-die extrusion method, an extrusion inflation method, or the like. Lamination of each layer of the rust-preventive film having a multi-layer structure can be performed by any method such as T-die coextrusion method, coextrusion inflation method, wet lamination method, dry lamination method, solventless dry lamination method, extrusion lamination method, coextrusion lamination method, etc. Among the above, the T-die coextrusion method and the coextrusion inflation method are preferable in terms of cost because they can reduce the number of steps compared to the lamination method.

[0071] For example, the case of producing the rust-preventive film of the present disclosure by the co-extrusion inflation method will be described. Note that, although the method of producing a rust-preventive film having a two-layer structure of a first layer 11 and a second layer 12 will be described here, a rust-preventive film having a three-layer structure of a first layer 11, a second layer 12, and a substrate layer 13 can also be produced in the same manner. When the above-mentioned barrier substrate layer is provided as the substrate layer 13, it can be manufactured by laminating the side of the above-mentioned barrier substrate layer having the inorganic oxide film 42 to the exposed side of the second layer 12 laminated on the first layer 11.

[0072] To produce a rust-preventive film having a two-layer structure of a first layer 11 and a second layer 12, first, resin compositions for forming the first layer 11 and the second layer 12 are prepared. Then, the first layer 11 and the second layer 12 are co-extruded and laminated by inflation film formation to produce a rust-preventive film having a two-layer structure. An aging treatment may be performed as necessary. In addition, the obtained rust-preventive film may be stretched uniaxially or biaxially as necessary.

[0073] The rust-preventive film can be subjected to secondary processing for the purpose of imparting surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubrication functions, optical functions, thermal functions, biocompatibility, and the like. Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (such as plating), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). In addition, the rust-preventive film can also be subjected to laminating (dry lamination or extrusion lamination), bag-making processing, and other post-treatment processing.

[0074] (Rust-preventive packaging body) The rust-preventive packaging body of the present disclosure is a packaging body used for packaging an article having a metal, and has the rust-preventive film of the present disclosure. More specifically, the rust-preventive packaging body of the present disclosure is composed of the rust-preventive film of the present disclosure and has the first layer 11 on the inner side. The form of the rust-preventive packaging body of the present disclosure is not particularly limited, and it can be made into various forms by folding the rust-preventive film of the present disclosure, overlapping it so as to wrap the contents, heat-sealing it, etc., and added value can also be imparted by printing and decoration.

[0075] For example, the rust-preventive packaging body in the form of a pouch can be manufactured by folding the rust-preventive film in half, or by preparing two rust-preventive films, overlapping them with the surfaces of the first layer facing each other, and heat-sealing the peripheral edges thereof to form rust-preventive packaging bodies of various shapes. For example, it can be heat-sealed in heat-sealing forms such as side-seal type, two-side seal type, three-side seal type, four-side seal type, envelope-pasting seal type, palm-pasting seal type (pillow seal type), pleat-seal type, flat-bottom seal type, corner-bottom seal type, gusset type, etc. to manufacture rust-preventive packaging bodies of various shapes. In the above, as the heat-sealing method, for example, methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, ultrasonic sealing, etc. can be used.

[0076] When manufacturing the rust-proof packaging body, the air inside the packaging body may be sucked and sealed at a pressure lower than the atmospheric pressure. Further, when manufacturing the rust-proof packaging body, it may be sealed while replacing the content space with a gas having a low oxygen concentration or a low humidity.

[0077] In the rust-proof packaging body of the present disclosure, the first layer 11 of the rust-proof film of the present disclosure is located on the inner layer side of the rust-proof packaging body, and the second layer 12 is located on the outer layer side of the first layer 11. That is, in the rust-proof packaging body of the present disclosure, the first layer 11 becomes a layer that contacts an article having a metal as the content of the packaging body. By having such a positional relationship, the rust-proof packaging body of the present disclosure can suppress the occurrence of rust on an article having a metal as the content. Further, in the rust-proof film of the present disclosure, since the second layer 12 on the outer layer side can contain a necessary amount of additives according to various purposes, the film-forming property of the rust-proof film of the present disclosure and the quality stability during long-term storage can be further improved. Further, in the rust-proof film 1 shown in FIG. 1, by optimizing the content of the slip agent contained in the second layer 12, the occurrence of pinholes due to rubbing during transportation can also be suppressed.

[0078] Further, in the rust-proof packaging body of the present disclosure, a base material layer 13 may be provided on the second layer (that is, the outer layer side). Thereby, various functions such as mechanical, physical, and chemical functions, for example, supporting properties, rigidity, flexibility, pinhole resistance, etc. can be imparted to the rust-proof packaging body of the present disclosure.

Example

[0079] The present disclosure will be described in more detail with the following examples and comparative examples, but the present disclosure is not limited only to these examples. Details of the raw materials used in the examples and comparative examples are as follows.

[0080] [Additive] Antioxidant: Phenolic antioxidant A060 manufactured by Adeka Corporation. Neutralizing agent: Calcium oxide HAL-J manufactured by Yoshizawa Petrochemical Industry Co., Ltd. (average particle diameter is 1 μm or more and 2 μm or less). Antiblocking agent (AB agent): Sodium aluminosilicate (sodium aluminosilicate) particles AMT100S2 (pH = 7) manufactured by Mizusawa Chemical Industry Co., Ltd. Slip agent: Stearic acid manufactured by Fujifilm Wako Pure Chemical Corporation

[0081] [Olefin resin] LDPE1: LDPE manufactured by Nippon Polyethylene Co., Ltd., Novatec LC520. Density 0.923 g / cm 3 , MFR 3.6 g / 10 min. LLDPE1: LLDPE manufactured by Prime Polymer Co., Ltd., Evolue SP2020. Density 0.916 g / cm 3 , MFR = 2.0 g / 10 min.

[0082] [Preparation of masterbatch] [Preparation of masterbatch 1] The antioxidant and LDPE1 were melt-blended at the following ratio to obtain masterbatch 1 (MB1). LDPE1 95 parts by mass Antioxidant 5 parts by mass

[0083] [Adjustment of masterbatches 2 to 4] According to the following formulation, melt-blending was carried out in the same manner as masterbatch 1 to obtain masterbatches 2 to masterbatch 4 (MB2 to MB4). MB2: LDPE1 95 parts by mass / Neutralizing agent 5 parts by mass MB3: LDPE1 95 parts by mass / Antiblocking agent 5 parts by mass MB4: LDPE1 95 parts by mass / Slip agent 5 parts by mass

[0084] [Preparation of masterbatch 5] The antioxidant and LDPE1 were melt-blended at the following ratio to obtain masterbatch 5 (MB5). LDPE1 90 parts by mass Antioxidant 10 parts by mass

[0085] [Adjustment of Masterbatches 6 to 8] According to the following formulation, melt blending was carried out in the same manner as for Masterbatch 1 to obtain Masterbatches 6 to 8 (MB6 to MB8). MB6: 90 parts by mass of LDPE1 / 10 parts by mass of neutralizing agent MB7: 90 parts by mass of LDPE1 / 10 parts by mass of antiblocking agent MB8: 90 parts by mass of LDPE1 / 10 parts by mass of slip agent

[0086] [Example 1] MB1, MB2, MB3, MB4, and LLDPE1 were dry blended at the following ratios to obtain the resin composition for the first layer of the rust preventive film of Example 1. MB1 0.1 part by mass MB2 0.1 part by mass MB3 0.1 part by mass MB4 0.1 part by mass LLDPE1 99.6 parts by mass Also, MB5, MB6, MB7, MB8, and LLDPE1 were dry blended at the following ratios to obtain the resin composition for the second layer of the rust preventive film of Example 1. MB5 1 part by mass MB6 1 part by mass MB7 1 part by mass MB8 1 part by mass LLDPE1 96 parts by mass The resin composition for the first layer and the resin composition for the second layer obtained above were formed into a film and laminated at 160 °C using the coextrusion inflation method to obtain a rust preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0087] [Example 2] MB1, MB2, MB3, MB4, and LLDPE1 were dry blended at the following ratios to obtain the resin composition for the first layer of the rust preventive film of Example 2. MB1 0.2 part by mass MB2 0.1 part by mass MB3 0.1 part by mass 0.1 part by mass of MB4 99.5 parts by mass of LLDPE1 Also, in the same manner as in Example 1, a resin composition for the second layer of the rust-preventive film of Example 2 was obtained. The resin composition for the first layer and the resin composition for the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust-preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0088] [Example 3] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain a resin composition for the first layer of the rust-preventive film of Example 3. 0.1 part by mass of MB1 0.2 part by mass of MB2 0.1 part by mass of MB3 0.1 part by mass of MB4 99.5 parts by mass of LLDPE1 Also, in the same manner as in Example 1, a resin composition for the second layer of the rust-preventive film of Example 3 was obtained. The resin composition for the first layer and the resin composition for the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust-preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0089] [Example 4] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain a resin composition for the first layer of the rust-preventive film of Example 4. 0.1 part by mass of MB1 0.1 part by mass of MB2 0.2 part by mass of MB3 0.1 part by mass of MB4 99.5 parts by mass of LLDPE1 Also, in the same manner as in Example 1, a resin composition for the second layer of the rust-preventive film of Example 4 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160°C using the co-extrusion inflation method to obtain a rust-proof film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0090] [Example 5] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain the resin composition of the first layer of the rust-proof film of Example 5. MB1 0.1 part by mass MB2 0.1 part by mass MB3 0.1 part by mass MB4 0.2 part by mass LLDPE1 99.5 parts by mass Also, in the same manner as in Example 1, the resin composition of the second layer of the rust-proof film of Example 5 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160°C using the co-extrusion inflation method to obtain a rust-proof film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0091] [Example 6] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain the resin composition of the first layer of the rust-proof film of Example 6. MB1 0.2 part by mass MB2 0.2 part by mass MB3 0.2 part by mass MB4 0.2 part by mass LLDPE1 99.2 parts by mass Also, in the same manner as in Example 1, the resin composition of the second layer of the rust-proof film of Example 6 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160°C using the co-extrusion inflation method to obtain a rust-proof film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0092] [Comparative Example 1] MB2, MB3, MB4, and LLDPE1 were dry blended at the following ratios to obtain the resin composition of the first layer of the rust preventive film of Comparative Example 1. MB2 0.1 part by mass MB3 0.1 part by mass MB4 0.1 part by mass LLDPE1 99.7 parts by mass Also, in the same manner as in Example 1, the resin composition of the second layer of the rust preventive film of Comparative Example 1 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160°C using the coextrusion inflation method to obtain a rust preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0093] [Comparative Example 2] MB1, MB2, MB3, MB4, and LLDPE1 were dry blended at the following ratios to obtain the resin composition of the first layer of the rust preventive film of Comparative Example 2. MB1 0.4 part by mass MB2 0.1 part by mass MB3 0.1 part by mass MB4 0.1 part by mass LLDPE1 99.3 parts by mass Also, in the same manner as in Example 1, the resin composition of the second layer of the rust preventive film of Comparative Example 2 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160°C using the coextrusion inflation method to obtain a rust preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0094] [Comparative Example 3] MB1, MB3, MB4, and LLDPE1 were dry blended at the following ratios to obtain the resin composition of the first layer of the rust preventive film of Comparative Example 3. MB1 0.1 part by mass MB3 0.1 part by mass 0.1 part by mass of MB4 99.7 parts by mass of LLDPE1 Also, in the same manner as in Example 1, a resin composition for the second layer of the rust preventive film of Comparative Example 3 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0095] [Comparative Example 4] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain a resin composition for the first layer of the rust preventive film of Comparative Example 4. 0.1 part by mass of MB1 0.4 part by mass of MB2 0.1 part by mass of MB3 0.1 part by mass of MB4 99.3 parts by mass of LLDPE1 Also, in the same manner as in Example 1, a resin composition for the second layer of the rust preventive film of Comparative Example 4 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0096] [Comparative Example 5] MB1, MB2, MB4, and LLDPE1 were dry-blended at the following ratios to obtain a resin composition for the first layer of the rust preventive film of Comparative Example 5. 0.1 part by mass of MB1 0.1 part by mass of MB2 0.1 part by mass of MB4 99.7 parts by mass of LLDPE1 Also, in the same manner as in Example 1, a resin composition for the second layer of the rust preventive film of Comparative Example 5 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust-preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0097] [Comparative Example 6] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain the resin composition of the first layer of the rust-preventive film of Comparative Example 6. MB1 0.1 part by mass MB2 0.1 part by mass MB3 0.4 part by mass MB4 0.1 part by mass LLDPE1 99.3 parts by mass Also, in the same manner as in Example 1, the resin composition of the second layer of the rust-preventive film of Comparative Example 6 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust-preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0098] [Comparative Example 7] MB1, MB2, MB3, and LLDPE1 were dry-blended at the following ratios to obtain the resin composition of the first layer of the rust-preventive film of Comparative Example 7. MB1 0.1 part by mass MB2 0.1 part by mass MB3 0.1 part by mass LLDPE1 99.7 parts by mass Also, in the same manner as in Example 1, the resin composition of the second layer of the rust-preventive film of Comparative Example 7 was obtained. The resin composition of the first layer and the resin composition of the second layer obtained above were formed into a film and laminated at 160 °C using a coextrusion inflation method to obtain a rust-preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0099] [Comparative Example 8] MB1, MB2, MB3, MB4, and LLDPE1 were dry-blended at the following ratios to obtain the resin composition for the first layer of the rust-preventive film of Comparative Example 8. MB1 0.1 part by mass MB2 0.1 part by mass MB3 0.1 part by mass MB4 0.4 part by mass LLDPE1 99.3 parts by mass Also, in the same manner as in Example 1, the resin composition for the second layer of the rust-preventive film of Comparative Example 8 was obtained. The resin composition for the first layer and the resin composition for the second layer obtained above were formed into a film and laminated at 160 °C using the coextrusion inflation method to obtain a rust-preventive film (60 μm thick) having the following two-layer structure. Layer structure: First layer / Second layer = 30 μm thick / 30 μm thick

[0100] The following evaluations were performed on the films of Examples 1 to 6 and Comparative Examples 1 to 8. The results are shown in Tables 1 and 2. In Tables 1 and 2, the AB agent refers to an anti-blocking agent.

[0101] <Evaluation method> [Film formability] The appearance of each film was observed with the naked eye, and the presence or absence of defects was evaluated according to the following evaluation criteria. ○: There were no wrinkles, bumps, peeling, etc. on the rust-preventive film. ×: There were wrinkles, bumps, peeling, etc. on the rust-preventive film.

[0102] [Rust prevention property] Each film was cut into 100 mm × 100 mm pieces, and after the first layers were opposed to each other and overlapped, impulse sealing was performed on the other three sides except for one side using an impulse sealer to prepare a 100 mm × 100 mm pouch with one side open. Next, the following metal piece was placed in the pouch as the content, the open side was sealed while sucking the air inside the pouch, and it was stored in a thermostatic chamber adjusted to 60 °C and 90% RH for 14 days, and the change in appearance was evaluated according to the following evaluation criteria. (Metal piece) Iron plate: Cold-rolled steel sheet (SPCC), 50 mm × 50 mm × 1 mm, degreased. Copper plate: Tough pitch copper plate (C1100P-1 / 4H), 50 mm × 50 mm × 1 mm, degreased. (Evaluation criteria) 〇: No rust and discoloration, or only pitting rust and slight discoloration occur. ×: Rust occurs on 50% or more of the area of the test piece.

[0103]

Table 1

[0104]

Table 2

Explanation of symbols

[0105] 1, 2 Rust preventive films 11 First layer 12 Second layer 13 Substrate layer

Claims

1. It has a first layer and a second layer laminated on one surface of the first layer, The first layer is composed of an olefin resin having heat-sealing properties, The olefin resin is polyethylene containing chlorine ions, The first layer has, as additives, an antioxidant, a neutralizing agent, an anti-blocking agent, and a slip agent, The antioxidant consists of a phenolic antioxidant, The neutralizing agent consists of calcium oxide, The anti-blocking agent consists of sodium aluminosilicate, The slip agent consists of stearic acid, The content of the antioxidant in the first layer is 50 ppm or more and 100 ppm or less, The content of the neutralizing agent in the first layer is 50 ppm or more and 100 ppm or less, The content of the anti-blocking agent in the first layer is 50 ppm or more and 100 ppm or less, The content of the slip agent in the first layer is 50 ppm or more and 100 ppm or less, The second layer is composed of an olefin resin, The second layer has, as additives, a phenolic antioxidant, calcium oxide, sodium aluminosilicate, and stearic acid, The total content of the additives contained in the second layer is An anti-rust film that is more than the total content of the additives contained in the first layer.

2. The anti-rust film according to claim 1, which has a base material layer laminated on the second layer.

3. The anti-rust film according to claim 2, wherein the base material layer is a barrier base material layer.

4. An anti-rust packaging body composed of the anti-rust film according to any one of claims 1 to 3 and having the first layer on the inside.

5. The anti-rust packaging body according to claim 4, wherein the pressure inside the packaging body is sealed at a pressure lower than atmospheric pressure.

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