JP2021160769A - Rustproof film - Google Patents

Abstract

[Problem] The present invention aims to provide an anti-rust film that is easy to manufacture and has a simple layer structure, yet can prevent rust from occurring in the contents during transportation and long-term storage, and an anti-rust packaging material and an anti-rust package produced using said anti-rust film. [Solution] A single-layer or multi-layer anti-rust film that contains at least a rust inhibitor and a binder resin, and also contains an antioxidant. [Selected Figure] Figure 1

Description

The present invention relates to a rust-preventive film that suppresses the generation of rust on the packaged contents, and a packaging material and a packaging body produced by using the rust-preventive film.
The rust-preventive film according to the present invention can be applied to products in various fields, and in particular, as a packaging material for accommodating metal products such as in-vehicle screws, shafts, metal plates, and electrical parts. It can be preferably used.

Packaging materials for the transportation and long-term storage of metal products made of metal materials and parts made of metal are being developed, and are higher and more stable so that the functions and properties of the metal products as the contents can be maintained. There is a demand for a packaging material that has rust resistance and can be manufactured by a simple manufacturing process with a simple layer structure.
Patent Documents 1 to 3 describe a packaging laminate containing a highly vaporizable rust preventive, which volatilizes at room temperature and exerts a rust preventive effect, in a resin for the purpose of preventing rust on the contents of metal products. However, there are concerns about effects other than the rust preventive effect, such as the need to seal with the exterior, or if the vaporized rust preventive agent adheres to the contents, the contents may deteriorate or functionally impair. Since it is troublesome to remove the adhering rust preventive, its use is limited, and a rust preventive film that does not use a volatile rust preventive is desired.

Japanese Unexamined Patent Publication No. 2010-254350 JP-A-2007-308726 Japanese Unexamined Patent Publication No. 2010-052751

The present invention solves the above-mentioned problems, and is a rust-preventive film capable of suppressing the generation of rust on the contents during transportation and long-term storage while having an excellent manufacturing suitability and a simple layer structure. Another object of the present invention is to provide a rust-preventive packaging material and a rust-preventive packaging body produced by using the rust-preventive film.

As a result of various studies, the present inventors have found that a rust-preventive film containing at least the rust-preventive agent defined by the present invention and a binder resin achieves the above object.
That is, the present invention is characterized by the following points.
1. 1. A single-layer rust-preventive film containing at least a rust-preventive agent and a binder resin.
The rust preventive is characterized by containing at least an antioxidant.
Rust-proof film.
2. A multi-layered rust-preventive film having at least a rust-preventive layer.
The rust preventive layer contains a rust preventive agent and a binder resin, and contains
The rust inhibitor contains at least an antioxidant and
A layer containing a thermoplastic resin is laminated on one side or both sides of the rust preventive layer.
Rust-proof film.
3. 3. The rust-preventive film according to 2 above, wherein the rust-preventive film is a co-press film.
4. The rust-preventive film according to 2 or 3 above, wherein the rust-preventive film further has an intermediate layer.
5. The rust-preventive film according to any one of 1 to 4, wherein the antioxidant contains a phenol-based antioxidant and / or a phosphorus-based antioxidant.
6. The rust preventive property according to any one of 1 to 5 above, wherein the rust preventive further contains one or more selected from the group consisting of fatty acids, metal fatty acids, and fatty acid esters. the film.
7. The rust-preventive film according to 6 above, wherein the fatty acid portion of the fatty acid, the metal fatty acid, and the fatty acid ester has 6 or more and 20 or less carbon atoms.
8. A rust-preventive packaging material comprising the rust-preventive film according to any one of 1 to 7 above.
9. A rust-preventive packaging body comprising the rust-preventive packaging material according to 8 above.

The rust-preventive film of the present invention, the rust-preventive packaging material and the rust-preventive packaging material produced by using the rust-preventive film solve the above-mentioned problems, are excellent in manufacturing suitability, and have a simple layer structure. , A rust-preventive film that can suppress the generation of rust on the contents during transportation and long-term storage, and a rust-preventive packaging material and a rust-preventive package made by using the rust-preventive film. Can be provided.

It is a schematic cross-sectional view which shows an example of the layer structure of the rust preventive film of this invention. It is a schematic cross-sectional view which shows an example of another aspect of the layer structure of the rust preventive film of this invention.

In each figure, the size and ratio of the members may be changed or exaggerated for the sake of clarity. In addition, for the sake of readability, unnecessary parts for explanation and repeated codes may be omitted.
Further, although omitted in each figure, an adhesive layer may be provided between the layers.
Furthermore, if necessary, in order to strengthen the adhesive strength (adhesion strength) between the layers, physics such as corona discharge treatment, ozone treatment, plasma treatment, glow discharge treatment, sandblast treatment, etc. are applied to the laminated surface of each layer. It is also possible to perform a chemical surface treatment such as a specific surface treatment or an oxidation treatment using a chemical in advance.

The rust-preventive film, the rust-preventive packaging material, and the rust-preventive packaging body of the present invention will be described in more detail below. The present invention will be described with reference to specific examples, but the present invention is not limited thereto.
In the present invention, the film and the sheet are treated as synonymous.

≪Rustproof film≫
The rust-preventive film of the present invention is a resin film containing at least a rust-preventive agent and a binder resin and having a heat-sealing property.
Further, the rust-preventive film of the present invention may be a single-layer film or a multi-layer film.
The rust preventive used in the rust preventive film of the present invention includes a group consisting of "alkaline agent for exhibiting alkalinity and neutralizing acidic substances", "antioxidant", "fatty acid, metal fatty acid, fatty acid ester". It is preferable that it contains two or more kinds selected from the group consisting of "one kind or two or more kinds selected", "acid gas adsorbent for adsorbing acidic gas" and the like. By using two or more kinds of rust preventives in combination, the rust preventive effect can be efficiently exhibited. Hereinafter, fatty acids are also referred to as a general term for fatty acids, metal fatty acids, and fatty acid esters.
In order to suppress the generation of rust, acid gas entering from the outside or acid gas existing in the packaged internal space may be adsorbed on the rust preventive film, or a rust inhibitor may be attached to the surface of the contents. By coating, it is effective to impart water repellency to the surface of the contents, prevent oxidation of the surface of the contents, and neutralize the acid gas that comes into contact with the surface of the contents. By using the agent in combination, these methods can be used in combination to efficiently exert the rust preventive effect.

The thickness of the rust-preventive film is not particularly limited, but is preferably 25 μm or more and 200 μm or less. If it is thinner than the above range, the rigidity will be too low or it will be easily torn, and if it is thicker than the above range, the rigidity will be too strong and it will be difficult to achieve a good balance of supportability, rust prevention effect and heat sealability. Usability as a material tends to deteriorate.

The rust-preventive film can be made highly transparent depending on the application.
The total light transmittance of the highly transparent rust-preventive film is preferably 50% or more.
The rust-preventive packaging material made of a highly transparent rust-preventive film has high transparency, and the rust-preventive packaging material made from the highly transparent rust-preventive packaging material has the contents, the label attached to the contents, and the contents. The characters and seals engraved on the object can be easily visually recognized.

Rust-proof films include, for example, workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, mold resistance, electrical properties, strength, etc. Various plastic compounding agents, additives and the like can be contained for the purpose of improving and modifying the above. The content can be arbitrarily contained from a very small amount to several tens of percent depending on the purpose.
In the above, general additives include, for example, antiblocking agents, lubricants, cross-linking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins. Etc. can be contained.

In the case of a single-layer rust-preventive film, the rust-preventive film of the present invention contains at least a rust-preventive agent and a binder resin in one layer.
When the binder resin has heat-sealing properties, one or both surfaces of the single-layer rust-preventive film can have heat-sealing properties.
The rust inhibitor may be uniformly dispersed in one layer, or may be dispersed with a concentration gradient. For example, when a concentration gradient is provided so that a large amount of rust preventive is present near the surface of one side and a small amount of rust preventive is present near the surface of the other side, the one side having a large amount of rust preventive is provided. The surface is likely to exhibit rust prevention efficiently, and the surface on one side with less rust inhibitor has high heat sealability.
By lowering the concentration of the rust preventive agent as a whole or increasing the concentration of the rust preventive agent in the central portion of the layer, the heat sealability on both sides of the rust preventive film can be improved.
The content of the rust preventive agent in the rust preventive film is preferably 0.1% by mass or more and 50% by mass or less, and if it is less than the above range, it is difficult to exhibit a sufficient rust preventive effect, and if it is larger than the above range. , The film-forming property and heat-sealing property tend to be inferior.

In the case of a multilayer rust preventive film, the rust preventive film of the present invention has at least a rust preventive layer containing a rust preventive agent and a binder resin.
The binder resin is a thermoplastic resin, and when the binder resin has a heat-sealing property, one side or both sides of the rust-preventive layer can have a heat-sealing property.
Further, it is preferable that a layer containing a thermoplastic resin is laminated on one side or both sides of the rust preventive layer.
The multilayer rust preventive film can have, for example, an intermediate layer and an outer surface layer that perform various functions depending on the application. In this case, the rust preventive film is preferably laminated in the order of the rust preventive layer, the intermediate layer, and the outer surface layer.
Then, each layer may be laminated via an adhesive layer.
The rust-preventive film suppresses the generation of rust on the contents by having a rust-preventive layer.
For example, if the thermoplastic resin contained in the outer surface layer is a heat-sealing resin, the multilayer rust-preventive film can have heat-sealing properties.
The rust preventive may be uniformly dispersed in the rust preventive layer, or may be dispersed with a concentration gradient. For example, when a concentration gradient is provided so that a large amount of rust preventive is present near the surface of one side and a small amount of rust preventive is present near the surface of the other side, the one side having a large amount of rust preventive is provided. The surface is likely to exhibit rust prevention efficiently, and the surface on one side with less rust inhibitor has high heat sealability.
By lowering the concentration of the rust preventive agent as a whole or increasing the concentration of the rust preventive agent in the central portion of the rust preventive layer, the adhesiveness between both interfaces of the rust preventive layer can be enhanced.
The content of the rust inhibitor in the rust preventive layer is preferably 0.1% by mass or more and 50% by mass or less. If it is less than the above range, it is difficult to exhibit a sufficient rust preventive effect, and if it is larger than the above range, it is said. The film-forming property and heat-sealing property tend to be inferior.

The multi-layered rust-preventive film preferably has a rust-preventive layer on one or both sides. The presence of the rust preventive layer on the surface facilitates the adhesion or coating of the rust preventive property on the surface of the contents.
The case where the surface is a rust preventive layer means that all or a part of the rust preventive layer is exposed on the surface.

<Rust inhibitor>
The rust preventive is a compound that suppresses the generation of rust on the contents packaged by the rust preventive film of the present invention.
The rust preventive agent in the present invention stays inside the rust preventive film of the present invention and adsorbs an acidic gas, or vaporizes and scatters from the rust preventive film of the present invention to the surface of the packaged contents. Rust can be suppressed by adhering by contact transfer, neutralizing acidic substances on the surface of the contents, repelling water to suppress the adhesion of water, and suppressing oxidation. ..

In the present invention, the rust preventive is preferably an antioxidant, and is further selected from the group consisting of "an alkaline agent for exhibiting alkalinity and neutralizing an acidic substance", "fatty acid, metal fatty acid, fatty acid ester" or one. It is preferable to contain two or more kinds selected from the group consisting of "two or more kinds" and "acid gas adsorbent for adsorbing acid gas".
When two or more kinds are used in combination, different effects such as acid gas adsorption, acid substance neutralization, water repellency, and oxidation suppression synergistically contribute, and rust prevention is synergistically improved.
The combinations of rust preventives contained are, for example, antioxidants and alkaline agents, antioxidants and fatty acids, antioxidants and alkaline agents and fatty acids, alkaline agents and fatty acids, alkaline agents and acid gas adsorbents, Fatty acids and acid gas adsorbents are preferred.

Details of each type of rust preventive contained in the rust preventive film of the present invention are as follows.

[Alkaline agent]
The alkaline agent in the present invention is a compound that exhibits alkalinity by itself, and can adhere to the surface of the contents to be packaged to neutralize an acidic substance that causes rust generation and suppress the generation of rust.
Examples of the composition of the alkaline agent include alkali metal compounds, alkaline earth metal compounds, and aluminum compounds.
The alkali metal in the present invention is an alkali metal in a broad sense, and refers to Li, Na, K, Rb, Cs, and Fr, which are metal elements of Group 1, and among these, Li, Na, and K are preferable.
Further, the alkaline earth metal is an alkaline earth metal in a broad sense, and refers to Be, Mg, Ca, SrBa, and Ra which are metal elements of Group 2.

Examples of the alkali metal compound include alkali metal oxides, alkali metal chlorides, alkali metal hydroxides, and the like, and specific alkali metal compounds include Li ₂ O, Na ₂ O, K ₂ O, LiCl, and the like. Examples include LiOH. Among these, Na ₂ O and K ₂ O are preferable.

Examples of the alkaline earth metal compound include alkaline earth metal oxide, alkaline earth metal chloride, alkaline earth metal hydroxide, and the like, and specific alkaline earth metal compounds include BeO, MgO, and the like. Examples thereof include CaO, SrO, BaO, RaO, MgCl ₂ , CaCl ₂ , Mg (OH) ₂ , Ca (OH) ₂ . Among these, MgO, CaO, Mg (OH) ₂ , Ca (OH) _{2, and the} like are preferable.

Specific examples of the aluminum compound include Al ₂ O ₃ and Al (OH) ₃ . Among these, Al ₂ O ₃ is preferable.

Among the above-mentioned specific alkaline agents, it is preferable to use one or more selected from the group consisting of _{MgO, CaO, Mg (OH) 2} , Ca (OH) ₂ , and Al ₂ O _3.

The alkaline agent is used as a powder, and the average particle size based on the number of powders is preferably 0.1 μm or more and 20 μm or less. If the average particle size is smaller than the above range, the alkaline agent tends to aggregate, and if it is larger than the above range, the surface area becomes small and the rust prevention property may be inferior.
The content of the alkaline agent contained in the rust preventive layer of the single-layer rust preventive film or the multi-layer rust preventive film is preferably 15% by mass or more and 50% by mass or less, and if it is less than the above range, sufficient protection is sufficient. The rust effect is hard to be exhibited, and if it is larger than the above range, the film-forming property and the heat-sealing property tend to be inferior.

[Antioxidant]
The antioxidant in the present invention can adhere to the surface of the contents to be packaged and suppress the generation of rust due to the oxidation of the surface of the contents.
As the antioxidant, a known and publicly available antioxidant used for packaging materials can be used, but phenolic antioxidants and phosphorus-based antioxidants are preferable, and among these, hydrophilic groups and hydrophobic groups are used. It is more preferable to have.

As a specific phenolic antioxidant, pentaerythritol tetrakis [3- (3,5-ditershally butyl-4-hydroxyphenyl) propionate] is preferable.
Specific phosphorus-based antioxidants include tris (2,4-ditershally butylphenyl) phosphite, 2,4,8,10-tetratershally butyl-6- (3- (3-methyl-4-4). Hydroxy-5-terriary butylphenyl) propoxy) dibenzo (d, f) (1,3,2) dioxaphosfepine is preferred.

The content of the antioxidant contained in the rust preventive layer of the single-layer rust preventive film or the multi-layer rust preventive film is preferably 0.1% by mass or more and 15% by mass or less, and is less than the above range. , Sufficient rust preventive effect is hard to be exhibited, and even if it is larger than the above range, the rust preventive effect is not improved so much, and the film forming property and the heat sealing property tend to be inferior, which is not preferable.

[Fatty acids]
The fatty acids in the present invention adhere to the surface of the contents to be packaged and exhibit a water-repellent effect to suppress the adhesion of water that causes rust to the surface of the contents to prevent the generation of rust. Can be suppressed.
Specific examples of fatty acids include fatty acids, metal fatty acids, and fatty acid esters.
In fatty acids, the aliphatic chain portion functions as a hydrophobic group, the hydrophilic group functions as a carboxylic acid portion as a hydrophilic group, the hydrophilic group adheres to the surface of the contents, and the hydrophobic group portion adheres outward. It is considered that water repellency is exhibited.
The composition of the fatty acids is preferably one in which the fatty acid portion has 6 or more carbon atoms and 20 or less carbon atoms. If the number of carbon atoms is less than the above range, the boiling point may be too close to the film forming temperature and bubbles may be generated or film forming may not be possible. There is a risk that vaporization / scattering and adhesion due to contact transfer will not occur easily on the surface of the film.
Specific examples of fatty acids include caproic acid, heptanic acid, nonanoic acid, octanoic acid, decanoic acid, undecylic acid, lauric acid, stearic acid, nonadesilic acid, arachidic acid and the like.

Specific examples of the metal fatty acid include alkali metal salts such as the above-mentioned fatty acids and alkaline earth metal salts, and Ca salt is preferable.
Specific examples of the fatty acid ester include alcohol esters such as the above fatty acids and glycerin fatty acid esters. As the glycerin fatty acid ester, glycerin tri-fatty acid ester is preferable, glycerin fatty acid ester is preferable, and glycerin tricaprylic acid ester is more preferable. ..
Among the above fatty acids, one or more selected from the group consisting of heptanic acid, octanoic acid, decanoic acid, lauric acid, stearic acid, caprylic acid, caprylic acid, calcium stearate, and glycerin tricaprylic acid ester are used. Is preferable.
The content of fatty acids contained in the rust-preventive layer of the single-layer rust-preventive film or the multi-layer rust-preventive film is preferably 0.1% by mass or more and 30% by mass or less, and less than the above range is sufficient. It is not preferable because the rust preventive effect is hard to be exhibited, and even if it is larger than the above range, the rust preventive effect is not so improved and the film forming property and the heat sealing property are easily deteriorated.

[Acid gas adsorbent]
The acid gas adsorbent in the present invention can adsorb acidic gases such as SO _x , NO _x , and carbon dioxide, and suppress the surface of the packaged contents from being rusted by these acidic gases. ..
By containing an acid gas adsorbent, the rust preventive film suppresses the invasion of these acid gases through the rust preventive film from the outside of the package, or enters the content storage portion inside the package. These existing acid gases can be adsorbed to reduce the concentration.
The acid gas adsorbent preferably contains one or more selected from the group consisting of hydrophobic zeolites, metal-supported zeolites, and amino group-supported porous bodies.
The acid gas adsorbent may have any outer shape such as spherical, rod-shaped, or elliptical, and may have any shape such as powder, lump, or granular, but is uniform when dispersed in the resin. From the viewpoint of dispersibility, kneading characteristics, film forming property, etc., the powder form is preferable.

The acid gas adsorbent is used as a powder, and the average particle size based on the number of powders is preferably 0.1 μm or more and 20 μm or less. Here, the average particle size is a value measured by a dynamic light scattering method. If the average particle size is smaller than the above range, the acid gas adsorbent tends to aggregate, and if it is larger than the above range, the surface area becomes small and the rust prevention property may be inferior.
The content of the acidic gas adsorbent contained in the rust preventive layer of the single-layer rust preventive film or the multi-layer rust preventive film is preferably 0.1% by mass or more and 30% by mass or less, and is less than the above range. , Sufficient rust preventive effect is hard to be exhibited, and even if it is larger than the above range, the rust preventive effect is not improved so much, and the film forming property and the heat sealing property tend to be inferior, which is not preferable.

(Hydrophobic zeolite)
Hydrophobic zeolite is a porous body, and the _{higher the SiO 2} / Al ₂ O ₃ molar ratio, which is a constituent, the higher the hydrophobicity, and the SiO ₂ / Al ₂ O ₃ molar ratio is 30/1 to 10000/1. Hydrophobic zeolite is preferred.
Due to the high hydrophobicity, the ability to adsorb acid gas having low polarity is improved without adsorbing water vapor having high polarity.
In the present invention, hydrophilic zeolite having a molar ratio in the above range is preferably used from the viewpoint of the balance between hygroscopic performance and availability.

(Metal-supported zeolite)
The metal-supported zeolite is a zeolite that supports a metal different from Si and Al. It is considered that the supported metal is actually supported on the zeolite in the form of a metal oxide or the metal atom as it is. In the present invention, both types of metal oxide-supported zeolite and metal atom-supported zeolite are collectively referred to as metal-supported zeolite.
When the gas component that causes rust comes into contact with the metal-supported zeolite, the gas component is ionized, bonded, and decomposed. It is considered that any reaction such as oxidation or reduction occurs and the ability to generate rust is lost.
As the supported metal species, those that do not easily react with moisture and those that have a lower ionization tendency than iron are preferable, and specifically, one or two species selected from the group consisting of copper, zinc, silver, platinum and the like. The above is preferable, and one or more selected from the group of copper, zinc, and silver is more preferable.
Also. The supported zeolite may be either a hydrophilic zeolite or a hydrophobic zeolite.

(Amino group-supported porous body)
The amino group-supported porous body is one in which a chemical adsorbent having an amino group is supported on the porous body.
As a supporting method, a known or conventional supporting method can be applied. For example, the porous body can be supported by impregnating the porous body with a solution containing a chemical adsorbent and drying it.
In the amino group-supported porous body, the amino group portion selectively reacts with an aldehyde compound or the like and is adsorbed, but physical adsorption characteristics for the pore portion of the porous body can also be expected.
As the porous body that supports the amino group, any compound having a large number of pores on its surface can be used, and an inorganic porous body is preferable, for example, zeolite, silicon dioxide, silicate, activated carbon, titania, phosphoric acid. Examples thereof include inorganic phosphates such as calcium, alumina, aluminum hydroxide, magnesium hydroxide, and mixtures thereof.
In particular, it is preferable to use aluminum hydroxide, zeolite, or silicate from the viewpoint of having a porous state having a pore size effective with respect to the molecular size and cluster size of the substance to be adsorbed and from the viewpoint of safety.

[Dispersion method of rust preventive]
The rust preventive is preferably contained via a masterbatch in which the rust preventive is melt-blended with a thermoplastic resin.
Specifically, the rust preventive is melt-blended with the thermoplastic resin at a relatively high concentration to adjust the masterbatch, and then the masterbatch and the components such as the binder resin are mixed so as to have the rust preventive concentration. It is preferable to use it as a dry blend.
Each of the melt-blended rust preventive and the thermoplastic resin may be one kind or two or more kinds, and even if one masterbatch contains one kind or two or more kinds of rust preventives. good.
The content of the rust inhibitor in the masterbatch is preferably 3% by mass or more and 95% by mass or less, more preferably 20% by mass or more and 90% by mass or less, and further preferably 30% by mass or more and 70% by mass or less. Within the above range, it is easy to contain a necessary and sufficient amount of the rust preventive in a dispersed state.
The above-mentioned thermoplastic resin may be the same as or different from the binder resin contained in the rust preventive layer.

<Binder resin>
The binder resin contained in the layer containing the rust preventive is preferably a resin having an affinity suitable for dispersing the rust preventive and having excellent film-forming property, and more preferably a resin having heat-sealing property.

Specific binder resins include polyolefin resins, polyester resins, polyamide resins, polyaramid resins, polycarbonate resins, polyacetal resins, fluororesins, ethylene-vinyl acetate copolymers, and ethylene-vinyl alcohol co-weights. Resins such as coalescence (EVOH), polyvinyl alcohol, polyacrylonitrile, and others are preferable. These resins may be used alone or in admixture of two or more.
Among these resins, polyolefin-based resins are preferable from the viewpoint of film-forming property.

Specific examples of the polyolefin-based resin include polyethylene-based resin, polypropylene-based resin, unsaturated carboxylic acid-modified resin of polyolefin-based resin, cyclic polyolefin resin, and cyclic olefin copolymer. As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and the like are preferably used. These polyolefin-based resins may be used alone or in admixture of two or more, or may be used in multiple layers containing different types of resins. These copolymerizable unsaturated carboxylic acids may be used alone or in admixture of two or more.
Among these polyolefin-based resins, polyethylene-based resins are preferable from the viewpoint of film-forming property.

Specific examples of polyethylene-based resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear (linear) low-density polyethylene (LLDPE), metallocene polyethylene, polypropylene, and ethylene. -Vinyl acetate copolymer, ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) acrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, unsaturated carboxylic acid of polyethylene polyolefin resin Modified resin, etc. can be mentioned. As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and the like are preferably used.
Among the above-mentioned polyethylene-based resins, low-density polyethylene (LDPE) and linear (linear) low-density polyethylene (LLDPE) are more preferable, and linear (linear) low-density polyethylene (LLDPE) is further preferable. These polyethylene-based resins may be used alone or in admixture of two or more.

<Rust prevention layer>
The rust preventive layer is a layer containing a rust preventive agent and a binder resin in a multi-layer rust preventive film.
The binder resin contained in the rust preventive layer is made of a thermoplastic resin and may or may not have a heat-sealing property. When it has a heat-sealing property, it preferably contains a heat-sealing resin, or the binder resin may contain a heat-sealing resin.
The rust preventive layer may be one layer containing two or more kinds of rust preventive agents, or may be composed of two or more layers containing rust preventive agents of different types and contents.
The rust preventive layer is preferably laminated on the surface of the rust preventive film having a multi-layer structure. By being laminated on the surface, rust prevention can be easily exhibited.

The content of the rust preventive agent in the rust preventive layer is preferably 0.1% by mass or more and 50% by mass or less. If it is less than the above range, it is difficult to exhibit a sufficient rust preventive effect, and if it is larger than the above range, the film-forming property and the heat-sealing property tend to be inferior.
The thickness of the rust preventive layer can be appropriately set by those skilled in the art, but is preferably 5 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and further preferably 10 μm or more and 50 μm or less. If it is thinner than the above range, it may not be able to exert a sufficient rust preventive effect, and even if it is thicker than the above group, the rust preventive effect is not improved so much, and the rigidity of the entire rust preventive film becomes too strong, making it difficult to use. There is a risk.

<Middle layer>
The intermediate layer has various layers capable of imparting various mechanical, physical, and chemical functions to the rust-preventive film, such as supportability, rigidity, flexibility, and pinhole resistance. Can be done.
For example, by having a water vapor barrier layer, it is possible to suppress the invasion of water into the content storage part inside the package, or to adsorb the water in the content storage part to reduce the humidity and suppress dew condensation. It is possible to impart excellent rust resistance to an object. Specific examples of the water vapor barrier layer include an inorganic vapor deposition layer and a metal foil layer.

Further, for example, as the resin for enhancing the supportability, as the resin, a polyolefin resin, a polyester resin, a polyamide resin, a polyaramid resin, a polycarbonate resin, a polyacetal resin, a fluorine resin, an ethylene-vinyl acetate copolymer, and ethylene. -Includes tough thermoplastic resins such as vinyl alcohol copolymers (EVOH), polyvinyl alcohols, polyacrylonitriles, and others. These resins may be used alone or in admixture of two or more, or may be used in multiple layers containing different types of resins.
Among these resins, polyolefin-based resins are preferable from the viewpoint of film-forming property.

Specific examples of the polyolefin-based resin include polyethylene-based resin, polypropylene-based resin, unsaturated carboxylic acid-modified resin of polyolefin-based resin, cyclic polyolefin resin, and cyclic olefin copolymer. As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and the like are preferably used. These polyolefin-based resins may be used alone or in admixture of two or more, or may be used in multiple layers containing different types of resins. These copolymerizable unsaturated carboxylic acids may be used alone or in admixture of two or more.
Among these polyolefin-based resins, polyethylene-based resins are preferable from the viewpoint of film-forming property.

Specific examples of polyethylene-based resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear (linear) low-density polyethylene (LLDPE), metallocene polyethylene, polypropylene, and ethylene. -Vinyl acetate copolymer, ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) acrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, unsaturated carboxylic acid of polyethylene polyolefin resin Modified resin, etc. can be mentioned. As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and the like are preferably used.
Among the above-mentioned polyethylene-based resins, low-density polyethylene (LDPE) and linear (linear) low-density polyethylene (LLDPE) are more preferable, and linear (linear) low-density polyethylene (LLDPE) is further preferable. These polyethylene-based resins may be used alone or in admixture of two or more.

The thickness of the intermediate layer can be appropriately set by those skilled in the art, but when the purpose is to impart appropriate strength and waist to the laminate, it is preferably 5 μm or more and 100 μm or less, and 10 μm or more and 50 μm. The following are more preferable.

<Outer surface layer>
The outer surface layer is a layer containing a thermoplastic resin.
As the thermoplastic resin used for the outer surface layer, many kinds of resins can be used as long as the heat sealability and film forming property of the entire film are not significantly adversely affected.
Specific examples of the thermoplastic resin include, but are limited to, general-purpose polyethylene, polypropylene, methylpentene polymer, polyolefin resins such as acid-modified polyolefin resins, and mixtures of these resins. Instead, the type of thermoplastic resin can be selected according to the purpose.
The outer surface layer is preferably laminated on the surface of the multi-layered rust preventive film.
The thickness of the outer surface layer is not particularly limited, but is preferably 10 μm or more and 100 μm or less. Within the above range, there is little possibility that the heat-sealing property and film-forming property of the entire film will be significantly adversely affected.

(Heat sealable resin)
The heat-sealing resin that can be used in the rust-preventive film of the present invention is not particularly limited as long as it can be melted and fused by heat, and a known heat-sealing resin can be used.
Specific examples of the heat-sealing resin include polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, metallocene polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ionomer resin. , Ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyolefin resin such as polyethylene or polypropylene, acrylic acid, methacrylic acid, Polyethylene resin modified with unsaturated carboxylic acid such as maleic anhydride, fumaric acid and others, ternary copolymer resin of ethylene- (meth) acrylic acid ester-unsaturated carboxylic acid, cyclic polyolefin resin, cyclic olefin copolymer, polyethylene Examples thereof include terephthalate (PET) and polyacrylonitrile (PAN).
Among these, a polyolefin-based resin is preferable, a polyethylene-based resin is more preferable among the polyolefin-based resins, and a low-density polyethylene (LDPE) and a linear (linear) low-density polyethylene (LLDPE) are further preferable among the polyethylene-based resins. , Linear (linear) low density polyethylene (LLDPE) is particularly preferred.

<Adhesive layer>
The adhesive used for the adhesive layer is not particularly limited, and DL (dry laminate) adhesive, EC (extrusion coat) adhesive, non-solvent laminate adhesive, any anchor coat adhesive, etc. may be used. can.
The adhesive may be a thermosetting type, an ultraviolet curable type, an electron beam curable type, or the like, and may be in any form such as an aqueous type, a solution type, an emulsion type, or a dispersed type, and its properties are , Film / sheet, powder, solid, etc., and the adhesive mechanism may be any of chemical reaction type, solvent volatilization type, thermosetting type, thermosetting type, and the like.

The components forming such an adhesive layer include a polyvinyl acetate-based adhesive such as polyvinyl acetate and a vinyl acetate-ethylene copolymer, and a copolymer of polyacrylic acid and polystyrene, polyester, polyvinyl acetate and the like. Polyacrylic acid-based adhesive consisting of, cyanoacrylate-based adhesive, ethylene copolymer-based adhesive consisting of a copolymer of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, and methacrylic acid, cellulose-based adhesive , Polyurethane adhesives, polyester adhesives, polyamide adhesives, polyimide adhesives, polyolefin adhesives such as LDPE, amino resin adhesives made of urea resin or melamine resin, phenol resin adhesives, epoxy Inorganic adhesives such as adhesives, reactive (meth) acrylic adhesives, chloroprene rubbers, nitrile rubbers, styrene-butadiene rubbers, etc., silicone adhesives, alkali metal silicates, low melting point glass, etc. Examples include agents.

<Method of manufacturing rust preventive film>
A method for producing the rust-preventive film of the present invention will be described. The production method shown below is an example and does not limit the present invention.
The rust-preventive film can be produced by any method such as a T-die extrusion method, an extrusion inflation method, or the like.
When the rust-preventive film has a multi-layer structure, the laminating of each layer is performed by a laminating method used in manufacturing ordinary packaging materials, for example, a wet lamination method, a dry lamination method, a solvent-free dry lamination method, and the like. It can be carried out by any method such as an extrusion lamination method, a co-extrusion lamination method, a T-die co-extrusion method, a co-extrusion inflation method, and the like.
Among the above, the multilayer rust preventive film is preferably a co-press film produced by a method including co-extrusion.
Then, when performing the above lamination, if necessary, pretreatment such as corona treatment and ozone treatment can be applied to the surface of each layer. Further, for example, an anchor coating agent such as isocyanate-based (urethane-based), polyethyleneimine-based, polybutagen-based, organic titanium-based, or polyurethane-based, polyacrylic-based, polyester-based, epoxy-based, polyvinyl acetate-based, cellulose-based, etc. Anchor coating agents such as adhesives for laminating such as, etc. can be arbitrarily used.

For example, a case where a rust-preventive film is produced by an inflation method will be described.
When the rust-preventive film is a single layer, first, a resin composition for forming the rust-preventive film is prepared, and the rust-preventive film is produced by inflation film formation.
When the rust-preventive film has multiple layers, first, a resin composition for forming each of the rust-preventive layer, the intermediate layer, and the outer surface layer is prepared. Then, the rust preventive layer, the intermediate layer, and the outer surface layer are co-extruded and laminated by the inflation film forming to produce a multi-layer rust preventive film. Then, further, aging treatment may be performed if necessary.
In this way, a laminate for packaging liquid contents or a packaging material for liquid contents can be produced.
Then, the obtained rust-preventive film may be stretched in the uniaxial direction or the biaxial direction, if necessary.

The purpose of the rust preventive film is to impart chemical function, electrical function, magnetic function, mechanical function, friction / wear / lubrication function, optical function, thermal function, surface function such as biocompatibility, etc. As a result, secondary processing can be performed.
Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, etc.) Coating, etc.) and the like. Further, the rust-preventive film can be subjected to a laminating process (dry laminating or extruding laminating), a bag making process, and other post-treatment processes.

≪Rust-proof packaging material≫
The rust-preventive packaging material of the present invention is a packaging material made from the rust-preventive film of the present invention, and may further contain layers having various functions, if necessary.
The rust-preventive packaging material has the same rust-preventive properties as the rust-preventive film, and can be used as, for example, a stretch film.

≪Rust-proof packaging body≫
The rust-preventive packaging body of the present invention is a packaging body made from the rust-preventive packaging material of the present invention.
The shape and form of the rust-preventive packaging body of the present invention are not particularly limited, and various shapes and forms can be obtained by bending the rust-preventive packaging material, stacking the contents so as to wrap them, and heat-sealing them. It is possible to add value by printing decoration.
For example, a pouch-shaped rust-preventive package can be produced with less rust-preventive packaging material than a bottle-shaped rust-preventive package, which is effective in saving resources.

For the pouch-shaped rust-preventive packaging material, for example, the rust-preventive packaging material is folded in half, or two rust-preventive packaging materials are prepared and the layers having heat-sealing properties are stacked so as to face each other. Align, and further attach the peripheral edges to, for example, side seal type, two-way seal type, three-way seal type, four-way seal type, envelope-attached seal type, gassho-attached seal type (pillow-seal type), fold-attached seal type, and flat-bottom seal. Various shapes of rust-preventive packaging can be produced by heat-sealing with a heat-sealing form such as a mold, a square bottom seal type, or a gusset type.
In the above, as the heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.

In the rust-preventive package, it is preferable that the rust-preventive layer of the rust-preventive packaging material is located inside the rust-preventive package and the outer surface layer is located inside.
By being packaged in this way, the rust-preventive package suppresses the permeation of acid gas from the outside and attaches a rust preventive agent to the surface of the contents to prevent the contents from being rusted. It can be suppressed efficiently.
When producing the rust-preventive package, the package may be sealed while sucking air in the package or replacing the content space with air having a low oxygen content or low humidity.

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples.
Details of the raw materials used in the examples are as follows.

[Antioxidant]
-Antioxidant 1: Phenolic antioxidant, A060 manufactured by ADEKA CORPORATION.
-Antioxidant 2: Phosphorus-based antioxidant 2112 manufactured by ADEKA CORPORATION.
-Antioxidant 3: A-612RG, a phenol + phosphorus mixed antioxidant manufactured by ADEKA CORPORATION.
-Antioxidant 4: Phenol + phosphorus synthetic antioxidant SUMILIZER GP manufactured by Sumitomo Chemical Co., Ltd.

[Fatty acids]
-Fatty acid 1: Enanthic acid manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.
-Fatty acid 2: Stearic acid manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.
-Metal fatty acid 1: Calcium stearate manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.
-Fatty acid ester 1: Triglyceride manufactured by Riken Vitamin Co., Ltd., Actor M2.

[Binder resin, thermoplastic resin]
-LLDPE1: LLDPE manufactured by Prime Polymer Co., Ltd., Evolu SP2020. Density 0.916 ^{g / cm 3} , MFR = 2.0 g / 10 minutes.
-LDPE1: LDPE manufactured by Japan Polyethylene Corporation, Novatec LC520. Density 0.923 g / cm ³ , MFR 3.6 g / 10 minutes.

<Preparation of masterbatch>
The masterbatch was prepared as follows.
[Preparation of Masterbatch 1]
LDPE1 and antioxidant 1 were melt-blended at the following ratios to obtain Masterbatch 1 (MB1).
LDPE1 95 parts by mass Antioxidant 15 parts by mass

[Adjustment of master batches 2-8]
According to the formulation shown in Table 1, master batches 2 to 8 (MB 2 to 8) were obtained by melt blending in the same manner as in master batch 1.

<Example>
A rust-preventive film containing a rust-preventive agent was prepared and various evaluations were carried out.

[Example 1]
MB1 and LLDPE1 were dry-blended at the following ratios to obtain a rust-preventive layer resin composition.
MB1 20 parts by mass LLDPE1 80 parts by mass The rust-preventive layer resin composition obtained above was formed by inflation film formation at 160 ° C. to obtain a rust-preventive film (30 μm thickness) consisting of only the rust-preventive layer. Then, various evaluations were carried out.

[Example 2]
MB1, MB7 and LLDPE1 were dry-blended at the following ratios to obtain a rust-preventive layer resin composition.
MB1 20 parts by mass MB7 20 parts by mass LLDPE1 60 parts by mass Using the rust-preventive layer resin composition obtained above, the same operation as in Example 1 was carried out to obtain a rust-preventive film (30 μm thickness) consisting of only the rust-preventive layer. Got Then, various evaluations were carried out in the same manner as in Example 1.

[Example 3]
MB1 and LLDPE1 were dry-blended at the following ratios to obtain a rust-preventive layer resin composition.
MB1 20 parts by mass LLDPE1 80 parts by mass The rust-preventive layer resin composition obtained above and LLDPE1 are formed and laminated by inflation film formation at 160 ° C. to form the following three-layer rust-preventive film (60 μm thickness). Got Then, various evaluations were carried out in the same manner as in Example 1.
Layer structure: Rust prevention layer / intermediate layer (LLDPE1) / outer surface layer (LLDPE1) = 15 μm thickness / 30 μm thickness / 15 μm thickness

[Examples 4 to 32]
A masterbatch was selected according to the description in Tables 2 to 8 and operated in the same manner as in Example 3 to prepare a rust-preventive film having a three-layer structure, which was evaluated in the same manner.

[Comparative Example 1]
An operation was carried out in the same manner as in Example 3 except that the rust preventive layer was formed only of LLDPE1 to prepare a rust preventive film having a three-layer structure, which was evaluated in the same manner.

<Evaluation method>
[Film formation]
The appearance of the rust-preventive 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.
X: The rust-preventive film had wrinkles, bumps, peeling, etc.

[Heat sealability]
The rust-preventive film is cut into 100 mm x 100 mm, and if there is a heat-sealable outer surface layer, the outer surface layers face each other, and after overlapping, a heat-seal tester (manufactured by Tester Sangyo Co., Ltd .: TP-701-A) is used. Using, heat-seal a 1 cm x 10 cm area so that the end is not heat-sealed and is divided into two parts, and further cut into strips with a width of 15 mm to prepare a test piece for heat-seal strength measurement. Made.
Each bifurcated end of this test piece is attached to a tensile tester, pulled so as to peel off the heat seal, measure the heat seal strength (N / 15 mm width), and use the following pass / fail criteria. A pass / fail judgment was made.
(Heat seal condition)
Temperature: 160 ° C
Pressure: 1 kgf / cm ²
Time: 1 second (tensile strength test conditions)
Test speed: 300 mm / min Load range: 50 N
(Pass / Fail Judgment Criteria)
◯: 30N / 15mm or more, passed.
X: Less than 30 N / 15 mm and failed.

[Rust prevention]
The rust-preventive film is cut into 100 mm × 100 mm, and if there is a heat-sealable outer surface layer, the outer surface layers face each other and are overlapped, and then a four-way seal is performed on the laminate using an impulse sealer to 100 mm. A pouch of × 100 mm was prepared.
Next, the pouch was filled with the following metal pieces and stored in a constant temperature bath adjusted to 60 ° C. and 90% RH for 14 days, and changes in appearance were evaluated according to the following evaluation criteria.
(piece of metal)
Iron plate: Cold rolled steel plate (SPCC), 50 mm x 50 mm x 1 mm, degreased.
Copper plate: Tough pitch copper plate (C1100P-1 / 4H), 50 mm x 50 mm x 1 mm, degreased.
(Evaluation criteria)
⊚: No rust and discoloration, or only spot rust and slight discoloration.
〇: Rust occurs in less than 10% of the area of the test piece.
Δ: Rust occurred in 10% or more and less than 50% of the area of the test piece.
X: Rust occurs in 50% or more of the area of the test piece.

1 Rust-proof film 2 Rust-proof packaging material 3 Rust-proof layer 3a Rust-preventive agent 4 Intermediate layer 5 Outer surface layer

Claims (9)

A single-layer rust-preventive film containing at least a rust-preventive agent and a binder resin.
The rust preventive is characterized by containing at least an antioxidant.
Rust-proof film. A multi-layered rust-preventive film having at least a rust-preventive layer.
The rust preventive layer contains a rust preventive agent and a binder resin, and contains
The rust inhibitor contains at least an antioxidant and
A layer containing a thermoplastic resin is laminated on one side or both sides of the rust preventive layer.
Rust-proof film. The rust-preventive film according to claim 2, wherein the rust-preventive film is a co-press film. The rust-preventive film according to claim 2 or 3, wherein the rust-preventive film further has an intermediate layer. The rust-preventive film according to any one of claims 1 to 4, wherein the antioxidant contains a phenol-based antioxidant and / or a phosphorus-based antioxidant. The item according to any one of claims 1 to 5, wherein the rust preventive further contains one or more selected from the group consisting of fatty acids, metal fatty acids, and fatty acid esters. Rust-proof film. The rust-preventive film according to claim 6, wherein the fatty acid portion of the fatty acid, the metal fatty acid, and the fatty acid ester has 6 or more and 20 or less carbon atoms. A rust-preventive packaging material comprising the rust-preventive film according to any one of claims 1 to 7. A rust-preventive packaging body comprising the rust-preventive packaging material according to claim 8.

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