JP2003205583A - Deoxidizing multi-layer film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen-absorbing multi-layer film which shows superb water vapor barrier properties and remarkable economy, film rigidity and shelf stability of contents. <P>SOLUTION: The oxygen-absorbing multi-layer film comprises an outer layer formed of a thermoplastic resin, an adhesive layer formed of an epoxy resin composition composed of a reaction cured product of an epoxy resin and an epoxy resin curing agent, an oxygen-absorbing layer containing a ferrous oxygen absorbing agent added to the thermoplastic resin and a sealant layer formed of an oxygen-permeable thermoplastic resin. In this film, the resin of the outer layer, the oxygen-absorbing layer or the sealant layer is a polypropylene and a gas barrier epoxy resin composition constituting the adhesive layer contains 30 wt.% or higher of a xylylenediamine unit (N-CH2-C6H4-CH2-N). Consequently, it is possible to prevent the fugacious disappearance of a moisture from a stored article to the outside of an oxygen-absorbing container from occurring. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen-absorbing multilayer film used as a packaging material for foods, pharmaceuticals, etc. for the purpose of storing contents by absorbing oxygen.

[0002]

2. Description of the Related Art In recent years, as a packaging material for storing contents, a plastic film or a container has been mainly used because of its lightness and economy. Required properties of plastic films used for packaging foods, pharmaceuticals, cosmetics, etc. are barrier properties against various gases, transparency,
Examples include retort resistance, impact resistance, flexibility, heat sealability, etc., but for the purpose of maintaining the performance or properties of the contents, oxygen and oxygen even under conditions such as high humidity or after retort processing A high barrier property against water vapor is particularly required.

On the other hand, an oxygen absorber such as an iron powder or the like packed with a breathable packaging material, or an oxygen-absorbing resin composition obtained by blending a thermoplastic resin with an oxygen absorber is used as a breathable packaging material. Label-type, packing-type, card-type, etc. oxygen scavengers, which are packaged as described above, are used to store foods, pharmaceuticals, and the like. Furthermore, as one of the deoxidizing packaging technology, a packaging container made of a multilayer material having a deoxidizing function, in which an oxygen absorbing layer made of a resin composition in which a thermoplastic resin is mixed with an oxygen absorbing agent is arranged, that is, deoxidizing Container development is underway.

An oxygen-absorbing resin composition prepared by blending an iron-based oxygen absorber with a resin is, for example, JP-A-60-15825.
7, JP-A-63-281964, JP-A-4
No. 90847 and Japanese Patent Application Laid-Open No. 7-268140 disclose that an iron-based oxygen absorbent is dispersed and mixed in a thermoplastic resin. JP-A-8-72941 and JP-A-7-2941
JP-A-309323 and JP-A-9-40024 describe an oxygen-absorbing multilayer body such as a multilayer sheet or a multilayer film having an iron-based oxygen-absorbing resin layer.

Generally, the oxygen-absorbing multilayer body comprises a protective outer layer,
The gas barrier layer, the oxygen absorption layer, and the sealant layer are formed by laminating the respective materials, and the gas barrier layer and the oxygen absorption layer are bonded by extrusion lamination or dry lamination. However, an oxygen-absorbing multilayer body consisting of a gas barrier layer, an adhesive layer, an oxygen-absorbing layer, and a sealant layer is compared with the above-mentioned ordinary barrier film,
Since the oxygen absorbing layer is provided, the thickness is inevitably increased, and there is a problem that the flexibility of the laminate is deteriorated.

As the gas barrier material forming the gas barrier layer, polyvinylidene chloride (PVDC) coat and film, ethylene-vinyl alcohol copolymer (EVOH resin) film, polyvinyl alcohol (PVA) coat film, and metaxylylene adipate. Mido films, inorganic vapor deposition films obtained by vapor deposition of alumina (Al ₂ O ₃ ) and silica (SiOx), aluminum foils, etc. are known, and they are used according to the type and content of the contents depending on their characteristics. When laminating the oxygen absorbing layer on the gas barrier material, a dry laminating method of applying an adhesive to the gas barrier material to adhere the oxygen absorbing layer, or applying an anchor coating agent to the gas barrier material as necessary, An extrusion laminating method or the like is used in which a molten resin composition layer serving as an oxygen absorbing layer is pressure-bonded thereon and laminated in a film shape. The adhesive or anchor coating agent used in these methods is mainly a two-component polyurethane-based adhesive consisting of a main agent having an active hydrogen group such as a hydroxyl group and a curing agent having an isocyanate group in terms of high adhesive performance. It is used (for example, JP-A-9-316422).

That is, the conventional multilayer body for oxygen absorption production is
In order to adhere to the gas barrier layer and the oxygen absorbing layer, it is necessary to separately provide a layer that plays a role of adhesion such as an adhesive layer or an anchor coat layer between both layers, which is economical and workability in the manufacturing process. It was at a disadvantage.

[0008]

The object of the present invention is to solve the above-mentioned problems, to have an oxygen absorbing function, to be excellent in water vapor barrier property, and to be excellent in economical efficiency, film rigidity and content storability. An object is to provide an oxygen-absorbing multilayer film used for packaging materials such as foods and pharmaceuticals.

[0009]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have used a cured product formed of a specific component as an epoxy resin adhesive between an outer layer and an oxygen absorbing layer, Furthermore, by selecting the resin that constitutes the layer, a laminated film excellent in various properties such as water vapor barrier property, gas barrier property, interlayer adhesion property, retort treatment resistance, impact resistance, flexibility and economic efficiency is obtained. The present invention has been made and the present invention has been achieved.

That is, according to the present invention, at least an outer layer made of a thermoplastic resin, an adhesive layer made of an epoxy resin composition which is a reaction cured product of an epoxy resin and an epoxy resin curing agent, a thermoplastic resin and an iron-based oxygen absorber. In the oxygen-absorbing multilayer film consisting of a sealant layer consisting of an oxygen-absorbing layer and an oxygen-permeable thermoplastic resin containing an outer layer or oxygen-absorbing layer, the sealant layer resin is polypropylene, the adhesive layer is a xylylenediamine unit ( N-CH2-C6H4-CH
An oxygen-absorbing multilayer film comprising a gas barrier epoxy resin composition containing 30% by weight or more of 2-N).

In the present invention, in particular, the gas barrier epoxy resin composition is obtained by curing an epoxy resin with an epoxy resin curing agent, and the epoxy resin constituting the gas barrier epoxy resin composition contains a xylylenediamine unit. It is an oxygen absorbing multilayer film which is an epoxy resin.
In particular, the present invention provides an oxygen-absorbing multilayer film in which the gas barrier epoxy resin composition is obtained by curing an epoxy resin with an epoxy resin curing agent, and the epoxy resin curing agent is an epoxy resin curing agent containing a xylylenediamine unit. Is.

One of the features of the present invention is that the outer layer, the oxygen absorbing layer or the sealant layer is made of polypropylene resin. This prevents moisture from volatilizing and disappearing from the article stored in the container to the outside of the container. Another one of the features of the present invention is that the xylylenediamine unit is used as an adhesive layer.
The point is to use a gas barrier epoxy resin composition containing 30% by weight or more of (N-CH2-C6H4-CH2-N). This allows
The use of gas barrier film such as aluminum foil can be omitted.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The oxygen absorbing multilayer film of the present invention will be described in detail. As the outer layer made of the thermoplastic resin used in the present invention, any one can be used as long as it can be coated with an adhesive layer, for example, a polyolefin film such as polyethylene or polypropylene, or a polyester film such as polyethylene terephthalate. Examples thereof include films, polyamide films such as nylon 6 and nylon 6,6, poly (meth) acrylic films, polystyrene films, saponified ethylene-vinyl acetate copolymer (polyvinyl alcohol, EVOH) films, and the like. Among these, a film using polypropylene is more preferable. These films are preferably uniaxially or biaxially stretched, and their thickness is practically about 10 to 300 μm, preferably about 10 to 100 μm.

It is desirable that various surface treatments such as flame treatment and corona discharge treatment be carried out on the outer surface of the adhesive-coated surface so that an adhesive layer free from defects such as film breakage and cissing is formed. Such treatment promotes good adhesion of the adhesive layer to the outer layer. In addition, after the surface of the outer layer is appropriately surface-treated, a printing layer can be provided if necessary. When providing a printing layer, a gravure printing machine,
General printing equipment that has been used for printing on conventional polymer films, such as flexographic printing machines, offset printing machines, can be applied as well. In addition, regarding the ink that forms the printing layer, azo-based, phthalocyanine-based pigments, rosin, polyamide resin, polyurethane and other resins, methanol, ethyl acetate, methyl ethyl ketone, etc. Inks that have been used in printing layers can be applied as well.

The adhesive layer in the present invention comprises a gas barrier resin composition containing 30% by weight or more of xylylenediamine units (N-CH2-C6H4-CH2-N). The adhesive layer is a thermosetting curing reaction product of an epoxy resin or an epoxy resin curing agent containing a xylylenediamine unit. A curing reaction product containing a xylylenediamine unit in both the epoxy resin and the epoxy resin curing agent is preferable.

The adhesive layer in the present invention exhibits good adhesiveness between the outer layer made of a thermoplastic resin and the oxygen absorbing layer or the intermediate layer. Further, the adhesive layer in the present invention has a high gas barrier property. The oxygen permeability coefficient of the adhesive layer is the temperature
Oxygen permeability coefficient of 0.1cc at 23 ℃ and 60% relative humidity
-mm / m ² · day · atm or less, the oxygen permeability of the outer layer coated with the adhesive under the conditions of temperature 23 ℃ and relative humidity 60%,
20cc / m ² day ・ atm or less, regardless of the type of outer layer. The epoxy resin and the epoxy resin curing agent used for the adhesive layer will be described in detail below.

The epoxy resin may be a saturated or unsaturated aliphatic compound, alicyclic compound, aromatic compound or heterocyclic compound, but when considering the expression of a high gas barrier property, the aromatic ring is used. Epoxy resins containing in the molecule are preferred. Specifically, tetraglycidylamine type epoxy resin of meta-xylylenediamine, tetraglycidylamine type epoxy resin of 1,3-bis (aminomethyl) cyclohexane, tetraglycidylamine type epoxy resin of diaminodiphenylmethane, triglycidyl type of paraaminophenol. Epoxy resin, diglycidyl ether type epoxy resin of bisphenol A, diglycidyl ether type epoxy resin of bisphenol F, phenol novolac type epoxy resin, diglycidyl ether type epoxy resin of resorcinol and the like can be used. In particular,
It is preferable to use a tetraglycidylamine type epoxy resin of metaxylylenediamine as an epoxy resin component. Further, in order to improve various properties such as flexibility, impact resistance and wet heat resistance, the above various epoxy resins can be mixed and used at an appropriate ratio.

The epoxy resin curing agent is composed of metaxylylenediamine or paraxylylenediamine and a polyfunctional compound having at least one acyl group capable of forming an amide group site to form an oligomer by reaction with an amine. The reaction product with the reaction product is the main component. Alternatively, a polyfunctional compound having at least one acyl group capable of forming an amide group site to form an oligomer by the reaction of metaxylylenediamine or paraxylylenediamine with an amine, and one having 1 to 8 carbon atoms. It is mainly composed of a reaction product with a divalent carboxylic acid and / or a derivative thereof.

The epoxy resin curing agent is the following (A) and (B)
Or a reaction product of (A), (B) and (C). (A) A polyfunctional compound having at least one acyl group (C) having 1 to 10 carbon atoms, which can form an amide group site to form an oligomer by reaction with (A) metaxylylenediamine or (A) paraxylylenediamine (B) 8 monovalent carboxylic acids and / or derivatives thereof

The epoxy resin curing agent is an amide compound having a plurality of amide bonds by a condensation reaction between metaxylylenediamine or paraxylylenediamine and the above-mentioned polyfunctional compound having an acyl group. The amide compound may form an oligomer by addition polymerization or polycondensation.

A polyfunctional compound having at least one acyl group capable of forming an amide group site to form an oligomer by the reaction of metaxylylenediamine or paraxylylenediamine with an amine is acrylic acid or methacrylic acid. And unsaturated carboxylic acids or polycarboxylic acids such as maleic acid, fumaric acid, succinic acid, malic acid, tartaric acid, adipic acid, isophthalic acid, terephthalic acid, pyromellitic acid and trimellitic acid. Derivatives of unsaturated carboxylic acids or polycarboxylic acids, such as esters, amides, acid anhydrides, acid chlorides can also be used. In particular,
Acrylic acid, methacrylic acid, and their esters,
Amides or acid anhydrides are preferred.

The proportion of the metaxylylenediamine or paraxylylenediamine and the unsaturated carboxylic acid or polycarboxylic acid capable of forming an amide group site to form an oligomer by the reaction of the amine is metaxylylenediamine. The molar ratio of the carboxyl group of unsaturated carboxylic acid or polycarboxylic acid to the amino group of amine or paraxylylenediamine is preferably in the range of 0.3 to 0.95.

Further, formic acid, acetic acid, propionic acid, butyric acid,
C1-C8 monovalent carboxylic acids such as lactic acid, glycolic acid and benzoic acid and their derivatives such as esters, amides, acid anhydrides and acid chlorides are used in combination with the above unsaturated carboxylic acids or polycarboxylic acids. Then, an amide compound formed by initiating a reaction with a diamine may be used.

Further, in order to improve various performances such as flexibility, impact resistance and wet heat resistance, the above various epoxy resin curing agents can be mixed and used in an appropriate ratio. The xylylenediamine unit (N-CH2 in the epoxy resin composition constituting the thermosetting gas barrier adhesive layer of the present invention
The content of -C6H4-CH2-N) is 30% by weight or more based on the weight of the cured epoxy resin component, preferably 40% by weight or more, and more preferably 50% by weight or more. The terminal of the xylylenediamine unit preferably forms an amide group site with an acyl group.

The xylylenediamine unit contained in the adhesive layer of the present invention has a high cohesive force, and the presence of the xylylenediamine unit in the epoxy resin curing agent in a high proportion as in the above range causes Higher oxygen barrier properties and good bond strength to flexible polymer films are obtained. On the other hand, the upper limit of the content of xylylenediamine units is preferably 95% by weight, more preferably 90% by weight.
Is. Adhesiveness may be insufficient when there are too many xylylenediamine units.

Regarding the mixing ratio of the epoxy resin and the epoxy resin curing agent which form the adhesive layer in the present invention, generally, the standard mixing ratio when the epoxy resin cured product is produced by the reaction between the epoxy resin and the epoxy resin curing agent is carried out. It can be a range. Specifically, the ratio of the number of active hydrogen in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin is 0.5 to 5.0, preferably 0.8 to 3.0.

For the adhesive layer in the present invention, a coating solution containing an epoxy resin composition comprising an epoxy resin and an epoxy resin curing agent as a coating film forming component is prepared, and the coating solution is used as an outer layer comprising a thermoplastic resin or oxygen absorption. It is formed by coating on the surface of a layer or the like and then drying or heat-treating as required. When the coating solution is prepared, the concentration of the epoxy resin composition is sufficient to obtain the cured epoxy resin composition, which may vary depending on the selection of the starting material. That is, the concentration of the epoxy resin composition depends on the kind and the molar ratio of the selected material, and when the solvent is not used, the concentration of the composition is about 5% by weight using a certain suitable organic solvent and / or water. It can take various states up to.

Suitable organic solvents include 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-. Glycol ethers such as 2-propanol, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, alcohols such as 2-butanol, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, Examples thereof include aprotic polar solvents such as N-methylpyrrolidone and water-insoluble solvents such as toluene, xylene and ethyl acetate, and relatively low boiling point solvents such as methanol and ethyl acetate are more preferable.

When the coating solution is applied to the outer layer made of a thermoplastic resin, the oxygen absorbing layer, etc., in order to assist the wetting of the surface of the substrate, the coating solution of the present invention contains a silicone or acrylic compound. A wetting agent may be added. Suitable wetting agents include BYK331, BYK333, BYK348, BYK381 available from Big Chemie. When these are added, the range of 0.01 wt% to 2.0 wt% is preferable based on the total weight of the cured reaction product (gas barrier layer).

In order to improve various properties such as gas barrier properties and impact resistance of the oxygen-absorbing multilayer film of the present invention, silica, alumina, mica, talc, aluminum flakes, glass flakes, etc. are contained in the epoxy resin composition. You may add the inorganic filler of. Such an inorganic filler is preferably flat. When an inorganic filler is added, it is preferably in the range of 0.01% by weight to 10.0% by weight based on the total weight of the resin composition after the curing reaction.

When the coating solution of the present invention is applied to the outer layer made of a thermoplastic resin, the oxygen absorbing layer, etc., the coating method generally used is roll coating, spray coating, air knife coating, dipping or brush coating. Any of the applied coating types can be used. Of these, roll coating or spray coating is preferable. For example, common roll coating or spraying techniques and equipment for applying the curable paint components may be applied.

Since the epoxy adhesive used in the present invention has a rapid curing reaction, it is not necessary to carry out post-curing by aging after laminating in order to secure sufficient adhesiveness.
The thickness of the adhesive layer after coating, drying and heat treatment on the thermoplastic outer layer, oxygen absorbing layer, etc. must have a lower limit of 0.1 μm, preferably 0.5 μm, and an upper limit of 20 μm, preferably 10 μm. Target. If it is less than 0.1 μm, it is difficult to exhibit sufficient gas barrier properties, while if it exceeds 20 μm, the flexibility is lost and the film thickness becomes uneven.

In the present invention, good adhesive strength is exhibited between the thermoplastic resin and the oxygen-absorbing layer because many functional groups present in the cured epoxy resin forming the adhesive layer are formed on the surface of each layer. This is because they interact strongly. Further, the epoxy resin cured product forming the adhesive layer of the present invention has a toughness,
Due to its excellent resistance to moist heat, it is possible to obtain an oxygen-absorbing multilayer film excellent in impact resistance, heat treatment resistance and the like. Further, the obtained multilayer film can be made into a thin film, has excellent flexibility, and has excellent bag-making properties.

The oxygen absorbing layer of the present invention is manufactured by blending a thermoplastic resin with an iron-based oxygen absorbing agent. In the present invention, the amount of the iron-based oxygen absorber compounded in the thermoplastic resin is 10 to 8 in the oxygen-absorbent resin composition.
The amount is 0% by weight, preferably 20 to 70% by weight. If the amount is more than this range, the processability of the resin composition will be problematic, and if it is less than this range, the oxygen absorption performance will be deteriorated. The iron-based oxygen absorbent is preferably fine in order to reduce the layer thickness of the oxygen absorption layer, and the average particle diameter is preferably 1 to 150 μm, and 5 to 100 μm.
μm is particularly preferred. The thickness of the oxygen absorption layer is 1 to 200 μ
m or less is preferable, and 5 to 100 μm or less is more preferable.

The iron powder in the iron-based oxygen absorbent used in the present invention is not particularly limited, and reduced iron powder, atomized iron powder, and electrolytic iron powder are used. Further, the particle size of the iron powder used for the iron-based oxygen absorber is preferably fine in order to reduce the layer thickness of the oxygen-absorbing resin, and the average particle size is preferably 1 to 150 μm,
5-100 micrometers is especially preferable. As the iron-based oxygen absorber, a mixture of the above-mentioned iron powder and metal halide is preferable. Metal halides act catalytically on the oxygen absorption reaction of iron powder. As the metal halide, for example,
Alkali metal or alkaline earth metal chlorides, bromides or iodides are used, and lithium, sodium, potassium, magnesium, calcium or barium chlorides or iodides are preferably used. The content of the metal halide is preferably 0.1 to 2 per 100 parts by weight of iron powder.
It is 0 part by weight, more preferably 0.1 to 5 parts by weight.

The metal halide is used together with the iron powder as an essential component of the oxygen absorbent containing iron powder as the main component, but it is preferable to add it in advance so as not to adhere to the iron powder and separate easily. For example, a ball mill, a method of mixing the metal halide with iron powder using a speed mill, a method of embedding the metal halide in the recesses of the iron powder surface, a method of attaching the metal halide to the iron powder surface using a binder, A method such as a method in which an aqueous metal halide solution and iron powder are mixed and then dried and attached to the surface of the iron powder may be used. A preferred iron-based oxygen absorber is a composition containing iron powder and a metal halide, and particularly preferably an oxygen absorber composed of a metal halide-coated iron powder obtained by adhering a metal halide to iron powder. The oxygen-absorbing resin composition of the present invention may be blended with components other than iron powder and metal halide.

Polyolefin is preferably used as the thermoplastic resin to which the iron-based oxygen absorber of the present invention is added. Examples of the polyolefin include low density polyethylene, medium density polyethylene, polyethylene exemplified by linear low density polyethylene and high density polyethylene, polypropylene homopolymer, propylene-ethylene block copolymer and propylene-ethylene random copolymer. Polypropylene, metallocene-catalyzed polyolefins such as metallocene polyethylene and metallocene polypropylene, polymethylpentene, elastomers exemplified by ethylene-vinyl acetate copolymer and ethylene-α-olefin copolymer, or a mixture thereof. . Among these, a mixture of propylene-homopolymer and polyethylene, a propylene-ethylene random copolymer, and a propylene-ethylene block copolymer are particularly preferable.

In the present invention, an intermediate layer made of a resin containing no oxygen absorbent may be provided between the adhesive layer and the oxygen absorbent layer in order to enhance the interlayer adhesive strength. The resin used for the intermediate layer is preferably the same as the resin used for the oxygen absorption layer described above in consideration of the compatibility with the oxygen absorption layer. The thickness of the intermediate layer is preferably 10 to 50 μm,
˜40 μm is particularly preferred.

The heat-sealing layer which constitutes the oxygen-absorbing multilayer body of the present invention is a portion which becomes a sealant when the oxygen-absorbing multilayer film of the present invention is used for a part or the whole of a packaging container, and is also a storage article. It also has a role as an isolation layer that separates the oxygen absorbing layer from each other, and also serves as an oxygen permeable layer that efficiently permeates oxygen because oxygen in the packaging container is quickly absorbed by the oxygen absorber in the oxygen absorbing layer.

The heat-sealing layer constituting the oxygen-absorbing multilayer film of the present invention can be used without limitation as long as it is a thermoplastic resin which can play the role of heat fusion and has oxygen permeability. be able to. For example, various polyethylenes such as low density polyethylene, linear low density polyethylene, ultra-low density polyethylene, metallocene-catalyzed polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-methyl acrylate copolymer, ethylene-acrylic. Ethyl acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, propylene homopolymer, propylene-ethylene block copolymer, propylene-ethylene random copolymer , Various polypropylenes such as polypropylene with a metallocene catalyst, polymethylpentene, and thermoplastic elastomers, and these can be used alone or in combination. Among these, polypropylenes are particularly preferable.

In the heat seal layer, color pigments such as titanium oxide, additives such as antioxidants, slip agents, antistatic agents and stabilizers, fillers such as calcium carbonate, clay, mica and silica, deodorants, etc. May be added.

The film thickness of the heat seal layer constituting the oxygen-absorbing multilayer film of the present invention is preferably 10 to 100 μm, more preferably 20 to 60 μm.
If the film thickness of the heat seal layer is less than 10 μm, the oxygen absorber of the oxygen absorbing layer is exposed on the surface and the heat seal strength decreases, which is not preferable. Further, if the thickness of the heat seal layer is more than 100 μm, it becomes unfavorable because the lamination becomes difficult, the oxygen permeability is lowered and the oxygen absorption performance of the film is lowered, and the manufacturing cost is further increased.

The total thickness of the oxygen-absorbing multilayer film of the present invention is preferably 125 μm or less, more preferably 115 μm.
It can be less than or equal to μm. The oxygen-absorbing multilayer film of the present invention does not need to separately provide a gas barrier layer constituting the laminated film, which is advantageous from the economical aspect. Also,
The oxygen-absorbing multilayer film of the present invention is excellent in impact resistance, retort resistance, and flexibility, and is advantageous in workability in filling contents as a container.

[0044]

EXAMPLES Examples of the present invention will be introduced below, but the present invention is not limited to these examples.

Coating Solution 1 1 mol of metaxylylenediamine was charged into a reaction vessel.
The temperature was raised to 60 ° C. under a nitrogen stream, and 0.67 mol of methyl acrylate was added dropwise over 1 hour. After completion of dropping, the mixture was stirred at 120 ° C for 1 hour, and the temperature was raised to 180 ° C in 3 hours while distilling off the produced methanol. Cool to 100 ° C and
A predetermined amount of methanol was added to 70% by weight to obtain an epoxy resin curing agent A which was an oligomer having an amide group site. Tetraglycidylamine type epoxy resin of meta-xylylenediamine (manufactured by Mitsubishi Gas Chemical Co., Ltd .; TETRAD)
-X) and 50 parts by weight of epoxy resin curing agent A and 90 parts by weight of epoxy resin curing agent A in a methanol / ethyl acetate = 1/1 solution (solid concentration: 30
% By weight) and add acrylic wetting agent (BIC
Chemie; BYK381) 0.02 parts by weight, and well stirred,
An adhesive coating liquid 1 was obtained.

Coating Solution 2 1 mol of metaxylylenediamine was charged into a reaction vessel.
The temperature was raised to 60 ° C. under a nitrogen stream, and 0.50 mol of methyl acrylate was added dropwise over 1 hour. After completion of dropping, the mixture was stirred at 120 ° C for 1 hour, and the temperature was raised to 180 ° C in 3 hours while distilling off the produced methanol. After cooling to 100 ° C., an epoxy resin curing agent B which is an oligomer having an amide group site was obtained. Metaxylylenediamine tetraglycidylamine type epoxy resin (Mitsubishi Gas Chemical Co., Ltd .; TETRAD-X)
A methanol / ethyl acetate = 1/1 solution (solid content: 30% by weight) containing 50 parts by weight and 66 parts by weight of an epoxy resin curing agent B was prepared, and an acrylic wetting agent (manufactured by BYK Chemie; BYK381). ) Was added and stirred well to obtain an adhesive coating liquid 2.

Coating Solution 3 A reaction vessel was charged with 1 mol of metaxylylenediamine.
The temperature was raised to 120 ° C. under a nitrogen stream, 0.50 mol of methyl acrylate was added dropwise over 1 hour, and the mixture was stirred at 120 ° C. for 0.5 hour. Further, 0.17 mol of malic acid was added little by little and stirred for 0.5 hours. The resulting water and methanol were distilled off, and the temperature was raised to 180 ° C. over 3 hours. Cool to 100 ° C and
A predetermined amount of methanol was added to 70% by weight to obtain an epoxy resin curing agent C which is an oligomer having an amide group site. Tetraglycidylamine type epoxy resin of meta-xylylenediamine (manufactured by Mitsubishi Gas Chemical Co., Ltd .; TETRAD)
-X) and 50 parts by weight of an epoxy resin curing agent C and 100 parts by weight of a methanol / ethyl acetate = 1/1 solution (solid content concentration;
30% by weight) was prepared, 0.02 part by weight of an acrylic wetting agent (manufactured by BYK Chemie; BYK381) was added thereto, and the mixture was stirred well to obtain an adhesive coating liquid 3.

Coating liquid 4 An epoxy resin curing agent (manufactured by Mitsubishi Gas Chemical Co., Inc.) which is a reaction product of metaxylylenediamine and methyl methacrylate in which the molar ratio of metaxylylenediamine and methyl methacrylate is about 2: 1. Gascamine 340) 70 parts by weight of methanol / ethyl acetate = 1/1 solution (solid content concentration: 30% by weight), metaxylylenediamine tetraglycidylamine type epoxy resin (Mitsubishi Gas Chemical Co., Ltd .; TETRAD- X)
50 parts by weight and 0.02 parts by weight of an acrylic wetting agent (manufactured by BYK Chemie, BYK381) were added and well stirred to obtain an adhesive coating liquid 4.

Coating liquid 5 Diglycidyl ether type epoxy resin of bisphenol F (manufactured by Japan Epoxy Resins Co .; Epicoat 807)
Of 50 parts by weight and 64 parts by weight of epoxy resin curing agent A in a methanol / ethyl acetate = 1/1 solution (solid content concentration: 30% by weight) were prepared, and an acrylic wetting agent (manufactured by BYK Chemie; BYK381) was added in an amount of 0.02 part by weight and stirred well to obtain an adhesive coating liquid 5.

Coating Solution 6 1 mol of tetraethylenepentamine was charged into a reaction vessel. The temperature was raised to 100 ° C. under a nitrogen stream, 0.4 mol of a bisphenol A diglycidyl ether type epoxy resin (Japan Epoxy Resin Co., Ltd .; Epicoat 828) was added dropwise over 1 hour, and the mixture was further stirred for 2 hours. Solid content concentration is 40% by weight
Then, a predetermined amount of methanol was added thereto to obtain an epoxy resin curing agent D which is an oligomer having an amide group site. Metaxylylenediamine tetraglycidylamine type epoxy resin (Mitsubishi Gas Chemical Co., Ltd .; TETRAD-X)
A methanol / ethyl acetate = 1/1 solution (solid content: 30% by weight) containing 50 parts by weight and 144 parts by weight of an epoxy resin curing agent D was prepared, and an acrylic wetting agent (manufactured by BYK Chemie; BYK381) was prepared therein. ) Was added and stirred well to obtain an adhesive coating liquid 6.

Coating liquid 7 As a polyurethane adhesive coating liquid containing no xylylenediamine unit, 50 parts by weight of a polyether component (TM-329 manufactured by Toyo Morton Co., Ltd.) and a polyisocyanate component (Toyo Morton Co., Ltd.) were used. Ethyl acetate solution (solid content: 30% by weight) containing 50 parts by weight of CAT-8B) was thoroughly mixed with stirring to obtain an adhesive coating liquid 7.

Coating Solution 8 As an epoxy adhesive coating solution containing no xylylenediamine unit, a diglycidyl ether type epoxy resin of bisphenol A instead of the tetraglycidylamine type epoxy resin of metaxylylenediamine (Japan Epoxy Resins Co., Ltd. ); 50 parts by weight of Epicoat 828) and 27 parts of epoxy resin hardener D instead of epoxy resin hardener A
Adhesive coating liquid 8 was obtained by using well by weight and stirring.

Oxygen-absorbing resin composition A 1000 kg of iron powder having an average particle size of 30 μm was put into a vacuum dryer with a heating jacket, and the pressure was reduced to 10 mmHg.
Calcium chloride 50% by weight aqueous solution 5 while mixing at 0 ° C
After spraying 0 kg, drying, mixing, sieving and removing coarse particles, an iron-based oxygen absorber 1 having an average particle diameter of 30 μm was obtained. Next, using a vented twin-screw extruder, ethylene-
Propylene Random Copolymer (Chisso Corporation, trade name F
8090) while extruding, side-feeding the iron-based oxygen absorber, polypropylene: iron-based oxygen absorber = 70:
The oxygen-absorbing resin composition A was obtained by supplying the mixture at a weight ratio of 30 and kneading, extruding from a strand die, cooling, and pelletizing with a pelletizer.

Oxygen-Absorbing Resin Composition B Iron-based oxygen absorber 1 was used to form a linear low-density polyethylene (Japan Polychem Co., Ltd.) using a twin-screw extruder with a vent.
Manufactured by Kernel KC580S, hereinafter referred to as LLDPE) while extruding side-feeding iron-based oxygen absorber,
LLDPE: iron-based oxygen absorber = supplied at a weight ratio of 70:30, kneaded, extruded from a strand die, cooled, and pelletized by a pelletizer to obtain an oxygen-absorbing resin composition B.

Film 1 An unstretched polypropylene film (produced by Showa Denko Plastic Products Co., Ltd., Aromar U, thickness) that is fed out using an extrusion laminator device consisting of a single-screw extruder, a T-die, a cooling roll and a slitter and a winder. Oxygen-absorbing resin composition A having 30 μm, hereinafter CPP) on both sides
Is sandwich-laminated with a thickness of 30 μm, the CPP surface is subjected to corona discharge treatment, and an oxygen-absorbing resin layer is sandwich-laminated with CPP30 (μm; the same applies hereinafter) /
A film 1 made of the oxygen absorption layer 30 / CPP30 was produced. The wetting tension (JISK6768) of the corona-treated CPP surface of the film 1 was 42 dyn / cm.

Film 2 Similarly, the prepared oxygen absorbing resin composition B was provided on the side opposite to the corona discharge treated surface of a colorless LLDPE film (TCS, manufactured by Tohcello Co., Ltd., thickness 30 μm) which was fed out. It is extrusion-laminated to a thickness of 30 μm, and then linear LLDPE (made by Dow Chemical Co., PT14
50) resin with 10% titanium oxide added to a thickness of 20 μm
Extrusion laminated with, LLDPE30 / oxygen absorption layer 30
/ A film 2 made of titanium oxide-containing LLDPE20 was prepared. The wetting tension (JISK6768) of the colorless polyethylene film surface of the film 2 is 40 dyn / cm.
Met.

Example 1 Coating solution 1 was applied to a stretched nylon film having a thickness of 25 μm at a coating amount of 4 g / m 2 (as solid content), dried at 80 ° C. for 30 seconds, and then the corona treated surface of film 1 Nylon 15 / adhesive layer 4 / CPP30 / by bonding with a nip roll and aging at 35 ° C for 1 day
A laminated film composed of the oxygen absorption layer 30 / CPP30 was produced. Xylylenediamine unit (N-CH2-C6H in the adhesive layer
4-CH2-N) was 62.4% by weight.

<Evaluation test> Opening area 100 × 150 mm
Barrier tray (Sumitomo Bakelite Co., Ltd. CEL-R
121), 150 g of cooked rice was charged, and the obtained laminated film was used to adjust the oxygen concentration in the container to 0.15%, which was then sealed and stored at 23 ° C. and 60% RH. Save 3
The oxygen concentration in the bag on the day and the flavor of the cooked rice on the day after 3 months were examined. The laminate strength (g / 15 mm) of the obtained laminated film was measured by a T-type peel test at a peel speed of 100 mm / min using the method specified in JIS K-6854. The results are shown in Table 1.

Example 2 A laminated film was produced in the same manner as in Example 1 except that the coating liquid 2 was used instead of the coating liquid 1. The xylylenediamine unit (N-CH2-C6H4-CH2-N) in the adhesive layer was 61.9% by weight. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

Example 3 A laminated film was prepared in the same manner as in Example 1 except that the coating liquid 3 was used instead of the coating liquid 1. The xylylenediamine unit (N-CH2-C6H4-CH2-N) in the adhesive layer was 59.8% by weight. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

Example 4 A laminated film was produced in the same manner as in Example 1 except that the coating liquid 4 was used instead of the coating liquid 1. The xylylenediamine unit (N-CH2-C6H4-CH2-N) in the adhesive layer was 60.6% by weight. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

Example 5 A laminated film was produced in the same manner as in Example 1 except that the coating liquid 5 was used instead of the coating liquid 1. The xylylenediamine unit (N-CH2-C6H4-CH2-N) in the adhesive layer was 43.0% by weight. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

Comparative Example 1 A laminated film was prepared in the same manner as in Example 1 except that the coating liquid 6 was used instead of the coating liquid 1. The xylylenediamine unit (N-CH2-C6H4-CH2-N) in the adhesive layer was 9.5% by weight. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

Comparative Example 2 A laminated film was produced in the same manner as in Example 1 except that the coating liquid 7 containing no xylylenediamine units was used in place of the coating liquid 1. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

Comparative Example 3 A laminated film was prepared in the same manner as in Example 1 except that the coating liquid 8 containing no xylylenediamine unit was used in place of the coating liquid 1. Table 1 shows the result of the evaluation test performed in the same manner as in Example 1.

[0066]

[Table 1]

Example 11 Coating solution 1 was applied to a PET film having a thickness of 12 μm, which had been printed, and the stretched nylon film having a thickness of 15 μm was laminated by the method of Example 1, and then the surface of the stretched nylon film was further laminated. To the film 2 by applying the coating liquid of Example 1 to
It was bonded to the oxygen absorption layer surface of. The lamination method was the same as in Example 1 to obtain an oxygen-absorbing multilayer film composed of PET / stretched nylon / CPP / oxygen-absorbing layer / CPP. The total thickness was about 127 μm, and the adhesive layer thickness was 10 μm. Using the obtained oxygen-absorbing multilayer film, a standing pouch (130 mm × 160) composed of two side films
mm) was produced. Using an automatic filling machine equipped with a mechanism that sends air to the mouth of the standing pouch to open the bag, the white porridge 150 is discharged from the opening of each of the prepared standing pouches.
g and filled with 10 cc of headspace air. After subjecting the filled bag to retort treatment at 120 ° C. for 30 minutes, the oxygen concentration in the bag was investigated and the performance was evaluated. The results are shown in Table 2.

Example 12 An oxygen-absorbing multilayer film was prepared in the same manner as in Example 11 except that the coating liquid 2 was used, and the performance was evaluated. The results are shown in Table 2.

Example 13 An oxygen-absorbing multilayer film was prepared in the same manner as in Example 11 except that the coating liquid 3 was used, and the performance was evaluated. The results are shown in Table 2.

Example 14 An oxygen-absorbing multilayer film was prepared in the same manner as in Example 11 except that the coating liquid 4 was used, and its performance was evaluated. The results are shown in Table 2.

Example 15 An oxygen-absorbing multilayer film was prepared in the same manner as in Example 11 except that the coating liquid 5 was used, and its performance was evaluated. The results are shown in Table 2.

Comparative Example 4 As a polyurethane adhesive coating liquid, 50 parts by weight of a polyether component (TM-329 manufactured by Toyo Morton Co., Ltd.) and a polyisocyanate component (CAT-8B manufactured by Toyo Morton Co., Ltd.) were used.
Ethyl acetate solution containing 50 parts by weight (solid content concentration: 30% by weight)
Was used instead of the coating liquid of Example 11, and an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd .; Eval EF-CR, thickness) was used as a barrier layer between the stretched nylon layer and the oxygen absorbing layer. Example 1 except that 15 μm) was used.
A film was prepared in the same manner as in 1. The composition of this film was PET / printing / stretched nylon / ethylene-vinyl alcohol copolymer / CPP / oxygen absorbing layer / CPP, and the total thickness was about 125 μm. The results of performance evaluation performed in the same manner as in Example 11 are shown in Table 2.

The films obtained in Examples 11 to 15 are
Although the total thickness of the film was thin, it had flexibility, and the contents could be easily filled as a bag container, the film obtained in Comparative Example 4 had a large film thickness and the opening of the standing pouch was not easy, The workability of filling the contents was not good. Further, the filled products obtained in Examples 11 to 15 have a temperature of 40 ° C.
Even after being stored for 3 months, the water did not evaporate and the flavor was maintained well.

[0074]

[Table 2]

Example 16 Coating solution 1 was coated on a stretched polypropylene film having a thickness of 25 μm at a coating amount of 4 g / m 2 (as solid content), and the coating solution was heated at 80 ° C. for 30 minutes.
After drying for 2 seconds, the surface of the film 2 showing a wetting tension of 40 mN / m is pasted with a nip roll, and at 35 ° C.
By aging for 1 day, a laminated film composed of the stretched polypropylene film 25 / adhesive layer 4 / LLDPE30 / oxygen absorbing layer 20 / titanium white LLDPE20 was produced. Xylylenediamine units in the adhesive layer
(N-CH2-C6H4-CH2-N) was 62.4% by weight.

<Evaluation test> 100 mm × 100 mm 3
After making a one-sided seal bag and filling 100 g of soy sauce so that the headspace air becomes 0 and sealing it, 40 ° C
Stored for 1 month. The weight of soy sauce did not change, and the flavor of soy sauce was retained well.

Example 17 The film used in Example 16 was used as one side and one side was treated with OPP.
25 / stretched nylon film 15 (manufactured by Mitsubishi Kojin Pax Co., Ltd .; Super Neil) / 100 mm × 100 mm 3-sided seal bag with LLDPE40 on one side,
Two sterile rice cakes were filled and stored at 35 ° C. and 60% RH for 2 months. Opened after 2 months, observe flavor and color tone,
It was confirmed that it was stored well.

[0078]

The oxygen-absorbing multilayer film of the present invention does not require a separate gas barrier layer such as an aluminum foil and is advantageous in terms of economy and workability in the manufacturing process. Further, the oxygen-absorbing multilayer film of the present invention is excellent in various properties such as water vapor barrier property, impact resistance, and retort treatment resistance in addition to the oxygen absorption function, and its interlayer adhesion also has practical performance. Therefore, it can be applied to various uses such as foods and pharmaceuticals.

The oxygen-absorbing multilayer film of the present invention can be reduced in total thickness and is excellent in flexibility, so that it is economical, easy to handle in bag making, workability in filling contents, and container. It is advantageous in terms of easiness of unsealing. Furthermore, in the oxygen-absorbing container using the oxygen-absorbing multilayer film of the present invention, it is possible to prevent water from volatilizing and disappearing out of the container from the articles contained in the container.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomotaka Wada             5-6 Higashi-Hachiman 5-2, Hiratsuka City, Kanagawa Prefecture             Ryogas Chemical Co., Ltd. Hiratsuka Research Center (72) Inventor Yoshiki Ito             5-6 Higashi-Hachiman 5-2, Hiratsuka City, Kanagawa Prefecture             Ryogas Chemical Co., Ltd. Hiratsuka Research Center (72) Inventor Satoshi Okada             5-6 Higashi-Hachiman 5-2, Hiratsuka City, Kanagawa Prefecture             Ryogas Chemical Co., Ltd. Hiratsuka Research Center F-term (reference) 4B021 LA15 LA16 LA24 MC04 MK09                       MP05                 4F100 AA23C AA23H AH03B AH03H                       AK01A AK01C AK01D AK07D                       AK48A AK53B BA04 BA07                       BA10A BA10D BA15 CA02B                       CA09C EJ37A GB15 GB23                       GB66 JB07 JB16A JB16C                       JB16D JD01 JD03B JD03D                       JJ03 JK10 JL03 JL11B                       JL12D YY00B

Claims (4)

[Claims] 1. An outer layer comprising at least a thermoplastic resin,
An adhesive layer composed of an epoxy resin composition composed of a reaction cured product of an epoxy resin and an epoxy resin curing agent, an oxygen absorption layer containing an iron-based oxygen absorbent in a thermoplastic resin, and a sealant layer composed of an oxygen permeable thermoplastic resin. In the oxygen-absorbing multilayer film consisting of (a) the outer layer, the oxygen-absorbing layer or the sealant layer resin is polypropylene, and (a) the gas barrier epoxy resin composition constituting the adhesive layer is a xylylenediamine unit (N -CH2-C6H4-CH2-N) in an amount of 30% by weight or more. 2. The oxygen-absorbing multilayer film according to claim 1, wherein the epoxy resin constituting the gas barrier epoxy resin composition is an epoxy resin containing a metaxylylenediamine unit or a paraxylylenediamine unit. 3. The oxygen-absorbing multilayer film according to claim 1, wherein the epoxy resin curing agent constituting the gas barrier epoxy resin composition is an epoxy resin curing agent containing a xylylenediamine unit. 4. The oxygen-absorbing multilayer film according to claim 1, wherein the adhesive layer has a thickness of 0.1 to 20 μm and has no other thermoplastic resin gas barrier layer or inorganic gas barrier layer.