JPH1034804A - Gas barrier resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier resin film which has excellent gas barrier properties and sufficient strength even in the case before and after boiling and which can be suitably thermally sealed and subjected to satisfactory moistureproofness. SOLUTION: In the gas barrier resin film in which an inorganic deposited layer and a sealant layer are sequentially provided on a base material, the base material is mainly a polyamide resin film. In this case, a compression modulus of elasticity per unit sectional area of the sealant layer at 95 deg.C is as large as 9.5 times or more of maximum shrinkage stress per unit sectional area in an arbitrary direction of the polyamide resin film at 170 deg.. And, maximum shrinkage factor in an arbitrary direction in the case of boiling it at 95 deg.C for 30min is 3.5% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier resin film, and more particularly to a gas barrier resin film having improved gas barrier properties and moisture proof properties, and excellent in handleability and transparency.

[0002]

2. Description of the Related Art Deterioration of food quality caused by the influence of microorganisms such as temperature, moisture, oxygen, ultraviolet light, and mold in the distribution and sales process is not only accompanied by a loss in sales but also a serious problem from the viewpoint of food hygiene. is there. Conventionally, food additives such as antioxidants and preservatives have been directly added to foods in order to prevent such deterioration in food quality. However, recently, from the standpoint of protecting consumers, regulations on these food additives have become stricter, and the amount of such additives has to be reduced. Furthermore, in recent years, food packaging forms have changed significantly due to changes in food distribution forms and dietary habits.

[0003] Therefore, in order to prevent deterioration in the quality of food without using food additives and to obtain a sufficiently satisfactory packaging form, it is impermeable to gas and moisture, and further subjected to freezing, boiling and retorting. And other processes,
There is a need for a packaging film that does not degrade the quality of the food.

[0004] Specifically, it is desired that a packaging film suppresses oxidation and denaturation of components such as proteins and oils and fats contained in foods such as fish meat, animal meat and shellfish, and retains taste and freshness. I have. Examples of such a packaging film that suppresses oxidation and denaturation include a gas barrier film that prevents air from permeating into food. The gas barrier film retains the aroma of the food and inhibits the permeation of water, so it suppresses moisture absorption deterioration in dry foods, and in water-containing foods, the water evaporates and the foods deteriorate and solidify. And a fresh flavor at the time of packaging can be maintained for a long time.

[0005] The gas barrier film also has excellent moisture-proof properties, for example, kneaded products such as kamaboko; dairy products such as butter and cheese; seasonings such as miso;
It is used for the packaging of luxury items such as tea and coffee; smoked foods such as ham and sausage; confectioneries such as castella and biscuits; and instant foods. Further, the gas barrier film is not limited to the above-mentioned food packaging film, but is extremely useful as a packaging film for pharmaceuticals requiring aseptic handling and electronic components requiring rust prevention.

An example of such a film having excellent gas barrier properties is polyethylene terephthalate (PET).
A film in which a metal layer such as aluminum is formed on a plastic film such as described above is known. The gas barrier film having such a metal layer formed thereon has an advantage that it has excellent gas barrier properties and is manufactured at low cost. However, since the gas barrier film is opaque, the packaged contents cannot be confirmed,
Furthermore, since microwaves are not transmitted, there is a problem that the contents packaged with this film cannot be heated using a microwave oven.

As an example of another gas barrier film, P
Films in which vinylidene chloride or ethylene vinyl alcohol copolymer is coated on a plastic film such as ET and oriented polypropylene (OPP) are known. However, this film has an insufficient gas barrier property against water vapor and oxygen, and has a problem that the gas barrier property is remarkably reduced particularly when treated at a high temperature. In addition, this film generates chlorine gas from vinylidene chloride at the time of incineration, so that there is a concern about the influence of pollution on the global environment.

[0008] JP-B 51-48551 discloses is capable of confirmation of the contents, and as a gas barrier film that can be used in microwave ovens, Si on the surface of the synthetic resin substrate such as PET _x O _y (e.g. , SiO ₂ ). However, Japanese Patent Publication No. 51-48551
In JP, Si _x O _y gas barrier properties are good
The film on which (x = 1, y = 1.3 to 1.8) has been deposited is brownish, and the transparency is insufficient.

[0009] JP 62-101428 discloses, in order to improve the transparency of the film, discloses the use of aluminum oxide in place of the Si _x O _y. However, this film has insufficient gas barrier properties against oxygen. Furthermore, this film is inferior in bending resistance (Gelvo property).

As another example of a gas barrier film, a film in which an inorganic vapor-deposited film such as silica or alumina is formed on a polyethylene film such as polyethylene terephthalate (PET) is known. Such a gas barrier film is made of, for example, an inorganic vapor-deposited layer, an adhesive layer, a stretched nylon (ONY) film, an adhesive layer, an unstretched polypropylene (CPP) on a PET film using polyester polyurethane as an adhesive layer. It is obtained by sequentially forming a film. However, when the gas barrier film is subjected to a boil treatment or a retort treatment, there is a problem that the stretched nylon film shrinks to deteriorate the gas barrier property.

Therefore, generally, on PET film,
Inorganic vapor deposition layer, adhesive layer, PET film, and CPP
A gas barrier film formed of a laminate in which films are sequentially formed is used. However, this gas barrier film has insufficient strength, for example, when dropped,
There is a problem that a part of the layer is broken.

Japanese Patent Publication No. 7-12649 discloses that in order to improve the strength of a gas barrier film, a heat shrinkage rate is previously reduced as a base film by a heat treatment (that is, when the film is heated at 120 ° C. for 5 minutes). The sum of the absolute values of the dimensional change rates in the vertical and horizontal directions is 2% or less.)
It discloses using a stretched nylon film. However, even if such a stretched nylon film is used as a substrate, the obtained gas barrier film has a problem that it does not satisfy a sufficient gas barrier property with respect to a boil treatment performed under high-temperature hot water. Further, the gas barrier film has a problem that the manufacturing process is complicated and it is necessary to perform a moisture-proof treatment such as packing with aluminum foil in order to prevent moisture absorption during transportation and storage.

Japanese Patent Application Laid-Open No. Hei 7-276571 discloses a laminate having an inorganic vapor-deposited layer, a nylon film layer, and a sealant layer formed on a base material in a sequential manner. Reduce shrinkage.
However, in this laminate, it is necessary to prepare a nylon film separately from the base material and laminate this, which increases the production cost. In addition, the yield of the laminated body becomes worse every time the number of laminations increases, and an expensive and complicated device is required for process management. Further, this laminate has a problem that it is necessary to perform a moisture-proof treatment such as packing with aluminum foil in order to prevent moisture absorption during transportation and storage.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an excellent gas barrier property and sufficient strength both before and after boiling treatment. And to provide a transparent gas barrier resin film having suitable heat sealing and good moisture-proof properties.

[0015]

The first gas barrier resin film of the present invention is a gas barrier resin film having an inorganic vapor-deposited layer and a sealant layer sequentially on a substrate, wherein the substrate is mainly a polyamide-based resin film. A compression elastic modulus per unit cross-sectional area of the sealant layer at 95 ° C. is at least 9.5 times a maximum shrinkage stress per unit cross-sectional area in any direction of the polyamide resin film at 170 ° C. Yes; and the maximum shrinkage in any direction when boiled at 95 ° C. for 30 minutes is 3.
5% or less, whereby the above object is achieved.

In a preferred embodiment, the adhesion strength between the substrate and the inorganic vapor-deposited layer when boiled at 95 ° C. for 30 minutes is 100 g / 15 mm or more.

In a preferred embodiment, an anchor coat layer is further provided between the substrate and the inorganic vapor-deposited layer, and the compression modulus of the anchor coat layer at 40 ° C. is 9.
8 kgf / mm ² or more.

In a preferred embodiment, an adhesive layer is further provided between the inorganic vapor-deposited layer and the sealant layer, and the compression elastic modulus of the adhesive layer at 40 ° C. is 8.8 kgf.
/ Mm ² or more.

The second gas barrier resin film of the present invention is a gas barrier resin film having an inorganic vapor-deposited layer and a sealant layer sequentially on a substrate, wherein the substrate comprises a polyamide resin film and an anchor coat layer. And
And the anchor coat layer is present so as to be in contact with the inorganic vapor-deposited layer; the compression elastic modulus per unit cross-sectional area of the anchor coat layer at 95 ° C is a unit breakage in any direction of the polyamide resin film at 170 ° C. Greater than or equal to 12.5 times the maximum shrinkage stress per area; and 95
The maximum shrinkage in any direction when boiled at 30 ° C. for 30 minutes is 3.5% or less.

In a preferred embodiment, the adhesion strength between the substrate and the inorganic vapor-deposited layer when boiled at 95 ° C. for 30 minutes is 100 g / 15 mm or more.

In a preferred embodiment, an adhesive layer is further provided between the inorganic vapor-deposited layer and the sealant layer, and the compression elastic modulus of the adhesive layer at 40 ° C. is 8.8 kgf.
/ Mm ² or more.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION As used herein, the term "boiling" refers to immersion in hot water at a predetermined temperature (for example, 95 ° C.).

Further, as used herein, the “arbitrary direction” of the film refers to the first or second gas barrier resin film of the present invention or the first or second gas barrier resin of the present invention. A direction parallel to a plane defined by a longitudinal direction and a lateral direction of a polyamide resin film described later used for the film.

<First Gas Barrier Resin Film> In the first gas barrier resin film of the present invention,
The maximum shrinkage in any direction when boiled for 30 minutes is 3.5% or less, preferably 1.5% or less, more preferably 0.7% or less. When the maximum shrinkage in any direction of the first gas barrier resin film of the present invention exceeds 3.5%, cracking or peeling of the inorganic vapor deposition layer described below occurs when boil treatment is performed, and sufficient gas barrier properties are obtained. Is not retained.

The first gas barrier resin film of the present invention is a transparent resin film having an inorganic vapor-deposited layer and a sealant layer sequentially on a substrate made of a polyamide resin film.

(Substrate) The substrate of the first gas barrier resin film of the present invention is a film mainly composed of a polyamide resin. This polyamide resin film has the following structural formula (i) or (ii):

[0027]

Embedded image

And a polyamide resin comprising a homopolyamide, a copolyamide, a mixture thereof, or a crosslinked product thereof having an amide repeating unit shown in (1).

Examples of homopolyamides include polycaproamide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-ω-aminononanoic acid (nylon 9), polyundecaneamide (nylon 11), Laurin lactam (nylon 12), polyethylene diamine adipamide (nylon 2,6), polytetramethylene adipamide (nylon 4,6), polyhexamethylene adipamide (nylon 6,6), polyhexamethylene sebaca Amide (nylon 6,10), polyhexamethylene dodecamide (nylon 6,12), polyoctamethylene adipamide (nylon 8,6), polydodecamethylene adipamide (nylon 10,6), polydodecamethylene Bacamide (nylon 10, 10), polydodecamethylene dodecamide (nylon 12 , 12) and meta-xylene diamine-6 nylon (MXD6).

Examples of copolyamides include caprolactam / laurin lactam copolymer, caprolactam / hexamethylene diammonium adipate copolymer, laurin lactam / hexamethylene diammonium adipate copolymer, hexamethylene diammonium adipate /
Hexamethylene diammonium sebacate copolymer, ethylene diammonium adipate / hexamethylene diammonium adipate copolymer, caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer, and the like.

Particularly preferred is polycaproamide.

Examples of the crosslinked product include compounds obtained by crosslinking the above homopolyamide or copolyamide with a methylol compound, an epoxy compound, an aziridine compound, or the like.

In the present invention, for the purpose of imparting flexibility to the obtained base film, the above polyamide resin is
Aromatic sulfonamides; p-hydroxybenzoic acid; plasticizers such as esters; an elastomer component having a low elastic modulus;
Alternatively, lactams can be blended. Examples of the elastomer component blended in the polyamide resin include ionomer resin, modified polyolefin resin, thermoplastic polyurethane, polyether block amide, polyester block amide, polyether ester amide elastomer, polyester elastomer, modified styrene heat Examples thereof include a plastic elastomer, a modified acrylic rubber, and a modified ethylene propylene rubber.

The above-mentioned polyamide resin film is preferably from 5 μm to 500 μm, more preferably from 10 μm to 1 μm.
It has a thickness of 00 μm. If the thickness of the polyamide-based resin film is less than 5 μm, the strength of the obtained resin film may be insufficient and the resin film may be easily broken. When the thickness of the polyamide resin film exceeds 500 μm, the obtained resin film may be too hard.

The above-mentioned polyamide resin film comprises an unstretched film or a uniaxially or biaxially stretched film. Such films are made using methods known to those skilled in the art. Further, when producing this film, any stretching ratio, heating temperature during stretching, and relaxation rate can be selected.

The base material used in the present invention may be a corona treatment, a flame treatment, a low-temperature plasma treatment, a glow discharge treatment, a reverse sputtering treatment, a rough surface, if necessary, in order to improve the adhesion strength with the inorganic vapor-deposited layer. A polyamide resin film having been subjected to a surface treatment such as a surface treatment may be used, or an anchor coat layer may be formed on the polyamide resin film, but is not particularly limited thereto.

The anchor coat layer is formed using, for example, any resin selected from the group consisting of: a reactive polyester resin; an oil-modified alkyd resin; a urethane alkyd resin; a melamine alkyd resin; An epoxy resin using an amine, a carboxyl group-terminated polyester, phenol, isocyanate, or the like as a curing agent; an isocyanate resin using an amine, urea, carboxylic acid, or the like as a curing agent; a urethane-polyester resin; a polyurethane resin;
Polyester resins; polyamide resins; reactive acrylic resins; vinyl chloride resins; and resins obtained by solubilizing or dispersing these in water.

The anchor coat layer has a compression modulus at 40 ° C. of preferably at least 9.8 kgf / mm ² , more preferably at least 35 kgf / mm ² , to further improve the gas barrier properties of the obtained resin film. obtain. When the compression elastic modulus of the anchor coat layer at 40 ° C. is less than 9.8 kg / mm ² , when the boil treatment is performed, the anchor coat layer does not act as a buffer against the heat shrinkage of the polyamide resin film, The formed inorganic vapor-deposited layer described later may be cracked or peeled off, and as a result, the gas barrier properties of the obtained resin film may be reduced. An anchor coat layer having such a compressive modulus may be obtained by directly using the resin forming the anchor coat layer, or by crosslinking with a crosslinking agent such as isocyanate, epoxy, or melamine, if necessary, or by plasma treatment. Or cross-linking by electron beam treatment,
Alternatively, it can be obtained by adding a metal alcoholate such as tetraethyl orthosilicate to the above resin.

In the first gas barrier resin film of the present invention, the thickness of the anchor coat layer that can be used is preferably 0.01 μm to 20 μm, more preferably 0.03 μm to 5.0 μm. If the thickness of the anchor coat layer is less than 0.01 μm, sufficient adhesion strength may not be obtained between the base material described below and the inorganic vapor deposition layer.
If the thickness of the anchor coat layer exceeds 20 μm, cracks may occur in the anchor coat layer.

(Inorganic Vapor Deposition Layer) The inorganic vapor deposition layer used in the first gas barrier resin film of the present invention imparts a high gas barrier property to the obtained transparent resin film, and has an effect on the environment even when discarded. A vapor-depositing compound that does not cause any problem is used. Examples of the vapor deposition compound include Si, Al, Ti, Zn, Zr, Mg, Sn, Cu, Fe, and C.
and metal such as e, oxides, nitrogens, fluorides, sulfides, and mixtures thereof.
More specific examples of the vapor deposition compound include SiO _x (where x is 1.0 to 2.0), alumina, titania, zinc sulfide, magnesia, zirconia, and cerium oxide. In particular, SiO _x (where x is 1.0 to
2.0), alumina, and mixtures thereof.

The inorganic vapor-deposited layer preferably has a thickness of 10 Å to 5000 Å, more preferably 50 Å to 2000 Å. If the thickness of the inorganic vapor-deposited layer is less than 10 angstroms, the resulting resin film may not have sufficient gas barrier properties. Conversely, the thickness of the inorganic vapor deposition layer is 5
Even if it exceeds 2,000 angstroms, the gas barrier properties and moisture resistance of the obtained resin film are not further improved, but the bending resistance may be lowered and the production cost may be increased.

In the first gas barrier resin film of the present invention, the adhesion strength between the substrate and the inorganic vapor-deposited layer when boiled at 95 ° C. for 30 minutes is preferably 100 g.
/ 15 mm or more, more preferably 800 g / 15
mm or more. The higher the adhesion strength, the more the obtained resin film maintains its gas barrier properties even after the boil treatment. If the adhesion strength is less than 100 g / 15 mm, the resulting resin film may impair the gas barrier properties due to boiling treatment.

(Sealant Layer) In the first gas barrier resin film of the present invention, the compression elastic modulus per unit area of the sealant layer at 95 ° C. is 170 ° C. in any direction of the polyamide resin film layer. 9.5 times or more of the maximum contraction stress per unit area,
It is preferably at least 15 times, more preferably at least 30 times, even more preferably at least 80 times. By setting the compression elastic modulus of the sealant layer within such a range, the obtained resin film is prevented from cracking or peeling of the inorganic vapor-deposited layer when subjected to the boil treatment, and has a sufficient gas barrier property against the boil treatment. Hold. Conversely, if the compression elastic modulus of the sealant layer is less than 9.5 times the maximum shrinkage stress of the layer made of the polyamide resin film, the obtained resin film will have an inorganic vapor deposition layer when boiled. Cracking or peeling occurs, and sufficient gas barrier properties are not maintained.

The sealant layer used in the first gas barrier resin film of the present invention is made of a thermoplastic resin. Examples of such thermoplastic resins include:
Polyethylene or ethylene-based copolymer; polyvinyl alcohol; ethylene-vinyl alcohol copolymer; olefin-based resin such as polypropylene and propylene-based copolymer; vinyl chloride-based resin such as polyvinyl chloride and vinyl chloride-based copolymer; Vinylidene chloride resins such as vinylidene-vinyl chloride copolymer; polyester resins such as polyethylene terephthalate; and fluorine resins such as polytetrafluoroethylene. further,
As the sealant layer, a film in which vinylidene chloride or the like is further coated by a known method on a film made of the thermoplastic resin may be used.

The sealant layer can be an unstretched film or a uniaxially or biaxially stretched film. Such films are made using methods known to those skilled in the art. Furthermore, when forming this film, any stretching ratio, heating temperature during stretching, and relaxation rate can be selected.

In the first gas barrier resin film of the present invention, the sealant layer may be a single layer or a composite layer.

When the sealant layer is a composite layer, each layer may be formed of a different thermoplastic resin, or each layer may be formed of a copolymer obtained from a monomer constituting the thermoplastic resin or a modified product of the thermoplastic resin. Or they can be formed from blends of these. Further, the composite layer is lower than the thermoplastic resin on at least one layer made of the thermoplastic resin in order to improve laminating property and heat sealing property between the sealant layer and the inorganic vapor-deposited layer. A composite layer obtained by forming a layer made of a polymer such as linear low-density polyethylene having a glass transition temperature (Tg) and a melting point may be used. Alternatively, in order to provide heat resistance, the composite layer is formed by forming a layer made of a polymer such as polypropylene having a higher glass transition temperature and melting point on at least one layer made of a thermoplastic resin. It may be a composite layer obtained.

The sealant layer preferably has a thickness of 5 μm to
It has a thickness of 300 μm, more preferably 20 μm to 100 μm. When the thickness of the sealant layer is less than 5 μm, the obtained resin film may not show sufficient heat sealing property. If the thickness of the sealant layer exceeds 300 μm, the thickness of the sealant layer may be too large, making it difficult to perform thermocompression bonding or easily causing cracks.

(Adhesive Layer) In the first gas barrier resin film of the present invention, an adhesive layer is formed between the inorganic vapor-deposited layer and the sealant layer in order to improve the adhesive force between them. Can be done.

The adhesive used in the adhesive layer is not particularly limited, but may be polyurethane resin, acrylic resin, polyester resin, epoxy resin, vinyl chloride resin, vinyl acetate resin, polyethylene resin, polypropylene. A known adhesive made of an adhesive resin such as a resin or a melamine resin can be used. Alternatively, the adhesive layer can be produced by mixing and melting two or more kinds of the above-mentioned adhesive resins in order to further improve the adhesiveness. Further alternatively, a compound having a carboxylic acid group, a (meth) acrylic acid group, or a (meth) acrylate ester group and an acid anhydride thereof; an epoxy compound having a glycidyl group or a glycidyl ether group; or A composition in which a curing agent containing an oxazoline group, an isocyanate group, an amino group, a hydroxyl group or the like is mixed may be used.

The adhesive layer has a compression modulus at 40 ° C. of preferably 8.8 kgf / mm ² or more, more preferably 30 kgf / mm ² or more, and even more preferably 5 kgf / mm ² or more.
By having 0 kgf / mm ² or more, the gas barrier properties of the obtained resin film can be further improved. 40
The compression elastic modulus of the adhesive layer at ℃ is 8.8 kg / mm ²
If less than, when performing a boil treatment, the adhesive layer does not act as a buffer against the heat shrinkage of the sealant layer, causing cracking or peeling of the formed inorganic vapor-deposited layer, and as a result, is obtained. There is a possibility that the gas barrier properties of the resin film may be reduced. The adhesive layer having such a compressive modulus uses a modified polyester such as an epoxy-modified polyester, an acrylic-modified polyester, or a urethane-modified polyester as the adhesive, or a metal alcoholate such as tetraethyl orthosilicate as the adhesive. Addition or silica sol (particle size 0.05 μm to 2.0 μm)
m) is obtained by adding 1% by weight to 25% by weight (in terms of solid content) based on the total weight of the adhesive layer, or by appropriately combining these.

(Additives) Known additives can be blended with the base material, the sealant layer, and the adhesive layer in optional amounts, if necessary. Examples of such additives include plasticizers, heat stabilizers, UV absorbers, antioxidants, colorants, fillers, antistatic agents, antibacterial agents, lubricants, and anti-blocking agents.

(Preparation of First Gas Barrier Resin Film) The first gas barrier resin film of the present invention is prepared as follows.

First, the polyamide resin film may be subjected to a surface treatment such as a corona treatment, a flame treatment, a low-temperature plasma treatment, a glow discharge treatment, a reverse sputtering treatment and a surface roughening treatment, if necessary. Next, an anchor coat layer is formed on the surface-treated polyamide resin film as necessary. The anchor coat layer may be formed in a separate step after the production step of the layer made of the polyamide resin film as described above (off-line method), or may be formed during the production step of the layer made of the polyamide resin film. May be used (in-line method). In the present invention, the anchor coat layer may be formed using a known method, and examples include a roll coat method, a reverse coat method, a roll brush method, a spray coat method, an air knife coat method,
The gravure coating method, the impregnation method, and the curtain coating method are mentioned. In this way, a substrate that has been surface-treated or has an anchor coat layer if necessary is produced.

Next, the substrate is heated by any means (for example, a resistance heating means, an induction heating means, and an electron beam heating means) so that the base material (anchor coat layer when an anchor coat layer is formed) is formed on the substrate. The deposition compound is deposited. A known method is used for vapor deposition of the vapor deposition compound. Examples of such a deposition method include physical vapor deposition methods such as a vacuum deposition layer, a sputtering method, and an ion plating method; PE
A chemical vapor deposition method such as CVD (plasma chemical vapor deposition); together with the above-mentioned vapor deposition compound, for example, oxygen,
A reactive vapor deposition method using a means for introducing nitrogen, hydrogen, argon, carbon dioxide, or water vapor, or a means such as ozone addition or ion assist is given. Further, at the time of this vapor deposition, an arbitrary bias voltage can be applied to the substrate. The substrate on which the above-mentioned deposition compound is deposited can be cooled using any means. In the first gas barrier resin film of the present invention, the production conditions such as the types of the vapor deposition compound and the reaction gas, and the heating and cooling temperatures can be arbitrarily changed.

Next, an adhesive layer is formed on the inorganic vapor-deposited layer by a known method, if necessary. Examples of the method for forming the adhesive layer include a dry lamination method; a wet lamination method using an emulsion of the above adhesive resin; a melt extrusion lamination method; and a coextrusion lamination method. The amount of the adhesive layer formed by using such a method is preferably ^{0.1g / m 2 ~10g / m 2} , more preferably from ^{1g / m 2 ~5g / m 2} .

Next, a sealant layer is formed on the inorganic vapor-deposited layer (adhesive layer if an adhesive layer is formed). The sealant layer can be formed by a method known to those skilled in the art, such as a dry lamination method and a melt extrusion lamination method.

Alternatively, the sealant layer can be formed by a known coating method. In such a coating method, the above-mentioned vinylidene chloride-based resin, polyester resin,
Solutions, emulsions, etc. of thermoplastic resins such as fluororesins
Alternatively, latex is used. In particular, a vinylidene chloride resin latex and a solution of vinylidene chloride using tetrahydrofuran as a solvent are preferable as the coating liquid. Furthermore, when using a coating solution containing a vinylidene chloride-based resin to form a sealant layer, an isocyanate-based, polyethyleneimine-based, organic titanium-based, or other adhesion promoter, and a polyurethane-based beforehand between the inorganic vapor-deposited layer. An adhesive such as polyester or the like can be applied by a known method. After forming the sealant layer, it is aged by using a method known to those skilled in the art, and the first of the present invention is obtained.
Is produced.

If necessary, any paper, aluminum foil, wood flake, cloth (for example, on the surface of one or both of the sealant layer and the polyamide resin film of the first gas barrier resin film) , Nonwoven fabric) and the like can be formed as a decorative layer, a protective layer, a reinforcing layer, and the like by a known method. Furthermore, the first gas barrier resin film of the present invention can be subjected to printing by a known method depending on the purpose of use on one or both surfaces of the base material and the sealant layer, or can be any printed film or A reinforcing film can be formed.

The first gas barrier resin film of the present invention thus produced is preferably 10 μm in terms of improving strength and flexibility and suppressing production costs.
It has a thickness of １０００1000 μm.

<Second Gas Barrier Resin Film> In the second gas barrier resin film of the present invention,
The maximum shrinkage in any direction when boiled for 30 minutes is 3.5% or less, preferably 1.5% or less, more preferably 0.7% or less. When the maximum shrinkage in any direction of the second gas barrier resin film of the present invention exceeds 3.5%, cracking or peeling of the inorganic vapor-deposited layer described later occurs when boil processing is performed, and sufficient gas barrier properties are obtained. Is not retained.

The second gas barrier resin film of the present invention is a transparent resin film having an inorganic vapor-deposited layer and a sealant layer sequentially on a base material comprising a polyamide resin film and an anchor coat layer.

(Substrate) In the second gas barrier resin film of the present invention, the polyamide resin film used for the substrate may further comprise an anchor in the same manner as the polyamide resin film of the first gas barrier resin film. It is produced by forming a coat layer. In addition, this polyamide-based resin film, in order to improve the adhesion strength with the inorganic vapor deposition layer described below, corona treatment as necessary,
Surface treatments such as flame treatment, low-temperature plasma treatment, glow discharge treatment, reverse sputtering treatment, and surface roughening treatment can be performed.
It is not particularly limited to these.

The anchor coat layer is formed on the polyamide resin film so as to be in contact with the inorganic vapor deposition layer. The anchor coat layer is produced in the same manner as the anchor coat layer of the first gas barrier resin film.

In the second gas barrier resin film of the present invention, the compression elastic modulus per unit area of the anchor coat layer at 95 ° C. is the maximum shrinkage per unit area of the polyamide resin film at 170 ° C. in any direction. 12.5 times or more of stress, preferably 20.5 times
It is at least twice, more preferably at least 160 times. By setting the compression elastic modulus of the anchor coat layer within such a range, the resulting resin film is prevented from cracking or peeling of the inorganic vapor-deposited layer when subjected to the boil treatment, and has a sufficient gas barrier property for the boil treatment. Hold. Conversely, if the compression modulus of the anchor coat layer is less than 12.5 times the maximum shrinkage stress of the layer made of the polyamide resin film, the obtained resin film will have an inorganic vapor-deposited layer when boiled. Cracking or peeling occurs, and sufficient gas barrier properties cannot be maintained.

(Inorganic Vapor Deposition Layer) The inorganic vapor deposition layer used in the second gas barrier resin film of the present invention is also produced in the same manner as the inorganic vapor deposition layer of the first gas barrier resin film.

In the second gas barrier resin film of the present invention, the adhesion strength between the substrate and the inorganic vapor-deposited layer when boiled at 95 ° C. for 30 minutes is preferably 100 g.
/ 15 mm or more, more preferably 800 g / 15
mm or more. The higher the adhesion strength, the more the obtained resin film maintains its gas barrier properties even after the boil treatment. If the adhesion strength is less than 100 g / 15 mm, the resulting resin film may impair the gas barrier properties due to boiling treatment.

(Sealant Layer) The sealant layer used in the second gas barrier resin film of the present invention is also produced in the same manner as in the first gas barrier resin film. Further, this sealant layer may be either a single layer or a composite layer, like the sealant layer of the first gas barrier resin film.

(Adhesive Layer) In the second gas barrier resin film of the present invention, an adhesive layer is also formed between the inorganic vapor-deposited layer and the sealant layer in order to improve the adhesive force. Can be done. The adhesive used for such an adhesive layer is the same as the adhesive used for the adhesive layer of the first gas barrier resin film.

The adhesive layer has a compression modulus at 40 ° C. of preferably 8.8 kgf / mm ² or more, more preferably 30 kgf / mm ² or more, and even more preferably 5 kgf / mm ² or more.
By having 0 kgf / mm ² or more, the gas barrier properties of the obtained resin film can be further improved. 40 ℃
Compression modulus of the adhesive layer at 8.8 kgf / mm ²
If less than, when performing a boil treatment, the adhesive layer does not act as a buffer against the heat shrinkage of the sealant layer, causing cracking or peeling of the formed inorganic vapor-deposited layer, and as a result, is obtained. There is a possibility that the gas barrier properties of the resin film may be reduced. The adhesive layer having such a compressive elastic modulus uses a modified polyester such as an epoxy-modified polyester, an acryl-modified polyester, or a urethane-modified polyester as the adhesive, or a metal alcoholate such as tetraethyl orthosilicate as the adhesive. Or silica sol (particle size 0.05 μm to 2.0 μm)
m) is 1% to 25% by weight based on the total weight of the adhesive layer
It is obtained by adding (in terms of solid content) or by appropriately combining them.

(Additives) In the second gas barrier resin film of the present invention, the base material, the sealant layer, and the adhesive layer may be blended with known additives in optional amounts, if necessary. . Examples of such additives include plasticizers, heat stabilizers, UV absorbers, antioxidants,
Coloring agents, fillers, antistatic agents, antimicrobial agents, lubricants, and anti-blocking agents are included.

(Preparation of Second Gas Barrier Resin Film) The second gas barrier resin film of the present invention is prepared as follows.

First, an anchor coat layer is formed on a polyamide resin film to prepare a base material. An inorganic vapor-deposited layer is formed on the anchor coat layer of the substrate. Next, an adhesive layer is formed on the inorganic vapor-deposited layer as needed, and finally, a sealant layer is formed on the inorganic vapor-deposited layer (adhesive layer if an adhesive layer is formed), Aging is performed by a known method. Each of the above steps can be performed in the same manner as in the first gas barrier resin film of the present invention. Thus, the second gas barrier resin film of the present invention is produced.

If necessary, any paper, aluminum foil, wood flakes, cloth (on either or both surfaces of the sealant layer of the second gas barrier resin film and / or the polyamide resin film) For example, a nonwoven fabric) can be formed by a known method as a decorative layer, a protective layer, a reinforcing layer, and the like. Further, the second gas barrier resin film of the present invention may be subjected to printing by a known method depending on the purpose of use on one or both surfaces of the base material and the sealant layer, or may be any printed film or A reinforcing film can be formed.

The second gas barrier resin film of the present invention thus produced is preferably 10 μm from the viewpoint of improving strength and flexibility and suppressing production costs.
It has a thickness of １０００1000 μm.

The first and second gas barrier resin films of the present invention have excellent transparency and gas barrier properties, and their gas barrier properties are not impaired even after boil processing. Therefore, the gas barrier resin film of the present invention is cut into an arbitrary shape by a method known to those skilled in the art, and is miso, pickles, prepared food, baby food, tsukudani, konjac, chikuwa, kamaboko, processed fishery products, meatball, hamburger , Genghis Khan, ham, sausage, other processed meat products, tea, coffee, tea, bonito, toro kombu, oil confectionery (eg, potato chips and butter peanuts), rice confectionery, biscuits, cookies, cakes, buns,
Castella, cheese, butter, rice cake, soup, sauce,
Food packaging materials such as ramen and wasabi; packaging materials for toiletries such as toothpaste; and industrial packaging materials in the chemical, medical, electronic, and mechanical fields such as pet food, pesticides, fertilizers, blood transfusion packs, semiconductors, and precision equipment. Useful for bags, lids, cups, tubes, standing bags, etc.

[0077]

EXAMPLES Examples of the present invention will be described below, but are not particularly limited thereto. Each evaluation item followed the following method.

<Compression Modulus> The compression modulus (kgf / mm ² ) at 95 ° C. of the sealant layers used in Examples 1 to 8 and Comparative Examples 1 to 3 was measured using an SS TMA measuring device (manufactured by Rigaku Corporation). ) Was measured in accordance with JIS K 7208. Similarly, the compression elastic modulus (kgf / mm ² ) at 95 ° C. of the anchor coat layers used in Examples 9 to 12 and Comparative Example 4 was measured.

<Maximum Shrinkage Stress of Polyamide Resin Film> Maximum shrinkage stress F at 170 ° C. of the polyamide resin films used in Examples 1 to 12 and Comparative Examples 1 to 4
(Kgf / mm ² ) was determined as follows.

First, as shown in FIG.
In accordance with D2838-83, based on the longitudinal direction X of the polyamide resin film 1 to be used, 0 °, 30 °, 4 °
Rectangular samples 11, 12, 13, 14, and 15 having the longitudinal directions of 5 °, 60 °, and 90 °, respectively, were cut out. Then these rectangular samples 1
The shrinkage stress (kgf / mm ² ) in the longitudinal direction of each of 1, 12, 13, 14, and 15 was measured according to ASTM D2838-83.
It measured according to. The maximum value of the shrinkage stresses obtained in 11 to 15 was defined as the maximum shrinkage stress F (kgf / mm ² ).

<Value B> Examples 1 to 8 and Comparative Example 1
From the compression elastic modulus E (kgf / mm ² ) at 95 ° C. of the sealant layer used in Nos. 1 to 3 and the maximum shrinkage stress F (kgf / mm ² ) of the polyamide resin layer at 170 ° C.

[0082]

(Equation 1)

The B value was calculated according to the following.

Similarly, the compressive modulus E (kgf / mm ² ) at 95 ° C. of the anchor coat layers used in Examples 9 to 12 and Comparative Example 4, and the maximum shrinkage stress of the polyamide resin layer at 170 ° C. The B value was calculated from F (kgf / mm ² ) according to the above equation (1).

<Maximum Shrinkage> A circular sample having a diameter of 200 mm was cut from the produced resin film. Then, a line L ₀ (diameter) is drawn on the circular sample, and passes through the center of the circular sample in directions of 30 °, 45 °, 60 °, and 90 ° with respect to the line L _0. Line segments L ₃₀ , L ₄₅ , L ₆₀ , and L ₉₀ (all of which correspond to the diameter of a circular sample) were drawn. Then, the circular sample was boiled in hot water at 95 ° C. for 30 minutes, and then immediately removed to remove L ₀ , L ₃₀ ,
The lengths of L ₄₅ , L ₆₀ , and L ₉₀ were measured, respectively, and the shrinkage percentage _Sn (%) was calculated from the following equation.

[0086]

(Equation 2)

[0087] of the resultant shrinkage S _n, the maximum value as the maximum shrinkage.

<Adhesion Strength> The resin films prepared in Examples 1 to 12 and Comparative Examples 1 to 4 were cured at 95 ° C. for 30 minutes.
Boiled. Next, the resin film subjected to the boil treatment was subjected to 90 according to JIS K6854.
(4) Using a peel test method, the peel interface is identified by using an electron microscope and a fluorescent X-ray analyzer (manufactured by Rigaku Denki Co., Ltd.). At the same time, the base material and the inorganic vapor-deposited layer are measured using Tensilon UTM2 (manufactured by Toyo Sokki Co., Ltd.). Was determined, and the adhesion strength (g / 15 mm) between the substrate and the inorganic vapor-deposited layer was calculated from the SS curve.

<Oxygen Permeability> One-day oxygen permeability (cc / m ² / at) per unit area of the produced resin film.
m / day) with an oxygen permeability measuring device (OX-TRAN 1
0 / 50A: manufactured by Modern Controls) and purged for 2 days at 0% humidity and 25 ° C. for measurement. Next, the resin film was immersed in hot water of 95 ° C. for 30 minutes, then taken out of the hot water and dried, and the oxygen permeability was measured in the same manner as described above. A smaller value of the oxygen permeability indicates that the resin film has more excellent gas barrier properties.

<Water Vapor Permeability> One-day water vapor permeability (g / m ² /
) With a water vapor permeability measuring device (PERMATRAN:
The temperature was measured by purging at 0% humidity and a temperature of 25 ° C. for 2 days using a modern control (manufactured by Modern Controls).

Next, the resin film was immersed in hot water at 95 ° C. for 30 minutes, then taken out of the hot water and dried, and the water vapor permeability was measured in the same manner as described above. A smaller value of the water vapor permeability indicates that the resin film has more excellent gas barrier properties.

Example 1 A nylon 6 film (maximum shrinkage stress at 170 ° C. 0.326 kgf / mm ² ) having a thickness of 15 μm was used as a polyamide resin film.
Only this polyamide resin film was used as a base material. Next, the substrate was supplied to a vacuum evaporation apparatus, and the pressure in the chamber of the apparatus was maintained at 1 × 10 ⁻⁵ Torr. Next, glass containing SiO ₂ and Al ₂ O ₃ as a vapor deposition compound in a weight ratio of 76:24 was vaporized by a 15 kW electron beam heating means in the vapor deposition apparatus, and 250 Å thick was formed on the substrate. Formed. The inorganic vapor deposited layer thus formed was colorless and transparent. Next, an adhesive (A310 / A10; Takeda Pharmaceutical Co., Ltd.) is formed on the inorganic vapor-deposited layer.
Was applied at a rate of ² g / m ^{2, and} a 55 μm unstretched polyethylene film (compression modulus at 95 ° C., 3.1 kgf / mm ² ) was dry-laminated as a sealant layer. After dry lamination, aging was performed at 45 ° C. for 4 days to obtain a resin film. Table 1 shows the evaluation results of the obtained resin films.

Example 2 Thickness of 55 as sealant layer
A resin film was obtained in the same manner as in Example 1, except that an unstretched polyethylene film having a thickness of μm (compression elastic modulus at 95 ° C. was 4.9 kgf / mm ² ) was used. Table 1 shows the evaluation results of the obtained resin films.

Example 3 A nylon 6 film (maximum shrinkage stress at 170 ° C. 0.633 kgf / mm ² ) having a thickness of 15 μm was used as a polyamide resin film.
An unstretched polyethylene film having a thickness of 55 μm as a sealant layer (having a compression
f / mm ² ), except that a resin film was obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained resin films.

Example 4 A nylon 6 film having a thickness of 15 μm (maximum shrinkage stress at 170 ° C. 0.120 kgf / mm ² ) was used as a polyamide resin film.
As a sealant layer, an unstretched polyethylene film having a thickness of 55 μm (having a compression
gf / mm ² ), except that a resin film was obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained resin films.

Example 5 A nylon 6 film having a thickness of 15 μm (maximum shrinkage stress at 170 ° C. 0.120 kgf / mm ² ) was used as a polyamide resin film.
Then, as a sealant layer, an unstretched polyethylene film having a thickness of 100 μm (having a compression elastic modulus at
A resin film was obtained in the same manner as in Example 1 except that kgf / mm ² ) was used. Table 1 shows the evaluation results of the obtained resin films.

Example 6 Example 1 was repeated except that silicon monoxide was used as the vapor deposition compound and an inorganic vapor deposition layer was formed.
A resin film was obtained in the same manner as described above. Table 1 shows the evaluation results of the obtained resin films.

<Example 7> On the polyamide resin film of Example 1, a 0.5 μm thick anchor coat layer was formed.
Polyester resin (compression modulus at 40 ° C. 8.8)
kgf / mm ² ) to prepare a substrate, and a resin film was obtained in the same manner as in Example 1 except that the inorganic vapor-deposited layer of Example 1 was formed on the anchor coat layer.
Table 1 shows the evaluation results of the obtained resin films.

Example 8 A polyester resin adhesive (compression modulus at 40 ° C. 9.8 kgf /
mm ² ), except that a resin film was obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained resin films.

Comparative Example 1 A sealant layer having a thickness of 55
A resin film was obtained in the same manner as in Example 1 except that an unstretched polyethylene film having a thickness of μm (compression elastic modulus at 95 ° C. was 2.1 kgf / mm ² ) was used. Table 1 shows the evaluation results of the obtained resin films.

<Comparative Example 2> 4 μm thick sealant layer
m of unstretched polyethylene film (compression elastic modulus at 95 ° C. is 3.1 kgf / mm ² )
A resin film was obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained resin films.

Comparative Example 3 A 2 μm thick polyvinyl alcohol-vinyl alcohol repeating unit (n) = 2000 as an anchor coat layer on the polyamide resin film of Example 1 with a saponification degree of 99 mol%; Nacalai Tesque, Inc. A resin film was obtained in the same manner as in Example 1 except that a substrate was prepared by coating the same as above, and the inorganic vapor-deposited layer of Example 1 was formed on the anchor coat layer. Table 1 shows the evaluation results of the obtained resin films.

[0103]

[Table 1]

As shown in Table 1, the resin films prepared in Examples 1 to 8 had very low oxygen permeability and excellent gas barrier properties. Furthermore, the resin films produced in Examples 1 to 8 had smaller changes in both the oxygen permeability and the water vapor permeability before and after the hot water treatment than the resin films of Comparative Examples 1 to 3. This indicates that the first gas barrier resin film of the present invention can maintain excellent gas barrier properties even after the boil treatment.

Example 9 A 15 μm nylon 6 film (maximum shrinkage stress at 170 ° C. 0.35 kgf / mm ² ) was used as a polyamide resin film, and an anchor coat layer having a thickness of 0.1 μm was formed on the polyamide resin film. A base material was prepared by coating a 5 μm polyester resin (compression modulus at 95 ° C. 4.4 kgf / mm ² ). Next, the substrate was supplied to a vacuum evaporation apparatus, and the pressure in the chamber of the apparatus was maintained at 1 × 10 ⁻⁵ Torr. Next, a glass containing SiO ₂ and Al ₂ O ₃ as a vapor deposition compound in a weight ratio of 63:37 is vaporized by a 15 kW electron beam heating means in the vapor deposition apparatus.
It was formed with a thickness of 320 Å on the substrate. The inorganic vapor deposited layer thus formed was colorless and transparent. Next, an adhesive (A310 / A10: manufactured by Takeda Pharmaceutical Co., Ltd.) was applied at a rate of ² g / m ² on the inorganic vapor-deposited layer, and a 55 μm unstretched polyethylene film was dry-laminated as a sealant layer. After dry lamination, 4 ℃ at 45 ℃
Aging was performed for a day to obtain a resin film. Table 1 shows the evaluation results of the obtained resin films.

Example 10 As an anchor coat layer,
Except that a polyester resin having a thickness of 0.5 μm (compression elastic modulus at 95 ° C. 7.2 kgf / mm ² ) was used,
A resin film was obtained in the same manner as in Example 9. Table 2 shows the evaluation results of the obtained resin films.

<Example 11> As an anchor coat layer,
A resin film was obtained in the same manner as in Example 9, except that a 0.5 μm-thick polyester resin (compression elastic modulus at 95 ° C., 56 kgf / mm ² ) was used. Table 2 shows the evaluation results of the obtained resin films.

<Example 12> As an anchor coat layer,
A resin film was obtained in the same manner as in Example 9, except that a 0.5 μm-thick polyoxymethylene resin (compression modulus at 95 ° C., 77 kgf / mm ² ) was used. Table 2 shows the evaluation results of the obtained resin films.

Comparative Example 4 A resin film was produced in the same manner as in Example 9 except that a polyester resin having a thickness of 0.5 μm (compression modulus at 95 ° C. 1.5 kgf / mm ² ) was used as the anchor coat layer. I got Table 2 shows the evaluation results of the obtained resin films.

[0110]

[Table 2]

As shown in Table 2, the resin films prepared in Examples 9 to 12 had very low oxygen permeability and had excellent gas barrier properties. Furthermore, the resin films produced in Examples 9 to 12 had smaller changes in both the oxygen permeability and the water vapor permeability before and after the hot water treatment than the resin film of Comparative Example 4. This shows that the second gas barrier resin film of the present invention can maintain excellent gas barrier properties even after the boil treatment.

[0112]

According to the present invention, a transparent gas barrier resin film having improved gas barrier properties can be provided. In particular, the gas barrier resin film of the present invention retains excellent gas barrier properties even after boil treatment or retort treatment, and has sufficient strength. Therefore, the gas barrier resin film of the present invention can prevent the formation of rust against food packaging film for which suitable heat sealing is desired, medical article packaging film for which aseptic condition is desired to be maintained, and moisture. It can be widely used as a desired film for packaging electronic parts.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing cutting out of a rectangular sample from a polyamide-based resin film when obtaining the maximum shrinkage stress of the polyamide-based resin film.

[Explanation of symbols]

 1 Polyamide resin film 11, 12, 13, 14, 15 Rectangular sample

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor, Chikao Morishige 2-1-1 Katata, Otsu-shi, Shiga Prefecture Inside Toyobo Co., Ltd. (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu-shi, Shiga Prefecture No.1 Toyobo Co., Ltd. Research Laboratory (72) Inventor Shinji Fujita 10-24 Toyocho, Tsuruga-shi, Fukui Prefecture Toyobo Co., Ltd. Film Research Laboratories

Claims (7)

[Claims] 1. A gas-barrier resin film having an inorganic vapor-deposited layer and a sealant layer sequentially on a substrate, wherein the substrate is mainly a polyamide-based resin film;
The compression elastic modulus per unit cross-sectional area of the sealant layer at 5 ° C. is at least 9.5 times the maximum shrinkage stress per unit cross-sectional area in any direction of the polyamide resin film at 170 ° C .; A gas barrier resin film having a maximum shrinkage in any direction of 3.5% or less when boiled for 30 minutes at a temperature of not more than 3.5%. 2. The adhesion strength between the substrate and the inorganic vapor-deposited layer when boiled at 95 ° C. for 30 minutes is 100 g.
The gas barrier resin film according to claim 1, which is at least / 15 mm. 3. The method according to claim 1, further comprising an anchor coat layer between the base material and the inorganic vapor-deposited layer, wherein the compression elastic modulus of the anchor coat layer at 40 ° C. is 9.8 kgf / mm ² or more. 3. The gas barrier resin film according to 1 or 2. 4. The method according to claim 1, further comprising an adhesive layer between the inorganic vapor-deposited layer and the sealant layer, wherein the compression elastic modulus of the adhesive layer at 40 ° C. is 8.8 kgf / mm ² or more. 4. The gas barrier resin film according to any one of 1 to 3. 5. A gas-barrier resin film having an inorganic vapor-deposited layer and a sealant layer sequentially on a substrate, wherein the substrate comprises a polyamide-based resin film and an anchor coat layer, and the anchor coat layer is A compressive modulus per unit sectional area of the anchor coat layer at 95 ° C .; a maximum shrinkage stress per unit sectional area in any direction of the polyamide resin film at 170 ° C. A gas-barrier resin film having a maximum shrinkage in any direction of 3.5% or less when boiled at 95 ° C. for 30 minutes. 6. The adhesive strength between the substrate and the inorganic vapor-deposited layer when boiled at 95 ° C. for 30 minutes is 100 g.
The gas barrier resin film according to claim 5, which is at least / 15 mm. 7. The method according to claim 1, further comprising an adhesive layer between the inorganic vapor-deposited layer and the sealant layer, wherein the compression elastic modulus of the adhesive layer at 40 ° C. is 8.8 kgf / mm ² or more. 7. The gas barrier resin film according to any one of 5 and 6.