JP3219570B2 - Gas barrier film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier film having transparency and excellent gas barrier properties against water vapor and oxygen, and suitable as a packaging film for foods, pharmaceuticals, precision electronic parts and the like.

[0002]

2. Description of the Related Art Packaging films used for foods, pharmaceuticals, precision electronic parts, etc., are required to have high transparency for the visibility and aesthetics of the contents, as well as due to moisture absorption and oxidation of the contents. Gas barrier properties are required to prevent alteration.

Therefore, Japanese Patent Application Laid-Open No. 55-59961 discloses that a polymer having excellent gas barrier properties such as vinylidene chloride or an ethylene-vinyl alcohol copolymer is coated on the surface of a base film such as a polyester film or a polypropylene film. Or a laminated film is disclosed. However, although the film on which the gas barrier polymer is laminated is excellent in transparency, the gas barrier property against water vapor, oxygen and the like is not yet sufficient. In particular,
At high temperatures, the gas barrier properties of water vapor, oxygen and the like are significantly reduced.

On the other hand, a composite film in which an inorganic thin film is formed on a base film, for example, a film obtained by depositing silicon oxide (Japanese Patent Publication No. 53-12953, Japanese Patent Application Laid-Open No.
No. 3137) and a film obtained by vacuum-depositing magnesium fluoride or the like (JP-A-1-297237). However, in such a composite film, when the thickness of the inorganic layer is increased to obtain a high gas barrier property against water vapor and oxygen, the transparency is reduced, the flexibility is reduced, and cracks and peeling are caused. Occurs. On the other hand, if the film thickness is reduced to ensure transparency, sufficient gas barrier properties cannot be obtained. In addition, Japanese Patent Application Laid-Open No.
No. 3137 describes a composite film obtained by depositing silicon oxide on polyvinylidene chloride-coated polyethylene terephthalate. However, in such a film, when a mechanical external force acts on the inorganic thin film of the surface layer by bending, kneading, or the like, peeling or a defective portion is generated, so that the gas barrier property is greatly reduced.

Japanese Unexamined Patent Publication (Kokai) No. 63-237940 discloses a composite film formed by laminating or coating a heat seal layer such as an ethylene-propylene copolymer on a film sputtered with indium oxide or tin oxide. It has been disclosed. JP-A-4-
JP-A-173137 and JP-A-1-202435 disclose a film in which a deposited layer of silicon oxide and a protective layer are formed on the surface of a substrate film, and the protective layer is
It is composed of a laminate layer of a film such as an ethylene-vinyl alcohol copolymer or a coating layer of a thermosetting resin. However, a film in which a heat seal layer or a protective layer is formed on an inorganic oxide layer still has low gas barrier properties, and has an oxygen permeability of only about 1 cc / m ² · 24 hr and a water vapor permeability of about 1 g / m ² · 24 hr. Further, a composite film obtained by laminating a resin film has a large film thickness.

As described above, a film having excellent gas barrier properties in addition to flexibility and transparency, even if the coating layer is thin, while suppressing a decrease in gas barrier properties due to the action of mechanical external force accompanying processing and use. Cannot be obtained, and the effect of protecting the contents and the visibility of the contents are still insufficient.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gas barrier film having excellent gas barrier properties and transparency even if the coating layer is thin.

Another object of the present invention is to provide, in addition to the above characteristics,
An object of the present invention is to provide a gas barrier film that has high gas barrier properties even at high temperatures, has excellent flexibility, and can suppress a decrease in gas barrier properties even when a mechanical external force such as bending or kneading acts.

[0009]

The present inventors have conducted intensive studies to achieve the above object. As a result, when the inorganic layer formed on the surface of the base film layer is coated with a resin having a high gas barrier property, transparency and flexibility can be improved. In addition to the properties, even if the coating layer is thin, a film having excellent gas barrier properties and not deteriorating the gas barrier properties even under the action of mechanical external force or high temperature was obtained, and the present invention has been achieved.

That is, the present invention relates to a polypropylene
At least one surface of the base film layer (1) composed of a limmer, polyester or polyamide is made of silicon oxide
Silicon dioxide particles are formed through a transparent inorganic layer (2) selected from the group consisting of oxides and aluminum oxide.
A gas barrier film covered with a barrier resin coating layer (3) not qualitatively contained ,
Resin coating layer (3) is vinylidene chloride
Contains polymer or ethylene-vinyl alcohol copolymer
Coating liquid to be applied directly to the surface of the inorganic layer (2)
Is formed to a thickness of 0.25 to 4 μm.
Barrier resin for thickness n1 (μm) of material layer (2)
Ratio n2 / of thickness n2 (μm) of coating layer (3)
Provided is a gas barrier film wherein n1 is 2 to 50 . The present invention further provides a polypropylene-based polymer,
Base film layer composed of polyester or polyamide
(1) Formed on at least one surface of the substrate, and silicon acid
With transparency selected from oxides and aluminum oxides
The inorganic layer (2) to be formed substantially contains silicon dioxide particles.
Barrier resin coating layer (3) formed
A method for producing a gas barrier film, comprising:
Nilidene copolymer or ethylene-vinyl alcohol copolymer
A coating solution containing a polymer is applied to the surface of the inorganic layer (2).
The barrier resin coating is applied directly to
The thickness of the metal layer (3) is set to 0.25 to 4 μm.
And a barrier for the thickness n1 (μm) of the inorganic layer (2).
Of thickness n2 (μm) of conductive resin coating layer (3)
Production of gas barrier film with n2 / n1 of 2 to 50
A fabrication method is also provided.

In this specification, the term “barrier resin coating layer” refers to a layer having a thickness of 2 μm and a temperature of 25 μm.
20 cc / m ² at 24 ° C. for 24 hours or less, water vapor permeability 20 g / m ^{2 at} a temperature of 40 ° C. and 90% relative humidity.
A layer containing a barrier resin for 24 hours or less.

As the polymer constituting the base film layer (1), various polymers capable of forming a film, for example, polyethylene, ethylene-ethyl acrylate copolymer, ionomer, polypropylene, ethylene-propylene copolymer, poly Polyolefins such as -4-methylpentene-1; polyethylene terephthalate, polyethylene-2,
6-naphthalate, polyester such as polybutylene terephthalate; nylon 6, nylon 11, nylon 1
2, nylon 66, nylon 610, nylon 6/6
6, polyamides such as nylon 66/610; aromatic polyamides; polyvinyl chloride; polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-acrylonitrile copolymer, vinylidene chloride- (meth) acrylic acid ester copolymer Vinylidene chloride-based resin such as coalesce; styrene-based resin such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer; polyvinyl alcohol; polyamideimide; polyimide; polyetherimide; polycarbonate; Polyary ether ketone; polyarylate; polyphenylene sulfide; polyphenylene oxide; polyparaxylene; polyacrylonitrile; Rubber hydrochloride; cellulosic polymers such as cellophane; - Le Oro chloroethylene, tetrafluoroethylene fluorocarbon resins such as propylene copolymer and a copolymer comprising the components of the various polymers are exemplified.
These polymers can be used alone or in combination of two or more.

Although the light transmittance of the base film layer can be appropriately selected, the total light transmittance for white light is usually 40% or more, preferably, for visibility and aesthetics of the package contents. It is desirable that it is 60% or more, more preferably 80% or more.

The base film layer (1) is made of an olefin polymer (especially a polypropylene polymer, etc.), polyester (especially, polyethylene terephthalate, etc.) or polyamide having excellent transparency, mechanical strength and packaging suitability. Is preferred.

The base film layer may be a single-layer film or a laminated film in which two or more polymer layers are laminated. The thickness of the substrate film layer is not particularly limited, and is appropriately selected in consideration of packaging suitability, mechanical strength, flexibility, and the like. The thickness is usually about 3 to 200 μm, preferably about 5 to 100 μm.

The base film layer can be formed by a conventional film forming method, for example, a melt forming method such as an inflation method or a T-die method, or a casting method using a solution. Further, the base film layer may be unstretched,
It may be uniaxially or biaxially stretched. As the stretching method, for example, a conventional stretching method such as roll stretching, rolling stretching, belt stretching, tenter stretching, tube stretching, or a combination thereof can be applied. The stretching ratio can be appropriately set according to the desired film properties, for example, 1.5 to 20 times in at least one direction, preferably 2 to 20 times.
It is about 15 times.

At least one surface of the substrate film layer is
Surface treatment may be performed. Examples of the surface treatment include corona discharge treatment, plasma treatment, glow discharge treatment, reverse sputtering treatment, flame treatment, chromic acid treatment, solvent treatment, and surface roughening treatment. In addition, if an inorganic layer and a barrier resin coating layer are formed on the surface-treated surface of the base film layer, the adhesion can be improved.

An undercoat layer may be formed on the surface of the base film layer instead of or together with the surface treatment. The undercoat layer can be composed of various resins, for example, a thermoplastic resin, a thermosetting resin, a light curable resin (an electron beam curable resin, an ultraviolet curable resin, or the like), or a coupling agent. Specifically, for example, acrylic resins, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polycarbonate, cellulose polymers such as nitrocellulose and cellulose acetate, thermoplastic resins such as rosin-modified maleic resin; urethane resins Urea resin, melamine resin, urea-melamine resin; thermosetting resin such as epoxy resin, alkyd resin, aminoalkyd resin; epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) Photocurable resins such as acrylates; silane coupling agents and the like. These can be used alone or in combination of two or more.

The undercoat layer may contain a coloring agent such as a general-purpose dye or pigment. The content of the coloring agent is appropriately selected within a range not to impair the transparency of the film, and is usually about 1 to 30% by weight based on the resin constituting the undercoat layer. The thickness of the undercoat layer is not particularly limited, but is usually about 0.1 to 5 μm.

The method of forming the undercoat layer is not particularly limited, and the organic or aqueous coating agent containing the components of the undercoat layer may be coated with a conventional coating method such as a roll coating method, a gravure coating method, a reverse coating method, a spray coating method and the like. It is performed by applying by a method and drying or curing. In the case where a photocurable resin is used, actinic light may be applied.

A feature of the present invention is that the surface of the base film (1) is coated in a specific order by combining the inorganic layer (2) having transparency and the barrier resin coating layer (3). is there. With this composite configuration, while suppressing the reduction of gas barrier properties at the time of the action of mechanical external force and at high temperatures,
A film having excellent gas barrier properties can be obtained even if the coating layer is thin, in addition to high transparency and flexibility.
This is considered as follows.

That is, the film of the present invention comprises a transparent inorganic layer (2) and a barrier resin coating layer (3).
Has a high affinity with, so that defects that cause a decrease in gas barrier properties are not generated. In addition to being excellent in transparency,
Even if the coating layer is extremely thin, a high gas barrier property can be obtained by the inorganic layer and the barrier resin coating layer, so that flexibility is not reduced and peeling or defects are not generated by external force. Also, by combining the barrier resin coating layer and the inorganic layer, excellent gas barrier properties can be obtained even at high temperatures. Therefore, the film of the present invention, for example, during the processing or use of the film, even when a mechanical external force such as bending or kneading, can suppress the decrease in gas barrier properties, and can exhibit high gas barrier properties even at high temperatures. Excellent gas barrier properties can be maintained over a long period of time.

The inorganic material constituting the inorganic layer (2) is not particularly limited as long as it can form a transparent thin film, and examples thereof include Group 2A elements of the periodic table such as beryllium, magnesium, calcium, strontium and barium; Titanium, zirconium, ruthenium, hafnium,
Periodic table transition element such as tantalum; Periodic table 2B such as zinc
Group 3B element such as aluminum, gallium, indium and thallium; Group 4B element such as silicon, germanium and tin; Simple substance such as selenium and tellurium such as Group 6B element and the like, including these elements Inorganic compounds, for example, oxides, halides, carbides, nitrides and the like can be mentioned. These can be used alone or in combination of two or more.

Preferred inorganic substances include, for example, Group 2A elements of the periodic table such as magnesium, calcium and barium; transition elements of the periodic table such as titanium, zirconium, tantalum and ruthenium; Group 2B elements of zinc and the like; aluminum, indium, A simple substance of a Group 3B element of the Periodic Table such as thallium; a Group 4B element of the Periodic Table such as silicon or tin; a selenium or other Group 6B element, or an oxide containing them.

Among them, tin oxide, indium oxide, or a composite oxide or silicon oxide thereof is preferable because of its excellent transparency and gas barrier properties. In particular, silicon oxide, in addition to the above properties, can form a dense thin film, high affinity with the polymer constituting the barrier resin coating layer,
Even if a mechanical external force acts, no cracks or defects are generated in the inorganic layer, and excellent gas barrier properties can be maintained for a long period of time.
The silicon oxide includes not only silicon monoxide and silicon dioxide but also a silicon oxide represented by a composition formula SiOx (where 0 <x ≦ 2).

The thickness of the inorganic layer is usually from 100 to 500.
0 Å (0.01 to 0.5 μm), preferably 300 to 1500 Å (0.03 to
0.15 μm). 100 thickness
If the thickness is less than Å, sufficient gas barrier properties cannot be obtained. If the thickness exceeds 5,000 Å, the barrier properties will not be significantly improved, which is economically disadvantageous.

The barrier resin coating layer is formed of a resin having high gas barrier properties as described above, for example, a vinylidene chloride copolymer, an ethylene-vinyl alcohol copolymer,
Polyamide-based polymer, polyvinyl alcohol-based polymer,
It contains polyacrylonitrile-based polymers, urethane-based polymers, and the like. The barrier resin of the gas barrier resin coating layer does not include a resin that does not exhibit the gas barrier properties, for example, a general urethane polymer. These barrier resins can be used alone or in combination of two or more.

Preferred barrier resins include, for example, vinylidene chloride copolymers and ethylene-vinyl alcohol copolymers. Vinylidene chloride-based copolymer is a copolymer of vinylidene chloride and other polymerizable monomers, such as a polymerizable monomer, for example,
Various acrylates such as vinyl chloride, vinyl acetate, crotonic acid, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, acrylonitrile, methacrylonitrile , Methacrylic acid and methacrylate corresponding to the above acrylate. Among these vinylidene chloride-based copolymers, vinylidene chloride-acryloniloryl copolymer, vinylidene chloride-methacrylic acid copolymer, vinylidene chloride-acrylate copolymer, vinylidene chloride-methacrylate copolymer, vinylidene chloride-
Vinyl acetate copolymers and the like are preferred. The vinylidene chloride content in the vinylidene chloride-based copolymer is usually from 85 to 85%.
It is about 99% by weight, preferably about 90 to 97% by weight.

The ethylene-vinyl alcohol copolymer is preferably a solvent-soluble ethylene-vinyl alcohol copolymer. In such an ethylene-vinyl alcohol copolymer, the ethylene content is usually 5 to 50 mol%, preferably 10 to 45 mol%, more preferably 2 to 50 mol%.
The molecular weight is usually about 10,000 to 1 mol%.
10,000, preferably about 40,000 to 50,000, saponification degree 99.5%
It is desirable that this is the case. Such a solvent-soluble ethylene-vinyl alcohol copolymer is soluble in water or a mixed solvent of water and alcohol, and can form a thin film by coating.

The barrier resin coating layer is formed of the above-mentioned barrier resin (preferably a vinylidene chloride copolymer or ethylene-vinyl alcohol copolymer) according to the desired gas barrier properties (oxygen, water vapor, carbon dioxide, etc.). At least one resin may be contained, or a plurality of resins may be contained. Further, the barrier resin coating layer may be composed of a plurality of layers containing a barrier resin. For example, the barrier resin coating layer may be composed of a plurality of layers including a layer containing a vinylidene chloride-based copolymer and a layer containing an ethylene-vinyl alcohol copolymer. The content of the barrier resin in the barrier resin coating layer is 50% by weight or more, preferably 75 to 100% by weight, and more preferably 90 to 100% by weight.
% By weight.

The thickness of the barrier resin coating layer is appropriately selected within a range not to impair the properties of the film, but is usually 0.05 to 15 μm, preferably 0.1 to 10 μm.
m, more preferably about 0.25 to 5 μm. When the thickness is less than 0.05 μm, sufficient gas barrier properties cannot be obtained, and when the thickness exceeds 15 μm, the gas barrier properties do not improve so much, which is economically disadvantageous.

In the present invention, the thickness ratio between the inorganic layer (2) and the barrier resin coating layer (3) can be appropriately set, but the ratio affects the gas barrier properties. For this reason, in order to obtain high gas barrier properties and resistance, the ratio of the thickness n2 (μm) of the barrier resin coating layer to the thickness n1 (μm) of the inorganic layer n2 / n
1 is usually 0.1 to 1500, preferably 0.5 to
It is desirably 60, more preferably about 2 to 50. When the thickness ratio is out of the above range, it is difficult to obtain a sufficient gas barrier property. When the ratio is less than 0.1, defects are easily generated in the inorganic layer due to external force,
If it exceeds 0, the gas barrier properties and the like are not so improved, and it is not economical.

On the surface of the barrier resin coating layer,
If necessary, a conventional surface treatment as exemplified in the base film layer may be applied.

The barrier resin coating layer is made of another polymer, for example, ethylene-vinyl acetate copolymer,
Olefin polymers such as ethylene-ethyl acrylate copolymer; acrylic polymers; styrene polymers; polyesters; polyacetals;
Polyvinyl chloride; vinyl chloride-vinyl acetate copolymer; polyamide; urethane polymer; acrylonitrile polymer; polycarbonate; chlorinated polyolefin;

As long as the transparency and gas barrier properties are not impaired, various additives such as stabilizers such as antioxidants, ultraviolet absorbers and heat stabilizers; cationic and anionic , A nonionic, amphoteric antistatic agent and other antistatic agents; crystal nucleus growth agents;
Hydrocarbon polymers such as rosin and its derivatives and their hydrogenated resins; plasticizers; fillers; higher fatty acid amides, higher fatty acids and their salts, higher fatty acid esters, mineral and vegetable natural waxes, polyethylene, etc. Waxes such as synthetic waxes; fine powdery lubricants such as inorganic lubricants such as silica fine powder and alumina fine powder; and organic lubricants such as polyethylene fine powder and acrylic fine powder; Good.

The barrier resin coating layer may contain the above-mentioned additives, an anti-blocking agent, and an adhesion improver such as polyethyleneimine and polyisocyanate.

The barrier film of the present invention is obtained by sequentially covering at least one surface of the base film layer (1) with a transparent inorganic layer (2) and a barrier resin coating layer (3). Obtainable.

The inorganic layer (2) is formed by a conventional method, for example,
Vacuum deposition, reactive deposition, sputtering, reactive sputtering, ion plating, reactive ion plating, CVD, plasma CVD,
It can be formed by coating the surface of the base film layer (1) with the above-mentioned inorganic substance by a laser CVD method or the like. The inorganic layer can be formed on one side or both sides of the base film layer.

The barrier resin coating layer can be formed by applying a coating solution containing a barrier resin to the surface of the inorganic layer. The coating solution can be prepared by selecting an appropriate solvent according to the type of the barrier resin, and may be in the form of either a solution or a dispersion.

For example, the solvent of the solution coating solution containing the vinylidene chloride-based copolymer can be appropriately selected according to the type of the vinylidene chloride-based copolymer, and examples thereof include ketones such as acetone, methyl ethyl ketone, and cyclohexanone. Ethers such as dioxane, diethyl ether and tetrahydrofuran; aromatic hydrocarbons such as benzene, toluene and xylene; esters such as ethyl acetate and butyl acetate; amides such as dimethylformamide and mixed solvents thereof. . Further, the dispersion liquid is usually commercially available in the form of an O / W emulsion.

The coating solution containing the ethylene-vinyl alcohol copolymer can be usually prepared using a mixed solvent of water and alcohol. Examples of such alcohols include methanol, ethanol, propanol, isopropanol, cyclohexanol and the like.

The above-mentioned coating liquid may contain the above-mentioned various additives, and may contain conventional additives such as an antifoaming agent and a viscosity modifier in order to enhance the coating property.

The coating method is not particularly limited, and a conventional method such as an air knife coating method, a roll coating method, a gravure coating method, a blade coater method, a dip coating method, and a spraying method can be employed. After the application of the coating solution, the coating is dried at a temperature of, for example, about 50 to 150 ° C., whereby a barrier resin coating layer can be formed.

The gas barrier film of the present invention includes
Depending on the type and use of the film, various coating layers and laminate layers, for example, a lubricating layer, an antistatic layer, a heat sealing layer, etc. may be formed.

The gas barrier film of the present invention can be used for various packaging materials such as foods for microwave ovens, retort foods, frozen foods, microwave sterilization, flavor barriers, pharmaceuticals, precision electronic parts, etc., and balloon forming materials such as balloons. Can be suitably used.

[0046]

The gas barrier film of the present invention is excellent in transparency because the surface of the base film layer is sequentially coated with an inorganic layer having transparency and a barrier resin coating layer having high gas barrier properties. In addition, even if the coating layer is thin, it has high gas barrier properties. In addition, even when a mechanical external force such as massaging acts or at a high temperature, a decrease in gas barrier properties can be suppressed, and excellent gas barrier properties can be exhibited over a long period of time.

[0047]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

COMPARATIVE EXAMPLE 1 On one surface of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm, 5 × 10
^-5 Torr vacuum under vacuum of 1000 Torr
An Angstrom silicon oxide deposited layer was formed as an inorganic layer to obtain a composite film.

Examples 1 and 2 A vinylidene chloride-based copolymer (trade name: Saran Resin F216, manufactured by Asahi Kasei Kogyo Co., Ltd.) was added to a mixed solvent of toluene / tetrahydrofuran = 1/2 (weight ratio) at a resin concentration of 15%.
The solution was dissolved so as to be a weight% to prepare a coating solution for a barrier resin coating layer.

This coating solution was applied to a vapor-deposited surface of the silicon oxide vapor-deposited film obtained in Comparative Example 1 with a thickness of 0.5 μm (Example 1) and 2.5 μm after drying using a bar coater.
After being applied so as to become (Example 2), it was dried in an oven at 105 ° C. for 30 seconds to form a barrier resin coating layer, thereby obtaining a composite film.

Example 3 An ethylene-vinyl alcohol copolymer (trade name: Soarnol 30L, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was dissolved in a mixed solvent of water / isopropanol = 1/1 (weight ratio).
The coating solution for the barrier resin coating layer was prepared by adjusting the resin concentration to 12% by weight.

This coating solution was applied to the vapor-deposited surface of the silicon oxide vapor-deposited film obtained in Comparative Example 1 using a bar coater so as to have a dried thickness of 4.0 μm.
After drying in an oven at 115 ° C. for 1 minute, a barrier resin coating layer was formed to obtain a composite film.

Comparative Examples 2 and 3 0.5 μm (Comparative Example 2) or 2.5 μm (Comparative Example 3) directly on polyethylene terephthalate film
A composite film was obtained in the same manner as in Examples 1 and 2, except that the barrier resin coating layer was formed.

Comparative Example 4 A common urethane resin solution [Takelac A615, trade name, manufactured by Takeda Pharmaceutical Co., Ltd.] was used instead of a coating solution containing a vinylidene chloride copolymer on the surface of the inorganic layer. A composite film was obtained in the same manner as in Example 1, except that a coating layer having a thickness of 5.0 μm was formed.

Comparative Example 5 Instead of the barrier resin coating layer, a urethane-based adhesive [ADCOTE 333E, manufactured by Toyo Morton Co., Ltd.] was applied on the surface of the inorganic layer so that the thickness after drying was about 2 μm. And a 30 μm-thick unstretched ethylene-propylene copolymer film was laminated by a dry lamination method to obtain a composite film.

Comparative Example 6 A vinyl chloride-vinyl acetate copolymer solution [Denki Kagaku Kogyo Co., Ltd.] was used instead of a coating solution containing a vinylidene chloride copolymer.
The product was manufactured in the same manner as in Example 2 except that a coating layer having a thickness of 2.5 μm was formed on the surface of the inorganic layer using DENKA 1000C (trade name).

Comparative Example 7 A coating layer having a thickness of 2.5 μm was formed on one surface of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm by using the same barrier coating liquid as in Example 2. Next, on the surface of the coating layer,
A silicon oxide deposited layer was formed in the same manner as in Comparative Example 1 to obtain a composite film.

Then, oxygen gas permeability and water vapor permeability of the gas barrier films obtained in Examples and Comparative Examples were evaluated as follows.

Oxygen gas permeability: same pressure method (measuring device: Morcon
OXTRAN TWIN) at 20 ° C. and 65% relative humidity. The unit is cc / m ² · 24 hr.

Water vapor transmission rate: Measuring instrument (MORCON PERMATRA)
NW200) under the conditions of 40 ° C. and 90% relative humidity. The unit is g / m ² · 24 hr.

Further, the film was manually rubbed once, and the oxygen gas permeability and the water vapor permeability before and after the film were measured, and the change in gas barrier properties due to the action of a mechanical external force was evaluated.

The results are shown in the table. In Example 3,
The oxygen permeability before hand massage was below the measurement limit.

[0063]

[Table 1] As is clear from the table, the films of Comparative Examples 1 to 7 do not have sufficient gas barrier properties, and the films of Comparative Examples 1, 6, and 7 show a marked decrease in gas barrier properties due to hand massage. On the other hand, the films of Examples 1 to 3 not only have extremely high gas barrier properties, but also can maintain excellent gas barrier properties even when a mechanical external force such as hand massage acts. In particular, as is clear from the comparison with Comparative Examples 1 to 3, by combining the inorganic layer and the barrier resin coating layer,
It shows extremely high gas barrier properties even when the thickness of the coating layer is small.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-62040 (JP, A) JP-A 1-267032 (JP, A) JP-A 4-107138 (JP, A) JP-A 2- 58023 (JP, A) JP-A-5-9317 (JP, A) JP-A-5-16284 (JP, A) JP-A-60-157852 (JP, A) JP-A-60-244540 (JP, A) JP-A-5-208475 (JP, A) JP-A-1-171633 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (2)

(57) [Claims] 1. A polypropylene-based polymer, polyester
At least one surface of the substrate film layer (1) composed of a silicon oxide or aluminum
Is selected from the oxides, and through the inorganic layer (2) having a transparent, gas barrier film that is coated with a <br/> barrier resin coating layer is substantially free (3) silicon dioxide particles And the barrier resin coating
The coating layer (3) is made of a vinylidene chloride copolymer or ethylene.
Before applying the coating solution containing the len-vinyl alcohol copolymer
Thickness by directly applying to the surface of the inorganic layer (2)
0.25 to 4 μm, and the inorganic layer (2)
Barrier resin coating layer for thickness n1 (μm)
The ratio n2 / n1 of the thickness n2 (μm) of (3) is 2 to 50
Is a gas barrier film . 2. Polypropylene polymer, polyester
Of base film layer (1) composed of polyester or polyamide
Formed on at least one surface, and silicon oxide;
Inorganic with transparency selected from aluminum oxide
A layer substantially free of silicon dioxide particles
Gas burr with rear resin coating layer (3) formed
A method for producing an adhesive film, comprising: vinylidene chloride
System copolymer or ethylene-vinyl alcohol copolymer
The coating solution is directly applied to the surface of the inorganic layer (2).
The barrier resin coating layer
(3) is formed in a thickness of 0.25 to 4 μm,
Barrier property tree for thickness n1 (μm) of inorganic layer (2)
Ratio n2 of thickness n2 (μm) of fat coating layer (3)
For producing a gas barrier film with / n1 of 2 to 50
Law.