JP2000334878A - Gas barrier film and package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high gas barrier properties and to prevent peeling during use by forming an inorg. oxide membrane layer on the surface of a plastic film and forming a polyethyleneimine layer on the surface thereof and directly forming a heat sealable resin layer by extrusion lamination. SOLUTION: An inorg. oxide membrane layer is formed on the surface of a plastic film and a polyethyleneimine layer is formed on the surface thereof and a heat sealable resin layer is directly formed on the surface thereof by melt extrusion lamination. The thickness of the plastic film is set to 3-500 μm and the pref. inorg. oxide membrane layer comprises a silicon oxide/ aluminum oxide binary inorg. oxide membrane. The thickness of the polyethyleneimine layer is usually set to about 0.001-10 μm and the heat sealable resin layer is formed by using low density polyethylene, an ethylene/vinyl acetate copolymer or linear low density polyethylene and set to about 3-100 μm in its thickness. Laminate strength is set to 250 g/15 mm or more.

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 and a package, and more particularly to foods, pharmaceuticals, chemicals, medical equipment, electronic parts, etc., which are excellent in gas barrier properties, retort resistance and pinhole resistance. TECHNICAL FIELD The present invention relates to a gas barrier film and a package used for packaging articles that require airtightness.

[0002]

2. Description of the Related Art As a transparent and environmentally friendly flexible film having an excellent barrier property against gases such as oxygen and water vapor, a laminated film in which an inorganic oxide thin film is formed on a plastic film is known. Such a laminated film further laminated with a heat-sealing resin layer is used as a packaging film or packaging for articles requiring airtightness such as food, pharmaceuticals, chemicals, medical equipment, and electronic components. It is used as a package made in a bag.

[0003]

The above-mentioned conventional gas barrier film and package are provided with a notch without using scissors or the like when cutting from the end to open it. The method of cutting by hand is convenient and preferred. However, a gas barrier film having a laminated inorganic oxide thin film layer and a package using the same have a large resistance to the hand when cut, and in a remarkable case, the contents jump out due to irregular catching. There was a problem. In particular, it is difficult to use for children and the elderly, who are not good at distributing power, and their use is limited. Further, the resin layer having heat sealability is easily peeled off from the inorganic oxide thin film layer, and there is a practical problem. Further, JP-A-5-309778 proposes that an aqueous anchor layer is formed in advance on a silicon oxide vapor-deposited thin film layer formed on a plastic film, and a polyethyleneimine-based anchor agent is used as the aqueous anchor layer. Are also shown. However, in a gas barrier film obtained by depositing an inorganic oxide thin film on a film that easily absorbs moisture such as a polyamide film, applying a water-based anchor agent in advance means that water for absorbing moisture is supplied. The inorganic oxide thin film cannot follow the elongation of the film due to moisture absorption, and the good gas barrier properties of the film having the inorganic oxide thin film layer cannot be maintained. Further, since the heat-sealing resin film is laminated via the adhesive, there is a problem that the performance inherent in the polyethyleneimine anchor cannot be exhibited.

[0004] The present invention solves the problems of the above-mentioned conventional gas barrier film and package, and the heat-sealing resin layer is firmly adhered to the inorganic oxide thin film layer to maintain a high gas barrier property. An object of the present invention is to provide an excellent gas barrier film and a package that can be cut smoothly by pulling by hand without forming a cutout portion at an end without peeling off during use. .

[0005]

Means for Solving the Problems To achieve the above object, the gas barrier film of the present invention comprises a plastic film having an inorganic oxide thin film layer formed on the surface thereof, and a polyethylene imine layer formed on the surface of the inorganic oxide thin film layer. Is formed,
A heat-sealable resin layer is directly formed on the surface of the polyethylene imine layer by melt extrusion lamination.

In the gas barrier film of the present invention having the above structure, the heat sealable resin layer is firmly adhered to the inorganic oxide thin film layer, retains a high degree of gas barrier properties, and may be peeled off during use. In addition, a notch can be provided at the end, and it can be cut smoothly by pulling by hand.

In this case, the inorganic oxide thin film may be a multi-component inorganic oxide thin film containing at least silicon oxide and aluminum oxide.

In this case, the plastic film may be a polyamide film.

Further, in this case, the package may be formed using the gas barrier film.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the gas barrier film and the package of the present invention will be described.

The plastic film used in the present invention is a film obtained by melt-extruding an organic polymer, stretching the film in the longitudinal direction and / or the width direction, cooling, and heat setting as necessary. Is polyethylene,
Polypropylene, nylon 4.6, nylon 6, nylon 6.6, nylon 12, polyethylene terephthalate, polyethylene-2,6-naphthalate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, wholly aromatic polyamide, polyamide imide, polyimide , Polyetherimide, polysulfone and the like.

Specific examples of preferable polyamides include polycaproamide (nylon 6), poly-ε-aminoheptanoic acid (nylon 7), poly-ε-aminononanoic acid (nylon 9), polyundecaneamide (nylon 11),
Polylaurin lactam (nylon 12), polyethylene diamine adipamide (nylon 2.6), polytetramethylene adipamide (nylon 4.6), polyhexamethylene adipamide (nylon 6.6), polyhexamethylene se Bacamide (nylon 6,10), polyhexamethylene dodecamide (nylon 6,12), polyoctamethylene adipamide (nylon 8.6), polydecamethylene adipamide (nylon 10.6), polydecamethylene Sebacamide (nylon 10.10), polydodecamethylene dodecamide (nylon 12.12), metaxylenediamine-6 nylon (MXD6), and the like.
Copolymers containing these as main components may be used. Examples thereof include caprolactam / laurin lactam copolymer, caprolactam / laurin lactam copolymer, caprolactam / hexamethylene diammonium adipate copolymer, and 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 di Ammonium sebacate copolymer and the like can be mentioned. It is also effective to mix these polyamides with plasticizers such as aromatic sulfonamides, p-hydroxybenzoic acid, and esters, as well as elastomer components and lactams having a low modulus of elasticity, as components for improving the flexibility of the film. It is.

As specific examples of preferred polyesters, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, etc. are used. When a polymer is used, the main component of the dicarboxylic acid component is terephthalic acid or 2,6-naphthalenedicarboxylic acid, as well as adipic acid, aliphatic dicarboxylic acids such as sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, 2, Aromatic dicarboxylic acids such as 6-naphthalenedicarboxylic acid and polyfunctional carboxylic acids such as trimellilotic acid and pyromellilotic acid are used. Further, the other main component of the glycol component is ethylene glycol or 1,4-butanediol,
Diethylene glycol, propylene glycol, 1,4
Aliphatic glycols such as butanediol and neopentyl glycol, aromatic glycols such as p-xylene glycol, alicyclic glycols such as 1,4-cyclohexanedimethanol, and polyethylene glycol having an average molecular weight of 150 to 20,000 are used. The preferable proportion of the copolymer component in the polyester is 20% or less.
When the amount of the copolymer component exceeds 20%, the film strength, transparency and heat resistance may be poor. These organic polymers are
Further, a small amount of another organic polymer may be copolymerized or blended.

Further, known additives such as an ultraviolet absorber, an antistatic agent, a plasticizer, a lubricant, and a coloring agent may be added to the organic polymer. The transparency of the plastic film is not particularly limited, but when used as a transparent gas barrier film, a film having a light transmittance of 50% or more is desirable.

The plastic film used in the present invention may have a corona discharge treatment, a glow discharge treatment, a flame treatment, a corona discharge treatment before the lamination of the inorganic oxide thin film layer, as long as the object of the present invention is not impaired. A surface treatment such as a surface roughening treatment may be performed, and a known anchor coating treatment, printing, and decoration may be performed.

The plastic film used in the present invention includes a sheet, and its thickness is preferably in the range of 3 to 500 μm, more preferably in the range of 6 to 300 μm.

In the present invention, the inorganic oxide forming the inorganic oxide thin film formed on at least one surface of the plastic film is not particularly limited as long as it can be formed into a thin film such as silicon oxide / aluminum oxide and magnesium oxide. However, preferred inorganic oxides are aluminum oxide and a multi-component inorganic oxide thin film containing silicon oxide, more preferably a silicon oxide-aluminum oxide binary inorganic oxide thin film.

[0018] The silicon oxide here, Si, consists of a mixture of silicon and various silicon oxides such as SiO and SiO _2, and aluminum oxide, Al, aluminum and various aluminum oxides such as AlO, Al ₂ O _3, or the And the amount of oxygen in each oxide varies depending on the production conditions. However, when silicon oxide and aluminum oxide are used in combination, the content of aluminum oxide in the inorganic oxide thin film is reduced. It is preferably 20 to 99% by weight, more preferably 20 to 75% by weight. More preferably, the specific gravity of the silicon oxide / aluminum oxide binary thin film satisfies the following condition.

The relation between the value of the specific gravity of the inorganic oxide thin film and the weight% of aluminum oxide in the inorganic oxide thin film is represented by D =
In the formula of 0.01A + b (D: specific gravity of the thin film, A: weight% of aluminum oxide in the thin film), when the value of b is smaller than 1.6, the structure of the aluminum oxide / silicon oxide based thin film When the value of the specific gravity of the thin film is greater than 2.2 in the value of b, the thin film tends to be hard.

For this reason, the specific gravity of the aluminum oxide / silicon oxide based thin film as the inorganic oxide thin film is determined by the relation between the specific gravity of the thin film and the aluminum oxide composition ratio in the thin film as D = 0.
When expressed by a relational expression of 01A + b (D: specific gravity of the thin film, A: weight% of aluminum oxide in the thin film), the value of b is preferably 1.6 to 2.2, and more preferably 1.7. To 2.1, but of course is not limited to this range. A multi-component inorganic oxide thin film containing silicon oxide / aluminum oxide and further containing other inorganic oxides is also highly effective as a gas barrier film.

In the above case, if the content of aluminum oxide in the silicon oxide / aluminum oxide based binary inorganic oxide thin film is less than 20% by weight, the gas barrier property is not always sufficient, and the silicon oxide / oxidation If the amount of aluminum oxide in the aluminum-based vapor-deposited film exceeds 99% by weight, the flexibility of the vapor-deposited film is reduced, the gas-barrier film is relatively weak in bending and dimensional change, and the effect of the combination of the two decreases. May occur.

In the present invention, the thickness of the inorganic oxide thin film is usually from 10 to 8,000, preferably from 50 to 50,000.
00 °. If the film thickness is less than 10 °, it is difficult to obtain a satisfactory gas barrier property, and if the film thickness exceeds 8,000 °, the effect of improving the gas barrier property corresponding thereto cannot be obtained, and the bending resistance and the manufacturing cost are reduced. On the contrary, it is disadvantageous.

A typical method for forming an inorganic oxide thin film will be described with reference to the formation of a silicon oxide / aluminum oxide-based thin film. As a thin film forming method by a vapor deposition method, there are physical methods such as a vacuum deposition method, a sputtering method, and an ion plating method. An evaporation method, a CVD method (chemical evaporation method), or the like is appropriately used. For example, when a vacuum deposition method is employed, a mixture of SiO ₂ and Al ₂ O ₃ or SiO ₂
And a mixture of Al and the like. For heating, resistance heating, high-frequency induction heating, electron beam heating, etc. can be adopted, and oxygen, nitrogen, hydrogen,
It is also possible to introduce reactive gas such as introduction of argon, carbon dioxide gas, water vapor, or the like, or to use reactive evaporation using means such as ozone addition or ion assist. Further, the film forming conditions such as applying a bias to the plastic film, heating and cooling the plastic film, and the like can be arbitrarily changed. The above-mentioned deposition material, reaction gas, substrate bias, heating / cooling, and the like can be similarly changed when a sputtering method or a CVD method is adopted.

According to such a method, it is possible to obtain a gas barrier film having excellent performance which is transparent and can withstand a boiling treatment, a retort treatment and a gelbo test (bending resistance test).

In the present invention, the polyethylene imine layer is a thin film layer containing polyethylene imine, and has a thickness of usually about 0.001 to 10 μm, preferably about 0.003 to 0.5 μm. The polyethyleneimine used to form the polyethyleneimine layer in the present invention is obtained by polymerization of ethyleneimine, and is a highly reactive high molecular weight water-soluble resin having a 3-membered ring structure amino group. Having a molecular weight of 100 to 10
Those having about 0000 and an amine value of about 20 are generally used. Polyethyleneimine is used as an anchor coating agent.
It is known that the adhesive strength is large with a small amount added,
Because it is water-soluble, one example of usage is to use an aqueous solution with water /
In general, it is used after being diluted with a mixture of alcohols.

In the present invention, the heat-sealable resin layer includes low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, ethylene-acrylic acid copolymer, Ethylene methacrylic acid copolymer, ethylene methyl acrylate copolymer, ethylene ethyl acrylate copolymer, ethylene methyl methacrylate copolymer, formed by ionomer,
These are directly melt-extruded and laminated on the polyethyleneimine layer by an extrusion lamination method. Practically, low-density polyethylene, ethylene-vinyl acetate copolymer or linear low-density polyethylene is often used. The thickness of the heat-sealable resin layer is generally about 3 to 100 μm, preferably about 5 to 70 μm.

The practicality of the gas barrier film according to the present invention is largely related to the lamination strength of the above-mentioned inorganic oxide thin film and the heat-sealable resin layer. Practicality including is improved. According to the study results of the present inventors, in order to have excellent gas barrier properties and to maintain the excellent properties as a package even after boiling treatment or retort treatment, the laminate strength is set to 250 g / 1.
Usually, it is 5 mm or more. More preferable lamination strength is 400 g / 15 mm or more, and further preferably 600 g / 15 mm or more. Laminate strength is 25
When it is less than 0 g / 15 mm, the characteristics as a package tend to decrease due to boiling treatment or retort treatment.

As described above, the laminate exhibiting excellent lamination strength even after the hot water treatment shows that the peeling between the inorganic oxide thin film and the heat-sealable resin layer and the destruction of the inorganic oxide thin film after the boiling treatment or the retort treatment. It does not occur, and excellent gas barrier properties and moisture resistance are maintained. It is considered that the reason for this is that if the lamination strength is large, the inorganic oxide thin film hardly peels off even when the heat-sealable resin layer slightly shrinks due to boiling treatment or retort treatment.

The gas barrier film of the present invention is excellent in gas barrier properties, retort resistance, pinhole resistance and the like, and is effective as it is for packaging foods, pharmaceuticals, medical equipment, electronic parts and other articles, or as a package. Can be used for

In the present invention, when the packaging material and package made of the gas barrier film are divided into types for food packaging, first of all, according to the type of food to be stored, it is convenient for dry food, water food, frozen food and the like. Can be divided into

The dried food packaging material and package are used for the following applications. Applicable contents include snacks such as potato chips and popcorn, rice crackers such as rice crackers and oysters, instant noodles and sprinkles, shaved knots, dried products such as laver, green tea,
There are luxury items such as coffee and tea, and grains such as flour, rice, and wheat, and the like, but are not limited thereto. Further, as a packaging material for dried food, various films or papers may be used to laminate the gas barrier film of the present invention in accordance with the required characteristics of the contents to be packaged. PE
On T) / PE, gas barrier film (on PET) / C
PP, NY / gas barrier film (on PET) / P
E, a gas barrier film (on NY) / PE, etc. can be considered. Furthermore, it may be subjected to printing for decoration or explanation of contents, or may be bonded to a design film or a reinforcing agent. Examples of the package for dried food in the present invention include bags, lid materials, cups, tubes, standing packs, trays, and the like, and there are no particular restrictions on the shape and type. For example, the pillow type , A three-sided seal, a four-sided seal, or the like can be used. The gas barrier film of the present invention is used as all or a part of the configuration of these packaging materials and packages.

The contents applicable to the packaging material for water-based foods and the packaging in the present invention include various pickles such as board and italian konnyaku, takuan pickles, soy sauce pickles, and Nara pickles, and various miso pastes. There are foods, soy sauce, sauces, ketchup, mayonnaise, and other seasonings that are enclosed with sauces, dashi, and mentsuyu, but are not limited to these. Various films may be laminated as packaging materials for aquatic foods according to the required characteristics of the contents to be packaged. Typical laminating configurations include gas barrier film (on NY) / PE, gas barrier film (on NY) )
/ CPP, gas barrier film (on PET) / PE,
A gas barrier film (on PET) / CPP may be considered. Furthermore, it may be subjected to printing for decoration or explanation of contents, or may be bonded to a design film or a reinforcing agent. Examples of the package for aquatic foods in the present invention include a bag, a lid material, a cup, a tube, a standing pack, a tray, and the like, and there is no particular limitation on the shape and type. , Three-sided seal, four-sided seal, etc. can be used,
The gas barrier film of the present invention is used as all or a part of the configuration of these packaging materials and packages. Since the packaging material and the packaging body having the gas barrier film of the present invention as a part or the whole of the constitution have a wide use temperature range, they can be applied to frozen foods.

Next, when the packaging material and the package in the present invention are classified by shape, they are classified into uses such as paper cartons, tubes, bags, cups, standing packs, and trays. For example, a paper carton is
This refers to a composite paper container, and as a packaging material for a paper carton, a laminate of paper, a plastic film, or the like and a gas barrier film is used. Roof shape (gebel top: gable to
p), brick type (brick type: brick type)
e), rectangular parallelepiped, cup shape and the like are not particularly limited. Moreover, you may combine with an inner bag, a spout, etc. Contents that can be applied as a paper carton application in the present invention include milk,
There are drinks such as yogurt juice and carbonated beverages, alcohols such as sake, shochu and whiskey, and seasonings such as soy sauce and sauces, but are not particularly limited thereto.

Next, as another example of the use of the packaging material and the packaging bag in the present invention, the packaging material and the packaging bag can be used as a packaging material or a package for a microwave oven or micro-sterilization utilizing the non-conductivity. It is also used for applications such as packaging with an oxygen scavenger. Similarly, there are various types of laminate configurations and shapes of the package. The gas barrier film constituting the packaging material and the package of the present invention is transparent and has high barrier properties. That is, depending on the type and thickness of the laminated film used as the heat seal layer, for example, when a 50 μm CPP film is used, the oxygen permeability is 3.0 cc / m ² · 24 hrs or less and the moisture permeability is 3.0 g / m 2. ^It has excellent barrier properties of 2.24 hrs or less. Therefore, the food packaged with the packaging material comprising the gas barrier film of the present invention can be stored for a long time.

[0035]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, but may be appropriately modified within the scope of the present invention. Of course, it is also possible to implement them, and all of them are included in the technical scope of the present invention. Also,
The evaluation method adopted in this specification was based on the following method.

(1) Cutability As shown in FIG. 1, a film 1 having a heat-sealing resin layer is heat-sealed with the heat-sealing resin layers facing each other. Notch 2 was inserted, and a sample for evaluating cutability was prepared. Cloth method: The film 1 including the fused portion 3 was cut by gripping both ends of the cutout portion 2 of the sample and pulling each other in a direction perpendicular to the film surface. Tearing method: The sample was torn in a Y-shape horizontally to the film surface and centered on the notch 2 of the sample.

(2) Laminate strength The laminate was peeled at 90 ° using a tensile tester (manufactured by Toyo Sokki Co., Ltd./trade name: Tensilon UTM2), and the SS curve between the oxide thin film and the heat sealable resin layer was obtained. Was measured and determined.

Example 1 Biaxially stretched nylon 6 film (manufactured by Toyobo Co., Ltd./trade name: N4142 (thickness: 15 μm)
m)) using a film obtained by depositing a binary oxide thin film of silicon oxide and aluminum oxide on one surface, using an extrusion laminator (manufactured by Modern Machinery Co., Ltd.) to achieve a speed of 80%.
Polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd./P1000 diluted with methanol and water and adjusted to a solid content of 3%) as an anchor agent was applied with a bow roll at a rate of mm / min, and the dry coat amount was 0.03 g. / Min. A heat-sealing resin (low-density polyethylene (manufactured by Sumitomo Chemical Co., Ltd./trade name: Sumikasen L705)) is extruded on the polyethylene imine layer at a resin temperature of 315 ° C. in the extruded portion, and the thickness of the heat-sealing resin layer is reduced to 15 μm. did. The gap with the chill roll at that time was 15 mm. Further, the low-density polyethylene layer was extruded and a sealant film (40 μm) (linear low-density polyethylene (manufactured by Toyobo Co., Ltd./L4202)) was laminated on the surface, and extrusion lamination of a three-layer structure was performed. The aging of the film wound after lamination was set longer than usual and the aging temperature was set high (condition: 50 ° C. × 4 days).

The resulting gas-barrier film comprising the laminated laminate was heat-sealed with the heat-sealing resin layers facing each other (sealing conditions: 160 ° C. × 2 kg ×
2 seconds) to produce a bag. When the cut property was evaluated,
Both the cloth method and the tearing method were easy to tear and were good. The laminate strength is 850g
/ 15 mm or more (sealant elongation state), and the cut property was also very good.

Comparative Example 1 In Example 1, an isocyanate-based adhesive (manufactured by Toyo Morton Co., Ltd./trade name: EL530 [A /
B]) Except for 0.2 g / m ² , the same processing was performed to obtain a laminate. The lamination strength of the obtained gas barrier film was as low as 200 g / 15 mm, the cut property was strong, and the cut was not easily cut.

(Comparative Example 2) In Example 1, 0.2 g of an isocyanate-based adhesive (trade name: EL510, manufactured by Toyo Morton Co., Ltd.) was used in place of polyethyleneimine as the anchor agent.
/ M ² to obtain a laminate. The laminate strength of the obtained gas barrier film was sufficiently high at 800 g / 15 mm, but the cut property was poor.

Example 2 A 5 cm × 5 cm bag was manufactured using the laminated laminate prepared in Example 1, Western confectionery was filled, and the opening was heat-sealed to seal the confectionery.
These were allowed to stand in a room at 25 ° C. × 65% for 6 months. After the standing, a taste test was carried out, but no change was observed in color, taste, and texture.

Example 3 Biaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd./trade name: E5100)
(Thickness: 12 μm)) using a film obtained by depositing a binary oxide thin film of silicon oxide and aluminum oxide on an extruding laminator (manufactured by Modern Machinery Corporation).
A three-layered packaging material was obtained in the same manner as in Example 1 except that an anchoring agent (polyethylene (trade name: AD372MW, manufactured by Toyo Morton Co., Ltd.)) was used at m / min. The laminate strength of the obtained gas barrier film is 700.
g / 15 mm, and the cut property was also good.

Example 4 A biaxially stretched nylon 6 film (manufactured by Toyobo Co., Ltd./trade name: N5342) was subjected to extrusion lamination (manufactured by Modern Machinery) using a film in which a silicon oxide thin film was deposited on one surface. , Speed 50m
At / min, extrusion lamination was performed using polyethylene (made by Dainichi Seika Co., Ltd./trade name: Seikadyne 4100) as an anchoring agent. At this time, the extruded resin temperature was set at 31.
The temperature was 0 ° C., the thickness of the heat-sealing resin layer was only 25 μm, and a two-layer structure was formed.

The heat-sealing resin layer of the obtained gas-barrier film comprising the laminated laminate was heat-sealed (sealing conditions: 140 ° C. × 1 kg × 2 seconds).
Then, sachets were manufactured. When the cut property was evaluated, both the cloth method and the tearing method were good.

(Comparative Example 3) In Example 4, an isocyanate-based adhesive (manufactured by Dainichi Seika Co., Ltd./trade name:
A bag was manufactured in the same manner except that Seikadyne 2710A / B) was used. When the cut property was evaluated, it was inferior.

[0047]

According to the gas barrier film and the package of the present invention, the heat-sealing resin layer is firmly adhered to the inorganic oxide thin film layer, retains a high degree of gas barrier properties, and peels off during use. It is possible to cut smoothly by providing a notch at the end and pulling by hand.

[Brief description of the drawings]

FIG. 1 is a view showing a main part of a gas barrier film of the present invention in which a notch is formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas barrier film 2 Notch 3 Heat seal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 65/40 B65D 65/40 D C08J 7/04 CFG C08J 7/04 CFGP // C08L 77:00 101: 00 (72) Inventor Seiji Iseki 2-1-1 Katata, Otsu-shi, Shiga F-term in Toyobo Co., Ltd. Research Laboratory (reference) 3E064 BA25 BA36 BA60 BB03 BC01 BC08 BC18 HP01 HP05 3E086 AD01 BA04 BA15 BA24 BA40 BB01 BB22 BB41 BB51 BB90 CA03 CA27 CA28 CA31 4F006 AA12 AA16 AA17 AA19 AA38 AA39 AB74 AB76 BA05 CA07 DA01 4F100 AA17B AA19B AA20B AK01A AK01D AK06 AK31C AK46A AK48 AK63 BA04 BA07 GB12 E17 GB10 E13 GB12 E13 GB12

Claims (4)

[Claims] 1. An inorganic oxide thin film layer is formed on the surface of a plastic film, a polyethylene imine layer is formed on the surface of the inorganic oxide thin film layer, and the surface of the polyethylene imine layer is directly heat-sealed by melt extrusion lamination. A gas barrier film comprising a resin layer formed thereon. 2. The gas barrier film according to claim 1, wherein the inorganic oxide thin film is a multi-component inorganic oxide thin film containing at least silicon oxide and aluminum oxide. 3. The gas barrier film according to claim 1, wherein the plastic film is a polyamide film. 4. A package comprising the gas barrier film according to claim 1, 2 or 3.