JP3352943B2 - Barrier film and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composite film useful for producing a barrier film and a method for producing the same, and a barrier film and a method for producing the same.

[0002]

2. Description of the Related Art Polypropylene films have many desirable properties including excellent optical properties such as transparency and gloss, tensile properties, mechanical properties such as Young's modulus, and substantially non-toxicity and odorlessness. Has characteristics. For this reason, the polypropylene film is widely used as a packaging material for foods, pharmaceuticals, agricultural chemicals, cosmetics, and the like.
In recent years, in order to impart a barrier property against oxygen gas and water vapor to a polypropylene film, the surface of the polypropylene film is coated with a vinylidene chloride copolymer or the like, or a thin film layer such as silicon oxide or aluminum oxide is formed. Barrier films have been proposed. However, these films cannot be said to have sufficient barrier properties to maintain the quality and freshness of foods and the like for a long period of time, and are often insufficient in terms of transparency.

Japanese Patent Application Laid-Open No. 8-142250 discloses a gas barrier film in which a thin film layer of aluminum oxide having a specific thickness and refractive index is formed on the surface of a plastic film such as a polypropylene film. However, in order to adjust the refractive index to a specific range, when forming a thin film of aluminum oxide, it is necessary to delicately control the temperature of the plastic film substrate and the flow rate of oxygen gas. Is disadvantageous.

When a barrier layer is formed on a polypropylene film, an adhesive is used or a corona discharge treatment or a charged plasma treatment is applied to the film surface in order to improve adhesion. However, even if such a method is adopted, the adhesion between the polypropylene film and the barrier layer is often not sufficient. In addition, a method of applying a resin modified with maleic anhydride or the like to the surface is also known, but it is not only disadvantageous in terms of cost but also may deteriorate excellent properties of the polypropylene-based film.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a barrier film having the following features:
An object of the present invention is to provide a composite film capable of providing high barrier properties and transparency and a method for producing the same. Another object of the present invention is to
An object of the present invention is to provide a barrier film having high barrier properties and transparency using a polypropylene-based film as a base material and a method for producing the same. It is still another object of the present invention to provide a barrier film having improved adhesion between a base film layer and a barrier layer while maintaining excellent properties of a polypropylene-based film, and a method for producing the barrier film.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have made a polypropylene-based film having high rigidity as a base material, and have formed a base film layer and a barrier layer. When a polypropylene-based copolymer layer is provided between them, it has been found that, while maintaining high transparency, the oxygen barrier property can be remarkably improved, and the adhesion between the base film layer and the barrier layer can be greatly improved.
The present invention has been completed.

That is, according to the present invention, at least one surface of a base film layer (A) composed of a polypropylene film having a polypropylene resin having an isotactic index of 95% or more is composed of a polypropylene copolymer. A composite film (except for a sheet for thermoforming) on which a coated layer (B) is formed, wherein the polypropylene-based film has a 1% elongation of a film test piece in a plastic tensile test method in accordance with JIS K 7127. Load F1 is 1.9 to 5 kgf / m
m ² , the thickness Tb of the base film layer (A) is 5 to 100 μm, the thickness Tc of the coating layer (B) is 0.5 to 5 μm, and the thickness of the base film layer (A). Provided is a composite film having a ratio Tb / Tc of Tb to the thickness Tc of the coating layer (B) of 4 or more [hereinafter sometimes referred to as a composite film (1)]. According to the present invention, a coating layer (B) composed of a polypropylene-based copolymer is formed on at least one surface of a polypropylene-based substrate film layer (A1) made of a polypropylene-based resin having an isotactic index of 95% or more. Composite film (except for thermoforming sheets), wherein the composite film is JI
In the plastic tensile test method based on SK7127, the load F1 when the film test piece was extended by 1%
Is in the range of 1.9 to 5 kgf / mm ² , and the thickness Tb of the base film layer (A1) is 5 to 10
0 μm, a composite film having a thickness Tc of the coating layer (B) of 0.5 to 5 μm and a ratio Tb / Tc of the thickness Tb of the base film layer (A1) to the thickness Tc of the coating layer (B) of 4 or more [ Hereinafter, it may be referred to as a composite film (2)].

The present invention further provides a base film layer (A) comprising a polypropylene film having a polypropylene resin having an isotactic index of 95% or more, wherein at least one surface of the substrate film layer (A) comprises a polypropylene copolymer. Film (except for thermoforming sheets) on which a coated coating layer (B) is formed, wherein the polypropylene-based film is a plastic tensile test method according to JIS K 7127, and the film test piece is 1%. Load F1 when extended is 1.9 to 5 kgf / m
a film comprising a range of m ^2, and polypropylene thickness Tb of the base film layer (A) is to 5 to 100 [mu] m, the thickness Tc of the coating layer (B) constitutes 0.5 to 5 [mu] m, the coating layer (B) Provided is a composite film (hereinafter sometimes referred to as a composite film (3)) having a copolymer having an MFR of 5 to 15 g / 10 minutes. According to the present invention, a coating layer (B) composed of a polypropylene-based copolymer is formed on at least one surface of a polypropylene-based substrate film layer (A1) made of a polypropylene-based resin having an isotactic index of 95% or more. Composite film (excluding thermoforming sheets), wherein the composite film is JIS
In the plastic tensile test method based on K7127, the film is a film in which the load F1 when the film test piece extends 1% is in the range of 1.9 to 5 kgf / mm ² , and the thickness of the base film layer (A1). Tb is 5 to 10
0 μm, thickness Tc of the coating layer (B) is 0.5 to 5 μm, and MF of the polypropylene copolymer constituting the coating layer (B)
Provided is a composite film (hereinafter, sometimes referred to as a composite film (4)) in which R is 5 to 15 g / 10 minutes.

Further, according to the present invention, in a plastic tensile test method made of a polypropylene resin having an isotactic index of 95% or more and conforming to JIS K 7127, a load F1 when a film test piece extends 1% is measured. The thickness Tb composed of a polypropylene-based film in the range of 1.9 to 5 kgf / mm ² is 5 to 100 μm
m, a coating layer (B) composed of a polypropylene copolymer on at least one surface of the base film layer (A).
Formed such that the thickness Tc of the coating layer (B) is 0.5 to 5 μm, and the ratio Tb / Tc of the thickness Tb of the base film layer (A) to the thickness Tc of the coating layer (B) is 4 or more. The present invention provides a method for producing a composite film (excluding thermoforming sheets). The present invention also relates to a polypropylene resin having an isotactic index of 95% or more and JIS K71.
In the plastic tensile test method according to No. 27, the load F1 when the film test piece was extended by 1% was 1.9 to 5
The MFR is 5 to 15 g on at least one surface of the base film layer (A) having a thickness Tb of 5 to 100 μm made of a polypropylene-based film having a range of kgf / mm ^2.
The present invention provides a method for producing a composite film (excluding a thermoforming sheet) for forming a coating layer (B) having a thickness Tc of 0.5 to 5 μm, which is composed of a polypropylene copolymer having a thickness of / 10 min.

Further, the present invention is characterized in that the composite film (1), (2), (3) or (4) has a barrier component other than a polypropylene resin on the surface on the coating layer (B) side. A barrier film (hereinafter, may be referred to as a barrier film (1)) on which a barrier layer (C) is formed.

According to the present invention, at least one surface of the polypropylene base film layer (A1) made of a polypropylene resin having an isotactic index of 95% or more is composed of a barrier component other than the polypropylene resin. Barrier film having a barrier layer (C) formed thereon, wherein a load F1 when the film test piece extends 1% is 1.9 to 5 kgf / mm in a plastic tensile test method based on JIS K 7127. ^2. A barrier film having a range of ² [hereinafter, may be referred to as a barrier film (2)] is provided.

The barrier film has an oxygen gas permeability of 1 to 35 cc / m ² · 24 hr and a wavelength of 550 n.
The light transmittance at m may be 70 to 95%.

According to the present invention, the composite film (1), (2), (3) or (4) has a barrier component other than a polypropylene resin on the surface on the coating layer (B) side. And a method for producing a barrier film for forming a barrier layer (C).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The composite film (1) of the present invention,
In (2), (3) and (4), at least one surface of the polypropylene base film layer (A) or (A1)
Coating layer (B) composed of polypropylene copolymer
Is formed.

[Polypropylene Base Film Layer] The polypropylene base film layer (A) in the composite films (1) and (3) has a film test piece content of 1% in a plastic tensile test method according to JIS K7127. Load F1 when extended is 1.9 to 5 kgf / mm
It is composed of a polypropylene film in the range of ² . The above test is more particularly 100 mm long
A rectangular test piece having a width of 15 mm (as the length between the chucks) and a width of 15 mm was prepared, and when the test piece was pulled at a speed of 300 mm / min in accordance with JIS K 7127 (plastic tensile test method), the test was performed. This is performed by determining the load F1 when the piece has grown by 1%. In the case of a test piece having an MD direction and a TD direction (for example, a test piece obtained by extrusion or the like), the value of F1 when pulled in the MD direction is obtained. The test piece can be prepared by subjecting the film to machining such as punching or cutting.

The F1 is preferably 2.0 to 3.5 k
gf / mm ² , more preferably 2.1-3.0 k
gf / mm ² . The value of F1 is 1.9 kgf / m
If it is less than m ² , high oxygen barrier properties cannot be obtained when a barrier layer is provided on the surface to form a barrier film. Also,
If the value of F1 exceeds 5 kgf / mm ² , the texture of the film is greatly reduced.

The polypropylene resin constituting the base film layer (A) is a homopolymer of propylene and other copolymerizable monomers, for example, ethylene, 1-butene, 3-methylpentene, 4-methyl Any of copolymers with pentene or the like may be used. In the case of a copolymer, the content of monomers other than propylene is preferably 1% or less, preferably less than 0.5%, more preferably less than 0.5%, so as not to impair the optical properties, mechanical properties and packaging properties. Is less than 0.3%.

The polypropylene resin has an isotactic index of usually 90% or more (90 to 100%), preferably 94% or more (94 to 100%), and more preferably 95% or more (95 to 100%). ). The isotactic index can be controlled by polymerization conditions such as a polymerization catalyst. The melting point of the polypropylene resin is usually 150 ° C. or higher (about 150 to 173 ° C.),
It is preferably 160 ° C. or higher (about 160 to 173 ° C.), and the MFR (melt flow rate) is usually 0.5 to 2
0 g / 10 minutes, preferably about 1 to 15 g / 10 minutes, and more preferably about 2 to 10 g / 10 minutes.

The crystallinity of the polypropylene resin in the base film layer (A) is, for example, about 45 to 65%, preferably about 50 to 62%, and more preferably about 52 to 60%. If the crystallinity is too small, it is difficult to obtain high rigidity, and the barrier properties of the resulting barrier film tend to decrease. The degree of crystallinity can be adjusted not only by polymerization conditions such as a polymerization catalyst, but also by film forming conditions (eg, cooling conditions, stretching ratio, etc.), addition of a crystal nucleating agent, and the like. In addition, in this specification, the crystallinity means a value obtained from the heat of fusion in differential thermal analysis.

The base film layer (A) may contain, in addition to the polypropylene resin, various conventional additives such as an ultraviolet absorber and an antistatic as long as the transparency and the adhesion to the barrier layer are not impaired. Agent, crystal nucleus growth agent, styrene resin, terpene resin, petroleum resin, dicyclopentadiene resin,
It may contain a hydrocarbon-based polymer such as a coumarone resin such as a coumaloninden resin, a phenol resin, rosin and a derivative thereof, or a hydrogenated resin thereof, a plasticizer, a filler, an antiblocking agent, an antioxidant, and the like.

Examples of the crystal nucleus growth agent include sorbitol-based crystal nucleus growth agents [eg, dibenzylidene sorbitol, bis (p-methylbenzylidene) sorbitol,
Bis (p-ethylbenzylidene) sorbitol, bis (chlorobenzylidene) sorbitol and the like], a phosphoric acid-based crystal nucleus growth agent [for example, sodium 2,2′-methylenebis (4,6-di-t-butylphenyl) phosphate, Bis (4-t-butylphenyl) sodium phosphate, etc.],
Benzoic acid-based crystal nucleus growth agent [for example, hydroxy-di (t
-Butylbenzoic acid) aluminum and the like]. Further, Ngester NU-100 [trade name, manufactured by Shin Nippon Rika Co., Ltd.], which is commercially available as a crystal nucleus growth agent, can also be suitably used. When a crystal nucleus growth agent is used, fine and uniform crystals are formed, so that the transparency of the film is improved and the rigidity is also increased. Further, since the crystallization temperature increases, the molding cycle can be shortened. The content of the crystal nucleus growth agent can be selected within a range that does not impair the adhesiveness, and is, for example, 0 to 3 parts by weight, preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the polypropylene resin.
0.5 parts by weight, more preferably about 0.01 to 0.2 parts by weight.

Examples of the antiblocking agent include fine powder antiblocking agents such as silica, alumina, synthetic zeolite, kaolin, talc, zinc oxide, magnesium oxide, zirconium oxide, titanium oxide, aluminum hydroxide, quartz powder, calcium carbonate, Inorganic fine powders such as magnesium carbonate and barium sulfate; polyester, nylon,
Thermoplastic resins such as polycarbonate, polyether sulfone, polyether imide, polyphenylene sulfide, polyether ether ketone, polyamide imide; crosslinked acrylic resin, crosslinked melamine resin, benzoguanamine resin, urea resin, amino resin, furan resin, epoxy resin, phenol Examples thereof include resins, unsaturated polyesters, vinyl ester resins, diallyl phthalate resins, and thermosetting resins such as polyimides. The fine powder blocking inhibitor preferably has a higher melting point or softening point than the temperature at the time of film formation in order to maintain the shape during film formation. These fine powders are used alone or in combination of two or more.

The fine powder anti-blocking agent may be spherical or amorphous. When a spherical anti-blocking agent is used, high blocking resistance can be imparted without lowering the transparency. The average particle size of the antiblocking agent can be selected within a range that does not impair the blocking resistance, the slipping property, and the transparency. For example, 0.1 to 7.5 μm.
m, preferably 0.5 to 5 μm, more preferably 1 to 4
It is about μm.

The content of the antiblocking agent is 0.01 to 0.5 with respect to 100 parts by weight of the polypropylene resin.
Parts by weight, preferably about 0.02 to 0.4 parts by weight, more preferably about 0.03 to 0.3 parts by weight. When the content of the antiblocking agent is 0.01 part by weight or less, the film tends to be blocked at the time of winding, and when it exceeds 0.5 part by weight, transparency may be reduced.

As the antioxidant, a conventional antioxidant,
For example, phenol-based, phosphorus-based, sulfur-based antioxidants and the like can be mentioned. Phenolic antioxidants include, for example,
2,6-di-t-butyl-p-cresol (BHT),
Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (Irganox 1010, manufactured by Ciba-Geigy Japan)
Are preferred. Antioxidants can be used alone or in combination of two or more.

The content of the antioxidant is, for example, 0 to 0.4 parts by weight with respect to 100 parts by weight of the polypropylene resin.
Preferably it is about 0.005 to 0.3 parts by weight. If the amount of the antioxidant is too large, the adhesion to the barrier layer tends to decrease.

The F1 value of the polypropylene film constituting the base film layer (A) can be easily adjusted by controlling the isotactic index of the polypropylene resin, the type and amount of the crystal nucleus growth agent, and the stretching ratio. it can. In particular, when a crystal nucleus growth agent such as Ngester NU-100 (trade name, manufactured by Shin Nippon Rika Co., Ltd.) is added, the crystal form of the polypropylene resin constituting the film is greatly changed, and high rigidity is easily achieved. Obtainable. More specifically, when the crystal nucleus growth agent is added,
Among the polycrystalline forms of the polypropylene-based resin, β-type crystals (β crystals) are preferentially expressed, and the rigidity of the film is greatly improved.

Preferred polypropylene films include:
β content is 10% or more (10 to 100%), preferably 20% or more (20 to 100%), more preferably 4% or more.
0% or more (40 to 100%) film is included. The β crystal can be confirmed by the presence of the (300) plane in the X-ray diffraction pattern. The β crystal can be quantified by measuring the area ratio of the melting endothermic peak in differential scanning calorimetry (DSC). The melting endothermic peak of the β crystal appears at around 154 ° C. under the condition of a heating rate of 20 ° C./min. The amount of β crystals can also be determined from the intensity ratio of a specific peak of X-rays.

The polypropylene film constituting the substrate film layer (A) has excellent transparency. For example, the light transmittance (transmittance at a wavelength of 550 nm) is 8
About 8 to 95%, and the F1 value is 1.8 kgf / mm ²
About 2% or more higher than conventional polypropylene-based films.

The base film layer (A) is prepared by subjecting a resin composition containing a polypropylene resin and, if necessary, the above-mentioned additives to a conventional molding method, for example, extrusion molding, blow molding, injection molding or the like. Can be manufactured. The film constituting the base film layer (A) may be unstretched, but is preferably uniaxially or biaxially stretched, particularly preferably biaxially stretched. Further, the stretched film may be heat-treated as necessary. The stretching ratio can be appropriately set according to the desired film properties, and at least one of the stretching ratios is 2 times or more (for example, 2 to 20 times), preferably 3 to 20 times.
It is about 15 times, more preferably about 5 to 10 times. In particular, the stretching ratio in the MD direction is 4 to 10 times, preferably 4.5 to 8 times, and more preferably 5 to 6 times.
The stretching ratio in the direction is 2 to 20 times, preferably 4 to 15 times.
And more preferably about 8 to 11 times.

The base film layer (A) may be a single layer or a multilayer in which two or more polypropylene resin layers are laminated. The thickness Tb of the base film layer (A) is 5 to 100 μm.

One of the main features of the composite films (2) and (4) is that the composite film itself is JIS K7.
When applied to the plastic tensile test method according to C.127, the load F1 when the film test piece elongates by 1% is 1.
It is in the range of 9 to 5 kgf / mm ² . F1
Is preferably about 2.0 to 3.5 kgf / mm ² , more preferably about 2.1 to 3.0 kgf / mm ² . When the value of F1 is less than 1.9 kgf / mm ² , high oxygen barrier properties cannot be obtained. Also, the value of F1 is 5 kgf /
If it exceeds mm ² , the texture of the film is greatly reduced. Since the F1 value of the composite films (2) and (4) substantially matches the F1 value of the film constituting the base film layer (A1), the base film layer (A1) in the composite films (2) and (4) is used. )), The composite film (1),
The above-mentioned F1 value can be easily achieved by using the same material as the base film layer (A) in (3).

[Coating Layer (B)] The coating layer (B) in the composite films (1), (2), (3) and (4) is made of a polypropylene copolymer. As the comonomer constituting the polypropylene copolymer, ethylene, 1-butene, 2-butene,
-Pentene, 1-hexene, 3-methylpentene, 4-
Alkenes having about 2 to 6 carbon atoms, such as methylpentene, are exemplified. Preferred polypropylene copolymers include propylene as a monomer component, for example, 80% by weight.
Copolymer containing at least about 80 to 99.9% by weight, preferably at least 84% by weight (about 84 to 99.9% by weight), and more preferably at least 92% by weight (about 9 to 99.7% by weight). It is.

More preferred polypropylene copolymers include propylene as a monomer component in an amount of 84-99.
9% by weight (preferably 92 to 99.7% by weight, more preferably 94 to 99% by weight), and at least one component selected from ethylene and butene (particularly, ethylene) is 0.1 to 16% by weight ( Preferably, the copolymer comprises 0.3 to 8% by weight, more preferably 1 to 6% by weight. If the content of the component selected from ethylene and butene is too small, the adhesion to the barrier layer is not significantly improved, probably because the amorphous region on the film surface is small. Conversely, copolymers having too high a content of components selected from ethylene and butene tend to be difficult to produce.

For the same reason as described above, there is an optimum range for the crystallinity of the copolymer constituting the coating layer (B), and the crystallinity determined from the heat of fusion in the differential thermal analysis is 10 to 55. %, More preferably 20%
５０50%. In general, the temperature rise rate in the differential thermal analysis is measured at 10 ° C./min.

Further, the M of the resin constituting the coating layer (B)
FR (melt flow rate) is based on the base film layer (A)
It is better to be higher than the polypropylene resin that constitutes
Usually 1 to 25 g / 10 min, preferably 2 to 20 g / 1
0 minutes, more preferably 5 to 15 g / 10 minutes. When a polymer having an MI lower than that of the polypropylene resin constituting the base film layer (A) is used, melt fracture is likely to occur.

The coating layer (B) may also contain an antioxidant and a blocking agent. The type and amount of the antioxidant are the same as in the case of the base film layer (A).
In the coating layer (B), the amount of the antiblocking agent to be added is desirably as small as possible so as not to generate a defective portion such as a pinhole in the barrier layer. The content of the antiblocking agent in the coating layer (B) is 0 to 0.2 parts by weight, based on 100 parts by weight of the copolymer constituting the coating layer (B).
Preferably 0 to 0.15 parts by weight, more preferably 0 to 0.15 parts by weight
0.1 parts by weight, especially 0-0.05 parts by weight, especially 0-
It is about 0.02 parts by weight.

It is preferable that the coating layer (B) does not contain other additives. However, as long as the adhesion to the barrier layer is not impaired, an ultraviolet absorber, an antistatic agent, and the like may be used, if necessary. Agents, plasticizers, waxes and the like.

The thickness Tc of the coating layer (B) is 0.5 to 5 μm
It is. Thickness Tb of base film layer (A) or (A1)
The ratio Tb / Tc of the coating layer (B) to the thickness Tc of the coating layer (B) is preferably 4 or more, preferably 5 to 50, more preferably 10 to 10.
It is about 30. When the ratio Tb / Tc is less than 4, when the dust generated during the production of the film is reused, the viscosity of the molten resin greatly decreases, and it becomes difficult to stably form the film. When Tc is less than 0.1 μm, it is difficult to obtain a composite film having a uniform thickness.

Composite films (1), (2) comprising a base film layer (A) or (A1) and a coating layer (B),
(3) or (4) may be unstretched, but is preferably stretched. The stretched film may be uniaxially stretched, but is preferably biaxially stretched. Further, the stretched film may be heat-treated as necessary.

The surface of the coating layer (B) is subjected to a surface treatment, for example, at least 36 dyne / cm, preferably 37 dyne / cm.
~ 45dyne / cm, more preferably 38 ~ 42d
A surface tension of about yne / cm may be developed. When the surface tension is less than 36 dyne / cm, the adhesion to the barrier layer tends to decrease.

[Production of Composite Film] In the method for producing a composite film of the present invention, the coating layer (B) is formed on at least one surface of the polypropylene base film layer (A). More specifically, the composite film can be manufactured by a dry lamination method, a coextrusion molding method, a coating method, or the like.

In the dry laminating method, for example, the resin composition (i) constituting the polypropylene base film layer (A) and the resin composition (ii) constituting the coating layer (B) are each subjected to extrusion molding or the like. A film can be produced by the molding method described above, and then the two films can be laminated together by using, for example, an anchor coat agent (or adhesive) such as a titanium-based, polyethyleneimine-based, or urethane-based film.

In the coextrusion molding method, the resin composition (i) constituting the polypropylene base film layer (A) and the resin composition (ii) constituting the coating layer (B) are subjected to coextrusion molding. Thereby, a composite film can be manufactured. Preferably, the extruded composite film is subjected to a stretching step.

For co-extrusion molding, an extruder equipped with a T die, a ring die and the like can be used. In such an extruder, the resin composition (i) and the resin composition (ii) are separately charged and melt-extruded into a die by an extruder, so that the resin composition is formed in a flow path in the die. (I) and the resin composition (ii) merge to form a composite. And
By cooling the multilayer film melt extruded from the die, a composite film is obtained. The coating layer (B) can be compounded on one side or both sides of the polypropylene base film layer (A).

The stretching of the composite film can be performed after cooling the composite film extruded from the die in the T-die method, and can be performed together with the melt extrusion from the die in the inflation method. As the stretching method, a conventional stretching method, for example, roll stretching, tenter stretching,
Examples include tube stretching and a stretching method combining these. The stretching ratio is the same as described above.

In the coating method, for example, a resin film constituting the polypropylene base film layer (A) is supplied to an extruder or the like to prepare a base film, and the surface of the base film is coated with the coating. A composite film can be obtained by coating a coating solution containing the resin composition constituting the layer (B) and drying the coating solution. As a coating method, a conventional method can be used. Prior to the coating, a titanium-based, polyethyleneimine-based, urethane-based anchor coating agent may be applied to the surface of the base film.

In the composite film of the present invention, the surface treatment of the coating layer (B) may be a conventional surface treatment, for example,
Corona discharge treatment, flame treatment, plasma treatment, ozone or ultraviolet irradiation treatment, electron beam irradiation treatment, or the like can be employed. Preferable surface treatment includes corona discharge treatment. The surface treatment may be performed prior to the stretching treatment of the film, but usually is often performed after the stretching treatment.

The composite film thus obtained is
It has high transparency and, when a barrier layer is formed on the surface, exhibits high adhesion to the barrier layer and does not impair the barrier function of the barrier layer. for that reason,
It can be suitably used as a component of a barrier film.

[Barrier Film] The barrier film (1) of the present invention comprises a polypropylene-based film on the surface of the composite film (1), (2), (3) or (4) on the side of the coating layer (B). A barrier layer (C) composed of a barrier component other than the resin is formed.

The barrier component constituting the barrier layer (C) includes (a) an inorganic compound and (b) a barrier polymer.

The inorganic compound (a) includes, for example, oxides of elements of Group 1 of the periodic table such as lithium oxide, sodium oxide and potassium oxide; magnesium oxide, calcium oxide,
Periodic group 2 element oxide such as strontium oxide and barium oxide; Periodic group 3 element oxide such as yttrium oxide and cerium oxide; Periodic group 4 element oxide such as titanium oxide and zirconium oxide; period such as vanadium oxide Group 5 element oxides such as chromium oxide; Group 7 element oxides such as manganese oxide; Periodic table 8 element oxides such as iron oxide; Periodic table 9 such as cobalt oxide Group 10 element oxides such as nickel oxide; Periodic table 11 element oxides such as copper oxide; Group 12 element oxides such as zinc oxide; boron oxide, aluminum oxide, indium oxide and the like Periodic Table 13 Group oxides of silicon; tin oxide, lead oxide, etc.
Group 4 element oxides; and composite oxides thereof; sulfides, halides, carbides, nitrides, and the like corresponding to the oxides. Among them, magnesium oxide, yttrium oxide, titanium oxide, zinc oxide, aluminum oxide, indium oxide, silicon oxide, tin oxide and the like are excellent in transparency and barrier properties. In a barrier film used as a packaging material for electromagnetic wave heating, as the inorganic compound (a), a non-conductive material such as an inorganic compound having low conductivity, an oxide (eg, silicon oxide), a halide, a carbide, and a nitride is used. Inorganic compounds can be used. The inorganic compound (a) can be used alone or in combination of two or more. Particularly preferred inorganic compounds (a) include inorganic oxides,
For example, silicon oxide and aluminum oxide are included.

Silicon oxide can form a dense thin film in addition to the above characteristics, and can maintain a high barrier property even at a high temperature for a long time. Silicon oxide includes not only silicon monoxide and silicon dioxide, but also a composition formula SiO _x (where 0 <x
.Ltoreq.2, preferably 0.8.ltoreq.x.ltoreq.1.7).

On the other hand, aluminum oxide has the advantage that the film is less colored than silicon oxide, the film thickness can be reduced, and the flexibility of the film can be improved.
In addition to Al ₂ O ₃ , the aluminum oxide has an atomic ratio of aluminum to oxygen of Al: O = 2: 2 to 3, preferably Al: O = 2: 2.3 to 2.9, and more preferably A: O.
l: O = 2: about 2.5 to 2.85 aluminum oxide (Al, Al ₂ O ₃ , Al ₂ O ₃ hydrate, Al (OH) ₃
Etc.).

The barrier layer composed of the inorganic compound (a) is formed by a conventional method, for example, a physical method (vacuum vapor deposition, reactive vapor deposition, sputtering, reactive sputtering, ion plating, A thin film layer of the inorganic compound (a) on the surface of the coating layer (B) of the composite film by a reactive ion plating method or a chemical method (CVD method, plasma CVD method, laser CVD method, etc.). It can be performed by forming. The inorganic compound thin film layer is often formed by a physical method such as vapor deposition.

The formation of a thin film by a vacuum deposition method or the like is performed by feeding the composite film wound up in a roll shape while removing the composite film.
While passing through a roll-to-roll vacuum evaporator reduced to about 0 ^-3 to 10 ^-6 Torr, an electron beam, high-frequency induction heating,
An inorganic substance (eg, aluminum metal, silicon oxide, etc.) is heated and evaporated by a low resistance heating method or the like. If necessary, the reactive vapor deposition can be performed in an oxidizing atmosphere or an atmosphere of a reactive gas such as nitrogen, methane, or hydrogen sulfide. Oxygen or the like is used as the reactive gas forming the oxidizing atmosphere. Oxygen may be diluted with water vapor or an inert gas before use. Further, an oxidizing gas such as ozone can be mixed with oxygen and used.

The thickness of the barrier layer composed of the inorganic compound (a) is, for example, 10 to 5000 Å, preferably 50 to 1000 Å, and more preferably 80 to 900 Å (particularly 100 to 900 Å).
800 angstrom).

In order to further improve the adhesion, prior to the formation of the inorganic compound (a) thin film layer, a titanium-based, polyethyleneimine-based, urethane-based An anchor coating agent of a system, polyester, acrylic, etc. may be applied beforehand. Preferred anchor coating agents include urethane-based and polyester-based anchor coating agents. The thickness of the anchor coat layer is, for example, 0.01 to 5 μm, preferably 0.0 to 5 μm.
It is about 5 to 2.5 μm.

Examples of the barrier polymer (b) include a vinylidene chloride polymer, an ethylene-vinyl alcohol polymer, a vinyl alcohol polymer, a polyamide polymer, a polyacrylonitrile polymer,
Examples thereof include gas barrier resins such as urethane polymers, and among them, vinylidene chloride polymers and ethylene-vinyl alcohol polymers are preferable.

The vinylidene chloride-based polymer is a copolymer of vinylidene chloride and another polymerizable monomer. Examples of the polymerizable monomer include vinyl chloride, vinyl acetate, crotonic acid, acrylic acid, methacrylic acid and methyl acrylate. , Ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate,
Acrylic esters such as isobutyl acrylate and t-butyl acrylate, and methacrylic esters corresponding thereto; acrylonitrile, methacrylonitrile, and the like. Among these vinylidene chloride-based copolymers, vinylidene chloride-acrylonitrile copolymer, vinylidene chloride-methacrylic acid copolymer, vinylidene chloride-acrylic ester copolymer, vinylidene chloride-methacrylic ester copolymer, vinylidene chloride -Vinyl acetate copolymers and the like are particularly preferred. The vinylidene chloride content in the vinylidene chloride-based copolymer is usually 85 to 99% by weight, preferably about 90 to 97% by weight.

As the ethylene-vinyl alcohol polymer, a solvent-soluble polymer is preferred. The ethylene content of the ethylene-vinyl alcohol-based polymer is usually 5 to
It is about 50 mol%, preferably about 10 to 45 mol%, more preferably about 25 to 35 mol%. The molecular weight is usually 10,000 to 100,000, preferably about 40,000 to 50,000, and the degree of saponification is desirably 99.5% or more.

The barrier layer composed of the barrier polymer (b) is formed by a conventional method, for example, a coating method,
This is performed by forming a layer of the barrier polymer (b) on the surface of the coating layer (B) of the composite film by a dry laminating method or the like. Preferred methods include coating methods. This barrier layer may be composed of a plurality of layers, depending on the desired gas barrier properties, or one layer may contain various types of resins.

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. The solvent for preparing the coating liquid can be appropriately selected according to the type of the polymer. For example, when a vinylidene chloride copolymer is used as the barrier polymer (b), ketones such as acetone, methyl ethyl ketone, and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, and xylene; tetrahydrofuran; Ethers such as dioxane and diethyl ether; ethyl acetate;
Esters such as butyl acetate; aprotic polar solvents such as N, N-dimethylformamide; and mixtures thereof. When a solvent-soluble ethylene-vinyl alcohol polymer is used, water; water and methanol, ethanol, propanol, isopropanol,
A mixed solvent with an alcohol such as cyclohexanol is used. The coating liquid may be a solution or an emulsion. After coating the coating liquid on the polypropylene film, for example,
By drying at a temperature of about 0 to 150 ° C., a barrier layer can be formed.

The thickness of the barrier layer composed of the barrier polymer (b) is, for example, 0.05 to 15 μm, preferably 0.1 to 10 μm, and more preferably 0.25 to 5 μm.
m. If the thickness is less than 0.05 μm, sufficient gas barrier properties cannot be obtained in many cases. If the thickness exceeds 15 μm, the barrier properties are not so much improved, which is economically disadvantageous.

To the barrier layer composed of the barrier polymer (b), the same additions as in the case of the above-mentioned polypropylene-based substrate film layer (A) are provided as long as the gas barrier properties, transparency and adhesion are not impaired. In addition to the agent, an adhesive such as polyethyleneimine and polyisocyanate may be included. The amount of the adhesive added is determined according to the barrier polymer (b).
For 100 parts by weight, for example, 0.5 to 30 parts by weight,
It is preferably about 1 to 10 parts by weight.

In order to further enhance the adhesion, prior to the formation of the barrier layer composed of the barrier polymer (b), the surface of the coating layer (B) of the composite film was previously coated in the same manner as described above. An anchor coat layer may be provided.

One of the main features of the barrier film (2) of the present invention is that the barrier film itself is made of JIS K7.
When subjected to a plastic tensile test according to H.127, the load F1 when the film test piece elongates 1% is 1.9 to 5
kgf / mm ² . The F1 is preferably about 2.0 to 3.5 kgf / mm ² , more preferably about 2.1 to 3.0 kgf / mm ² . F
If the value of 1 is less than 1.9 kgf / mm ² , high oxygen barrier properties cannot be obtained. The value of F1 is 5 kgf / mm ²
If it exceeds, the texture of the film is greatly reduced. Since the F1 value of the barrier film (2) substantially matches the F1 value of the polypropylene-based film used as the base material, the barrier film (2) is formed using a polypropylene-based base film having the above-mentioned F1 value. It can be manufactured by the same method as the barrier film (1).

The barrier film thus obtained is a highly rigid polypropylene-based film in which the load F1 when the film test piece extends 1% is within a specific range according to the plastic tensile test method according to JIS K 7127. Is used as the base material or the rigidity of the barrier film itself is high, so that the barrier properties, particularly the gas barrier properties against oxygen and the like, are greatly improved. The details of this reason are unknown, but are presumed as follows. That is, when a barrier layer (for example, a thin film layer of aluminum oxide) is formed on the base film layer via the coating layer,
When winding up the finished barrier film, tension is applied to the film. Therefore, when the rigidity of the substrate film layer is low, the substrate film layer is elongated, and the surface barrier layer is easily cracked and cracked, and the permeability of oxygen and the like is increased. On the other hand, for example, when a film having high rigidity is used as the base film, cracks or the like hardly occur in the barrier layer on the surface, and thus it is considered that high barrier properties can be secured. In addition, the barrier film of the present invention has high transparency because the transparency of the base film can be increased.

For example, the barrier film (1) of the present invention
Has an oxygen gas permeability of about 1 to 35 cc / m ² · 24 hr (particularly about ^{2 to} 30 cc / m ² · 24 hr, especially about 3 to 15 cc / m ² · 24 hr), and a wavelength of 55
The light transmittance at 0 nm is about 70 to 95% (particularly about 75 to 95%, especially about 78 to 93%).

Further, since the barrier film of the present invention has a coating layer made of a specific resin, the adhesion strength between the barrier layer and the coating layer adjacent to the barrier layer is greatly increased. To be improved. For example, the adhesion strength is usually 120 gf / 15 mm or more (for example, 120 to 150
0 gf / 15 mm), preferably 200 gf / 15
mm (e.g., about 200 to 1500 gf / 15 mm), more preferably 300 gf / 15 mm or more (e.g., about 300 to 1500 gf / 15 mm).
In many cases, it is about 00 to 1000 gf / 15 mm.
The higher the adhesion strength, the better. The adhesion strength can be determined as follows.

That is, two barrier films were prepared, the surfaces of the barrier layers were adhered to each other with an epoxy-based adhesive, and the adhered film was 100 mm long and 15 mm wide.
mm to form a test piece.
According to 7127 (Plastic tensile test method), when the same side edge of the two films on which the test piece is bonded is gripped and pulled at a speed of about 200 mm / min in the MD direction, the interlayer of the test piece is (Gf)
/ 15 mm), the adhesion strength of the barrier film can be determined.

As described above, the barrier film of the present invention is excellent in oxygen barrier properties, adhesion and transparency, so that it can be used in various fields such as foods, pharmaceuticals, agrochemicals, cosmetics and precision electronic parts. It can be suitably used as a material.

[0073]

According to the composite film of the present invention, when used as a component of a barrier film, high barrier properties and transparency can be imparted. According to the method for producing a composite film of the present invention, the composite film can be produced easily.
Further, the barrier film of the present invention has high barrier properties and transparency while using a polypropylene-based film as a base material. Further, the adhesion strength between the base film layer and the barrier layer is extremely high. According to the method for producing a barrier film of the present invention, the above-mentioned barrier film can be easily produced.

[0074]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In addition, F1 value, oxygen gas permeability,
Light transmittance and adhesion strength were determined by the following methods.

[F1] The film was cut to a length of 100
mm, a width of 15 mm, and a thickness of 20 μm, a rectangular test piece was prepared, and the test piece was subjected to M at a speed of 300 mm / min according to JIS K 7127 (plastic tensile test method).
The specimen was pulled in the direction D, and the load F1 (kgf / mm ² ) when the test piece was elongated by 1% was determined. [Oxygen gas permeability] Mocon method [Oxygen permeability measuring device O
Using xtran100 (manufactured by Modern Control),
Measured under conditions of 20 ° C. and 80% RH], thereby obtaining oxygen gas permeability (cc / m ² · 24 hr). [Light transmittance] Spectrophotometer (Hitachi Ltd., U
3300), and the transmittance at a wavelength of 550 nm was defined as the light transmittance. [Adhesion strength] It was determined by the method described above. In each case, peeling occurred between the barrier layer and the coating layer of one of the two films.

Example 1 Isotactic polypropylene (MFR = 2.2 g /
10 minutes, isotactic index 96%, melting point 163
C) 100 parts by weight, 0.1 parts by weight of Ngester NU-100 [manufactured by Shin Nippon Rika Co., Ltd.] as a crystal nucleus growth agent,
A polypropylene resin composition (i-1) comprising 0.23 parts by weight of an antioxidant and 0.02 parts by weight of silica having an average particle size of 1.7 μm as an antiblocking agent was prepared. In addition, this resin composition is supplied to an extruder equipped with a T-die, extruded at a temperature of 250 to 260 ° C. to form a sheet, and the obtained sheet is vertically stretched at 130 to 160 ° C. by 5 mm. The film was stretched twice, subsequently stretched 10 times in the transverse direction at 160 ° C., and then heat-treated at 160 ° C. for 10 seconds. The F1 of the film obtained was 2.3 kgf / mm ² . On the other hand, a polypropylene-based copolymer resin comprising 100 parts by weight of a polypropylene-based random copolymer (MFR = 8 g / 10 min, melting point: 146 ° C., crystallinity: 45%) containing 2.6% by weight of an ethylene component, and 0.02 parts by weight of an antioxidant Composition (ii) was prepared. Supplying the resin compositions (i-1) and (ii) to an extruder equipped with a T-die,
Co-extrusion was performed at a temperature of 250 to 260 ° C. to form a sheet having a two-layer structure. The obtained sheet is 130-1
The film was stretched 5 times in the machine direction at 60 ° C., then 10 times in the transverse direction at 160 ° C., and then heat-treated at 160 ° C. for 10 seconds. Further, the surface of the coating layer composed of the resin composition (ii) is subjected to corona discharge treatment, and a surface wetting tension of 40 dyne / c.
m was prepared. The thickness of the obtained composite film is 20 μm (the thickness of the base film layer composed of the resin composition (i-1) is 19 μm, the thickness of the coating layer composed of the resin composition (ii) is 1 μm), and F1 is 2.3kgf / m
m ² . The crystallinity of the polymer constituting the base film layer was about 57%, and the β crystal content was 50%. Using a continuous vacuum vapor deposition apparatus having an electron beam heating evaporation source, aluminum metal is vapor-deposited on the surface of the coating layer of the composite film while introducing oxygen gas, and a thin film of aluminum oxide ( Film thickness:
490 angstroms). The resulting barrier film has an oxygen gas permeability of 13 cc / m ² · 24 h.
r, the light transmittance was 85%, and the adhesion strength between the thin film and the coating layer was 360 gf / 15 mm. F1 of this barrier film was 2.3 kgf / mm ² .

Example 2 A barrier film was obtained in the same manner as in Example 1 except that the thickness of the aluminum oxide thin film was changed to 930 Å. The resulting barrier film has an oxygen gas permeability of 7 cc / m ² · 24 hr and a light transmittance of 80.
%, The adhesion strength between the thin film and the coating layer is 360 gf
/ 15 mm. In addition, F of this barrier film
1 was 2.3 kgf / mm ² .

Comparative Example 1 Isotactic polypropylene (MFR = 2.2 g /
10 min, 94% isotactic index, melting point 162
C) 100 parts by weight, 0.23 part by weight of an antioxidant, silica having an average particle size of 1.7 μm as an antiblocking agent.
13 parts by weight of a polypropylene resin composition (i-
2) was prepared. Using this resin composition, without adding a crystal nucleus growth agent, supply to an extruder equipped with a T die,
Extrusion was performed at a temperature of 250 to 260 ° C. to form a sheet. The obtained sheet was stretched 5 times in the longitudinal direction at 130 to 160 ° C, stretched 10 times in the transverse direction at 160 ° C, and then heat-treated at 160 ° C for 10 seconds. Further, the surface is subjected to a corona discharge treatment, and a surface wetting tension of 40 dyne / cm.
Film was made. The thickness of the obtained film (base film) was 20 μm, and F1 was 1.8 kgf / mm ² . The crystallinity of the polymer constituting the base film was about 50%, and the β crystal content was substantially 0%. The melting endothermic peak in DSC analysis (heating rate 20 ° C./min) appeared only at around 162 ° C. Using a continuous vacuum vapor deposition device having an electron beam heating evaporation source, aluminum metal was vapor-deposited on the surface of the film subjected to corona discharge treatment while introducing oxygen gas, and aluminum oxide was deposited on the film. Thin film (thickness:
440 angstroms). The resulting barrier film has an oxygen gas permeability of 110 cc / m ² · 24.
hr, the light transmittance is 85%, and the adhesion strength between the aluminum oxide thin film and the base film layer is 100 gf /
It was 15 mm.

Comparative Example 2 A barrier film was obtained in the same manner as in Comparative Example 1, except that the thickness of the thin film of aluminum oxide was changed to 900 Å. The resulting barrier film had an oxygen gas permeability of 53 cc / m ² · 24 hr and a light transmittance of 79.
%, The adhesion strength between the thin film and the substrate film layer is 1%
It was 00 gf / 15 mm.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-126409 (JP, A) JP-A 8-156204 (JP, A) JP-A 8-290536 (JP, A) JP-A 10- 67079 (JP, A) JP-A-60-210647 (JP, A) JP-A-10-34846 (JP, A) JP-A-61-31248 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) B32B 1/00-35/00

Claims (18)

(57) [Claims] 1. A coating layer comprising a polypropylene-based copolymer on at least one surface of a base film layer (A) comprising a polypropylene-based film comprising a polypropylene-based resin having an isotactic index of 95% or more. B) formed composite film (thermoforming sheet)
And the polypropylene-based film is a plastic tensile test method based on JIS K 7127, wherein the load F1 when the film test piece extends 1% is in the range of 1.9 to 5 kgf / mm ² . And the thickness Tb of the base film layer (A) is 5
100 μm, and the thickness Tc of the coating layer (B) is 0.5 to 5 μm.
m, a composite film wherein the ratio Tb / Tc of the thickness Tb of the base film layer (A) to the thickness Tc of the coating layer (B) is 4 or more. 2. The composite film according to claim 1, wherein the polymer constituting the base film layer (A) has a crystallinity of 45 to 65%. 3. The composite film according to claim 1, wherein the β-crystal content of the polymer constituting the base film layer (A) is 10% or more. 4. A coating layer (B) made of a polypropylene copolymer is formed on at least one surface of a polypropylene base film layer (A1) made of a polypropylene resin having an isotactic index of 95% or more. A composite film (excluding a sheet for thermoforming) , wherein the composite film has a load F1 of 1.9 to 5 kgf / cm when the film test piece is stretched by 1% in a plastic tensile test method according to JIS K7127. mm ² , and of the base film layer (A1).
The thickness Tb is 5 to 100 μm, the thickness Tc of the coating layer (B) is 0.5 to 5 μm, and the ratio Tb / Tc of the thickness Tb of the base film layer (A1) to the thickness Tc of the coating layer (B) is 4 or more. Is a composite film. 5. The polypropylene copolymer as a monomer component comprises 84 to 99.9% by weight of propylene and 0.1 to 16% by weight of at least one component selected from ethylene and butene. Or the composite film according to 4. 6. The polypropylene copolymer has an MFR of 1 to 25 g / 10 minutes and a crystallinity of 10 to 55.
5. The composite film according to claim 1, wherein 7. The composite film according to claim 1, wherein the content of the antiblocking agent in the coating layer (B) is 0 to 0.2 part by weight based on 100 parts by weight of the polypropylene copolymer. 8. A coating layer made of a polypropylene copolymer on at least one surface of a base film layer (A) made of a polypropylene film having a polypropylene resin having an isotactic index of 95% or more. B) formed composite film (thermoforming sheet)
And the polypropylene-based film is a plastic tensile test method based on JIS K 7127, wherein the load F1 when the film test piece extends 1% is in the range of 1.9 to 5 kgf / mm ² . And the thickness Tb of the base film layer (A) is 5
100 μm, and the thickness Tc of the coating layer (B) is 0.5 to 5 μm.
m, a composite film in which the MFR of the polypropylene copolymer constituting the coating layer (B) is 5 to 15 g / 10 minutes. 9. A coating layer (B) made of a polypropylene copolymer is formed on at least one surface of a polypropylene base film layer (A1) made of a polypropylene resin having an isotactic index of 95% or more. A composite film (excluding a sheet for thermoforming) , wherein the composite film has a load F1 of 1.9 to 5 kgf / cm when the film test piece is stretched by 1% in a plastic tensile test method according to JIS K7127. mm ² , and of the base film layer (A1).
The thickness Tb is 5 to 100 μm, and the thickness Tc of the coating layer (B) is
A composite film having a MFR of 0.5 to 5 μm and a polypropylene copolymer constituting the coating layer (B) of 5 to 15 g / 10 minutes. 10. A JIS K7 made of a polypropylene resin having an isotactic index of 95% or more.
127, in a plastic tensile test method based on
The load F1 when the film specimen extends 1% is 1.9 to
A coating layer (B) made of a polypropylene-based copolymer is coated on at least one surface of a base film layer (A) having a thickness Tb of 5 to 100 μm and made of a polypropylene-based film in a range of 5 kgf / mm ² , Coating layer (B)
The composite film (for thermoforming) is formed such that the thickness Tc of the base film layer (A) is 0.5 to 5 μm and the ratio Tb / Tc of the thickness Tb of the base film layer (A) to the thickness Tc of the coating layer (B) is 4 or more . Shi
Manufacturing method ) . 11. A JIS K7 made of a polypropylene resin having an isotactic index of 95% or more.
127, in a plastic tensile test method based on
The load F1 when the film specimen extends 1% is 1.9 to
An MFR of 5 to 15 μm is formed on at least one surface of the base film layer (A) having a thickness Tb of 5 to 100 μm and made of a polypropylene film having a range of 5 kgf / mm ^2.
A method for producing a composite film (excluding a thermoforming sheet ) for forming a coating layer (B) having a thickness Tc of 0.5 to 5 μm and composed of a polypropylene copolymer having a g / 10 min. 12. A barrier film (C) comprising a barrier component other than a polypropylene resin is formed on the surface of the composite film according to claim 1, 4, 8 or 9 on the side of the coating layer (B). Barrier film. 13. A barrier layer composed of a barrier component other than a polypropylene resin on at least one surface of a polypropylene base film layer (A1) composed of a polypropylene resin having an isotactic index of 95% or more. A barrier film having C) formed thereon, wherein J
In the plastic tensile test method based on IS K 7127, the load F when the film test piece is extended by 1%
A barrier film wherein 1 is in the range of 1.9 to 5 kgf / mm ² . 14. An oxygen gas permeability of 1 to 35 cc / m ^2.
A light transmittance of 70 at 24 hours and a wavelength of 550 nm;
The barrier film according to claim 12 or 13, which has a content of about 95%. 15. The barrier film according to claim 12, wherein the barrier layer (C) is a thin film layer of an inorganic compound. 16. The barrier film according to claim 15, wherein the inorganic compound is aluminum oxide. 17. A barrier layer (C) and said barrier layer (C)
The barrier film according to any one of claims 12 to 16, wherein the adhesive strength to a layer adjacent to the film is 120 gf / 15 mm or more. 18. A barrier, wherein a barrier layer (C) composed of a barrier component other than a polypropylene resin is formed on the surface of the composite film according to claim 1, 4, 8 or 9 on the side of the coating layer (B). Method of manufacturing conductive film.