JPH1067079A - Film with barrier property and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a film with barrier properties which exhibits high adhesion properties to a coating layer by compositely forming a specific coated layer on a base polymer layer of polypropylene, and further, laminating a coating layer on the coated layer. SOLUTION: A coated layer comprising polypropylene polymer containing 0.1-16 pts.wt. of an ethylene component or/and a butene component is compositely formed on, at least, one of the faces of a base polymer layer of polypropylene. In addition, a coating layer consisting mainly of polymer with barrier properties other than polypropylene is laminated on the coated layer to obtain film with barrier properties. If the content of the ethylene component or/and the butene component is too small, an amorphous area on the surface of the film is decreased resulting in the deterioration of the adhesion properties between the amorphous area and a coating resin. On the contrary, if the content is too large, the production of this film with barrier properties is difficult.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a barrier film and a method for producing the same, and more particularly, to improving the adhesion between a polypropylene polymer layer and a resin layer having a barrier property such as PVDC (vinylidene chloride polymer). Barrier film and a method for producing the same.

[0002]

2. Description of the Related Art Polypropylene films have a number of 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. Therefore,
Polypropylene films are widely used especially as food packaging materials. Further, in order to provide a barrier property against oxygen gas, water vapor, and the like and a heat sealing property, a vinylidene chloride-based copolymer or the like is often coated.

[0003] However, when a polypropylene film is coated with a vinylidene chloride copolymer or the like, an adhesive is used to improve the adhesion, or the surface of the film is subjected to a corona discharge treatment or a charged plasma treatment. . However, even in such a method, the adhesion between the polypropylene film and the coating layer is often not sufficient. There is also a method in which a resin modified with maleic anhydride or the like is used for the surface layer, but this is not only disadvantageous in terms of cost but also may degrade the excellent properties of the polypropylene film.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a barrier film having improved adhesion to a resin layer having a barrier property, such as a vinylidene chloride polymer, while maintaining the excellent properties of a polypropylene film. An object of the present invention is to provide a conductive film and a method for producing the same.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies to achieve the above object, and as a result, the content of an ethylene component and / or a butene component on the surface of a polypropylene film has a large adhesion to a coating layer. Was found to be involved.

That is, in the barrier film of the present invention, an ethylene component and / or a butene component is added to at least one surface of a base polypropylene-based polymer layer in an amount of 0.1 to 16%.
A barrier comprising a coating layer containing a polypropylene-based polymer contained in parts by weight, and a coating layer mainly composed of a polymer having a barrier property other than polypropylene-based layer laminated thereon. It is a sex film. In this specification,
A layer formed on the base polypropylene-based polymer layer is referred to as a “coating layer”, and a layer formed on the coating layer by a method such as coating is referred to as a “coating layer”. Also,
"Composite" refers to forming a coating layer on the surface of a base polypropylene film, and "lamination" refers to forming a coating layer on the surface of the composite film.
Further, "film" also includes "sheet" having a substantially two-dimensional structure unless otherwise specified.

The base polypropylene film layer is made of a polypropylene resin excellent in optical properties, mechanical properties and packaging suitability, and is preferably a crystalline polypropylene resin. In addition, ethylene, butene-1,3-
Copolymers such as methylpentene and 4-methylpentene may be used, but in order not to lose the above-mentioned properties, their content is preferably 1% or less, and preferably less than 0.5%.
More preferably, it is less than 0.3%. The isotactic index (II) of the polypropylene resin is not particularly limited as long as the properties of the film are not impaired.
In many cases, it is 90% or more, and usually a resin having 94% or more is preferred. Further, its melting point is 150 ° C. or higher, preferably 160 ° C. or higher, and MI (melt index) is 0.5 to 20 g / 10 min, preferably 1 to 15 g / 10 min.
Min, more preferably 2 to 10 g / 10 min.

[0008] The base material polypropylene-based film layer includes various additives, for example, an ultraviolet absorber, as long as the adhesiveness with the coating layer is not impaired by bleeding or the like.
Hydrocarbons such as antistatic agents, crystal nucleus growth agents, styrene resins, terpene resins, petroleum resins, dicyclopentadiene resins, coumarone resins such as coumaloninden resin, phenol resins, rosin and its derivatives and their hydrogenated resins. It may contain a polymer, a plasticizer, a filler, an antiblocking agent, and an antioxidant.

The base polypropylene film layer may be a single-layer film or a film in which two or more types of polypropylene resin layers are laminated. The thickness is not particularly limited, and is, for example, about 1 to 250 μm, and preferably about 5 to 100 μm. Further, in the sheet, the thickness of the base material polypropylene layer may be about 0.1 to 5 mm.

A feature of the present invention resides in that a coating layer containing a polypropylene-based copolymer containing an ethylene component is laminated on at least one surface of the base polypropylene-based film layer. The content of the ethylene component and / or the butene component is preferably 0.1 to 16 parts by weight, preferably 0.3 to 8 parts by weight, and more preferably about 1 to 6 parts by weight. If these contents are too small, the amorphous region on the film surface is reduced, so that the adhesion to the coating resin is reduced. If the contents are too large, production becomes difficult.

For the same reason as described above, the crystallinity of the polymer also has an optimum range. The crystallinity determined from the heat of fusion in differential thermal analysis is preferably 10 to 55%, and more preferably 20 to 50%. %. Usually, the heating rate in the differential thermal analysis is measured at 10 ° C./min. Furthermore, its MI
Is preferably higher than the base polypropylene-based polymer, and is usually 1 to 25 g / 10 minutes, preferably 2 to 20 g.
/ 10 minutes, more preferably 5 to 15 g / 10 minutes.
It is not preferable to use a polymer having an MI lower than that of the base polypropylene-based polymer because melt fracture occurs.

The coating layer may also contain an antioxidant or a fine powder antiblocking agent. Examples of the antioxidant include phenol-based, phosphorus-based, sulfur-based, and the like. Among the phenol-based agents, 2,6-di-t-butyl-p
-Cresol (BHT), tetrakis [methylene-3-
(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (Nippon Ciba Geigy,
Irganox 1010) and the like. The content is preferably 0 to 0.15 parts by weight, preferably 0.005 to 5 parts by weight based on 100 parts by weight of the polypropylene resin.
0.10 parts by weight. When the amount of the antioxidant exceeds 0.15 parts by weight, the adhesion to the coating resin is reduced. As a fine powder antiblocking agent, silica, alumina, synthetic zeolite, kaolin, talc, zinc oxide,
Inorganic fine powders such as magnesium oxide, zirconium oxide, titanium oxide, aluminum hydroxide, quartz powder, calcium carbonate, magnesium carbonate, barium sulfate, polyester, nylon, polycarbonate, polyether sulfone, polyetherimide, polyphenylene sulfide,
Thermoplastic resins such as polyetheretherketone and polyamideimide, crosslinked acrylic resin, crosslinked melamine resin, benzoguanamine resin, urea resin, amino resin, furan resin, epoxy resin, phenol resin, unsaturated polyester, vinyl ester resin, diallyl phthalate resin And a thermosetting resin such as polyimide. The fine powder preferably has a melting point or a softening point higher than the temperature at the time of film forming in order to maintain the shape during film forming. Usually, these fine powders are used alone or in combination of two or more.

The fine powder antiblocking agent may be true spherical or amorphous, but when a spherical antiblocking agent is used, high blocking resistance can be imparted without lowering the transparency. The average particle size of the anti-blocking agent can be selected according to the thickness of the coating layer within a range that does not impair the blocking resistance, the slipping property, and the transparency. For example, 0.1 to 7.5 μm, preferably 0.5 to 5μ
m, more preferably 1 to 4 μm. The content of the antiblocking agent is 0.01 to 0.5 part by weight, preferably 0.02 part by weight, based on 100 parts by weight of the polypropylene resin.
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
When the amount is less than 0.5 parts by weight, the film is likely to be blocked at the time of winding, and when the amount exceeds 0.5 parts by weight, transparency may be reduced.

The coating layer preferably contains no components other than those described above. However, as long as the adhesion to the coating resin is not impaired, an ultraviolet absorber, an antistatic agent, a plasticizer, It may contain wax and the like.

The thickness T of the base polypropylene film layer
b and the thickness Tc of the coating layer can be selected within a range that does not impair the characteristics of the composite film. For example, Tc is 0.1 μm or more and Tb / Tc is 4 or more, and preferably Tc is 0.1 μm or more.
Tb / Tc is 5 to 50 at 2 to 10 μm, more preferably 0.5 to 5 μm, and Tb / Tc is about 10 to 30. When the ratio Tb / Tc is less than 4, when the dust generated during film production is reused, the viscosity of the molten resin is greatly reduced, and it is difficult to form a stable film. Also, T
When c is less than 0.1 μm, it is difficult to form a uniform composite.

The composite film composed of the base polypropylene film layer and the coating layer 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.

Further, prior to coating, the coating layer is subjected to a surface treatment so that the coating layer has a thickness of 36 dyne / cm or more, preferably 37 to 45 dyne.
A surface tension of dyne / cm, more preferably about 38 to 42 dyne / cm, may be developed. If the surface tension is less than 36 dyne / cm, the adhesion to the coating layer is reduced.

The barrier film of the present invention comprises a step of compounding a coating layer comprising a polypropylene resin containing an ethylene component and / or a butene component on at least one surface of a base polypropylene film layer; Can be produced through a step of laminating a coating layer having

The film can be composited by a dry lamination method in which the film is composited with a base polypropylene film using an anchor coating agent such as a titanium-based, polyethyleneimine-based or urethane-based film. Can be produced by a co-extrusion molding method.

In the coextrusion molding method, a resin composition mainly comprising a polypropylene resin constituting the base polypropylene film layer and a resin composition constituting the coating layer are subjected to coextrusion molding to form a composite. Film can be manufactured. Preferably, the extruded composite film is subjected to a stretching step.

For coextrusion molding, an extruder equipped with a T die, a ring die and the like can be used. In such an extruder, the resin composition (1) constituting the base polypropylene film layer and the resin composition (2) constituting the coating layer are separately charged, and are put into a die by the extruder. By the melt extrusion, the resin composition (1) and the resin composition (2) are merged in the flow path in the die to form a composite.
The coating layer can be compounded on one side or both sides of the base polypropylene film layer. By cooling the multilayer film melt-extruded from the die, a composite film is obtained.

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.

Examples of the stretching method include a conventional stretching method, for example, a roll stretching, a tenter stretching, a tube stretching or a combination thereof. The stretching ratio can be appropriately set according to the desired film properties, and the stretching ratio in at least one direction is at least 2 times, preferably about 5 to 10 times.

As the surface treatment of the coating layer, a conventional surface treatment such as a corona discharge treatment, a flame treatment, a plasma treatment, an ozone or ultraviolet 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 of the film, but is usually performed after the stretching.

The composite polypropylene film of the present invention thus obtained exhibits high adhesion to the coating layer despite its simple composition and structure. Therefore, the laminated polypropylene film can be suitably used in a wide range of applications such as packaging materials.

The polymer having a barrier property to be used in the coating layer can be selected according to the use of the laminated polypropylene film, for example, a vinylidene chloride polymer,
Gas-barrier resins such as ethylene-vinyl alcohol-based polymer, vinyl alcohol-based polymer, polyamide-based polymer, polyacrylonitrile-based polymer, and urethane-based polymer are exemplified, and vinylidene chloride-based polymer and ethylene-vinyl alcohol-based polymer are particularly preferred. The vinylidene chloride-based polymer is a copolymer of vinylidene chloride and another polymerizable monomer. Examples of such a polymerizable monomer include vinyl chloride, vinyl acetate, crotonic acid, acrylic acid, methyl acrylate, ethyl acrylate, and the like. Examples thereof include propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, acrylonitrile, methacrylonitrile, methacrylic acid, and methacrylate corresponding to the above acrylate. Among these vinylidene chloride-based copolymers, vinylidene chloride-acrylonitrile copolymer, vinylidene chloride-methacrylic acid copolymer, vinylidene chloride-acrylate copolymer, vinylidene chloride-methacrylate copolymer, vinylidene chloride-vinyl acetate copolymer Polymers and the like are particularly preferred. The vinylidene chloride content of the vinylidene chloride copolymer is usually 85%.
To 99% by weight, preferably about 90 to 97% by weight. In addition, the coating liquid, depending on the type of copolymer, acetone, toluene, MEK, THF, dioxane, diethyl ether, cyclohexane non, benzene, xylene, ethyl acetate, butyl acetate, DMF, etc.,
It may be a solution type or an emulsion type dissolved in the mixture, and is used after being prepared such that the thickness of the coating layer is in a range that does not impair gas barrier properties and transparency.

[0027] The ethylene-vinyl alcohol polymer is preferably soluble in a solvent.
Usually, it is about 5 to 50 mol%, preferably about 10 to 45 mol%, and 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.
Such a solvent-soluble ethylene-vinyl alcohol-based polymer is soluble in water or a mixed solvent of water and an alcohol such as methanol, ethanol, propanol, isopropanol, and cyclohexanol, and can form a thin film by coating. These coating layers can be formed by using a conventional method, for example, a method such as coating and laminating. Even if the coating layer is composed of a plurality of layers depending on a desired gas barrier property, one layer may be composed of various types. May be contained. The coating method is not particularly limited, and a common 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 coating the coating solution, the coating solution is dried at a temperature of, for example, about 50 to 150 ° C., whereby a barrier resin coating layer can be formed. Coating thickness is 0.05 ~
It is 15 μm, preferably 0.1 to 10 μm, more preferably 0.25 to 5 μm. If the thickness is less than 0.05 μm, sufficient gas barrier properties cannot be obtained, and if it exceeds 15 μm, the barrier properties do not improve so much, which is economically disadvantageous.

In order to further improve the adhesion, prior to coating, an anchor coating agent such as a titanium-based, polyethyleneimine-based or urethane-based coating is used on the surface of the base polypropylene-based polymer layer, if necessary. Urethane-based ones are preferred. The thickness of the anchor coat layer can be selected in a wide range in which adhesion can be ensured, and is, for example, about 0.01 to 5 μm, and preferably about 0.05 to 2.5 μm.

Regardless of whether or not these anchor coating agents are used, the coating layer may be made of other additives similar to the above-described base polypropylene film layer, as long as the transparency, adhesion and gas barrier properties are not impaired. And an adhesive such as polyethyleneimine and polyisocyanate. The amount of the adhesive is preferably 0.5 to 30 parts, and more preferably 1 to 10 parts, per 100 parts of the barrier resin.

Examples of the metal oxide thin film layer include tin oxide, aluminum oxide, indium oxide, composite oxides thereof, and silicon oxide, which are excellent in transparency and barrier properties. In particular, silicon oxide can form a dense thin film in addition to the above properties, and can maintain high barrier properties even at high temperatures for a long time. The silicon oxide includes not only silicon monoxide and silicon dioxide but also a composition formula SiOx (where 0 <x ≦ 2, preferably 0.8 ≦
x ≦ 1.5) is included.

In the packaging material for electromagnetic wave heating, inorganic compounds having low conductivity, for example, non-conductive inorganic substances such as oxides, halides, carbides and nitrides can be used. Preferred non-conductive inorganics include oxides such as silicon oxide.

The metal oxide thin film layer can be formed by a conventional method, for example, a physical method (vacuum deposition method, reactive deposition method, sputtering layer, reactive sputtering layer, ion plating method, reactive ion plating method, etc.). It can be formed by coating the surface of the anchor coat layer with the above-mentioned inorganic substance by a chemical method (CVD method, plasma CVD method, laser CVD method, or the like). The inorganic 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 while feeding a base film having an anchor coat layer wound up in a roll shape to 10 ⁻³ to
The inorganic compound can be heated and evaporated by an electron beam, high-frequency induction heating, a low resistance heating method, or the like while being passed through a roll-to-roll vacuum evaporator reduced to about 10 ⁻⁶ Torr, thereby continuously depositing the inorganic compound.

[0033]

According to the barrier film of the present invention, a specific coating layer is compounded on at least one surface of the base polypropylene polymer layer, and a coating layer is further laminated thereon. It has high adhesion to the coating layer without impairing the properties of the polypropylene film. In addition, despite its simple configuration, it has excellent characteristics as described above, so that it can be suitably used as various packaging materials in the fields of foods, pharmaceuticals, precision electronic components, and the like.

[0034]

【Example】

(Example 1) The following compositions were used as the raw material (A) for the base polypropylene-based polymer layer and the raw material (B) for the coating layer.

Raw material (A) for base polypropylene-based polymer layer: isotactic polypropylene (MI = 2 g)
/ 10 min, 94% isotactic index, melting point 162
100 ° parts by weight of 2,6-di-tert-butyl-p-cresol (BH) as an antioxidant.
T) in an amount of 0.2 part by weight, tetrakis [methylene-3- (3
', 5'-Di-t-butyl-4'-hydroxyphenyl) propionate] methane in an amount of 0.05 part by weight, and an anti-blocking agent having a mean particle diameter of 2.2 μm.
A composition containing 13 parts by weight.

Material (B) for coating layer: 3.6 ethylene component
% Of a polypropylene random copolymer (MI =
8, melting point 140 ° C, crystallinity 45%)
0.2 parts by weight of 2,6-di-t-butyl-p-cresol (BHT) as an antioxidant, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxy) Phenyl) propionate] methane 0.05 part by weight,
A composition to which 0.13 parts by weight of silica having an average particle size of 2.2 μm is added as an antiblocking agent.

The raw materials (A) and (B) are supplied to an extruder equipped with a T-die, respectively, and co-extruded at a temperature of 250 to 260 ° C. to form two layers having a layer structure of (B) / (A). A two-layer sheet was made. The obtained sheet is stretched 5 times in the machine direction at 130 to 160 ° C., and then 10 times in the transverse direction at 160 ° C.
After stretching twice, it was heat-treated at 160 ° C. for 10 seconds. Further, the surface of the layer (B) of the film was subjected to corona discharge treatment to prepare a composite film having a surface wetting tension of 40 dyne / cm. The thickness of the obtained composite film is 21 μm (the thickness of layer A is 20 μm).
μm, and the thickness of the B layer was 1 μm.

(Example 2) A polypropylene random copolymer as a raw material (B) for a coating layer was prepared by mixing an ethylene component with 5% (MI = 2.5, melting point: 158 ° C., crystallinity: about 4).
0%), a composite film was prepared under the same conditions as in Example 1.

Example 3 A polypropylene random copolymer as a raw material (B) for a coating layer was prepared by adding an ethylene component of 0.3.
% (MI = 2.5, melting point: 158 ° C., crystallinity: about 53%), and a composite film was prepared under the same conditions as in Example 1.

Example 4 A polypropylene random copolymer as a raw material (B) for a coating layer was prepared by mixing an ethylene component 1.5
% (MI = 9, melting point 135 ° C., crystallinity about 3
0%), a composite film was prepared under the same conditions as in Example 1.

Example 5 In the same manner as in Example 1 except that the thickness of the layer A was 18 μm and the thickness of the layer B was 3 μm,
A composite film of layers was made.

(Comparative Example 1) A polypropylene random copolymer as the coating layer raw material (B) was converted to a monopolymer containing no ethylene (MI = 2, melting point 162 ° C, crystallinity 5
6%), except that the composite film was prepared under the same conditions as in Example 1.

(Comparative Example 2) In the same manner as in Example 1 except that the thickness of the layer A was 14 μm and the thickness of the layer B was 7 μm,
A composite film of layers was made.

Then, the adhesive strength of the adhesive to the coating layer of the films obtained in the above Examples and Comparative Examples and the film forming property of the composite film were evaluated as follows.

The raw materials (A) and (B) corresponding to (T) were placed on a (B) layer surface of the composite film of Example 1 by
SiO ₂ was deposited to a thickness of 200 Å by a sputtering method. Peel strength of SiO ₂ film is 400
g / width 15 mm, O ₂ -TR 0.5, WU-TR 0.
It was 8.

Example 7 Al ₂ O 3 was deposited to a thickness of 200 angstroms on the layer (B) of the composite film of Example 1 by a sputtering method. The peel strength of the Al ₂ O ₃ film is 400 g / width 15 mm, and the O ₂ -TR is 0.
5, WU-TR was 0.8. (Comparative Example 3) SiO2 was deposited on the (B) layer surface of the composite film of Comparative Example 1 in the same manner as in Example 6. Peel strength is 50
g, O ₂ -TR was 3.7, and WU-TR was 2.5. The barrier property is poor only by soft hand massage
The iO ₂ film will crack.

[Film Formability of Composite Film] The raw materials (A) and (B) corresponding to the above Examples and Comparative Examples were respectively supplied to an extruder equipped with a T-die, and co-extruded and formed at a temperature of 260 ° C. Then, a two-layer, two-layer sheet having a layer structure of (B) / (A) was prepared and stretched 5 times in the machine direction at 140 ° C.
The film was stretched 10 times in the transverse direction at a temperature of ° C, and the film forming property was evaluated based on the following criteria.

Good: A film can be continuously formed without cutting, and a film having a thickness accuracy within ± 3% is obtained.

Poor: The film could not be formed continuously, and the thickness accuracy was ±
Films exceeding 3% are obtained. [Measurement Method 1 of Adhesive Strength] An anchor coat agent was prepared by mixing 90% by weight of AD335AE (manufactured by Toyo Morton Co., Ltd.) and 10% by weight of CAT10 (manufactured by Toyo Morton Co., Ltd.). After applying the obtained liquid to the surface of the layer B of each laminated film so as to have an anchor coat amount of 0.5 g / m ² at the time of drying, an emulsion liquid containing PVDC as a main component is applied at 4 g of the PVDC at the time of drying. / M ² . Thereafter, the coated surfaces were bonded together with an epoxy adhesive. A load of 40 g / cm ² was applied to the bonded portion and left for 24 hours in an atmosphere of 40 ° C. and 90% RH. Then, a part of the adhesive surface was peeled off, and the tensile strength was measured using a tensile tester (Tensilon, manufactured by Toyo Boardwin Co., Ltd.).
Peel strength (g / width 15 mm) was measured at a speed of 00 mm / min.

[Measurement Method 2 of Adhesive Strength] PVDC (manufactured by Asahi Kasei Kogyo Co., Ltd., trade name: Saran Range F216) and urethane-based adhesive were mixed with toluene / THF without applying an anchor coat agent to the surface of layer B of each laminated film = 1/2 (weight ratio) mixed solvent so that the concentration of PVDC is 15% by weight (urethane-based adhesive is 5 parts per 100 parts of PVDC).
Part), except that the coating was performed so that the applied amount of PVDC at the time of drying was 2 g / m ^2.
The adhesive strength was measured in the same manner as described above.

[Measurement Method 3 of Adhesion Strength] The same anchor coating agent as in the measurement method 1 of adhesion strength was applied to the surface of the layer B of each laminated film, and then an ethylene-vinyl alcohol copolymer (Nippon Synthetic Chemical Industry Co., Ltd. Co., Ltd., product name Soarnol 30
L) was adjusted to a resin concentration of 12% by weight in a mixed solvent of water / isopropanol = 1/1 (weight ratio), and the dry ethylene-vinyl alcohol copolymer was 4 g / m ^2.
The adhesive strength was measured in the same manner as in the above-described method 1 for measuring the adhesive strength, except that the coating was performed such that

Tables 1, 2, 3, and 4 summarize the results. As is clear from the table, the laminated films of Examples 1 to 6 exhibit an adhesive strength three times or more as compared with Comparative Examples 1 to 3, and are excellent in film-forming properties.

[0053]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B32B 9/00 B32B 9/00 A 27/30 27/30 C B65D 65/40 B65D 65/40 D C08J 7/04 CES C08J 7/04 CES 7/06 CES 7/06 CESZ // C08L 23/10 C08L 23/10

Claims (6)

[Claims] A coating layer containing a polypropylene polymer containing an ethylene component and / or a butene component in an amount of 0.1 to 16 parts by weight is composited on at least one surface of the base polypropylene polymer layer. A barrier film comprising a non-polypropylene barrier layer laminated on top. 2. The barrier film according to claim 1, wherein the polymer other than the polypropylene-based polymer is a vinylidene chloride-based polymer. 3. The MI of a polypropylene-based polymer in a coating layer.
Is 1 to 25 g / 10 min. 3. The barrier film according to claim 1, wherein the degree of crystallinity calculated from the heat of fusion of the differential thermal analysis is 10 to 55%. 4. 4. The method according to claim 1, wherein the coating layer has a thickness Tc of at least 0.1 μm and a ratio Tb / Tb / thickness Tb of the base polypropylene polymer layer.
4. The barrier film according to claim 1, wherein Tc is 4 or more. 5. The barrier film according to claim 1, wherein the barrier layer is a metal oxide thin film layer. 6. A composite material comprising a coating layer containing a polypropylene-based polymer containing 0.1 to 16 parts by weight of an ethylene component and / or a butene component on at least one surface of the base polypropylene-based polymer layer. A method for producing a barrier film, comprising laminating thereon a coating layer mainly composed of a polymer having a barrier property other than polypropylene.