JP2001009982A - Gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent gas barrier property even under a high humidity by forming a coating film of which the major constituent components are an inorganic plate-form particle and a water-soluble polymer, on one surface of a thermoplastic resin base material, and making the coating film contain a wet penetrating agent. SOLUTION: On one surface of a thermoplastic resin base material of polyolefin, polyethylene terephthalate, polybutylene terephthalate or the like, a coating film of which the major constituent components are an inorganic plate-form particle wherein one plate-form particle is formed by superposing ultra-thin unit crystal layers of kaolinite, halloysite, verculite or the like, and a water-soluble polymer using a cellulose derivative of a polyvinyl alcohol based polymer, carboxymethyl cellulose or the like, is formed. Then, in the coated film, a wet penetrating agent which is a laterally symmetrical nonionic particle having a structure wherein a hydrophilic group comprising a triple bond of a hydroxyl group and carbon-carbon, is pinched by a hydrophobic group comprising a branched hydro-carbon, is contained.

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 more particularly to a gas barrier film having high gas barrier properties under high humidity, adhesion to a substrate, and excellent gas barrier properties after lamination. .

[0002]

2. Description of the Related Art In the field of packaging of foods and medicines, if oxygen or the like enters from the outside air, the contents cannot be stored for a long period of time due to deterioration of the contents. Therefore, a film having a gas barrier property capable of preventing entry of outside air. Is being developed.

[0003] Polymer Engineering and Science, Vol. 20, No. 22, pp. 1543-1546 (1)
According to the gas barrier film that has been conventionally developed, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, and the like are used.
However, since polyvinylidene chloride contains a chlorine atom and polyacrylonitrile contains a -CN group, environmental problems at the time of disposal have been raised in recent years. Further, since polyvinyl alcohol contains an -OH group, the humidity dependence of gas barrier properties is large, and the gas barrier properties are significantly reduced at high humidity. Even an ethylene-vinyl alcohol copolymer in which the humidity dependence of polyvinyl alcohol has been improved, gas barrier properties at high humidity are not yet sufficient.

On the other hand, silicon oxide (JP-B-53-12953)
And aluminum oxide (JP-A-62-1799).
A film in which an inorganic substance such as No. 35 is vapor-deposited on the surface of a substrate has been developed. However, the formation of these films requires a very high cost due to the addition of the vapor deposition process, and the lack of flexibility of the inorganic coating and poor adhesion to the base material make it difficult to handle as a film. There is a problem.

As means for solving these problems, a film in which a base material is provided with a coating film composed of a metal oxide and polyvinyl alcohol (JP-A-56-4563, etc.) has been developed. As for the gas barrier property at the time, it is not yet at a satisfactory level. Further, a film having a gas barrier layer composed of an inorganic layered compound and a high hydrogen bonding compound (JP-A-6-93133, JP-A-7-41)
However, there is a great disadvantage in terms of productivity because long-term drying or heat treatment is required in the process of forming the gas barrier layer in order to obtain a high barrier property, and the adhesion between the coating material and the base material is high. Is also low. If the adhesion to the base material is high, a highly reliable packaging material that does not break the bag or deform the bag when processed into a packaging bag or the like can be obtained.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional gas barrier film and to have excellent gas barrier properties even under high humidity.
An object of the present invention is to provide a gas barrier film having excellent adhesion to a substrate and excellent gas barrier properties even after secondary processing such as printing, laminating, and packaging bags.

[0007]

In order to achieve the above object, a gas barrier film according to the present invention comprises inorganic plate-like particles and a water-soluble polymer as main components on at least one surface of a thermoplastic resin substrate. A film having a coating film formed thereon, characterized in that the coating film contains a wetting penetrant.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with preferred embodiments. The present invention, by forming a coating film composed of inorganic plate-like particles and a water-soluble polymer and a wetting penetrant, high gas barrier properties under high humidity,
A gas barrier film having both adhesion and gas barrier properties after secondary processing such as printing, laminating, and packaging bags has been developed, and is promising as a packaging material having high reliability in storage stability.

In the present invention, it is necessary that the coating film contains a wetting penetrant in order to improve the gas barrier properties, adhesion and the gas barrier properties after secondary processing of printing, laminating, packaging bags, and the like. . By incorporating a wetting penetrant into the coating film, the adhesion to the substrate is improved, and surface defects (pinhole-like film detachment) of the coating film are reduced, resulting in gas barrier properties and
In particular, the gas barrier properties after the secondary processing are improved. The wetting penetrant is used in an amount of 0.01 to 0.01% based on the total weight of the components of the coating film after drying.
20 wt%, preferably 0.02 to 10
wt% is more preferable, and 0.05 to 0.5 wt% is particularly preferable. If the content of the wetting penetrant is less than 0.01 wt%, no effect is obtained, and if it exceeds 20 wt%, the transparency of the dried coating film may be deteriorated.

[0010] Wetting penetrants are hydroxyl groups and carbon-
It is a symmetrical nonionic molecule having a structure in which a hydrophobic group made of a branched hydrocarbon sandwiches a hydrophilic group consisting of a carbon triple bond, and an acetylene diol compound is particularly preferable. The acetylenic diol compound is, for example, 2,4,7,9-tetramethyl-5-decyne-4,7-diol-diether, 2,4,7,9-tetramethyl-5-decyne-4,
7-diol-di (polyoxyethylene) m + n ether (m + n = 4 mol%), 2,4,7,9-tetramethyl-5-
Decyne-4,7-diol-diethylene glycol,
2,4,7,9-tetramethyl-5-decyne-4,7-
Diol-dipropylene glycol, 3,5-dimethyl-1-hexyn-3-ol, and the like, and mixtures thereof. Among them, 2,4,7,9-tetramethyl-5-decyne-4,7-diol-di (polyoxyethylene) m + n ether (m + n = 4 mol%) has an affinity for the coating film component. This is preferred because it has good properties and is highly effective in improving the adhesion between the substrate and the coating film.

The inorganic plate-like particles in the present invention are very thin and simple.
In which the co-crystal layers overlap to form one plate-like particle
Particles, preferably those that swell and cleave in the solvent
New Among these, clay conversion with swelling ability in solvent
Compounds are preferably used. Expansion to a solvent in the present invention
Water is distributed between extremely thin unit crystal layers
Is a clay compound that has the property of absorbing, swelling,
Has Si⁴⁺Is O^2-To form a tetrahedral structure
Layer and Al³⁺, Mg²⁺, Fe²⁺, Fe³⁺, Li ⁺Etc. are O
^2-And OH^-Layer coordinated with respect to octahedral structure
Are combined in a one-to-one or two-to-one relationship and stacked to form a layer
Constructs a structure and is synthesized even if it is natural
It may be something. Typical examples are kaolinite,
Halloysite, montmorillonite, verculite, sa
Ponite, dickite, nacrite, antigorai
G, pyrophyllite, hectorite, beidellite,
Margarite, talc, tetrasilyl mica, white cloud
Mother, phlogopite, chlorite, etc., for two or more
May be. The average particle diameter of the inorganic plate-like particles is particularly limited.
However, 20 nm or more is preferable.

In the present invention, the water-soluble polymer refers to a polymer which can be completely dissolved or finely dispersed in water at normal temperature.
For example, polyvinyl alcohol-based polymers or derivatives thereof, carboxymethyl cellulose, cellulose derivatives such as hydroxyethyl cellulose, oxidized starch, etherified starch, starches such as dextrin, polyvinylpyrrolidone, copolymerized polyester containing a polar group such as sulfoisophthalic acid , Vinyl polymers such as polyhydroxyethyl methacrylate or a copolymer thereof,
Examples include acrylic polymer, urethane polymer, ether polymer, and functional group modified polymers such as carboxyl group, amino group, and methylol group of these various polymers. It is preferably a polyvinyl alcohol polymer or a derivative thereof, and particularly preferably a saponification degree of 80 mol%.
The above polyvinyl alcohol is a copolymerized polyvinyl alcohol having a vinyl alcohol unit of 60 mol% or more.
The polymerization degree of the polyvinyl alcohol-based polymer or a derivative thereof is preferably 100 to 5000, and 500 to 3000.
Is more preferable, and 1200 to 2500 is particularly preferable.

Further, in the present invention, the coating film may contain a crosslinking agent. The mixing ratio is 0.01 to 10%, preferably 0.05 to 8%, by weight based on the components of the coating film.
The crosslinking agent to be used is not particularly limited as long as it has reactivity with a water-soluble polymer, but an epoxy-based crosslinking agent, an isocyanate-based crosslinking agent, a melamine-based crosslinking agent, an oxazoline-based crosslinking agent, a silane coupling agent, and the like. Is used.

The mixing ratio of the inorganic plate compound / water-soluble polymer in the present invention is preferably in the range of 5/95 to 60/40 by weight. When it is smaller than 5/95, the gas barrier property is reduced, and when it is larger than 60/40, the adhesion and the gas barrier property after secondary processing such as printing, lamination, and packaging bags are reduced.

In the present invention, the peel strength between the thermoplastic resin substrate and the coating film is preferably 0.5 N / cm or more after being left in an atmosphere at a temperature of 40 ° C. and a humidity of 90% for 2 days.
More preferably, it is 1.0 N / cm or more. If the peel strength is lower than 0.5 N / cm, the coating film is peeled off during secondary processing or after bag-making, and the gas barrier property is undesirably deteriorated.

In the present invention, from the viewpoint of gas barrier properties, in particular, gas barrier properties after secondary processing, it is preferable that the number of surface defects of 0.2 μm or more on the coating film surface is 5 or less per 10 cm ² . More preferably, the number is three or less. The surface defect of this size is of a size that can be visually confirmed, and when a coating film is formed on a coating film, it may cause unevenness in the formation of the coating layer. The most effective way to reduce the number of surface defects to 5 or less is to add the wetting penetrant, but in addition, the coating is filtered to cut solids (gels, foreign substances) and aggregates. Method, a method of mechanically dispersing by using the above-mentioned apparatus subjected to shearing force and shear stress, a method of using a mixed solvent of water / lower alcohol as a solvent of a coating agent, and a dispersibility by surface treatment of plate-like particles. And the like are preferably used. Of course, it is also important to prevent air bubbles from being mixed in the coating material. Therefore, a method of using a water / lower alcohol mixed solvent as a solvent for the coating material having an effect of lowering the surface tension of the coating material is particularly preferably used.

The viscosity of the coating composition obtained by adding a wetting penetrant to the mixed coating composition comprising the inorganic plate-like particles and the water-soluble polymer as main components of the present invention is preferably 1000 cps or less.
More preferably 500 cps or less, particularly preferably 1 cps
00 cps or less. However, when the viscosity of the coating material is 5 cps or less, repelling may occur when a thin coating of 0.1 μm or less is applied to the base material, and when it exceeds 1000 cps, the high-speed coating property is poor, which is not preferable in production. Also,
Filtering the mixed coating material, 100 μm or more,
It is preferable to cut solids (gels and foreign substances) and aggregates of preferably 50 μm or more. By forming a coating material having a low viscosity and cutting solids and agglomerates, coating properties are improved and a coating speed of 100 m / min or more is possible.

The thickness of the coating film in the present invention is not particularly limited.
10 μm is preferred, and 0.3 to 6 μm is particularly preferred.

Various additives may be added to the coating in a weight ratio of 20 to the extent that gas barrier properties and transparency are not impaired.
% Or less. As the various additives,
Inorganic or organic particles, antioxidants, weathering agents, heat stabilizers,
Lubricants, crystal nucleating agents, ultraviolet absorbers, coloring agents and the like. As inorganic or organic particles, for example, calcium carbonate,
Titanium oxide, silicon oxide, calcium fluoride, lithium fluoride, alumina, barium sulfate, zirconia, calcium phosphate, crosslinked polystyrene particles, and the like.

Further, in order to enhance the interaction between the plate compound and the polymer, between the polymer and the plate compound, etc. in forming the coating film, a divalent or higher valent metal salt, a catalyst component and the like are added. Is also good. It is desirable to use an acetate, a sulfate, a nitrate, or the like containing calcium, magnesium, aluminum, or the like because moisture resistance is improved. The amount is about 1 to 10000 ppm based on the coating film.

Further, in the present invention, since the process abrasion resistance and the gas barrier property at the time of laminating an unstretched propylene film or the like with an adhesive therebetween are improved, the surface roughness parameter of the coating film surface is Rt. / Ra is preferably 20 or less, more preferably 15 or less, even more preferably 13 or less, and particularly preferably 10 or less. Also,
Rt is preferably 1.4 μm or less, and
m or less, more preferably 1.0 μm or less. Here, Rt is the maximum height, the distance between the maximum peak and the deepest valley of the surface roughness curve, and Ra is the center line average roughness. If Rt is greater than 1.4 μm, the projections are shaved during the secondary processing and the wear resistance is poor, and if Rt is 0.05 μm or less, the slip properties are poor and wrinkles may occur during winding.

As a method for setting the surface roughness parameter Rt / Ra to 20 or less and Rt to 1.4 μm or less, a coating material in which components of a coating film are dispersed very uniformly on a smooth thermoplastic resin base material is used. Produced, the temperature of the coating surface is 160 ℃ or less,
A method of forming a coating film by drying within a drying time of 60 seconds or the like is used. The details of the above parameters are described in “Measurement / Evaluation of Surface Roughness” by Jiro Nara (General Technology Center, 1
983).

The thermoplastic resin substrate used in the present invention is necessary mainly for imparting mechanical properties and film processability, and includes various commercially available thermoplastic resin films. Although not particularly limited, typical examples include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate, nylon 6, and nylon 12
Such as polyamide, polyvinyl chloride, ethylene vinyl acetate copolymer or saponified product thereof, polystyrene, polycarbonate, polysulfone, polyphenylene oxide, polyphenylene sulfide, aromatic polyamide,
Polyimide, polyamide imide, cellulose, cellulose acetate, polyvinylidene chloride, polyacrylonitrile,
Polyvinyl alcohol and the like, and copolymers thereof. Polyesters such as polyethylene terephthalate and polyolefins such as polyethylene and polypropylene are preferred from the viewpoints of cost performance, transparency, gas barrier properties and the like.

These thermoplastic resin substrates may be unstretched, uniaxially stretched, or biaxially stretched, but from the viewpoint of dimensional stability and mechanical properties, those stretched biaxially are particularly preferred. Various additives may be contained in the thermoplastic resin base material. For example, antioxidants, weathering agents, heat stabilizers, lubricants, nucleating agents, ultraviolet absorbers, coloring agents and the like.
Further, inorganic or organic particles may be contained as long as the transparency is not impaired. For example, talc, kaolin, calcium carbonate, titanium oxide, silicon oxide, calcium fluoride, lithium fluoride, alumina, barium sulfate,
Zirconia, mica, calcium phosphate, crosslinked polystyrene-based particles, and the like. The average particle size is preferably 0.001 to 10 μm, more preferably 0.003 to
5 μm. The average particle diameter is a particle diameter obtained by taking a photograph at a magnification of 10,000 to 100,000 using a transmission microscope or the like and calculating the number average.

Further, these thermoplastic resin substrates are preferably transparent. Light transmittance is 40%
Or more, more preferably 60% or more. The thermoplastic resin substrate is preferably smooth. The thickness of the thermoplastic resin substrate is not particularly limited, but 2 to 1000
μm is preferred.

In the present invention, it is preferable to provide a layer made of metal and / or metal oxide on the coating film from the viewpoint of gas barrier properties and adhesion. The metal and / or metal oxide is not particularly limited, but is preferably a metal such as Al and Si and / or a metal oxide.

Next, a typical method for producing the gas barrier film of the present invention will be described. The method for forming the coating film on the thermoplastic resin substrate is not particularly limited, and may be an extrusion lamination method or a melt coating method, but the composition of the coating film is that thin film coating can be performed at a high speed. It is preferable to apply a gravure coat, a reverse coat, a spray coat, a kiss coat, a comma coat, a die coat, a knife coat, an air knife coat or a metalling bar coat to a dispersion solution in which the components are dispersed in various solvents.
Prior to coating, the thermoplastic resin substrate is subjected to a known adhesion promoting treatment, for example, a corona discharge treatment in air, a nitrogen gas, a mixed gas of nitrogen / carbon dioxide gas, other atmospheres, a plasma treatment under reduced pressure, and a flame treatment. , UV treatment, application of an anchor coat agent and the like. Further, as a thermoplastic resin substrate, polyester such as polyethylene terephthalate,
When a biaxially stretched film of a polyolefin such as polypropylene is used, either an off-line coating or an in-line coating may be used.

The method for drying the coating film is not particularly limited, and a hot roll contact method, a heat medium (air, oil, etc.) contact method, an infrared heating method, a microwave heating method, and the like can be used. Drying of the coating film
From the viewpoint of gas barrier properties, the drying is preferably performed within the range of 60 ° C to 160 ° C, and the drying time is 1 to 60 ° C.
Seconds, preferably 3 to 30 seconds.

The coating containing the components of the coating film is preferably a solution in which the inorganic plate compound is uniformly dispersed or swelled in the solvent and the water-soluble polymer is uniformly dissolved or dispersed. As the solvent, water or a mixed solution of water / lower alcohol is used, but a mixed solution of water / lower alcohol is preferably used from the viewpoint of gas barrier properties, adhesion and productivity under high humidity. The lower alcohol is an alcoholic compound having a linear or branched aliphatic group having 1 to 3 carbon atoms. For example, methanol, ethanol, n- or iso-propanol is preferably used. In addition, water /
The mixing ratio of alcohol is 99/1 to 20/80 by weight.
Is preferred. If the mixing ratio is greater than 99/1, there are problems such as insufficient gas barrier properties under high humidity, poor adhesion between the coating layer and the substrate, and a decrease in productivity. The dispersibility in the solvent deteriorates.

In order to impart coatability to the film, the mixed solvent may contain another water-soluble organic compound as the third component as long as the stability of the dispersion solution is maintained. Is also good. Examples of the water-soluble organic compound include alcohols such as methanol, ethanol, n- or iso-propanol, glycols such as ethylene glycol and propylene glycol, methyl cellosolve,
Glycol derivatives such as ethyl cellosolve and n-butyl cellosolve; polyhydric alcohols such as glycerin and wax; ethers such as dioxane; esters such as ethyl acetate; and ketones such as methyl ethyl ketone.
Further, the pH of the dispersion solution is from 2 to 11 in view of the stability of the solution.
Is preferable.

The method of adjusting the coating agent is not particularly limited,
A method of uniformly dispersing an inorganic plate compound in a solvent and then mixing it with a solution in which a water-soluble polymer is uniformly dissolved in a solvent is effectively used. It is preferred that the compounds are very uniformly dispersed.
Further, the solution may contain a crosslinking agent, particles, and the like.

In the present invention, a gas barrier film having excellent gas barrier properties and adhesion can be obtained by providing a layer made of metal and / or metal oxide by a conventionally known vapor deposition method.

[Method for Evaluating Characteristics] The method for evaluating characteristics used in the present invention is as follows. (1) Gas barrier property According to ASTM-D-3985, an oxygen permeability measuring device (OX-TRAN 2/20, manufactured by Modern Control Co., Ltd.)
Was used to measure oxygen permeability. Measurement condition is temperature 23
° C and a relative humidity of 80%. Oxygen permeability is 300ml /
m ² · d · MPa / one sheet thickness or less was regarded as good.

(2) Gas barrier properties after lamination A polyurethane adhesive is coated on the coating surface of the film by a gravure coater at 2 μm, passed through an oven maintained at 80 ° C., dried, and then a 25 μm unstretched polypropylene film (CPP3529T manufactured by Toray Synthetic Film Co., Ltd.)
And passed through a pair of nip rolls of a metal roll and a rubber roll maintained at 80 ° C., and a load of 1 kg / c.
m and dry lamination was performed. The gas barrier properties of the film after the lamination were measured by the method described above. When the oxygen permeability deteriorated by 50% or more due to the temperature, tension, load, and the like during lamination, the evaluation was evaluated as x;

(3) Peeling strength between coating film and substrate (coating film adhesion) The above-mentioned laminated product was aged for 48 hours in a thermo-hygrostat kept at a temperature of 40 ° C. and a relative humidity of 90%, and then subjected to 15 hours.
The film was cut to a width of mm, and the CPP and the present coating film were peeled off using Tensilon, and the peel strength was determined. The peeling was performed under an atmosphere of 90 °, a peeling speed of 10 cm / min, 23 ° C. and a relative humidity of 65%.

(4) Surface Defects The transmitted light image of the film was measured with an optical microscope (magnification: 10 times).
The number of defects having a size of 0.2 μm or more per 10 cm ² was measured, and the measurement was performed 20 times at different observation locations. The average value was defined as the number of surface defects. 5 or less surface defects per 10 cm ² were evaluated as ○, 10 or more as ×, and Δ between them was evaluated as Δ. In the transmitted light image, a portion having a diameter of 0.2 μm or more when the area of the black portion and the portion observed on the ring was converted into an equivalent circle was regarded as a defect.

(5) Particle size: Centrifugal sedimentation type particle size distribution analyzer CA, manufactured by Horiba, Ltd.
Using PA-700, the inorganic plate-like particles were dispersed in a solution having the same solvent composition as that of the coating agent used for forming the coating film, and heated at 23 ° C.
Was measured.

(6) Maximum height Rt and average surface roughness R
a It was measured using a high-precision thin film step measuring device ET-10 manufactured by Kosaka Laboratory Co., Ltd. The measurement conditions are as follows, and the average value measured 20 times can be used as each value. Stylus tip radius: 0.5 μm Stylus load: 5 mg Measurement length: 1 mm Cut-off: 0.08 mm

(7) Content of Wetting Penetrant in Coating Film The coating film on the film surface is scraped with a single blade, and the shaved material is removed using a micro FT-
It was determined by a calibration curve method using an IR (Fourier exchange infrared spectrophotometer).

[0040]

Example 1 Montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia-G) as inorganic plate-like particles was dispersed in purified water to a concentration of 5 wt% (solution A). Degree of saponification as a water-soluble polymer
5 mol%, polyvinyl alcohol having a polymerization degree of 3000 (hereinafter abbreviated as PVA) was dispersed in purified water so as to be 5 wt% (Solution B). After mixing the liquid A and the liquid B at a weight ratio of 50/50, the acetylenic diol compound 2,4,7,9-tetramethyl-5-decyne-4,7-
Diol-di (polyoxyethylene) m + n ether (m + n
= 4 mol%), the mixing ratio of the mixed liquid of liquid A and liquid B / wetting penetrant is 100 / 0.5 by weight, isopropyl alcohol (IPA) is 10 wt% by weight with respect to all coating agents, solid A coating composition was prepared so as to have a concentration of 4 wt%. The coating was subjected to corona discharge treatment (carbon dioxide / nitrogen mixed gas (volume ratio 8
3:17), a gravure coater (coating speed 100 m / m) applied to a biaxially stretched polypropylene film ("Trefane" T-2400 type, manufactured by Toray Industries, Inc., thickness: 22 μm) having a treatment strength of 60 W · min / m ² ). Min), the mixture was guided into a hot-air drying dryer, dried at 120 ° C. for 5 seconds under low tension, and the film was wound. Table 1 shows the properties of the obtained film. The obtained film was excellent in gas barrier properties, adhesion, and gas barrier properties after secondary processing.

Examples 2 to 5 Films were obtained in the same manner as in Example 1 except that the coating composition, coating thickness, and substrate were changed. Table 1 shows the properties of the obtained film.

In Example 2, the acetylenic diol compound 2,4,7,9-tetramethyl-5-
Desine-4,7-diol-diethylene glycol, a water-soluble polymer having a saponification degree of 99.5 mol% and a polymerization degree of 17
A film was obtained in the same manner as in Example 1 except that PVA No. 00 was used. The obtained film was excellent in gas barrier properties, adhesion, and gas barrier properties after secondary processing.

In Example 3, the acetylene diol compound 2,4,7,9-tetramethyl-5 was used as a wetting penetrant.
-Biaxially stretched polyester film with corona discharge treatment (in air) using -decine-4,7-diol-dipropylene glycol, sodium tetrasilyl mica (manufactured by Topy Industries, Ltd.) as an inorganic plate compound A film was obtained in the same manner as in Example 1 except that (Lumirror, manufactured by Toray Industries, Inc., thickness: 12 μm) was used. The obtained film was excellent in gas barrier properties, adhesion, and gas barrier properties after secondary processing.

In Example 4, a solvent-type urethane adhesive "Takelac" A310 (Takeda Pharmaceutical Co., Ltd.) was applied to the corona discharge treated surface of the biaxially oriented polypropylene film of Example 1.
Co., Ltd.) and curing agent “Takenate” A3 (Takeda Pharmaceutical Co., Ltd.)
Co., Ltd.) was mixed in 1/1 and an anchor coating agent having a solid content of 2% with ethyl acetate was applied to form an anchor coat layer having a thickness of 0.2 μm and then the coating film of Example 1 was provided. Was obtained in the same manner as in Example 1. The obtained film was excellent in gas barrier properties, adhesion, and gas barrier properties after secondary processing.

In Example 5, a film was obtained in the same manner as in Example 1 except that one part of aminomethoxysilane was added as a silane coupling agent to the coating composition of Example 1. The obtained film was excellent in gas barrier properties, adhesion, and gas barrier properties after secondary processing.

Comparative Example 1 A film was obtained in the same manner as in Example 1 without using a wetting penetrant. Table 1 shows the properties of the obtained film. As is clear from Table 1, the obtained film was found to be inferior in gas barrier properties and adhesion.

Comparative Example 2 A film was obtained in the same manner as in Example 1 without using the inorganic plate-like particles. Table 1 shows the properties of the obtained film. It was found that the obtained film had significantly poor gas barrier properties and adhesion.

Comparative Example 3 Example 1 was repeated except that spherical silica was used instead of the inorganic plate-like particles, and a polyurethane ionomer was used as the water-soluble polymer.
In the same manner as in Example 1, a film shown in Table 1 was obtained. It was found that the obtained film had significantly poor gas barrier properties and adhesion.

[0049]

[Table 1]

[0050]

According to the gas barrier film of the present invention, the gas barrier film not only has excellent gas barrier properties, but also has gas barrier properties after secondary processing such as printing, laminating, and packaging bags, and coating film adhesion under high humidity. Can be used as any packaging material.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 7/04 CER C08J 7/04 CERP CEZ CEZP // C08L 101: 00 F term (reference) 3E067 AB01 AB81 AB96 BA12A BB11A BB15A BB16A BB18A BB22A BB26A CA04 CA06 EE32 EE35 GD08 4F006 AA12 AA15 AA16 AA19 AA20 AA32 AA35 AA36 AA38 AA39 AA40 AB20 AB64 AB76 BA01 BA05 CA07 4F100 AA01B AC03 AH02H AK01A AK03A AK07 AK21B BA02 CA30B CC00B DE01B GB23 GB66 JB09B JB16A JD02 JK06 JL11 JM02B YY00

Claims (5)

[Claims] Claims: 1. A film comprising a thermoplastic resin substrate on at least one surface of which a coating film containing inorganic plate-like particles and a water-soluble polymer as main components is formed, wherein the coating film contains a wetting penetrant. A gas barrier film characterized by the following: 2. The method according to claim 1, wherein the peel strength between the thermoplastic resin substrate and the coating film is 0.5 N / cm or more after being left in an atmosphere at a temperature of 40 ° C. and a humidity of 90% for 2 days. Item 2. The gas barrier film according to Item 1. 3. The gas barrier film according to claim 1, wherein the water-soluble polymer is a polyvinyl alcohol-based polymer or a derivative thereof. 4. The gas barrier film according to claim 1, wherein the thermoplastic resin substrate is made of an olefin resin. 5. The gas barrier film according to claim 1, wherein the wetting penetrating agent is an acetylenic diol compound.