JPH11151786A - Gas barrier film and packing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film holding gas barrier properties, close adhesiveness and transparency under high humidity. SOLUTION: In a film wherein a coating film containing inorg. plate-shaped particles and a water-soluble polymer as main constituents is formed on at least the single surface of a thermoplastic resin base material, a gas barrier film wherein the viscosity of the water-soluble polymer in an aq. dispersion with a solid concn. of 10 wt.% is 2000 cPs or less is formed. The obtained film is excellent not only in gas barrier properties but also in close adhesiveness and transparency and can be used as a packing material.

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, excellent adhesion to a substrate, and excellent transparency.

[0002]

2. Description of the Related Art In the field of packaging of foods and medicines, if there is intrusion of oxygen or the like from the outside air, the contents cannot be stored for a long time due to deterioration of the contents. Is being developed.

[0003] Polymer Engineering and Science, Vol. 20, No. 22, pp. 1543-1546 (1)
According to December 986), gas barrier films that have been conventionally developed include polyvinylidene chloride, polyacrylonitrile, and polyvinyl alcohol.

However, polyvinylidene chloride has a chlorine atom,
Since polyacrylonitrile contains -CN groups,
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 with ethylene-vinyl alcohol copolymers having improved humidity dependence of polyvinyl alcohol, the gas barrier properties at high humidity are not yet satisfactory.

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 involves a vapor deposition process, which results in extremely high costs, the lack of flexibility of the inorganic coating, and poor adhesion to the substrate due to poor adhesion to the substrate. There is a problem.

As a means for solving these problems, a film in which a substrate 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.

[0007]

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 gas barrier properties even under high humidity and to have adhesion and transparency to a substrate. It is to provide a gas barrier film.

[0008]

According to the present invention, in order to achieve the above-mentioned objects, a coating film containing inorganic plate-like particles and a water-soluble polymer as main components is formed on at least one surface of a thermoplastic resin substrate. In the formed film, the viscosity of the water-soluble polymer in an aqueous dispersion having a solid content of 10% by weight was 200%.
It is made of a gas barrier film characterized by being at most 0 cps.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when a coating film composed of inorganic plate-like particles and a water-soluble polymer is formed on a thermoplastic resin substrate, the viscosity of the water-soluble polymer in an aqueous dispersion is controlled. Has developed a gas barrier film that combines high gas barrier properties, adhesion and transparency under high humidity, and is promising as a highly reliable packaging material that has excellent preservability and allows the contents to be confirmed. .

In the present invention, the viscosity of the water-soluble polymer in the aqueous dispersion having a solid content of 10% by weight is 2,000 cp.
s or less. By controlling the viscosity of the water-soluble polymer in the aqueous dispersion, the dispersibility of the polymer and the inorganic plate-like particles in the coating material is improved, so that the dispersibility in the coating film is also improved. As a result, gas barrier properties, adhesion and transparency under high humidity are improved, and coarse projections on the coating surface due to agglomerates in the coating material can be reduced, so that the coating film is also abraded by friction and the like. Reduced and stable gas barrier properties are maintained. Preferably 1000 cp
s or less, more preferably 500 cps or less, particularly preferably 100 cps or less.

The water-soluble polymer in the present invention is a polymer which can be completely dissolved or finely dispersed in water at normal temperature, such as a polyvinyl alcohol polymer or a derivative thereof, carboxymethylcellulose, hydroxyethylcellulose and the like. Cellulose derivatives, oxidized starch,
Starches such as etherified starch and dextrin,
Polyvinylpyrrolidone, copolymerized polyester containing a polar group such as sulfoisophthalic acid, vinyl-based polymer such as polyhydroxyethyl methacrylate or its copolymer, acrylic polymer, urethane-based polymer, ether-based polymer or these Carboxyl groups of various polymers,
Examples include functional group-modified polymers such as amino groups and methylol groups.

Preferable is a polyvinyl alcohol polymer or a derivative thereof, and particularly preferable is a saponification degree of 80.
Mol% or more of polyvinyl alcohol; and 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 1500 or less, more preferably 1200 or less, and particularly preferably 1000 or less.

In the present invention, the inorganic plate-like particles are inorganic particles in which ultra-thin unit crystal layers overlap to form one plate-like particle, and those which swell and cleave in a solvent are preferable. Among them, a clay compound having a swelling property in a solvent is particularly preferably used.

[0014] The clay compound having swelling property to solvent in the present invention is a clay compound having coordinated water unit crystal layers very thin, the property of absorbing and swelling, generally Si ⁴⁺ is O
^2- coordinated layers forming a tetrahedral structure and Al ³⁺ , Mg
²⁺ , Fe ²⁺ , Fe ³⁺ , Li ^{+ and the} like coordinate with O ²⁻ and OH ⁻ to form an octahedral structure in one-to-one or two-layer relation.
They are combined one by one and stacked to form a layered structure, which may be natural or synthetic. Representative examples are montmorillonite, beidellite, saponite, hectorite, kaolinite, halloysite,
Vermiculite, dickite, nacrite, antigorite, pyrophyllite, margarite, talc,
Examples include tetrasilyl mica, muscovite, phlogopite, and chlorite. Particularly, montmorillonite, beidellite, hectorite and saponite, which are called smectites, are preferably used.

The particle size of the inorganic plate-like particles is not particularly limited. If the particle size is 0.2 μm or less, particularly 0.05 μm or less, the adhesion is improved, and the particle size is 1 μm or more, especially 5 μm.
If it is at least m, the gas barrier properties will be improved. It is preferable to include two or more types of inorganic plate-like particles having different particle diameters because these characteristics are compatible.

In the present invention, the coating film may contain an amine compound represented by the following general formula (1).

[0017]

Embedded image General formula (1) In the formula, R1 is hydrogen or an alkyl chain having 1 to 6 carbon atoms or a substituted product thereof, or an aryl chain or a substituted product thereof. R2 is hydrogen or an alkyl chain having 1 or more carbon atoms or a substituted product thereof, or an aryl chain or a substituted product thereof. The substituted product, R3, is an alkyl chain having 1 or more carbon atoms or a substituted product thereof, or an aryl chain or a substituted product thereof.

The substituent of the above-mentioned substituent is an amino group,
Imino group, nitrilo group, alkoxy group, carboxyl group, sulfone group, cyano group, methylol group, hydroxyl group, chlorine group or the like, or alkoxysilane, alkoxytitanium, metal alkoxide group such as alkoxyaluminum or a hydrolyzate thereof, As the substituent, an alkyl chain or an aryl chain substituted with one or more of these substituents is preferably used. Specific amine compounds include alkylamines such as butylamine and hexylamine; aminoalcohols such as aminoethyl alcohol, aminohexyl alcohol and aminoethylaminoethanol; diamines such as ethylenediamine and propylenediamine; aminoacetic acid and aminohexane. An acid, an amino acid such as aminododecanoic acid, an amino group-containing silane coupling agent such as γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, or an ethyleneimine unit or a butyleneimine unit;
Polyalkylenimine which is a polymer of hexamethyleneimine units or a copolymer of these units,
Among them, amino acids such as aminoacetic acid, aminohexanoic acid and aminododecanoic acid, amino group-containing silane coupling agents such as γ-aminopropyltriethoxysilane and γ- (2-aminoethyl) aminopropyltrimethoxysilane, or polyethyleneimine are used. It is preferably used.

Polyethylene imine having a linear structure represented by the following general formula (2), or a commercially available polyethylene imine having a branched structure represented by the following general formula (3) (11892) Chemical Products, 466
P., Jan. 22, 1992, published by The Chemical Daily). The amine compound is preferably contained in an amount of 0.01 to 40% by weight based on the total weight of the components constituting the coating film.

[0020]

Embedded image General formula (2)

[0021]

Embedded image General formula (3)

Further, in the present invention, a cross-linking agent may be contained in the coating film. The mixing ratio is 0.01
Is preferably from 10 to 10% by weight, and more preferably from 0.05 to 10% by weight.
8% by weight. 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-like particles / water-soluble or water-dispersible polymer in the present invention is from 1/99 to weight ratio.
The range of 60/40 is preferred. It is preferably at least 1/99 from the viewpoint of gas barrier properties, and is preferably 6/99 from the viewpoint of adhesion.
It is preferably 0/40 or less.

Further, the coating film may be oriented in at least one direction. For orientation in at least one direction, an in-line coating method is preferably used. The orientation state of the coating film can be analyzed using a known technique, for example, a refractive index method, a total reflection infrared spectrum method, a total reflection Raman spectrum method, or the like.

In the present invention, the thickness of the coating film is not particularly limited.
10 μm is preferable, and in the case of in-line coating, 0.0 μm
1 to 0.5 μm is more preferable, and in the case of off-line coating, 0.3 to 6 μm is more preferable.

The present invention also relates to a film having a main component of inorganic plate-like particles and a water-soluble polymer as a coating film and a packaging material using the film. 7 inorganic plate-like particles and water-soluble polymer
0% by weight or more.

As long as the gas barrier properties and transparency are not impaired, various additives may be contained in an amount of 30% by weight or less. Examples of the various additives include an antioxidant, a weathering agent, a heat stabilizer, a lubricant, a nucleating agent, an ultraviolet absorber, and a coloring agent. In addition, as long as transparency and gas barrier properties are not impaired, 20% by weight or less of inorganic or organic particles may be contained. 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-like particles and the polymer, between the polymers or between the plate-like particles 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 preferably about 1 to 10000 ppm based on the coating film.

Further, in the present invention, the process of laminating an unstretched propylene film or the like with an adhesive therebetween improves abrasion resistance and improves gas barrier properties. It is preferably 0.1 μm or less, more preferably 0.08 μm or less, and 0.08 μm or less.
6 μm or less is particularly preferred. Further, Rp is preferably 1 μm or less, more preferably 0.8 μm or less, and particularly preferably 0.6 μm or less.

Ra is the center line average roughness, and Rp is the distance between the maximum peak of the surface roughness curve and the center line.
The average value measured each time is defined as each value. For details on the parameters, see "Method of measuring and evaluating surface roughness" by Jiro Nara
(Comprehensive Technology Center, 1983). Stylus tip radius: 0.5 μm Stylus load: 5 mg Measurement length: 1 mm Cut-off: 0.08 mm

As a method of setting the surface roughness parameter Ra to 0.1 μm or less and Rp to 1 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 prepared. For example, a method of forming a dried coating film in which the temperature of the coating film surface is 180 ° C. or less and the drying time is 30 seconds or less is preferably used. In order to uniformly disperse the components of the coating film, mechanically forcibly disperse the coating material using a homomixer, jet agitator, ball mill, kneader, sand mill, three rolls, etc., which are subject to shear force and shear stress. In particular, it is particularly important to uniformly disperse the plate-like particles so as not to cause secondary agglomeration, and a method of mechanically dispersing the particle dispersion using the above-described apparatus is preferably used. When a homomixer, a jet agitator or the like is used, it is more preferable to carry out at 1000 rpm or more.

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. From the viewpoints of cost performance, transparency, gas barrier properties, etc., polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene are preferable, and polyolefins such as polyethylene and polypropylene are more preferable. .

When a polyolefin resin is used as the thermoplastic resin substrate, the nitrogen / carbon atomic ratio N / C value of the surface of the coating film side is preferably 0.001 to 0.1, more preferably 0 to 0.1. .0015 to 0.08, particularly preferably 0.002 to 0.05. With this range,
The adhesion is improved.

The N / C value is determined by X-ray photoelectron spectroscopy (ESC
A). In order to determine the N / C value of the film on which the coating film is formed, the coating film may be removed by hot water treatment, sputtering, or the like, and the spectrum of the substrate surface may be measured. Alternatively, the composition distribution in the depth direction may be measured using a secondary ion mass spectrometer (SIMS).

In order to keep the N / C value within the above range, the substrate surface before the coating layer is formed is subjected to a corona discharge treatment or a plasma treatment in a rare gas under reduced pressure.
The atmosphere during corona discharge treatment was nitrogen gas (oxygen concentration was 3 v
ol% or less), carbon dioxide or a mixed gas of nitrogen / carbon dioxide is preferable, and a mixed gas of nitrogen / carbon dioxide (volume ratio =
95/5 to 50/50) are more preferred. In addition, plasma treatment is performed while introducing a small amount of argon, helium, carbon dioxide gas or the like into a vessel having a degree of vacuum of about 10 ⁻² Pa, and performing a glow discharge from the electrode to which a high voltage is applied toward the surface A of the film. I do. At this time, carbon dioxide gas is preferred from the viewpoint of processing effect and economic efficiency. The processing intensity is voltage × current /
Calculated from (electrode width × film running speed) (W · min / m ² ), preferably 5 to 400, more preferably 10 to 200, and still more preferably 20 to 100.

The heat shrinkage at 120 ° C. of the formed film is preferably 1% or less for stabilizing gas barrier properties.

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.

The thermoplastic resin base material may contain various additives. 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,
Examples include kaolin, calcium carbonate, titanium oxide, silicon oxide, calcium fluoride, lithium fluoride, alumina, barium sulfate, zirconia, mica, calcium phosphate, and crosslinked polystyrene particles. The average particle diameter is preferably 0.001 to 10 μm, more preferably 0.01 to 10 μm.
03 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. The light transmittance is preferably 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 is preferably 2 to 1000 μm.

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.

When the gas barrier film of the present invention is used as a packaging material, the gas barrier film may be used alone or may be laminated with another material. Other materials are not particularly limited as long as they are generally used materials, paper, metals such as Al and Si or oxides thereof,
Non-woven fabric, resin layer and the like can be mentioned. For the resin layer, a non-stretched or biaxially stretched film, a co-extruded film, a coating film, a vapor-deposited film, a melt-extruded resin, and the like are used. Polyolefins such as polyethylene and polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene Polyester such as -2,6-naphthalate, nylon 6, nylon 1
2, such as polyamide, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate or its saponified product, ethylene vinyl acetate copolymer or its saponified product, polystyrene,
Examples include aromatic polyamide, ionomer resin, polycarbonate, polysulfone, polyphenylene oxide, polyphenylene sulfide, polyimide, polyamide imide, cellulose, cellulose acetate, polyacrylonitrile, and the like, and copolymers thereof. Also, the lamination structure is not particularly limited, and a printing layer, an adhesive layer, and an anchor layer may be provided between the film and another material.

Next, a typical method for producing the gas barrier film of the present invention will be described, but is not limited to the following.

The method for forming a coating film on a thermoplastic resin substrate is not particularly limited, and an extrusion lamination method or a melt coating method may be used. However, since a thin film can be coated at a high speed, the coating method can be used. 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 metaling bar coat to a dispersion solution in which the components of the film 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 or the like. Of course, the anchor treatment may be performed using a known anchor treatment agent such as a urethane resin, an epoxy resin, or polyethyleneimine.

When a biaxially stretched film of a polyester such as polyethylene terephthalate or a polyolefin such as polypropylene is used as the thermoplastic resin substrate, either an off-line coating method or an in-line coating method may be used. When the in-line coating is used, it is preferable to perform the coating before the film is heat-set. Heat setting refers to crystallizing a film stretched by a known technique by heat-treating the film at a temperature higher than the stretching temperature and lower than the melting point of the film while holding the film. Therefore, since before heat setting is before heat treatment, unstretched,
Immediately after uniaxial stretching in the longitudinal direction or transverse direction, coating on the film immediately after biaxial stretching is preferred. More preferably coating on the film immediately after uniaxial stretching,
After that, it is particularly preferable that the film is further stretched uniaxially and heat-set.

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 agent containing the components of the coating film is preferably a solution in which inorganic plate-like particles are uniformly dispersed or swelled in a solvent and a water-soluble polymer is uniformly dissolved or dispersed. As the solvent, water or a mixed solution of water / lower alcohol is used. The use of a mixed solution of water / lower alcohol enables drying to be performed in a short time. 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. The mixing ratio of water / lower alcohol is preferably 100/0 to 20/80 by weight, and 99/1 to 50/80.
/ 50 is more preferred. If the mixing ratio is less than 20/80, the dispersibility of the components of the coating film in the solvent will be deteriorated.

The concentration of the coating agent is not particularly limited, but is preferably 2.5% by weight or more from the viewpoint of productivity such as viscosity of the coating agent and drying efficiency. When having a low-concentration coating agent of less than 2.5% by weight, a method of adding a highly volatile low-boiling solvent having affinity for water to the solvent of the coating agent. A method performed at a temperature or the like is used.

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 preferred.

The method of preparing the coating agent is not particularly limited,
A method in which the plate-like particles are uniformly dispersed in a solvent and then mixed with a solution in which the water-soluble or water-dispersible polymer is uniformly dissolved in the solvent is effectively used. It is preferred that the polymer and the plate-like particles are very uniformly dispersed.

In particular, since the inorganic plate-like particles may be agglomerated in the dispersion liquid, after dispersing the plate-like particles in a solvent, a homomixer or a jet that is subjected to shearing force and shear stress is used. A method in which mechanical forced dispersion treatment is performed using an apparatus such as an agitator, a ball mill, a kneader, a sand mill, or a three-roll mill is preferably used. For example, after the plate-like particles are uniformly dispersed in water at a concentration of several percent by weight, a dispersion treatment is performed using a homomixer or the like, and then mixed with a polymer aqueous solution uniformly dispersed in water at a concentration of several percent by weight, and then mixed again. A method of performing a dispersion treatment and adjusting the concentration by adding a lower alcohol and water is preferably used. Further, the coating agent 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.

The method of laminating other materials when used as a packaging material is not particularly limited, and a general extrusion laminating method, a dry laminating method, a wet laminating method, a hot melt melt laminating method and the like are used.

[0053]

[Evaluation method of characteristics] The evaluation method of characteristics used in the present invention is as follows.

(1) Gas barrier property Oxygen permeability measuring apparatus (OX-TRAN 2/20, manufactured by Modern Control Co., Ltd.) according to ASTM D-3985.
Was used to measure oxygen permeability. Measurement condition is temperature 23
° C and a relative humidity of 75%. Oxygen permeability is 30ml /
(M ² · d · MPa) or less was regarded as good.

(2) Adhesion Using a polyurethane adhesive, an unstretched polypropylene film (CPP, T350 manufactured by Toray Synthetic Film Co., Ltd.)
1, 50 μm) is adhered to the coating surface of this film with a dry laminator, and after aging at 40 ° C. for 48 hours, each surface opposite to the surface in contact with the adhesive is reinforced with cellophane tape and cut to a width of 15 mm. And 18 of this film
0 ° peeling was performed using Tensilon, and the peel strength at that time was determined. The peeling was performed at a peeling speed of 10 cm / min and at 23.
The test was performed in an atmosphere at a temperature of 65 ° C. and a relative humidity of 65%. Adhesion is 1N /
cm or more was regarded as good.

(3) Transparency SEP-H-2 according to JIS-K-6714-58
Haze measured with a system turbidity meter (manufactured by Nippon Seimitsu Kogaku Co., Ltd.) was used. Transparency of 10% or less was regarded as good.

(4) Viscosity of Water-Soluble Polymer The water-soluble polymer was dispersed in pure water so as to have a solid concentration of 10% by weight, and the viscosity of the solution at 23 ° C. was measured with a B-type viscometer.

[0058]

EXAMPLE 1 Montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia-G) was used as an inorganic plate-like particle in an amount of 3% by weight in a water / isopropyl alcohol (hereinafter IPA) mixed solvent (weight ratio: 95).
/ 5) (Solution A). As a water-soluble polymer, polyvinyl alcohol having a degree of saponification of 98 mol% and a degree of polymerization of 500 (hereinafter abbreviated as PVA) is adjusted to 3% by weight of water / IPA.
It was dispersed in a mixed solvent (weight ratio 95/5) (Solution B). The viscosity of the PVA at a solid concentration of 10% by weight is 50 cp.
s. Liquid A and liquid B were mixed at a weight ratio of 50/50 to prepare a coating having a solid content of 3% by weight. The coating was subjected to corona discharge treatment (carbon dioxide / nitrogen mixed gas (volume ratio 83:
17) Medium, processing strength = 60 W · min / m ² ) biaxially oriented polypropylene film (“Torayfan” manufactured by Toray,
Reverse coater (coating speed 20m /
Min), and guided into a hot-air drying dryer, dried at 120 ° C. for 15 seconds under low tension, and wound up.
Table 2 shows the properties of the obtained film. Gas barrier properties,
A film having excellent adhesion and transparency was obtained.

Examples 2 to 4 Films were obtained in the same manner as in Example 1 except that the coating composition, coating thickness, and substrate were changed. Table 2 shows the properties of the obtained film.

In Example 2, as a water-soluble polymer, PVA having a saponification degree of 88 mol% and a polymerization degree of 1000 (solid content of 1%) was used.
When the coating film shown in Table 1 was obtained in the same manner as in Example 1 using a viscosity of 0% by weight (200 cps), a film having excellent gas barrier properties, adhesion, and transparency was obtained.

In Example 3, sodium tetrasilyl mica (manufactured by Topy Industries) was used as the inorganic plate-like particles, and a water-soluble polymer having a saponification degree of 98 mol% and a polymerization degree of 1700 was used.
VA (viscosity at a solid content of 10% by weight is 1100 c
ps), the substrate was subjected to corona discharge treatment (in air) 2
Example 1 A coating film having the composition shown in Table 1 was formed using an axially stretched polyester film ("Lumirror" manufactured by Toray Industries, Ltd., thickness: 12 m).
As a result, a film having excellent gas barrier properties and adhesion was obtained.

In the fourth embodiment, Al metal was deposited on the thermoplastic resin base material of the first embodiment by using an electron beam heating type evaporator under a high vacuum to a thickness of 40 to 50 nm on a film. When a coating film was formed in the same manner as in Example 1, a film having excellent gas barrier properties, adhesion, and transparency was obtained.

Comparative Example 1 A film was obtained in the same manner as in Example 1 except that no plate-like particles were used. As is clear from Table 2, the obtained films were inferior in gas barrier properties and adhesion.

Comparative Example 2 A water-soluble polymer having a degree of saponification of 99.6 mol% and a degree of polymerization of 2
A film was obtained in the same manner as in Example 1, except that 400 PVA (viscosity at a solid content concentration of 10% by weight was 3000 cps) was used. As a result, a film having poor gas barrier properties, adhesion and transparency was obtained.

Example 5 An unstretched polypropylene film (CPP, T3501, manufactured by Toray Synthetic Film Co., Ltd., 50 μm) was coated on the film obtained in Example 1 with a polyurethane-based adhesive. After laminating with a dry laminator at 40 ° C. for 48 hours, the CPP side was laminated with a vertical bag making machine.
20 cm). The obtained bag was cut open, and the gas barrier property was 13.0, and a film excellent in gas barrier property was obtained even after bag making.

[0066]

[Table 1]

The meanings of the abbreviations in the table are as follows. PP is a biaxially oriented polypropylene film (thickness: 20)
μm, corona discharge treatment (treatment intensity = 60 W · min / in a nitrogen gas / carbonic acid mixed gas (volume ratio 83:17))
m ² )), PET is a biaxially oriented polyethylene terephthalate film (thickness: 12 μm, corona discharge treatment in air), PVA1 is a polyvinyl alcohol having a saponification degree of 98 mol%, polymerization degree of 500, PVA2 is a saponification degree of 88 mol%, polymerization 1000 degree polyvinyl alcohol, PVA3
Polyvinyl alcohol having a degree of saponification of 98 mol% and a degree of polymerization of 1700, PVA4 is a polyvinyl alcohol having a degree of saponification of 99.6 mol% and a degree of polymerization of 2400, particles 1 are montmorillonite (Kunimine Industries, Kunipia-G), and particles 2 are sodium tetra Silylic mica (manufactured by Topy Industries).

[0068]

[Table 2]

[0069]

The film obtained by the present invention can be used as any packaging material because it has not only excellent gas barrier properties but also excellent adhesion and transparency.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/32 B32B 27/32 C

Claims (6)

[Claims] 1. A film in which a coating film containing inorganic plate-like particles and a water-soluble polymer as main components is formed on at least one surface of a thermoplastic resin substrate, wherein the solid content concentration of the water-soluble polymer is 10% by weight. 2000c viscosity in aqueous dispersion
a gas barrier film having a pressure of not more than ps. 2. The gas barrier film according to claim 1, wherein the water-soluble polymer is a polyvinyl alcohol polymer or a derivative thereof. 3. The gas barrier film according to claim 2, wherein the molecular weight of the polyvinyl alcohol polymer or a derivative thereof is 1500 or less. 4. The gas barrier film according to claim 1, wherein said thermoplastic resin substrate is made of an olefin resin. 5. The method according to claim 1, wherein a layer comprising a metal and / or a metal oxide is provided on the coating or between the coating and the thermoplastic resin substrate. The gas barrier film according to the above. 6. A packaging material having one or more layers of the film according to claim 1.