JP7428455B1 - metallized film - Google Patents

Abstract

To provide a metallized film having high gas barrier properties against gases such as water vapor and oxygen and high adhesion strength between a film base material and a metal thin film layer. The metallized film A of the present invention has a layer structure in which at least an anchor coat layer 2 and a metal thin film layer 3 are sequentially laminated on one surface of a film base material 1, and the anchor coat layer 2 has a viscosity average molecular weight of 500. It is a layer containing at least a main resin which is a polyester resin of ~10,000, a curing agent which is an isocyanate compound, and an additive, and the solid content weight ratio of the main resin: curing agent is 100:20 to 200. + curing agent):additive=100:10 to 200 (solid weight ratio), and the additive is a compound having a glucose ring. Examples of the curing agent include aromatic isocyanate compounds and alicyclic isocyanate compounds.

Description

TECHNICAL FIELD The present invention relates to a metallized film used for packaging materials for foodstuffs, medicines, etc.

Hitherto, transparent gas barrier films are known in which a metal oxide thin film layer such as an aluminum oxide thin film layer or a silicon oxide thin film layer is laminated on one side of a plastic film.
In addition, a transparent gas barrier film is also known in which a top coat layer made of resin is laminated on the metal oxide thin film layer for the purpose of improving printing suitability and gas barrier properties (water vapor permeability and oxygen permeability). .

For example, in Patent Document 1 below, as a gas barrier film, an anchor coat layer of a urethane resin made of an acrylic resin and an isocyanate resin, an inorganic oxide layer, and an overcoat layer are sequentially provided on at least one surface of a base material. The arranged ones are disclosed.
However, the gas barrier film described in Patent Document 1 cannot provide excellent gas barrier properties when the base material is an unstretched polypropylene (CPP) film and the inorganic oxide layer is a silicon oxide thin film layer. Also, in order to obtain excellent gas barrier properties, the thickness of the anchor coat layer must be increased. When made into a laminated film, there was a problem in that excellent adhesion (interlayer peel strength) could not be obtained.

Regarding the method of laminating a gas barrier film and another plastic film to form a laminated film, there has been a method in which an adhesive layer is laminated on the gas barrier film or other plastic film, and the adhesive layer is laminated through the adhesive layer. Two methods are known: a method in which a molten resin such as polyethylene is poured between a gas barrier film and another plastic film, and the two are laminated together via the molten resin (extrusion lamination method). .

Japanese Patent Application Publication No. 2015-51520

The object of the present invention is to solve the problems in the above-mentioned prior art, have excellent gas barrier properties, and further, when the metal-deposited film of the present invention is laminated with other plastic films to form a laminated film, It is an object of the present invention to provide a metallized film having excellent adhesion strength (interlayer peel strength) between the metallized film and another plastic film even in a 180 degree peel test.
In this specification, excellent gas barrier properties mean that the water vapor permeability measured in accordance with JIS K 7129A method is 5 g/m ² · 24 hr or less, and the oxygen permeability measured in accordance with JIS K 7126B method. It means that the degree is 5cc/ ^m2・24hr or less.
In addition, excellent adhesion means that the adhesion strength between the metallized film and other plastic films is 200 g/15 mm or more in a 180 degree peel test measured in accordance with JIS K 6854-2 method. .

As a result of various studies, the present inventors coated the surface of the film base material with a coating liquid containing at least a polyester resin having a specific viscosity average molecular weight, a curing agent that is an isocyanate compound, and a compound having a glucose ring. The present invention was completed based on the discovery that the above-mentioned problems can be solved by forming an anchor coat layer by coating and forming a metal thin film layer on the anchor coat layer.

That is, the present invention has the following configuration.
[1] A metallized film having a layer structure in which at least an anchor coat layer and a metal thin film layer are sequentially laminated on one surface of a film base material,
The anchor coat layer is a layer containing at least a main resin which is a polyester resin having a viscosity average molecular weight of 500 to 10,000, a curing agent which is an isocyanate compound, and an additive, and the solid content weight of the main resin and curing agent is The ratio is base resin: curing agent = 100:20 to 200, and the total weight of the base resin and curing agent to the solid weight ratio of the additive is base resin + curing agent: additive = 100:10 to 200. , a metal vapor deposited film characterized in that the additive is a compound having a glucose ring.
[2] The metal-deposited film according to [1], wherein the curing agent is selected from the group consisting of aromatic isocyanate compounds and alicyclic isocyanate compounds.
[3] The metal vapor deposited film according to [1] or [2], wherein a top coat layer is formed on the metal thin film layer.

In the metallized film of the present invention, the anchor coat layer provided between the film base material and the metal thin film layer allows, for example, the base material to be a 25 μm thick unstretched polypropylene (CPP) film and the metal thin film element to In the case of a silicon oxide thin film layer with a thickness of 35 nm, excellent gas barrier properties with a water vapor permeability of 2.6 g/m ² 24 hr and an oxygen permeability of 1.5 cc/m ² 24 hr are achieved, and the film base material Regarding the adhesion strength between the metal thin film layer and the metal thin film layer, excellent adhesion with an adhesion strength of 400 g/15 mm in a 180 degree peel test is achieved.

1 is a cross-sectional view (layer structure diagram) of a metallized film A according to an embodiment of the present invention. 2 is a cross-sectional view (layer structure diagram) when a top coat layer 4 is provided on the metal thin film layer 3 of the metal vapor deposited film A of FIG. 1. FIG.

As shown in FIG. 1, the metallized film A of the present invention has a layer structure in which at least an anchor coat layer 2 and a metal thin film layer 3 are laminated in this order on one surface of a film base material 1. This anchor coat layer 2 is a layer containing at least a main resin which is a polyester resin having a viscosity average molecular weight of 500 to 10,000, a curing agent which is an isocyanate compound, and an additive. , a compound having a glucose ring is blended as an additive. By adding a compound having a glucose ring, excellent gas barrier properties and adhesion are achieved.
In the present invention, the ratio of the base material, curing agent, and additives constituting the anchor coat layer 2 is such that the solid weight ratio of the base material and the hardening agent is 100:20 to 200, and The total weight of the base material and hardening agent and the solid content weight ratio of the additive are base material + hardening agent:additive = 100:10 to 200. Excellent gas barrier properties and adhesion between the two layers are achieved. In the present invention, a particularly preferred solid content weight ratio of base agent:curing agent:additive is 100:100:100.
In addition, by setting the proportions of the main agent, curing agent, and additives in the anchor coat layer 2 within the above range, the anchor coat layer is heat resistant so that it will not be deteriorated by the heat generated when forming the metal thin film layer on the anchor coat layer. The metal-deposited film of the present invention can easily exhibit desired gas barrier properties and adhesion.

Hereinafter, details of each layer constituting the metal vapor deposited film A of the present invention will be explained.
(Film base material 1)
The film substrate 1 used in the metallized film of the present invention is not particularly limited, and may include various types such as polyethylene terephthalate film, polyethylene film, polypropylene film, polyamide film, cellophane film, nylon film, and biodegradable resin film. Plastic film can be used.
This film base material 1 may be unstretched, uniaxially stretched, or biaxially stretched, and may contain various additives such as antistatic agents, colorants, and heat stabilizers.

The above-mentioned film base material 1 may be a plastic film that has been subjected to surface treatments such as an easy-adhesive coating or corona treatment in order to strengthen the adhesion between the plastic film and the anchor coat layer. A plastic film made of plastic film is also included in the film base material 1 in the present invention.

The thickness of the film base material 1 is not particularly limited, but from the viewpoint of plasticity, thermal stability, mechanical properties, etc., it is preferably in the range of 2 to 250 μm, more preferably in the range of 9 to 125 μm. preferable. If the thickness of the film base material 1 is thinner than 2 μm, it is not preferable because curls, wrinkles, etc. may easily occur when producing the metallized film of the present invention. If it is thicker than 250 μm, it is not preferable because the workability becomes poor when producing the metallized film of the present invention and the production cost also increases.

(Anchor coat layer 2)
The anchor coat layer 2 in the present invention has a polyester resin (polyester polyol) having a viscosity average molecular weight of 500 to 10,000 as a main ingredient, an isocyanate compound (isocyanate group-containing compound) as a curing agent, and a glucose ring as an additive. This layer is formed by coating (coating) a coating liquid containing a compound having the following on the film base material 1 described above, followed by drying and curing.
In the present invention, by providing such an anchor coat layer 2, the adhesion strength between the film base material 1 and the metal thin film layer 3 can be increased. The metallized film of the invention can exhibit excellent gas barrier properties and adhesion.

The above polyester resin is a polymer whose main components are a polybasic acid component and a polyhydric alcohol component.
Polybasic acid components constituting the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, naphthalene dicarboxylic acid, and biphenyldicarboxylic acid; oxalic acid, succinic acid, succinic anhydride, Saturated aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, icosanedioic acid, hydrogenated dimer acid; fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid anhydride Unsaturated aliphatic dicarboxylic acids such as citraconic acid and dimer acid; 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid and its anhydride; Examples include cycloaliphatic dicarboxylic acids such as tetrahydrophthalic acid and its anhydride.

Polyhydric alcohol components constituting the polyester resin include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1, Aliphatic glycols such as 5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol; 1 , 4-cyclohexanedimethanol; alicyclic glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol; 2,2-bis[4-(hydroxy) Bisphenols (bisphenol A, etc.) such as ethoxy)phenyl]propane and their ethylene oxide adducts, bisphenols (bisphenol S, etc.) such as bis[4-(hydroxyethoxy)phenyl]sulfone, and their ethylene oxide adducts, etc. It will be done.

Furthermore, trifunctional or higher functional polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. may be included as the polyhydric alcohol component.

The polyester resin may be copolymerized with monocarboxylic acid, monoalcohol, or hydroxycarboxylic acid, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and benzoic acid. , p-tert-butylbenzoic acid, cyclohexanoic acid, 4-hydroxyphenylstearic acid, stearyl alcohol, 2-phenoxyethanol, ε-caprolactone, lactic acid, β-hydroxybutyric acid, p-hydroxyethoxybenzoic acid, etc. can be used.

The viscosity average molecular weight of the polyester resin in the present invention is preferably within the range of 500 to 10,000, more preferably within the range of 1,500 to 9,000. In this case, if the viscosity average molecular weight of the polyester resin exceeds 10,000, the compatibility with the compound having a glucose ring becomes poor, making it impossible to obtain both excellent gas barrier properties and adhesion.

In the present invention, the isocyanate compound (isocyanate group-containing compound) of the curing agent constituting the anchor coat layer 2 is preferably selected from the group consisting of aromatic isocyanate compounds and alicyclic isocyanate compounds, such as dicyclohexylmethane. -4,4'-diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, norbornene diisocyanate, xylene diisocyanate, diphenylmethane-4,4'-diisocyanate , various diisocyanates such as diphenylmethane-2,4'-diisocyanate, 2,4-tolylene diisocyanate (TDI), and 2,6-tolylene diisocyanate, various modified products thereof, and dimers obtained by polyfunctionalizing them, Examples include adducts, allophanates, trimers, carbodiimide adducts, biurets, polymers thereof, and polymers added with polyhydric alcohols. A particularly preferred isocyanate compound in the present invention is xylene diisocyanate (XDI).
In the present invention, the solid content weight ratio of base agent:curing agent is in the range of 100:20 to 200, more preferably in the range of 100:50 to 150.

In the present invention, examples of compounds having a glucose ring as additives constituting the anchor coat layer 2 include polysaccharides such as cellulose and pullulan, and their methylated products, nitrated products, acetylated products, carboxymethylated products, cyanoethylated products, Derivatives such as myristoylated products may also be used. Examples include cellulose acetate butyrate, cellulose acetate, methylcellulose, nitrocellulose, pullulan, myristoyl pullulan, and the like.
In the present invention, the solid content weight ratio of base resin + curing agent: additive is in the range of 100:10 to 200, more preferably in the range of 100:20 to 100.

The thickness of the anchor coat layer 2 in the present invention is preferably within the range of 0.1 μm to 3.0 μm, particularly preferably within the range of 0.3 μm to 1.0 μm. At this time, if the thickness of the anchor coat layer 2 exceeds 3.0 μm, it will easily peel off from the film base material 1 due to the internal stress of the anchor coat layer 2, and if the thickness is less than 0.1 μm, the thickness It may not be uniform. In the present invention, in order to improve the adhesion strength between the film base material 1 and the anchor coat layer 2, the film base material 1 is subjected to surface treatment such as an easy-adhesive coating and corona treatment before forming the anchor coat layer 2. may have been done.
The coating method (coating method) for the anchor coat layer 2 includes, for example, bar coater, knife coat, die coat, gravure coat, microgravure coat, spray coat, dip coat, screen printing, etc., but is not particularly limited.
Further, as a drying method for drying the coated anchor coat layer 2, for example, one or a combination of two or more methods of applying heat such as hot air drying, hot roll drying, high frequency irradiation, infrared irradiation, and UV irradiation can be used. can.

(Metal thin film layer 3)
As the material for the metal thin film layer 3 (evaporation material), various conventionally known metals such as aluminum, silicon, chromium, tin, gold, silver, copper, zinc, nickel, and indium can be used. It may be selected as appropriate depending on the purpose. Further, the metal thin film layer may be a thin film layer of the above-mentioned conventionally known metal oxides, sulfides, or nitrides.
As a method for forming the metal thin film layer 3, conventionally known methods such as vacuum evaporation, sputtering evaporation, and CVD can be used. In the case of vacuum evaporation, heating evaporation using an electron beam, laser beam, etc. can be used. is preferably used.

The thickness of the metal thin film layer 3 formed on the surface of the anchor coat layer 2 is generally preferably within the range of 3 nm to 300 nm, more preferably within the range of 3 nm to 150 nm, and the value may be selected as appropriate. Ru.
If the thickness of the metal thin film layer 3 is less than 3 nm, a uniform film may not be obtained or the desired gas barrier performance may not be exhibited. In addition, if the thickness of the metal thin film layer 3 exceeds 300 nm, the film cannot maintain its flexibility, and the metal thin film layer may be bent or stretched after film formation due to external factors. Cracks may occur, and desired gas barrier properties may not be achieved.

(Top coat layer 4)
In the present invention, a top coat layer 4 may be provided on the metal thin film layer 3 as shown in FIG. Resin, vinyl chloride resin, polyester resin, acrylic resin, urethane resin, melamine resin, epoxy resin, etc. may be one type of various known resins, or a mixed resin of two or more types, depending on the purpose. You can select it as appropriate.
In the present invention, gas barrier properties are further improved by forming the top coat layer 4.
Moreover, various additives such as a curing agent, an antistatic agent, an ultraviolet absorber, a coloring agent, a heat stabilizer, and a silane coupling agent may be added to the top coat layer 4 as necessary.
When using a silane coupling agent in the top coat layer 4, the silane coupling agent to be used may be vinyl-based, epoxy-based, styryl-based, methacrylic-based, acrylic-based, amino-based, isocyanurate-based, ureide-based, mercapto-based, Various silane coupling agents such as sulfide type and isocyanate type can be used, and may be appropriately selected depending on the desired purpose. Such a top coat layer 4 can be formed by coating a paint mixture of the above-mentioned components by a conventionally known coating method such as a gravure coating method, a reverse coating method, a die coating method, or the like.
The thickness of the top coat layer 4 is preferably in the range of 0.1 to 3.0 μm, more preferably in the range of 0.1 to 1.0 μm, from the viewpoint of gas barrier properties and adhesion.

The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

[Physical property comparison experiment based on differences in resins constituting the anchor coat layer and the presence or absence of additives]
An unstretched polypropylene (CPP) film (thickness: 25 μm) was prepared as a film base material, and the following two types of resins were prepared as main ingredients for forming an anchor coat layer.
・Polyester resin (viscosity average molecular weight: 8,000)
・Acrylic resin (viscosity average molecular weight: 8,000)
Further, the aforementioned XDI isocyanate was used as a curing agent, and commercially available nitrocellulose (NC) was prepared as an additive.

Using the above two types of base materials, the coating liquid was added so that the solid content weight ratio of base material: hardening agent was 100:100, and the additive (NC) was added to the solid content of base material: hardening agent: additive. A coating solution was prepared with a weight ratio of 100:100:100, coated on one side of the CPP film using a gravure method, dried and cured to form an anchor having the thickness listed in Table 1 below. A coat layer was formed. Then, a 35 nm thick silicon oxide thin film layer was formed on the surface of this anchor coat layer by vacuum evaporation to prepare a measurement sample.
As a comparison, a sample in which a silicon oxide thin film layer was formed without providing an anchor coat layer was also prepared.
Gas barrier properties of each test sample were measured using the water vapor permeability test and oxygen permeability test described below. Further, the adhesion strength was measured by the following 180 degree peel test.

[Water vapor permeability test]
(Measuring method)
In accordance with the JIS K 7129A method, the water vapor permeability of each test sample was measured using a water vapor permeability measuring device (L80-4000J manufactured by Lissy, Switzerland) in an atmosphere at a temperature of 40° C. and a humidity of 90%.

[Oxygen permeability test]
(Measuring method)
In accordance with the JIS K 7126B method, the oxygen permeability of each test sample was measured using an oxygen permeability measuring device (MOCON OX-TRAN, manufactured by Mocon, USA) in an atmosphere of 23°C and 75% humidity. .

[Measurement of adhesion strength]
(Test sample)
An adhesive resin for dry lamination was coated on the metal thin film layer of each measurement sample to form an adhesive layer, and a laminated film was produced by laminating it with a 12 μm thick PET film, each having a width of 15 mm and a length. It was cut into 10 cm pieces and used for measurement.

[180 degree peel test]
(Measuring method)
In accordance with the JIS K 6854-2 method (Adhesives - Peel adhesive strength test method - Part 2: 180 degree peel), the adhesion strength between the metallized film and other plastic film was measured for each test sample. (Peeling speed: 300mm/min)

(Test results)
The above measurement results are shown in Table 1 below.

From the results in Table 1 above, when the resin constituting the anchor coat layer was a polyester resin, higher adhesion strength was obtained than that of an acrylic resin. Further, when the film base material is a CPP film with a thickness of 25 μm and the metal thin film layer is a silicon oxide thin film layer with a thickness of 35 nm, the anchor coat layer is a layer containing at least a polyester resin, an isocyanate compound, and an additive. As a result, excellent gas barrier properties and excellent adhesion were achieved.

[Physical property comparison experiment I based on differences in anchor coat layer thickness]
An unstretched polypropylene (CPP) film (thickness: 25 μm) was used as a film base material, and the aforementioned polyester resin having a viscosity average molecular weight of 8,000 was prepared as a main ingredient for forming an anchor coat layer.
Further, the aforementioned XDI isocyanate was used as a curing agent, and commercially available nitrocellulose (NC) was prepared as an additive.

Coating liquids were prepared using the above main ingredients so that the solid content weight ratio of main agent: curing agent: additive was 100:100:100, and coated on one side of the above film base material (CPP film) using a gravure method. Coating was performed, dried and cured to form an anchor coat layer having the thickness listed in Table 2 below. Then, a 35 nm thick silicon oxide thin film layer was formed on the surface of this anchor coat layer by vacuum evaporation to prepare a measurement sample.
For each test sample, gas barrier properties were measured using the water vapor permeability test and oxygen permeability test described above, and for adhesion strength, a laminated film was prepared in the same manner as described above, and the adhesion was determined using the 180 degree peel test described above. The strength was measured.
The above measurement results are shown in Table 2 below.

From the results in Table 2 above, it was confirmed that by forming an anchor coat layer containing a polyester resin, a curing agent, and nitrocellulose (NC), gas barrier properties were improved and water vapor permeability and oxygen permeability were reduced. It was confirmed that particularly high adhesion strength was obtained when the thickness of the anchor coat layer was less than 1 μm.

[Experiment I comparing physical properties with different types of film base materials]
As film base materials, PET film (thickness 12 μm), polyethylene (PE) film (thickness 17 μm), biaxially oriented polypropylene (OPP) film (thickness 20 μm), and cellophane film (thickness 20 μm) were prepared, and anchors were prepared. The above-mentioned polyester resin having a viscosity average molecular weight of 8000 is used as the main material for forming the coat layer, and the above-mentioned curing agent and additives are added to this resin so that the solid content weight ratio of main material: curing agent: additive is 100. :100:100, coated on one side of the above four types of film base materials by gravure method, dried and cured to form an anchor coat with the thickness listed in Table 3 below. formed a layer. Then, a 40 nm thick aluminum thin film layer was formed on the surface of this anchor coat layer by vacuum evaporation to prepare a measurement sample.
For each test sample, gas barrier properties were measured using the water vapor permeability test and oxygen permeability test described above, and for adhesion strength, a laminated film was prepared in the same manner as described above, and the adhesion was determined using the 180 degree peel test described above. The strength was measured.
The above measurement results are shown in Table 3 below.

From the results in Table 3 above, the water vapor permeability and oxygen permeability of the four types of measurement samples described above are similar, with a water vapor permeability of 0.1 g/m ² 24 hr and an oxygen permeability of 0.1. Or 0.5 cc/m ² ·24 hr, it was confirmed that it had excellent gas barrier properties and adhesion. However, in terms of adhesion strength, PE film has higher adhesion strength than cellophane film, OPP film has better adhesion than PE film, and PET film has higher adhesion strength than OPP film. was gotten.

[Physical property comparison experiment II based on differences in the thickness of the anchor coat layer]
A CPP film with a thickness of 25 μm was used as the film base material, the above-mentioned polyester resin with a viscosity average molecular weight of 8000 was used as the main agent for forming the anchor coat layer, and the above-mentioned curing agent was added to this resin as the main agent: The coating liquid was added so that the solid content weight ratio of the curing agent was 100:100, and the additive cellulose acetate butyrate (CAB) was added so that the solid content weight ratio of main agent: curing agent: additive was 100:100: 100 was prepared, and one side of the above CPP film was coated using a gravure method, dried and cured to form an anchor coat layer having the thickness shown in Table 4 below. Then, a 35 nm thick aluminum thin film layer was formed on the surface of this anchor coat layer by vacuum evaporation to prepare a measurement sample.
For each test sample, gas barrier properties were measured using the water vapor permeability test and oxygen permeability test described above, and for adhesion strength, a laminated film was prepared in the same manner as described above, and the adhesion was determined using the 180 degree peel test described above. The strength was measured.
The above measurement results are shown in Table 4 below.

From the results in Table 4 above, it was found that if cellulose acetate butyrate (CAB) was not added to the coating solution for forming the anchor coat layer, excellent adhesion of 200 g or more could not be obtained. . In addition, when comparing the case where the thickness of the anchor coat layer is 0.4 μm, excellent gas barrier properties and adhesion can be achieved by incorporating cellulose acetate butyrate (CAB) into the coating liquid for forming the anchor coat layer. It was confirmed that both oxygen permeability and adhesion strength were significantly improved.

[Physical property comparison experiment using different types of additives, amounts of additives, and types of deposited metals]
Three types of additives were prepared: nitrocellulose (NC), myristoyl pullulan, and cellulose acetate butyrate (CAB). Then, changes in gas barrier properties and adhesion were investigated using additives added in the parts by weight listed in Table 5 with respect to a total of 100 parts by weight of the base resin and curing agent. (35 nm silicon oxide thin film layer). Furthermore, a metal vapor deposited film was prepared in which an aluminum (AL) thin film layer having the same thickness as the silicon oxide thin film layer was formed as a metal thin film layer, and physical properties were compared based on the difference in the type of vapor deposited metal. Regarding the adhesion strength, a laminated film was prepared in the same manner as described above, and the adhesion strength was measured by the 180 degree peel test described above.
The above measurement results are shown in Table 5 below.

From the results in Table 5 above, it was confirmed that excellent gas barrier properties and adhesion were exhibited regardless of whether NC, myristoyl pullulan, or CAB was added. It has also been found that a metal-deposited film with particularly excellent gas barrier properties and adhesion can be obtained when the additive (NC) is blended in a range of 10 to 200 parts by weight based on a total of 100 parts by weight of the base agent and curing agent. Ta. It was also confirmed that the aluminum thin film layer was superior to the silicon oxide thin film layer in terms of gas barrier properties (water vapor permeability and oxygen permeability).

[Comparison experiment of compatibility with additives due to difference in viscosity average molecular weight of polyester resin for anchor coat layer formation]
Seven types of resins having the viscosity average molecular weights listed in Table 6 below were prepared as polyester resins for forming the anchor coat layer, and additives nitrocellulose (NC) and myristoyl were prepared using the following measurement method. The compatibility with pullulan and CAB was measured.
(Compatibility test method with additives)
Coating liquids (base resin: curing agent = 100:100) for forming anchor coat layers were prepared using the above seven types of polyester resins, and additives were added to each coating liquid as main resin: curing agent: additive. = 100:100:100, and the compatibility of each additive was visually evaluated. The evaluation criteria are as follows.

(Evaluation criteria)
○: Additives dissolve (no gelation of coating liquid, no cloudiness)
×: Additives do not dissolve (coating liquid gels and becomes cloudy)
The above measurement results are shown in Table 6 below.

From the results in Table 6 above, when the viscosity average molecular weight of the polyester resin for anchor coat layer formation is less than 500 and when it exceeds 10,000, the nitric acid contained in the coating liquid for anchor coat layer formation is It was confirmed that the compatibility with cellulose, CAB, and myristoyl pullulan deteriorated.

[Comparison experiment of physical properties based on differences in viscosity average molecular weight of polyester resin for forming anchor coat layer]
Resins having a viscosity average molecular weight of 500 to 20,000 were prepared as polyester resins for forming the anchor coat layer, and metallized films were produced using the above-mentioned curing agent and additive (NC). In addition to the metal vapor deposited film described above, a metal vapor deposited film in which a top coat layer with a thickness of 0.1 μm is formed on the metal thin film layer using a coating liquid having a composition described in the margin of Table 7. (Film base material: CPP film or OPP film) was also produced.
Then, for each metallized film, the gas barrier properties and the adhesion strength of the laminated film produced in the same manner as described above were measured. The metallized film on which the top coat layer was formed was coated with an adhesive resin for dry lamination on the top coat layer to form an adhesive layer, and then laminated with a PET film having a thickness of 12 μm to form a laminated film.
In addition, with the aforementioned polyester resins with viscosity average molecular weights of 300, 13,000, and 20,000, the coating solution gelled and became cloudy, making it impossible to form an anchor coat layer on the film base material. excluded from.
The above measurement results are shown in Table 7 below.

From the results in Table 7 above, it is clear that when a polyester resin with a viscosity average molecular weight in the range of 500 to 10,000 is used for forming the anchor coat layer, a metallized film with particularly excellent gas barrier properties and adhesion can be obtained. Therefore, the viscosity average molecular weight range of the polyester resin used for forming the anchor coat layer in the present invention was set in the range of 500 to 10,000. It was also confirmed that gas barrier properties (water vapor permeability and oxygen permeability) were further improved by providing a top coat layer on the metal thin film layer.

[Physical property comparison experiment II using different types of film base materials]
A PET film (thickness: 12 μm) and a CPP film (thickness: 25 μm) were prepared as film base materials.
On the other hand, the above-mentioned polyester resin with a viscosity average molecular weight of 8000 is used as the main material for forming the anchor coat layer, and the above-mentioned curing agent and additive (NC) are added to this resin in a ratio of main material: curing agent: additive. A coating liquid was prepared with a solid weight ratio of 100:100:100, coated on one side of each of the above film substrates by a gravure method, dried and cured, and the results are shown in Table 8 below. A thick anchor coat layer was formed. Thereafter, a 40 nm thick aluminum thin film layer was formed on the surface of this anchor coat layer by vacuum evaporation to prepare measurement samples (Examples 1 to 6).
As a comparison, samples were prepared in which an aluminum thin film layer was formed on the surface of a PET film or a CPP film without providing an anchor coat layer (Comparative Examples 1 and 2).
For each of the above test samples, gas barrier properties were measured using the water vapor permeability test and oxygen permeability test described above, and for adhesion strength, a laminated film was prepared in the same manner as described above and subjected to the 180 degree peel test described above. The adhesion strength was measured.
The above measurement results are shown in Table 8 below.

As shown in Table 8, all of the metallized films of the present invention in Examples 1 to 6 had a water vapor permeability of 0.3 g/m ² ·24 hr or less and an oxygen permeability of 1.6 cc/m ² · It was 24 hours or less, and had excellent gas barrier properties. On the other hand, it was confirmed that all of the metallized films of Comparative Examples 1 and 2 had poorer gas barrier properties than the metallized film of the present invention.

Regarding adhesion strength, all of the metallized films of the present invention in Examples 1 to 6 had an adhesion strength of 200 g/15 mm or more in a 180 degree peel test between the film base material and the anchor coat layer. On the other hand, all of the metallized films of Comparative Examples 1 and 2 had an adhesion strength of less than 200 g/15 mm in a 180 degree peel test between the film base material and the anchor coat layer, and had excellent adhesion. It has been confirmed that this is not the case.

A Metal vapor deposited film 1 Film base material 2 Anchor coat layer 3 Metal thin film layer 4 Top coat layer

Claims (3)

A metal vapor deposited film having a layer structure in which at least an anchor coat layer and a metal thin film layer are sequentially laminated on one surface of a film base material,
The anchor coat layer is a layer containing at least a main resin which is a polyester resin having a viscosity average molecular weight of 500 to 10,000, a curing agent which is an isocyanate compound, and an additive, and the solid content weight of the main resin and curing agent is The ratio is base resin: curing agent = 100:20 to 200, and the total weight of the base resin and curing agent to the solid weight ratio of the additive is base resin + curing agent: additive = 100:10 to 200. , the additive is a compound having a glucose ring , and
A metal vapor deposited film characterized in that the thickness of the anchor coat layer is within the range of 0.1 μm to 3.0 μm . The metallized film according to claim 1, wherein the curing agent is selected from the group consisting of aromatic isocyanate compounds and alicyclic isocyanate compounds. The metal vapor deposited film according to claim 1 or 2, further comprising a top coat layer formed on the metal thin film layer.

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