JP4649794B2 - Highly transparent barrier film and method for producing the same - Google Patents

Description

【００４４】
表１の結果より、実施例１はバリア性フイルムの透明性も良く、蒸着フイルム及びバリア性フイルムの酸素透過度及び水蒸気透過度も小さい。比較例１は蒸着薄膜層の表面をプラズマ処理しなかったので、バリア性フイルムの透明性が劣っている。比較例２及び比較例３はバリア性フイルムの透明性は良いが、蒸着フイルム及びバリア性フイルムの酸素透過度及び水蒸気透過度が劣っている。
【００４５】
【発明の効果】
本発明の高透明バリア性フイルムは、透明な基材の上に、基材の表面に近い側が酸素元素比率が多く、膜厚の外側に向けて酸素元素比率が小さくなった組成の傾斜構造の酸化アルミニウムの蒸着薄膜層を形成させ、前記蒸着薄膜層を形成させた直後にその表面をプラズマ処理しているので、他の層との密着性もよく、かつ、透明性が向上している。さらに、前記プラズマ処理した蒸着フイルムの蒸着薄膜層のプラズマ処理面にガスバリア性被膜層を積層しているので、従来のバリア性フイルムに比べて優れたガスバリアを有しており、食品分野あるいは非食品分野などの広い範囲で優れたバリア性包装材料として利用できる。
【図面の簡単な説明】
【図１】本発明の高透明バリア性フイルムの側断面図である。
【図２】本発明の高透明バリア性フイルムの蒸着薄膜層を形成させる真空蒸着装置の説明図である。
【図３】従来のバリアフイルムの蒸着薄膜層を形成させる真空蒸着装置の説明図である。
【符号の説明】
１…基材
２…蒸着薄膜層
３…プラズマ処理面
４…蒸着フイルム
５…ガスバリア性被膜層
６…高透明バリア性フイルム
１０、３０…真空蒸着装置
１１…真空チャンバー
１２…巻き出し部
１３…巻き取り部
１４…ガイドロール
１５…冷却ドラム
１６…酸素供給部
１７…酸素ガス供給口
１８…真空ポンプ
１９…るつぼ
２０…膜厚計
２１…プラズマ処理装置
２２…蒸着原材料
ｄ…冷却ドラム表面と酸素ガス供給口の長さ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transparent gas barrier material used in the packaging field of foods, pharmaceuticals, precision electronic components and the like.
[0002]
[Prior art]
In recent years, packaging materials used for packaging foods, pharmaceuticals, precision electronic components, etc. have been improved in order to suppress the alteration of contents, especially the oxidation and alteration of proteins and oils and fats in food, and to maintain the taste and freshness. In addition, in pharmaceutical products that require handling under aseptic conditions, in order to suppress the alteration of active ingredients and maintain their efficacy, and to prevent corrosion of metal parts, insulation defects, etc. in precision electronic parts, It is necessary to prevent the influence of oxygen, water vapor, or other gas that alters the contents of the packaging material, and it is required to have gas barrier properties that block these gases.
[0003]
Therefore, a packaging film made of a polymer resin that is generally said to have a relatively high gas barrier property such as polypropylene (KOP), polyethylene terephthalate (KPET), or ethylene / vinyl alcohol copolymer (EVOH) coated with vinylidene chloride resin. A metal foil made of a metal such as aluminum (hereinafter referred to as Al), and a packaging film such as a metal vapor deposited film obtained by depositing a metal such as Al or a metal compound on a polymer resin film have been generally used.
[0004]
However, the packaging film coated with the above gas barrier resin or the packaging film using only the polymer resin composition alone has a gas barrier property as compared with a metal deposition film in which a metal foil such as Al or a metal or a metal compound is deposited. Not only is it inferior, but it is also susceptible to temperature and humidity, and depending on the change, the gas barrier property may be further deteriorated. On the other hand, metal foils such as Al and metal vapor deposited films deposited with metal or metal compounds are less affected by temperature, humidity, etc. and have excellent gas barrier properties, but these materials are used because they are opaque. When the package is filled with the contents, the contents cannot be seen through from the outside.
[0005]
Therefore, as a packaging material that overcomes these drawbacks, recently, a vapor deposition film in which a ceramic thin film is formed on a substrate made of a transparent polymer material by a vapor deposition method or the like has been put on the market.
[0006]
As a material for the ceramic thin film, aluminum oxide, silicon oxide, magnesium oxide, calcium oxide and the like can be candidates in terms of safety and raw material price. However, since silicon oxide has a color peculiar to the material, it cannot be highly transparent, and magnesium oxide and calcium oxide have a high sublimation temperature of the raw material, and therefore the evaporation rate in the vapor deposition process is slow. For this reason, if a thin film having a thickness of about 200 mm sufficient for exhibiting barrier properties is to be deposited, the film formation time becomes long, leading to high costs, and there is a disadvantage that commercial profitability is not suitable.
[0007]
For the above reasons, a method of forming a vapor-deposited thin film layer of aluminum oxide by a reactive vapor deposition method has attracted the most attention because of its low cost and transparency. Further, by coating the vapor-deposited thin film layer with polyvinyl alcohol or the like, the water vapor barrier property is 1 g / m ² . A barrier film of about 24 hours can be obtained.
[0008]
[Problems to be solved by the invention]
However, the vapor deposition thin film layer formed by the reactive vapor deposition method of oxygen gas and aluminum vapor deteriorates the barrier property when the ratio of oxygen gas at the time of reaction is excessive, and the transparency decreases when the ratio of aluminum vapor is excessive. Therefore, composition control is very difficult.
[0009]
In the conventional method, as shown in FIG. 3, when oxygen gas is mixed with aluminum vapor, the length from the center lower end of the cooling drum 15 in the vacuum chamber 11 of the vacuum deposition apparatus 30 to the oxygen gas supply port 17, that is, d It has been produced by a method in which oxygen gas is supplied into an aluminum vapor atmosphere from a position where the distance exceeds 150 mm, and aluminum vapor and oxygen gas are reacted to form a deposited thin film layer of aluminum oxide on the substrate 1.
[0010]
In the reactive vapor deposition method in which oxygen gas is supplied from the position as described above, a vapor deposition thin film having a relatively uniform composition is formed. However, pinpoint chemical composition control is required, and the composition changes due to changes in the amount of evaporated aluminum. It is not able to cope with it sufficiently and deviates from the ideal chemical composition, causing a decrease in barrier properties. Therefore, a barrier film using a vapor deposited thin film layer of aluminum oxide has a water vapor barrier property of 0.5 g / m ² . A high barrier property of 24 h or less was not expressed.
[0011]
An object of the present invention is to prevent a barrier deterioration due to a change in the composition of a metal oxide of a vapor-deposited thin film layer formed on at least one surface of a substrate, and to have a barrier film having a high barrier property while maintaining a high transparency, and The manufacturing method is provided.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention is a laminate in which an aluminum oxide vapor-deposited thin film layer and a gas barrier film layer are laminated on at least one surface of a base material made of a polymer material. slope but formed by reactive deposition of aluminum vapor and oxygen gas, and the composition of the deposited thin layer near the surface of the substrate side has a larger oxygen ratio, the oxygen ratio toward the outside of the film thickness smaller A highly transparent barrier film characterized by having a structure and further comprising a plasma-treated surface of the formed vapor-deposited thin film layer.
[0014]
Next, the invention according to claim 2 is the highly transparent barrier film according to the invention according to claim 1 , wherein the thickness of the deposited thin film layer is in a range of 50 to 3000 mm.
[0015]
Next, the invention according to claim 3 is the invention according to claim 1 or 2 , wherein the gas barrier coating layer comprises a water-soluble polymer, (a) one or more metal alkoxides and hydrolysis thereof. Or (b) a highly transparent barrier film characterized by comprising at least one of tin chloride.
[0016]
Next, an invention according to claim 4 is the highly transparent barrier film according to the invention according to claim 3 , wherein the water-soluble polymer is polyvinyl alcohol.
[0017]
Next, an invention according to claim 5 is the invention according to claim 3 or claim 4 , wherein the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof. It is a barrier film.
[0018]
Next, the invention according to claim 6 is a deposited thin film layer in which aluminum oxide is deposited and formed in sequence on at least one surface of a base material made of a polymer material by a reactive deposition method of aluminum vapor and oxygen gas. 6. A method for producing a highly transparent barrier film for producing a highly transparent barrier film according to any one of claims 1 to 5, characterized in that the surface of said film is laminated with a plasma treatment and a gas barrier film layer.
Next, the invention is a deposition thin film layer of high transparency barrier film in the manufacturing method of the high transparency barrier film of the 請 Motomeko 6, wherein when forming a reactive vapor deposition method, vacuum oxidizing gas according to claim 7 It is a method for producing a highly transparent barrier film, wherein the film is introduced from a supply port at a position of 10 mm or more and 150 mm or less from the surface of the cooling drum in the vapor deposition apparatus on the substrate unwinding side.
[0019]
Next, the invention according to claim 8, in the production of highly transparent barrier film in the manufacturing method of the high transparency barrier film of the 請 Motomeko 6, wherein, after forming a vapor deposition thin film layer in a vacuum vapor deposition apparatus, the vapor deposition A method for producing a highly transparent barrier film, characterized in that a surface of a thin film layer is subjected to plasma treatment.
[0020]
[Action]
According to the present invention, the composition of the vapor-deposited thin film layer on the side close to the surface of the substrate is composed of an oxide vapor-deposited thin film layer having an inclined structure in which the oxygen ratio is large and the oxygen ratio is small toward the outside of the film thickness. Since the aluminum ratio on the film surface is increased, a sufficiently reactive surface is formed, and the coating property of the coating agent laminated on the deposited thin film layer is improved. Furthermore, transparency is improved by the plasma treatment of the deposited thin film layer after the thin film is formed. Furthermore, since the gas barrier coating layer is laminated on the plasma-deposited thin film layer, it has higher gas barrier properties.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
The highly transparent barrier film of the present invention and the production method thereof will be described below along the embodiments.
[0022]
FIG. 1 is a side sectional view of a highly transparent barrier film 6 according to the present invention, in which a substrate 1, a deposited thin film layer 2, a plasma treatment surface 3, and a gas barrier coating layer 5 are formed in this order in the thickness direction of the film. .
[0023]
The substrate 1 is a polymer material having transparency, and in particular, it may be colorless and transparent, and those usually used as packaging materials are preferable. For example, those having mechanical strength and dimensional stability such as polyethylene terephthalate (PET), polypropylene (PP), and nylon (Ny) are preferable, and those processed into a film shape and further stretched biaxially are preferable. . Furthermore, a film having excellent surface smoothness and a small amount of additives is preferable. Further, in order to improve the adhesion of the deposited thin film layer to the surface of the substrate 1, corona treatment, low temperature plasma treatment, ion bombardment treatment may be performed as pretreatment, and further chemical treatment, solvent treatment, etc. You may give it.
[0024]
The thickness of the substrate 1 is not particularly limited, but is preferably in the range of 5 to 100 μm in consideration of suitability as a packaging material, workability when laminating other films or forming a deposited thin film layer, and the like. . In consideration of mass productivity, it is desirable to use a long film so that a vapor-deposited thin film layer can be continuously formed.
[0025]
The vapor deposition thin film layer 2 is formed by a so-called reactive vapor deposition method in which aluminum metal is used as a vapor deposition raw material and a thin film is formed in the presence of a mixed gas of oxygen gas, carbon dioxide gas and inert gas.
[0026]
Furthermore, the surface of the vapor-deposited thin film layer 2 is plasma-treated on the treatment surface 3, and the plasma treatment improves the adhesion when laminating other layers and improves the transparency. .
[0027]
The thickness of the deposited thin film layer 2 is preferably in the range of 50 to 3000 mm, and the value is appropriately selected. However, if the film thickness is 50 mm or less, a uniform thin film may not be formed on the entire surface of the substrate 1, and the function as a gas barrier material may not be sufficiently achieved. On the other hand, if the film thickness exceeds 3000 mm, flexibility cannot be maintained in the deposited thin film, and it is not good because the deposited thin film may be cracked due to external factors such as bending and pulling after the deposition.
[0028]
The gas barrier coating layer 5 is further laminated on the vapor-deposited thin film layer 2 in order to give high gas barrier properties, and its constituent components are a water-soluble polymer and (a) one or more metals. It is formed by applying a coating agent mainly comprising an aqueous solution containing at least one of alkoxide and hydrolyzate or (b) tin chloride or a water / alcohol mixed solution. A solution in which a water-soluble polymer and tin chloride are dissolved in an aqueous (water or water / alcohol mixed) solvent, or a solution in which a metal alkoxide is directly or previously hydrolyzed is mixed with a metal oxide. The deposited thin film layer 2 is formed by coating and heating and drying.
[0029]
Examples of the water-soluble polymer used in the gas barrier coating layer 5 include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate. In particular, when polyvinyl alcohol (hereinafter referred to as PVA) is used, gas barrier properties are most excellent. PVA as used herein is generally obtained by saponifying polyvinyl acetate, from a so-called partially saponified PVA in which several tens percent of acetic acid groups remain to completely saponified PVA in which only several percent of acetic acid groups remain. Including, but not limited to.
[0030]
The tin chloride may be stannous chloride (SnCl ₂ ), stannic chloride (SnCl ₄ ), or a mixture thereof, and may be an anhydride or a hydrate.
[0031]
Further, the metal alkoxide is preferably tetraethoxysilane, triisopropoxyaluminum or a mixture thereof.
[0032]
As a method for applying the gas barrier coating layer 5, conventionally known means such as a dipping method, a roll coating method, a screen printing method, a spray method and the like that are usually used can be used. The film thickness after drying may be 0.01 μm or more, but if the thickness exceeds 50 μm, cracks are likely to occur in the film, so the range of 0.01 to 50 μm is preferable.
[0033]
FIG. 2 is a schematic view of a vacuum deposition apparatus 10 for forming a deposited thin film layer of a highly transparent barrier film of the present invention by a reactive deposition method. After the base material 1 is mounted on the unwinding part 12 of the vacuum vapor deposition apparatus 10 and the vapor deposition metal raw material 22 is loaded in the crucible 19, the degree of vacuum is 1.3 × 10 ^{−2 to} 13 in the vacuum chamber 11 by the vacuum pump 18. After evacuating in the range of × 10 ⁻² Pa, the vapor-deposited metal raw material 22 in the crucible 19 is transferred to the electron beam heating system while conveying the substrate 1 from the unwinding section 12 through the guide roll 14 to the winding section 13 ( The oxygen gas is supplied from the oxygen gas supply port 17 into the aluminum vapor atmosphere. It is preferable that the oxygen gas supply port 17 has a length from the surface of the cooling drum 15 on the unwinding side of the base material 1, that is, a distance d is 10 mm or more and 150 mm or less. If the thickness is less than 10 mm, there is concern about contact with the cooling drum 15 due to a change in the shape of the oxygen supply port due to the radiant heat of the molten metal. Absent.
[0034]
The highly transparent barrier film of the present invention has a thin film thickness 20 measured immediately after the vapor deposition thin film layer 2 is formed on the surface of the substrate 1 by the reactive vapor deposition method in the vacuum vapor deposition apparatus 10 of FIG. Transparency can be improved by plasma-treating the surface of the vapor-deposited thin film layer 2 with the plasma processing apparatus 21 after measuring the above. By performing the plasma treatment after the film thickness meter 20, it is possible to make the film transparent while maintaining the film thickness controllability.
[0035]
The plasma treatment may be either a direct-current plasma method or a high-frequency plasma method, but a powerful treatment method such as a hollow anode, which is a kind of high-frequency method, is preferable. The processing gas is generally argon, but the effect increases when an oxidizing gas such as oxygen is used in combination.
[0036]
【Example】
The highly transparent barrier film of the present invention will be described with reference to specific examples.
[0037]
<Adjustment of coating solution for gas barrier coating layer>
89.6 g of 0.1N hydrochloric acid was added to 10.4 g of tetraethoxysilane, and the mixture was stirred for 30 minutes and hydrolyzed to obtain a solid content solution of 3 wt% (in terms of SiO ₂ ) and a polyvinyl alcohol 3 wt% water / isopropyl alcohol solution (water / Isopropyl alcohol was mixed in a weight percent ratio of 90/10) to a weight percent ratio of 60/40 to prepare a coating solution.
[0038]
<Example 1>
In the aluminum vapor atmosphere using the biaxially stretched polyester film having a thickness of 12 μm as the substrate 1 and using the vacuum vapor deposition apparatus 10, the aluminum metal used as the vapor deposition raw material 22 is heated and evaporated by the electron beam heating method. Oxygen gas is introduced from the oxygen gas supply port 17 to be reacted, and the composition on the side close to the surface of the substrate 1 has a large oxygen content ratio, and the total composition of the gradient structure in which the oxygen content ratio is small toward the outside of the film thickness. A vapor-deposited film 4 was formed by forming a vapor-deposited thin-film layer 2 of aluminum oxide having a thickness of 200 mm and further treating the surface of the vapor-deposited thin-film layer 2 with DC plasma. Further, the vapor deposition film 4 is mounted on another coater, and the coating solution of the gas barrier coating layer is applied to the plasma treatment surface 3 of the vapor deposition thin film layer 2 of the vapor deposition film 4 by a gravure coating method and dried. A gas barrier coating layer 5 having a thickness of 5 μm was formed to prepare a highly transparent barrier film 6 of the present invention.
[0039]
<Comparative example 1>
A barrier film for comparison was prepared in the same manner as in Example 1 except that a deposited film in which the surface of the deposited thin film layer 2 was not plasma-treated was used.
[0040]
<Comparative example 2>
A biaxially stretched polyester film having a thickness of 12 μm is used as the substrate 1, and oxygen is used in an aluminum vapor atmosphere in which the aluminum metal used as the deposition raw material 22 is heated and evaporated by the electron beam heating method using the vacuum deposition apparatus 30. Oxygen gas was introduced from the gas supply port 17 and reacted to prepare a vapor deposition film in which a vapor deposition thin film layer 2 of aluminum oxide having a uniform composition and a total thickness of 200 mm was formed on the surface of the substrate 1. Next, the surface of the vapor-deposited thin film layer of the vapor-deposited film was subjected to plasma treatment with a separate plasma treatment apparatus. Further, the plasma-treated vapor deposition film is mounted on a coater, and the gas barrier coating layer coating solution is applied to the vapor deposition thin film layer of the vapor deposition film by a gravure coating method and dried to form a gas barrier coating having a thickness of 0.5 μm. Layer 5 was formed to produce a comparative barrier film.
[0041]
<Comparative Example 3>
In Comparative Example 2, a comparative barrier film was prepared in the same manner except that a vapor deposition film in which the surface of the vapor deposition thin film layer 2 was not plasma-treated was used.
[0042]
<Evaluation>
Using the vapor deposition film and the barrier film of Example 1 and Comparative Examples 1 to 3, the light transmittance, oxygen permeability, and water vapor permeability of each film were measured and evaluated by the following measuring methods. The results are shown in Table 1.
(1) Light transmittance (%)
Using a spectrophotometer (UV-3100, manufactured by Shimadzu Corporation), the light transmittance at a wavelength of 350 nm of the barrier film was measured.
(2) Oxygen permeability (ml / m ² · 24h · atm)
Using a modern control (MOCON OXTRAN 10 / 50A), the oxygen permeability of the deposited film and the barrier film was measured in an atmosphere of 30 ° C. and 70% RH.
(3) Water vapor permeability (g / m ² · 24h)
Using a modern control (MOCON PERMATRAN W6), the water vapor permeability of the deposited film and the barrier film was measured in an atmosphere of 40 ° C. and 90% RH.
[0043]
[Table 1]

[0044]
From the results shown in Table 1, Example 1 has good transparency of the barrier film, and the oxygen permeability and water vapor permeability of the vapor deposition film and the barrier film are also small. In Comparative Example 1, since the surface of the deposited thin film layer was not plasma-treated, the transparency of the barrier film was inferior. In Comparative Example 2 and Comparative Example 3, the transparency of the barrier film is good, but the oxygen permeability and water vapor permeability of the deposited film and the barrier film are inferior.
[0045]
【The invention's effect】
The highly transparent barrier film of the present invention has a gradient structure having a composition in which the oxygen element ratio is large on the side close to the surface of the substrate and the oxygen element ratio decreases toward the outside of the film thickness on a transparent substrate. Since the vapor deposition thin film layer of aluminum oxide is formed and the surface is plasma-treated immediately after the vapor deposition thin film layer is formed, the adhesion with other layers is good and the transparency is improved. Further, since the gas barrier coating layer is laminated on the plasma processing surface of the vapor deposition thin film layer of the plasma-treated vapor deposition film, it has a gas barrier superior to that of the conventional barrier film and can be used in the food field or non-food. It can be used as an excellent barrier packaging material in a wide range of fields.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a highly transparent barrier film of the present invention.
FIG. 2 is an explanatory view of a vacuum deposition apparatus for forming a deposited thin film layer of a highly transparent barrier film of the present invention.
FIG. 3 is an explanatory view of a conventional vacuum deposition apparatus for forming a deposited thin film layer of a barrier film.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Deposition thin film layer 3 ... Plasma processing surface 4 ... Deposition film 5 ... Gas barrier film layer 6 ... High transparency barrier film 10, 30 ... Vacuum deposition apparatus 11 ... Vacuum chamber 12 ... Unwinding part 13 ... Winding Taking part 14 ... Guide roll 15 ... Cooling drum 16 ... Oxygen supply part 17 ... Oxygen gas supply port 18 ... Vacuum pump 19 ... Crucible 20 ... Film thickness meter 21 ... Plasma processing apparatus 22 ... Raw material d ... Cooling drum surface and oxygen gas Supply port length

Claims (8)

On at least one side of the substrate made of a polymer material, depositing a thin layer of aluminum oxide, in a laminate with a gas barrier coating layer, reactive evaporation thin layers of oxide aluminum and aluminum vapor and oxygen gas The deposited thin film formed by the vapor deposition method has a gradient structure in which the composition of the deposited thin film layer on the side close to the surface of the substrate has a large oxygen ratio and the oxygen ratio is small toward the outside of the film thickness. A highly transparent barrier film, characterized in that the surface of the layer is made by plasma treatment. High transparency barrier film according to claim 1, wherein the thickness of the deposited thin film layers, characterized in that in the range of 50～3000A. The gas barrier coating layer comprises a water-soluble polymer and at least one of (a) one or more metal alkoxides and hydrolysates thereof, or (b) tin chloride. Alternatively, the highly transparent barrier film according to claim 2 . 4. The highly transparent barrier film according to claim 3 , wherein the water-soluble polymer is polyvinyl alcohol. 5. The highly transparent barrier film according to claim 3 , wherein the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof.   Aluminum oxide is sequentially deposited on at least one surface of a base material made of a polymer material by a reactive vapor deposition method of aluminum vapor and oxygen gas, and the surface of the formed thin film layer is subjected to plasma treatment and a gas barrier coating layer. A method for producing a highly transparent barrier film for producing the highly transparent barrier film according to any one of claims 1 to 5, wherein the film is laminated. The deposition thin film layer of high transparency barrier film in 請 Motomeko 6 method for producing a high transparency barrier film according to the time of forming a reactive vapor deposition method, an oxidizing gas unwinding base of the cooling drum of the vacuum evaporation apparatus A method for producing a highly transparent barrier film, which is introduced from a supply port at a position of 10 mm to 150 mm from the surface on the side. During the production of highly transparent barrier film in 請 Motomeko 6 method for producing a high transparency barrier film according, immediately after having formed a deposited thin film layer in a vacuum vapor deposition apparatus, the surface of the deposition film layer to a plasma treatment A method for producing a highly transparent barrier film.

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