JP2002337262A - High gas barrier film and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having high gas barrier properties by easily and stably forming a vapor-deposited thin film layer of a gradient metal oxide composition from a front surface of the film toward the outside of a thickness of the thin film at the time of forming the thin film layer on the front surface of a base film. SOLUTION: In a laminate in which a vapor-deposited thin film layer 2 of an aluminum oxide and a gas barrier coating layer 3 are sequentially laminated on at least one surface of the base film 1 made of a polymer material, the vapor-deposited thin film of the aluminum oxide is formed by a reactive vapor- depositing method of a metal vapor and an oxidative gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent gas barrier material used in the field of packaging foods, pharmaceuticals, precision electronic parts and the like.

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods, pharmaceuticals, precision electronic parts, etc., suppress deterioration of contents, especially oxidation and deterioration of proteins and oils and fats in foods, and further improve taste and freshness. In pharmaceuticals that need to be retained and handled in a clean state, the deterioration of active ingredients is suppressed, and in order to maintain efficacy, corrosion of metal parts and insulation failure are prevented in precision electronic components. Therefore, it is necessary to prevent the influence of oxygen, water vapor, and other gases that alter the contents of the packaging material, and it is required to have a gas barrier property that blocks these gases (gas).

[0003] Therefore, polypropylene (KOP) coated with a vinylidene chloride resin and polyethylene terephthalate (KPE) coated with a vinylidene chloride resin have been conventionally used.
T) or ethylene-vinyl alcohol copolymer (E
Packaging film or aluminum (hereinafter referred to as Al) using a polymer resin composition such as VOH), which is generally considered to have relatively high gas barrier properties, as a packaging material as a gas barrier material
Such as metal foil, polymer resin film and Al
Packaging materials using a metal-deposited film on which a metal or a metal compound such as the above is deposited have been generally used.

However, the packaging material using the above-mentioned polymer resin composition as a gas barrier material has a higher temperature and humidity than a foil using a metal or a metal compound such as Al or a metal vapor-deposited film having these vapor-deposited layers formed thereon. Gas barrier properties tend to be degraded due to the influence of On the other hand, a foil using a metal or a metal compound such as Al or a metal vapor-deposited film formed with these vapor-deposited layers is less affected by temperature, humidity, etc., and is excellent in gas barrier properties. It has drawbacks such that it cannot be confirmed by seeing through.

[0005] Therefore, as a packaging material which overcomes these drawbacks, a vapor deposition film formed by forming a ceramic thin film on a base made of a transparent polymer material by a vapor deposition method or the like has recently been put on the market.

As the material of the ceramic thin film, silicon oxide such as aluminum oxide (AlO _x ) and silicon monoxide (SiO), magnesium oxide, calcium oxide, and the like can be candidates in terms of safety, raw material price, and the like. However, silicon oxide cannot be made highly transparent because of its inherent color, and magnesium oxide and calcium oxide have a high sublimation temperature of the raw material, which results in a low evaporation rate in the vapor deposition step. For this reason, if a thin film having a thickness of about 200 mm, which is sufficient for exhibiting gas barrier properties, is to be deposited, there is a disadvantage in that the film formation time becomes long, leading to high cost, and commercial profitability is not met. .

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 attention from the viewpoints of low cost of raw materials and transparency. Further, by applying a coating such as polyvinyl alcohol on the vapor-deposited thin film layer, the water vapor barrier property is 1 g / m ² . A high water vapor barrier film of about 24 hours can be obtained.

[0008]

However, when the above-mentioned thin film layer of aluminum oxide is formed by a reactive evaporation method, the thin film layer formed by the reaction between aluminum vapor and oxygen gas in the apparatus is reacted. When the oxygen ratio at the time is too large, the gas barrier property is deteriorated, and when the aluminum vapor is too large, the transparency is lowered, so that the composition control is very difficult. When oxygen gas is mixed and reacted with aluminum vapor, a vacuum evaporation apparatus 10 is conventionally used as shown in FIG.
Oxygen gas is supplied into the aluminum vapor atmosphere from the position from the center lower end surface of the cooling drum 15 in the vacuum chamber 11 to the oxygen gas supply port 17, that is, the position where the distance d exceeds 150 mm. It has been produced by a method in which a vapor-deposited thin film layer made of aluminum oxide is formed on the base film 1 by reacting a gas.

In the reactive vapor deposition method in which oxygen gas is supplied from the above-described position, it is necessary to control the chemical composition in a pinpoint manner. It is difficult to obtain, and this has caused a decrease in gas barrier properties.

Further, in the conventional method, aluminum oxide on the surface of the vapor-deposited thin film layer becomes excessive in oxygen element, so that a film surface having poor adhesion to other components is formed, and a gas barrier layer further laminated on the vapor-deposited thin film layer is formed. Insufficient adhesion of the functional coating layer caused gas barrier properties to decrease. For these reasons, the gas barrier film using aluminum oxide has a water vapor barrier property of 0.5 g / m ² . 24h
The following high gas barrier properties were not exhibited.

[0011] An object of the present invention is to form a vapor deposition thin film layer having a metal oxide composition inclined from the film surface to the outside of the thickness of the vapor deposition thin film when the vapor deposition thin film layer is formed on the surface of the base film. It is intended to provide a film having high gas barrier properties by being formed stably and stably.

[0012]

According to a first aspect of the present invention, a thin film layer of aluminum oxide and a gas barrier film layer are sequentially laminated on at least one surface of a base film made of a polymer material. A high gas barrier film, wherein the deposited thin film of aluminum oxide in the laminate is formed by a reactive vapor deposition method of a metal vapor and an oxidizing gas.

Next, a second aspect of the present invention is the high gas barrier property according to the first aspect, wherein the metal vapor is aluminum vapor and the oxidizing gas is oxygen gas. It is a film.

Next, a third aspect of the present invention is the high gas barrier according to the first or second aspect, wherein the thickness of the vapor-deposited thin film layer is in the range of 50 to 3000 °. It is a sex film.

Next, according to a fourth aspect of the present invention, in the first aspect of the present invention, the gas barrier coating layer comprises a water-soluble polymer and one of (a) The above metal alkoxide and its hydrolyzate or (b)
A high gas barrier film comprising at least one of tin chloride.

A fifth aspect of the present invention is the high gas barrier film according to the fourth aspect, wherein the water-soluble polymer is polyvinyl alcohol.

Next, the invention according to claim 6 is characterized in that, in the invention according to claim 4 or 5, the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum or a mixture thereof. It is a high gas barrier film.

According to a seventh aspect of the present invention, there is provided the high gas barrier film according to any one of the first to sixth aspects, wherein the aluminum oxide deposited thin film layer is formed by reacting a metal vapor with an oxidizing gas. When forming by a vapor deposition method, a high gas barrier film characterized in that the oxidizing gas is introduced from a supply port at a position of 10 mm or more and 150 mm or less from the surface of the substrate unwinding side of the cooling drum in the vacuum evaporation apparatus. It is a manufacturing method.

[0019]

According to the present invention, aluminum oxide having a large ratio of oxygen element is formed on the side close to the surface of the base film, and aluminum oxide having a gradient composition in which the ratio of aluminum element is gradually increased toward the outer side of the film thickness. Since the vapor-deposited thin film layer is formed, more stable gas barrier properties can be obtained, and the outer surface of the obtained vapor-deposited thin film layer is a metal oxide having a large aluminum element ratio,
The adhesion of the gas barrier coating layer laminated thereon is improved, and higher gas barrier properties are achieved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The high gas barrier film of the present invention will be described below in detail along with embodiments.

FIG. 1 is a side sectional view of a high gas barrier film showing one embodiment of the present invention. In the thickness direction of the film, a base film 1, an aluminum oxide vapor-deposited thin film layer 2, a gas barrier film layer 3 are formed. Note that a film in which the deposited thin film layer 2 is laminated on the base film 1 is referred to as a deposited film 4.

The base film 1 is a polymer material having transparency, and it is sufficient that the base film 1 is colorless and transparent, and is preferably used as a packaging material. For example, those having mechanical strength and dimensional stability such as polyethylene terephthalate (PET), polypropylene (PP), and nylon (Ny) resin are preferable, and those obtained by processing these into a film shape and further stretching in biaxial directions are preferable. Used. Further, a film having excellent surface smoothness and having 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 base film 1, a corona treatment, a low-temperature plasma treatment, an ion bombardment treatment may be performed as a pretreatment, and a chemical treatment, a solvent treatment, etc. May be applied.

Although the thickness of the base film 1 is not particularly limited, it is 5 to 100 μm in consideration of suitability as a packaging material and workability when laminating another film or forming a vapor-deposited thin film layer. Is preferable.

In consideration of mass productivity, it is desirable to use a long film so that a vapor-deposited thin film layer can be formed continuously.

The deposited thin film layer 2 is formed by using aluminum metal as an evaporation raw material and forming a thin film in the presence of a mixed gas of oxygen gas, carbon dioxide gas and an inert gas. Desirable. In addition, a metal oxide deposited thin film layer can be continuously formed by reactive sputtering or reactive ion plating.

The thickness of the deposited thin film layer 2 is 50 to 300.
It is desirably within the range of 0 °, and the value is appropriately selected. However, if the film thickness is less than 50 °, a uniform thin film may not be formed on the entire surface of the base film 1 and the function as a gas barrier material may not be sufficiently achieved. On the other hand, if the film thickness exceeds 3000 °, flexibility cannot be maintained in the deposited thin film,
This is not preferable because the deposited thin film may be cracked by external factors such as bending and pulling after film formation.

The gas barrier coating layer 3 is further laminated on the vapor-deposited thin film layer 2 in order to impart high gas barrier properties, and its constituent components are a water-soluble polymer and one of (a) An aqueous solution or a water / alcohol mixed solution containing at least one of the above metal alkoxide and hydrolyzate or (b) tin chloride is applied to form a coating agent. A solution prepared by dissolving a water-soluble polymer and tin chloride in an aqueous (water or water / alcohol mixture) solvent or a solution prepared by mixing a solution obtained by directly or previously hydrolyzing a metal alkoxide with a metal oxide Formed on the deposited thin film layer 2 by heating and drying.

The water-soluble polymer used for the gas barrier coating layer 3 includes polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, sodium alginate and the like.
In particular, when polyvinyl alcohol (hereinafter, referred to as PVA) is used, the gas barrier property is most excellent. PV here
A is generally obtained by saponifying polyvinyl acetate, and is a so-called partially saponified P in which several tens% of acetic acid groups remain.
Completely saponified PV in which only a few% of acetic acid groups remain from VA
A is not particularly limited.

Further, 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.

Further, the metal alkoxide is preferably tetraethoxysilane, triisopropoxyaluminum or a mixture thereof.

As the method of applying the gas barrier coating layer 3, conventionally known means such as a commonly used dipping method, roll coating method, screen printing method, spraying method and the like can be used. The coating thickness after drying is 0.0
The thickness may be 1 μm or more, but if the thickness exceeds 50 μm, cracks are likely to occur in the film, so the range is preferably 0.01 to 50 μm.

FIG. 2 is a schematic view of a vacuum deposition apparatus for forming a deposited thin film layer of the high gas barrier film of the present invention by a reactive deposition method. The base film 1 is mounted on the unwinding section 12 of the vacuum vapor deposition apparatus 10, and the vapor-deposited metal raw material 20 is loaded on the crucible 19, and then the vacuum pump 18 is used to load the vacuum chamber 11.
After the inside is evacuated to a degree of vacuum of 1.3 × 10 ^{−2 to} 13 × 10 ⁻² Pa, the substrate film 1 is conveyed from the unwinding unit 12 to the winding unit 13 via the guide roll 14, The vapor deposition metal raw material 20 in the crucible 19 is heated and evaporated by an electron beam heating method (not shown), and at the same time, oxygen gas is supplied from the oxygen gas supply port 17. Oxygen gas supply port 17
Is the space from the surface of the cooling drum 15 on the unwinding side of the substrate film 1, that is, the distance d is 10 mm or more and 150 m
m or less. If the thickness is less than 10 mm, 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 or the like is concerned. Absent.

[0033]

EXAMPLES The high gas barrier film of the present invention will be described with reference to specific examples, but the present invention is not limited to these examples.

<Preparation of coating solution for gas barrier coating layer> 0.1N hydrochloric acid was added to 10.4 g of tetraethoxysilane.
6 g was added and stirred for 30 minutes to hydrolyze the solid content of 3% by weight.
(In terms of SiO ₂ ) and a polyvinyl alcohol 3% by weight water / isopropyl alcohol solution (water / isopropyl alcohol is 90/10 in terms of weight%) at 60% by weight.
/ 40 to prepare a coating solution.

<Example 1> A base film 1 having a thickness of 1
A 2 μm biaxially stretched polyester film is used. After mounting the base film 1 on the unwinding section 12 of the vacuum evaporation apparatus 10 shown in FIG.
Is loaded with aluminum, heated and evaporated by an electron beam heating method, oxygen gas is supplied from an oxygen gas supply port 17, and the base film 1 is conveyed from the unwinding section 12 to the winding section 13 at a speed of 120 m / min. By doing
A roll-up unit 13 winds up a vapor deposition film 4 in which a 200 ° -thick aluminum oxide vapor-deposited thin film layer 2 is formed on a base film 1. Further, the vapor-deposited film 4 is mounted on a gravure coater machine, and the gas-barrier film layer coating solution is applied on the vapor-deposited thin film layer 2 by a gravure coating method and dried, and the gas barrier film layer having a thickness of 0.5 μm is formed. Thus, a high gas barrier film of the present invention was obtained.

<Comparative Example 1> A base film 1 having a thickness of 1
A 2 μm biaxially stretched polyester film is used. After mounting the base film 1 on the unwinding section 12 of the vacuum evaporation apparatus 30 shown in FIG.
Is loaded with aluminum, heated and evaporated by an electron beam heating method, oxygen gas is supplied from an oxygen gas supply port 17, and the base film 1 is conveyed from the unwinding section 12 to the winding section 13 at a speed of 120 m / min. By doing
A roll-up unit 13 winds up a vapor deposition film 4 in which a 200 ° -thick aluminum oxide vapor-deposited thin film layer 2 is formed on a base film 1. Further, the vapor-deposited film 4 is mounted on a gravure coater machine, and the gas-barrier film layer coating solution is applied on the vapor-deposited thin film layer 2 by a gravure coating method and dried, and the gas barrier film layer having a thickness of 0.5 μm is formed. 3 was obtained to obtain a gas barrier film for comparison.

<Evaluation> The light transmittance, oxygen transmittance and water vapor transmittance of the gas barrier films of Example 1 and Comparative Example 1 were measured by the following measuring methods to evaluate the transparency and gas barrier properties. Table 1 shows the results. (1) Light transmittance A wavelength of 400 nm in a state in which a deposited thin film layer of aluminum oxide and a gas barrier coating layer are sequentially laminated on a base film.
The light transmittance of the spectrophotometer (manufactured by Shimadzu Corporation, UV-
3100). (2) Oxygen Permeability In a state where a vapor-deposited thin film layer of aluminum oxide is formed on a substrate film and a state where a gas barrier coating layer is laminated on the surface of the vapor-deposited thin film layer, each oxygen permeability is manufactured by Modern Control. (MOCON OXTRAN, 10/50
The measurement was performed at 25 ° C. in a 100% RH atmosphere using A). (3) Water Vapor Permeability In a state where a vapor-deposited thin film layer of aluminum oxide is formed on a substrate film and a gas barrier coating layer is laminated on the surface of the vapor-deposited thin film layer, each water vapor permeability is manufactured by Modern Control. (MOCON PERMATRAN, W
Using 6), the measurement was performed at 40 ° C. in a 90% RH atmosphere.

[0038]

[Table 1]

From the results shown in Table 1, it can be seen that Example 1 has good transparency, oxygen gas barrier properties and water vapor barrier properties, while Comparative Example 1 has good transparency and oxygen gas barrier properties but has poor water vapor barrier property. .

[0040]

According to the high gas barrier film of the present invention, when a thin film layer of aluminum oxide is formed on a base film, a thin film of aluminum oxide having a high oxygen element ratio is formed on the side close to the surface of the film. Since the vapor deposition thin film layer of the gradient composition composed of aluminum oxide having a large ratio of the aluminum element toward the outside of the film thickness is formed by the reactive vapor deposition method, even in a state where only the vapor deposition thin film layer of aluminum oxide is formed. It has good gas barrier properties, and furthermore, by laminating a gas barrier property coating layer on the deposited thin film layer, it is possible to express even higher gas barrier properties, good productivity, good transparency, and A high gas barrier film could be obtained. By laminating a sealant film or the like on this high gas barrier film, it can be used as a gas barrier packaging material for a wide range of uses.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a high gas barrier film of the present invention.

FIG. 2 is a schematic explanatory view of a vacuum deposition apparatus for forming a deposited thin film layer of a high gas barrier film of the present invention.

FIG. 3 is a schematic explanatory view of a conventional vacuum evaporation apparatus for forming an evaporated thin film layer of a gas barrier film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Deposition thin film layer 3 ... Gas barrier coating layer 4 ... Deposition film 10, 30 ... Vacuum deposition apparatus 11 ... Vacuum chamber 12 ... Unwinding part 13 ... Winding part 14 ... Guide roll 15 ... Cooling drum 16 ... Oxygen supply section 17 ... Oxygen gas supply port 18 ... Vacuum pump 19 ... Crucible 20 ... Evaporated metal raw material d ... Cooling drum surface and length of oxygen gas supply port

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F100 AA05C AA19B AH02C AH06C AH08C AK01A AK01C AK21C AK42 AR00C AT00A BA10A BA10C EH46 EH66B EH662 EJ38 GB15 GB23 JA20B JB09C JD02 AJ03B00 DB03

Claims (7)

[Claims] 1. A laminate in which a deposited thin film layer of aluminum oxide and a gas barrier coating layer are sequentially laminated on at least one surface of a substrate film made of a polymer material, wherein the deposited thin film of aluminum oxide is formed of a metal vapor and an oxidized film. A high gas barrier film comprising a film formed by a reactive vapor deposition method with a reactive gas. 2. The method according to claim 2, wherein said metal vapor is aluminum vapor.
2. The high gas barrier film according to claim 1, wherein the oxidizing gas is oxygen gas. 3. The thickness of said vapor-deposited thin film layer is 50-3000Å.
3. The method according to claim 1, wherein
The high gas barrier film as described in the above. 4. A gas barrier coating layer comprising a water-soluble polymer and at least one of (a) at least one metal alkoxide and a hydrolyzate thereof and (b) tin chloride. The high gas barrier film according to any one of claims 1 to 3. 5. The high gas barrier film according to claim 4, wherein said water-soluble polymer is polyvinyl alcohol. 6. The high gas barrier film according to claim 4, wherein the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof. 7. The method according to claim 1, wherein the vapor-deposited thin film layer of aluminum oxide of the high gas barrier film is formed by a reactive vapor deposition method of a metal vapor and an oxidizing gas. 10 mm or more and 150 mm from the surface on the substrate unwinding side of the cooling drum in the vacuum evaporation apparatus
A method for producing a high gas barrier film, wherein the film is introduced from a supply port at the following position.