JP2003105527A - Vapor deposited film of aluminum oxide and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a method of obtaining a vapor deposited film of aluminum oxide, by which the vapor deposited film of aluminum oxide having stable characteristics, e.g. stable gas barrier performance can be easily obtained even when production conditions such as process speed are changed. SOLUTION: The vapor deposited film of aluminum oxide is characterized in that the ratio (A/B) of the intensity (A) of the X-ray fluorescence kcps (aluminum Kα ray) of the vapor deposited film (1) of aluminum oxide to the intensity (B) of the X-ray fluorescence kcps (aluminum Kα ray) of the vapor deposited film (2) of aluminum oxide, obtained without introducing oxygen is in the range of >=0.55 and <=0.90, and the method for producing the vapor deposited film of aluminum oxide is also provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aluminum oxide vapor-deposited film having excellent transparency and gas barrier properties against oxygen or water vapor, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, as a barrier material against oxygen or water vapor, an inorganic oxide such as silicon oxide or aluminum oxide is applied to a plastic substrate by vacuum deposition method, sputtering method, ion plating method, chemical vapor deposition method. A transparent gas-barrier film formed of the same or the like is drawing attention.

Usually, in order to produce a gas barrier film having an aluminum oxide vapor deposition film, aluminum oxide is vapor-deposited on a plastic substrate while oxygen gas is supplied to aluminum which has been heated and vaporized by an electron beam to oxidize it. Has been adopted. However, since the aluminum vaporized by heating and oxygen react very easily, for example, if the supply amount of oxygen is increased, a dense film cannot be formed, and as a result, a film excellent in gas barrier property, particularly water vapor barrier property is obtained. I can't. On the other hand, if the supply amount of oxygen is reduced, the transparency is lowered, and in any case, it is necessary to strictly control the supply amount of oxygen and the evaporation amount of aluminum to obtain a film having stable gas quality and excellent gas barrier properties. is there.

As one of the methods for controlling the amount of aluminum oxide vapor deposition, for example, a method of maintaining the ratio of the average amount of aluminum vaporized (mol / min) to the amount of introduced oxygen gas (mol / min) within a specific range. (Japanese Patent Laid-Open No. 62-103359) is known, but in such a method, the amount of aluminum adhering to the film and the amount of aluminum that causes loss in the deposition preventive plate and the like differ depending on conditions,
Since the reaction state between aluminum and oxygen changes depending on the evaporation rate of aluminum, a film having the same barrier property may not always be obtained even with the same ratio, and an aluminum oxide vapor deposition film with stable quality such as gas barrier property can be obtained. There is a possibility that it will not. Further, a method of controlling the light transmittance during vapor deposition (Japanese Patent Laid-Open No. 2001-81219) is known, but the light transmittance is determined by two factors such as the oxidation state of aluminum and the film thickness of the deposited film. There is a possibility that an aluminum oxide vapor deposition film having stable quality such as gas barrier property cannot be obtained only by the light transmittance. Further, a method of controlling X of AlOx of the vapor deposition film (Japanese Patent Laid-Open No. 11-1704).
No. 27 gazette) is known, but it is difficult to measure the amount of oxygen during vapor deposition in a vapor deposition machine, and when the produced vapor deposition film is exposed to the atmosphere once and measured, it reacts with oxygen in the atmosphere. Since the value of X varies, similarly, there is a possibility that an aluminum oxide vapor deposition film having stable quality such as gas barrier property cannot be obtained.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies to develop a method for easily obtaining an aluminum oxide vapor-deposited film whose quality such as gas barrier property is stable even if manufacturing conditions such as processing speed are changed. As a result, the ratio of the fluorescent X-ray intensity (A) kcps of the aluminum oxide vapor deposition film (1) to the fluorescent X-ray intensity (B) kcps of the aluminum vapor deposition film (2) when oxygen is not introduced is set within a specific range. As a result, it was found that an aluminum oxide vapor deposition film having stable quality such as gas barrier properties can be obtained, and the present invention was reached.

[0006]

Means for Solving the Invention

SUMMARY OF THE INVENTION That is, according to the present invention, the fluorescent X-ray intensity (A) kc of the obtained aluminum oxide vapor deposition film (1)
The ratio of the ps (aluminum Kα ray) to the fluorescent X-ray intensity (B) kcps (aluminum Kα ray) of the aluminum vapor deposition film (2) obtained without introducing oxygen (A /
B) is 0.55 ≦ (A / B) ≦ 0.90 and relates to an aluminum oxide vapor deposition film and a method for producing the same.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Aluminum Oxide Vapor Deposition Film The aluminum oxide vapor deposition film of the present invention is obtained without fluorescent oxygen X-ray intensity (A) kcps and oxygen introduction of the aluminum oxide vapor deposition film (1) obtained on a film substrate. The ratio (A / B, hereinafter sometimes referred to as “adhesion rate”) of the aluminum vapor deposition film (2) to the fluorescent X-ray intensity (B) kcps is 0.55 ≦ (A / B) ≦ 0.90. ,
A film formed by vapor deposition of aluminum oxide in the range of 0.60 ≦ (A / B) ≦ 0.80 is preferable. If the adhesion rate is less than 0.55, the film will not be excellent in gas barrier properties and the like, whereas if the adhesion rate is more than 0.90, the film will be inferior in transparency.

The fluorescent X-ray intensity (A) kcps of the aluminum oxide vapor deposited film (1) in the present invention can be obtained by the following method. That is, by introducing a predetermined amount of oxygen into the vapor deposition machine, the light transmittance during processing to a predetermined value, obtained by controlling the evaporation amount of aluminum, or
An aluminum oxide film obtained by introducing and reacting a predetermined amount of oxygen under controlled conditions such that predetermined aluminum is vapor-deposited is sampled, and a fluorescent X-ray analyzer Z is used.
SX100s (manufactured by Rigaku Denki Kogyo Co., Ltd.) was used to measure the Kα ray of aluminum, and the fluorescent X-ray intensity was measured by
kcps.

The fluorescent X-ray intensity (B) kcps of the aluminum vapor-deposited film (2) obtained without introducing oxygen is such that during the production of aluminum oxide, the introduction of oxygen is stopped under the same conditions as the sampling of the aluminum oxide film. The obtained aluminum vapor-deposited film is sampled, and the Kα ray of aluminum is measured using a fluorescent X-ray analyzer ZSX100s (manufactured by Rigaku Denki Kogyo Co., Ltd.), and the fluorescent X-ray intensity is defined as (B) kcps. The aluminum oxide vapor-deposited film of the present invention preferably has a fluorescent X-ray intensity (A) kcps of 0.5 to 10 of aluminum oxide (1).
kcps, more preferably 0.5 to 8 kcps, still more preferably 0.5 to 5 kcps. By setting it in this range, an aluminum oxide vapor deposition film having excellent transparency and barrier properties can be obtained.

The film thickness of aluminum oxide is not particularly limited, but is usually 15Å to 500Å, preferably 20Å to
It is 450Å. If it is less than 15 Å, a film having excellent gas barrier properties may not be obtained, while if it is 500 Å or more, the film may lack flexibility.

The aluminum oxide vapor-deposited film of the present invention may be laminated with a heat-sealing layer on the film substrate surface and / or the aluminum oxide vapor-deposited surface in order to impart heat sealability. Examples of such a heat-sealing layer include ethylene, propylene, butene-1, and hexene-which are generally known as heat-sealing layers.
Α-, such as 1,4-methyl pentene-1 and octene-1
Olefin homopolymer or copolymer, high-pressure low-density polyethylene, linear low-density polyethylene (so-called LLDP
E), high-density polyethylene, polypropylene, polypropylene random copolymer, polybutene, poly-4-methylpentene-1, low crystalline or amorphous ethylene.
Polyolefins such as propylene random copolymers, ethylene / butene-1 random copolymers, propylene / butene-1 random copolymers, alone or in combination of two or more, ethylene / vinyl acetate copolymer (EVA) or EVA And a composition of polyolefin and the like can be used.

The aluminum oxide vapor-deposited film of the present invention may have a top coat layer on the vapor-deposited surface in order to protect the vapor-deposited surface or to improve printability on the surface thereof. The top coat layer is a polyester resin, It is provided by coating a urethane resin, an epoxy resin, a melamine resin, or the like. Further, in order to further stabilize the barrier property, a polyvinyl alcohol-based resin, an ethylene-vinyl alcohol copolymer resin, an organic silicon-based coating (including a sol-gel method) material, or a barrier material such as polyvinylidene chloride may be coated.

[0013] film substrate according to the film substrate present invention is typically a sheet-shaped or film-shaped base material made of a thermoplastic resin. As the thermoplastic resin, various known thermoplastic resins, for example, polyolefin (polyethylene, polypropylene,
Poly 4-methyl / 1-pentene, polybutene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, polymethaxylene adipamide, etc.), polyvinyl chloride , Polyimide, ethylene-vinyl acetate copolymer, polyacrylonitrile,
Examples thereof include polycarbonate, polystyrene, ionomer, and mixtures thereof. Of these, thermoplastic resins having good stretchability and transparency, such as polypropylene, polyethylene terephthalate, and polyamide, are preferable. The substrate made of such a thermoplastic resin film may be a non-stretched film or a stretched film.

On one or both sides of the film substrate,
To improve the adhesion with aluminum oxide, for example,
Surface activation treatment such as corona treatment, flame treatment, plasma treatment, undercoat treatment, primer coat treatment and flame treatment may be carried out. The thickness of the film substrate is usually in the range of 5 to 50 μm, preferably 9 to 30 μm.

Production Method of Aluminum Oxide Vapor Deposition Film The production method of the aluminum oxide vapor deposition film of the present invention is as follows:
When reacting oxygen and aluminum vapor in vacuum on the above film substrate to form aluminum oxide, the fluorescent X-ray intensity (A) kcps and oxygen of the obtained aluminum oxide vapor deposition film (1) are not introduced. Fluorescent X-ray intensity (B) kcp of the obtained aluminum vapor deposition film (2)
The ratio (A / B) with s is 0.55 ≦ (A / B) ≦ 0.9
It is a method of forming an aluminum oxide vapor deposition film in the range of 0, preferably 0.60 ≦ (A / B) ≦ 0.80.
Fluorescence X of the obtained aluminum oxide vapor deposition film (1)
The linear intensity (A) kcps depends on the amount of oxygen introduced, and when the amount of oxygen introduced (oxidation degree) increases, the amount of vapor deposition as aluminum decreases, so the fluorescent X-ray intensity (A) decreases and If the amount of introduction is small, the amount of vapor deposition as aluminum increases, so that the fluorescent X-ray intensity (A) increases. The fluorescent X-ray intensity (B) kcps represents the amount of aluminum vapor deposited when oxygen is not introduced at all.

Further, the amount of aluminum oxide (metal aluminum) deposited depends on the processing speed (processing speed) of the film substrate to be deposited, the efficiency with which evaporated aluminum adheres to the film substrate (vapor deposition efficiency), and the evaporation rate of aluminum. Etc., and there is a correlation between the amount of aluminum oxide (aluminum) vapor deposition and the light transmittance of the vapor deposition film. If the oxidation state is the same, aluminum oxide (aluminum)
When the amount of vapor deposition of (1) increases, the light transmittance of the vapor deposition film during processing decreases.

It is more preferable to equip the vapor deposition tank with a fluorescent X-ray measuring device so that the fluorescent X-ray intensity (B) of the obtained aluminum oxide vapor deposition film can be measured to directly control the conditions.

When a fluorescent X-ray measuring device is not installed in the vapor deposition tank, the vapor deposition film is prepared in advance by changing the processing speed, the evaporation amount of metal aluminum, the oxygen introduction amount, etc. by the vapor deposition device used. It is preferable to measure (A) and (B) and obtain a calibration curve of (A) and (B) with the processing speed, the evaporation amount of metallic aluminum, the amount of oxygen introduced, the light transmittance, and the like. Then, to set A / B within such a range, specifically, for example, the amount of introduced oxygen to be reacted and the amount of evaporation of aluminum can be controlled. The amount of oxygen introduced can be controlled to be constant using a mass flow controller. The amount of introduced oxygen greatly varies depending on the processing speed, the film thickness, etc., but for example, when the vapor deposition speed is 600 m / min and the light transmittance is 83%, the width is preferably 0.9 to 1 m per width.
It may be 4.6 L / min, and more preferably 1.9 to 4.2 L / min. The evaporation amount of aluminum can be controlled on the basis of the light transmittance of the aluminum vapor deposition film at 350 nm or the light transmittance of the aluminum oxide vapor deposition film with a constant introduced oxygen. If a device for measuring light transmittance (light transmittance meter) is installed in the vapor deposition tank, the light transmittance of aluminum oxide can be constantly monitored during vapor deposition. In that case, the light transmittance of the aluminum oxide vapor deposition film is preferably 70% to 95%.
%, More preferably 75% to 90%, A / B can be set in a desired range.

The introduction position of oxygen that oxidizes aluminum is installed in the unwinding direction side of the base film, in the width direction in the adhesion-preventing plate, so that oxygen is introduced toward the aluminum vapor in the rotating direction side of the cooling roll. It is preferable to install. At this position, it is only necessary to supply oxygen to the aluminum vapor-deposited on the base film (it is not necessary to supply oxygen to the aluminum adhered to the deposition preventive plate etc.). It is possible to prevent the deterioration of the degree of vacuum by introducing.

As a method for heating aluminum, various known methods such as an electron beam (EB) method, a high frequency induction heating method, and a resistance heating method can be used. Among them, the electron beam vacuum vapor deposition method is more preferable because it has good thermal efficiency, can be vapor-deposited at a high speed, and can easily obtain a uniform film thickness distribution.

From the viewpoint of production, the vapor deposition rate is preferably as high as possible within the range of the apparatus, but preferably 10 to 1000 m / min.
It is preferably 50 to 1000 m / min, and stable production is possible within this range.

From the viewpoint of removing static electricity and surface treatment of the film base material, immediately after unwinding the film base material in the vapor deposition tank,
Plasma treatment may be performed. Examples of methods for generating plasma include direct current glow discharge, high frequency discharge, and microwave discharge. Further, it is necessary to introduce a gas for the discharge, and examples of the gas include various gases generally used in the discharge, such as argon, helium, oxygen, and nitrogen.

In electron beam heating vacuum vapor deposition, the film substrate is charged by secondary electrons and reflected electrons from the electron beam during vapor deposition. In order to remove these static electricity, it is necessary to perform plasma treatment immediately after vapor deposition. Examples of methods for generating plasma include direct current glow discharge, high frequency discharge, and microwave discharge. In addition, it is necessary to introduce gas for discharge, such as argon, helium, oxygen, nitrogen, etc.
There are various gases commonly used in electric discharge.

[0024]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

The physical properties in Examples and Comparative Examples were measured by the following measuring methods. (1) Measurement of oxygen permeability 50 μm with the vapor deposition surface of the vapor deposition film immediately after vapor deposition inside
m LLDPE (density 0.920 g / cm ³ , MFR
(3.8 g / 10 minutes), and the film dry-laminated was measured under the conditions of a temperature of 20 ° C. and a humidity of 90% RH using an oxygen transmission rate measuring device (MOCON: OXTRAN2 / 20). (2) Water vapor permeability measurement Immediately after vapor deposition, with the vapor deposition surface of the vapor deposition film inside, 50 μm
m of LLDPE and dry-laminated film, calcium chloride was added as the content, and the surface area was 0.01 m.
^The bag is made so that it becomes ² , and the temperature is 40 ° C and the humidity is 90% RH.
The sample was allowed to stand for 3 days under the above condition, and the water vapor permeability was measured by the weight difference. (3) Fluorescent X-ray intensity fluorescent X-ray analyzer (Rigaku Denki Kogyo: ZSX100s)
Was used to measure the Kα ray of aluminum. (4) Control of light transmittance and aluminum evaporation amount The light transmittance of 350 nm (PET was set to 100%) was measured in the vapor deposition tank, and the light transmittance was adjusted to a specified value.
The output of the electron beam was controlled to adjust the evaporation amount of aluminum.

Example 1 A 12 μm biaxially stretched polyethylene terephthalate film (PET film) was used as a base material, and aluminum was heated and evaporated on one side by an electron beam heating method, and oxygen was supplied at 4.1 L / min per 1 m width. Light transmittance 80
%, The vapor deposition rate was 600 m / min. Table 1 shows the physical property values of the obtained vapor deposition film.

Example 2 Using a 12 μm biaxially stretched PET film as a base material, aluminum was heated and evaporated on one side by an electron beam heating method, oxygen was supplied at 3.7 L / min per 1 m width, and the light transmittance was increased. Deposition was performed at 80% and a deposition rate of 600 m / min. Table 1 shows the physical property values of the obtained vapor deposition film.

Example 3 Using a 12 μm biaxially stretched PET film as a base material, aluminum was heated and evaporated on one side by an electron beam heating method, oxygen was supplied at 3.7 L / min per 1 m width, and the light transmittance was increased. Deposition was carried out at a deposition rate of 600 m / min at 77%.
Table 1 shows the physical property values of the obtained vapor deposition film.

Example 4 A 12 μm biaxially stretched PET film was used as a base material, and aluminum was heated and evaporated on one side by an electron beam heating method, oxygen was supplied at 3.4 L / min per 1 m width, and the light transmittance was increased. Deposition was performed at 80% and a deposition rate of 600 m / min. Table 1 shows the physical property values of the obtained vapor deposition film.

Comparative Example 1 A 12 μm biaxially stretched PET film was used as a base material, and aluminum was heated and evaporated on one side by an electron beam heating method, oxygen was supplied at 4.6 L / min per 1 m width, and the light transmittance was increased. The deposition rate was 85% and the deposition rate was 600 m / min.
Table 1 shows the physical property values of the obtained vapor deposition film.

Comparative Example 2 A 12 μm biaxially stretched PET film was used as a base material, and aluminum was heated and evaporated on one surface thereof by an electron beam heating method, and the light transmittance was 61%, and the vapor deposition rate was 600 m / min. Table 1 shows the physical property values of the obtained vapor deposition film.

[0032]

[Table 1]

As can be seen from Table 1, in Examples 1 to 4, aluminum oxide vapor deposition films having a good water vapor barrier property were obtained immediately after vapor deposition. Further, in Comparative Example 1 or 2, a vapor deposition film having a good barrier property is not obtained.

[0034]

As is clear from the above description, when oxygen and aluminum vapor are reacted in vacuum to form aluminum oxide on the film substrate, 0.55 ≦ adhesion rate (A / B) By producing an aluminum oxide vapor deposition film in the range of ≤0.90, it is possible to obtain an aluminum oxide vapor deposition film having a stable oxygen gas barrier property and a good water vapor barrier property even immediately after vapor deposition. In this way, by controlling the quality of the aluminum oxide vapor deposition film based on the deposition rate, even at various vapor deposition rates,
Appropriate vapor deposition conditions can be found, and an aluminum oxide vapor deposition film having a stable barrier property can be manufactured. This aluminum oxide vapor deposition film can be used for various packaging applications such as foods, pharmaceuticals, cosmetics, and industrial materials.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuya Toyama             9th Kitatone, Sowa Town, Sarushima District, Ibaraki Prefecture             Within the corporation F-term (reference) 4F006 AA11 AA31 AB74 BA05 DA01                 4K029 AA11 AA25 BA03 BA44 BC08                       CA01

Claims (4)

[Claims] 1. A fluorescent X-ray intensity (A) kc of an aluminum oxide vapor-deposited film (1) obtained on one surface of a substrate film.
The ratio of the ps (aluminum Kα ray) to the fluorescent X-ray intensity (B) kcps (aluminum Kα ray) of the aluminum vapor deposition film (2) obtained without introducing oxygen (A /
An aluminum oxide vapor-deposited film, characterized in that B) is vapor-deposited with aluminum oxide in the range of 0.55 ≦ (A / B) ≦ 0.90. 2. The aluminum oxide vapor-deposited film according to claim 1, wherein the fluorescent X-ray intensity (A) kcps of aluminum oxide (1) is 0.5 kcps to 10 kcps. 3. A fluorescent X-ray intensity (A) kcps (aluminum) of the aluminum oxide vapor deposition film (1) obtained when oxygen and aluminum vapor are reacted in a vacuum to form aluminum oxide on a film substrate. X-ray intensity (B) kcps (aluminum K) of the aluminum vapor deposition film (2) obtained without introducing Kα rays and oxygen
A method for producing an aluminum oxide vapor-deposited film, characterized in that the ratio (A / B) to (alpha rays) is in the range of 0.55 ≦ (A / B) ≦ 0.90. 4. The reaction between oxygen and aluminum vapor is carried out in the direction of rotation of a cooling roll and toward aluminum vapor from a supply port in which oxygen is provided on the unwinding side of a substrate film and in the widthwise direction within an adhesion-preventing plate. The method for producing an aluminum oxide vapor-deposited film according to claim 3, wherein the method is performed by supplying the aluminum oxide film.