JPH07145256A - Transparent metallized film - Google Patents

Abstract

PURPOSE:To obtain a transparent metallized film having colorless transparency, excellent water vapor barrier properties.waterproofness, fragrance retention, oxidation prevention, heat resistance, strength and flexibility. CONSTITUTION:A mixing layer 3 consisting of SiC and SiOY (Y<=2) and an SiOx film composed of an SiO2 layer 4 (1.7<Z<=2) is formed from interface of a substrate film 2 on the substrate film. Since the mixing layer 3 forms a dense and uniform thin film on the substrate interface, the mixing film shows improved adhesiveness and excellent flexibility and exhibits function as a barrier layer to a lower molecule such as oxygen or steam diffused and permeated from the inside and the outside of the substrate film 2. Further the SiO2 layer 4 is laminated to the outer layer of the mixing film, the resultant film has no light absorption in a visible light region, or less light absorption and the color of the film become colorless and transparent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film laminate for packaging used in the field of packaging foods, pharmaceuticals, precision electronic products, etc., and particularly has gas barrier properties such as transparency, moisture resistance, aroma retention, and oxidation resistance, and heat resistance. The present invention relates to a transparent vapor deposition film having properties, strength, and flexibility.

[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, particularly oxidation and deterioration of proteins and fats and oils in foods, and further improve taste and freshness. In order to maintain the product, to suppress the deterioration of the active ingredient in pharmaceutical products that require aseptic handling, and to maintain its efficacy, in precision electronic parts, corrosion of metal parts, poor insulation, etc. may occur. In order to prevent the above, it is necessary to prevent the influence of oxygen, water vapor, and other gases that change the contents passing through the packaging material, and it is required to have a gas barrier property of blocking these gases.

Therefore, a polymer resin composition which is conventionally said to have a relatively high gas barrier property, such as polypropylene (KOP) coated with vinylidene chloride resin, polyethylene terephthalate (KPET) or ethylene vinyl alcohol copolymer (EVOH), has been conventionally used. The packaging film used as a gas barrier material, a metal foil made of a metal such as Al, a suitable polymer resin composition (alone, even a resin that does not have a high gas barrier property)
A packaging film using a metal deposition film obtained by depositing a metal or a metal compound as a packaging material has been generally used.

However, the packaging film using only the above-mentioned polymer resin composition is inferior in gas barrier property as compared with a foil using a metal or a metal compound such as Al or a metal vapor deposition film formed with a vapor deposition film. However, it is susceptible to temperature and humidity, and the gas barrier property may be further deteriorated depending on the change. Further, a polymer resin composition containing a large amount of chlorine has problems such as generation of toxic gas during incineration and accelerated deterioration of an incinerator due to high calorific value during incineration.

On the other hand, a metal vapor-deposited film on which a foil or vapor-deposited film using a metal such as Al or a metal compound is formed is
It is not affected by humidity, etc., and has excellent gas barrier properties, but it is not possible to see through the contents of the package, and when disposing after use, a laminated material laminated with aluminum foil or aluminum vapor deposition film. It is difficult to separate and collect the packaging material consisting of
It had the drawback of having to be treated as an incombustible.

Therefore, as a packaging material that overcomes these drawbacks, for example, US Pat.
A metal oxide such as magnesium oxide, silicon oxide, aluminum oxide or tin oxide as described in JP-A-3-28017 is formed on a polymer film by a vapor deposition method or a sputtering method to form a vapor deposition film. Formed films are being developed. This film is known to have transparency and gas barrier properties such as oxygen and water vapor,
It is suitable as a packaging material having both transparency and gas barrier properties that cannot be obtained by a metal vapor deposition film. In particular, those obtained by vacuum deposition of silicon oxide have been put to practical use.

[0007]

However, as shown in FIG. 2, a SiO _x vapor deposition film (0 <X ≦
From the graph showing the oxygen permeability (cc / m ² / day) and the light transmittance% (λ = 350 nm) of 2), the oxygen permeability decreases and the gas barrier property improves when the oxidation degree decreases.
The light transmittance decreases and the transparency deteriorates. That is, the oxygen permeability and the transparency depend on the degree of oxidation X, and the silicon oxide thin film having a low degree of oxidation such as silicon monoxide (SiO) has absorption in the visible wavelength region because the thin film itself has absorption. When the vapor-deposited film, which has a light yellow color and is vapor-deposited, is used as a packaging material, it has a bad appearance, and the color reproducibility of printing during printing as the packaging material is poor. In addition, since this vapor-deposited film lacks flexibility in the silicon oxide thin film, is vulnerable to physical impact such as rubbing and bending, and has poor adhesion with the substrate, it requires careful handling. When post-processing packaging materials such as printing, laminating, slitting, and bag making, there is a problem that cracks occur and the gas barrier properties are significantly reduced, caution is required when handling the film, and there is a problem that the versatility is reduced. ing. The thin film material itself is also expensive, and there is a problem in that cost performance is low, such as an increase in cost if the vapor-deposited thin film layer is thickened in order to suppress deterioration of gas barrier properties.

Therefore, the present invention is colorless and transparent, and has excellent gas barrier properties such as moisture proof / water proof, aroma retention, and antioxidant, and has heat resistance, strength, and flexibility, and is easy to manufacture and handle. It is intended to provide an easy transparent vapor deposition film.

[0009]

The invention according to claim 1 is
In a transparent vapor deposition film in which a SiO _x film (0 <X ≦ 2) is formed on a base film, the SiO _x film is a mixing layer composed of SiC and SiO _y (Y ≦ 2) from the base film interface. And SiO _Z layer (1.7 <Z ≦ 2)
The transparent vapor deposition film is characterized in that and are sequentially laminated.

According to a second aspect of the invention, there is provided a transparent vapor deposition film according to the first aspect of the invention, wherein the mixing layer has a layer thickness of 2 to 20 nm.

A third aspect of the present invention is based on the first aspect of the invention, wherein the mixing layer has a transparent vapor deposition characterized in that at least a part of SiO _Y (Y ≦ 2) has a Si—C bond. It is a film.

According to a fourth aspect of the present invention, based on the first aspect of the invention, the transparent vapor deposition is characterized in that the content of SiC constituting the mixing layer is continuously changed from the base film interface. It is a film.

[0013]

According to the present invention, SiO _{x is formed} on the base film.
A transparent vapor-deposited film formed by forming a film (0 <X ≦ 2) is formed by using a SiO _x film from the base film interface to SiC and SiO.
_A mixing layer composed of _Y (Y ≦ 2) and SiO _Z
Since it is composed of layers (1.7 <Z ≦ 2), the mixing layer composed of SiC and SiO _Y having a _Y value of 2 or less forms a dense and uniform thin film at the interface. It exhibits improved adhesion and flexibility, and also functions as a barrier layer against low molecules such as oxygen and water vapor that diffuse and permeate from inside and outside the base film. Furthermore since the outer layer thereof the value of Z is laminated SiO _Z layer of 1.7 to 2, no light absorption in the visible wavelength range, or less,
The color of the film becomes colorless and transparent.

[0014]

EXAMPLE An example of the present invention will be described in detail. FIG. 1 is a schematic diagram illustrating the structure of the transparent vapor deposition film of the present invention.

In FIG. 1, reference numeral 1 is a transparent vapor deposition film of the present invention, which comprises a substrate 2, a mixing layer 3 composed of SiC and SiO _Y (Y ≦ 2), and a SiO _Z layer (1.7 <Z ≦).
2) 4 are sequentially stacked.

The substrate 2 is in the form of a sheet or a film, and is made of polyolefin (polyethylene, polypropylene, polybutene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, etc.), polyamide ( Nailon-6, nylon-66, etc.), polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyimide, ethylene-vinyl alcohol copolymer, etc., or copolymers of monomers or copolymers in combination with different monomers. Can be used as
It is appropriately selected from the above materials according to the application. The base material 2 is preferably stretched in the longitudinal and transverse directions from the viewpoint of strength, dimensional stability and heat resistance. Further, the thickness of the base material 2 is determined depending on the application, but from the viewpoint of strength, the thickness is preferably in the range of 3 to 400 μm, particularly 6 to 200 μm.

The polymer resin material used for the base material 2 includes, for example, an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant,
Known additives such as colorants and stabilizers can be added,
It is added as needed.

Further, the surface of the substrate 2 may be subjected to surface modification such as corona treatment / plasma treatment (= discharge treatment), flame treatment, chemical treatment, anchor coat treatment, etc. as a pretreatment to improve the adhesion of the coating film. It is possible.

Next, SiC and SiO _Y (Y ≦
The method for forming the mixing layer 3 composed of 2) is
The surface of the base material 2 is previously treated by plasma discharge consisting of a discharge gas containing at least carbon and oxygen to introduce functional groups such as C—O groups and C═O groups onto the surface of the base material 2. An evaporation material made of Si, SiO or a mixture of SiO and SiO ₂ is formed on the upper surface by a known method such as a vacuum evaporation method, various ion plating methods and a sputtering method. Thus, by introducing a functional group such as a C—O group or a C═O group on the surface to form a SiO _x film, a highly active C
The —O group and the C═O group are bonded to the vapor deposition particles Si and SiO to form the mixing layer 3 composed of SiC and SiO _Y.

The thickness of the mixing layer 3 is 2 to 20n.
m, preferably 2 to 12 nm. Oxygen permeability (cc / m ² / d) with respect to the mixing layer thickness shown in FIG.
From the graph showing ay) and light transmittance% (λ = 350 nm), it can be said that the oxygen permeability is suppressed low and the light transmittance is high by the mixing layer having a constant layer thickness. However, when the thickness is less than 2 nm, the oxygen permeability increases and the gas barrier property and the adhesiveness cannot be improved, and when the thickness is more than 20 nm, the light transmittance decreases and the deposited film is colored. It suffices that the mixing layer 3 be present in an extremely thin film thickness, and a part of the surface of the tissue of the base material 2 (for example, a polyethylene terephthalate film) shows a Si—C bond state, so that the base material 2 and the mixing layer 3 are naturally integrated, and have stronger adhesion.

The Y value of SiO _Y constituting the mixing layer 3 is in the range of 0 <Y ≦ 2 when the vapor deposition film is etched by an argon ion beam and measured by photoelectron spectroscopy. , Particularly preferably 1.7 ≦ Y
The range is ≦ 2.

The discharge gas used in the plasma treatment in the present invention contains a compound having at least carbon and oxygen, such as pure oxygen, carbon dioxide, carbon monoxide, nitrogen, CmHn (m, n ≦ 10). Representative hydrocarbons,
Alkylsilanes such as monosilane, disilane, methylsilane, methyldisilane and hexamethyldisiloxane, alkyldisilanes and the like can be used alone or in combination. Further, argon, helium, xenon, a mixture of argon and xenon, which are inert gases in air, in an amount of 5 to 95% by volume can be used.

The plasma can be generated by introducing the above-mentioned discharge gas into a hermetically-sealed container and using various known methods such as capacitive coupling such as internal electrode type, external electrode type, coil type, inductive coupling, etc. , AC power, high frequency (2450MH
z), electric power can be applied by microwave (13.56 Hz) to generate plasma, and high frequency discharge is preferable from the viewpoint of discharge stability and treatment effect.

The optimum conditions of this plasma differ depending on the type and generation conditions, but for example, high frequency power of 50 to 1000 W is introduced into a closed system container having a pressure of 1 × 10 ^-4 to several Torr to create a plasma space. The deposition surface of the material is 0.0
It can be easily processed by exposing it for about 1 to 3 seconds.

[0025] After the surface treatment of the substrate 2 as described above, followed by deposition Si, SiO or SiO, and SiO ₂ mixture of SiO ₂ as an evaporation material, SiC and Si
2 to 20 nm mixing layer 3 made of O _Y (Y ≦ 2)
And a SiO _Z layer 4 (1.8 ≦ Z ≦ 2) are sequentially laminated to obtain a vapor deposition film.

The SiO _Z layer 4 (1.7 <Z) located on the outer layer
≦ 2) does not significantly contribute to the gas barrier property,
In order to protect the mixing layer, the layer thickness is about 1 to 50 nm. In this case, if the layer thickness is more than 50 nm, cracks are likely to occur in the vapor deposition film. Further, when the value of Z is smaller than 1.7, the vapor-deposited film becomes a lower oxide and light absorption due to oxygen deficiency occurs, so that the vapor-deposited film is colored light yellow, which is not preferable. However, the SiO _Z layer 4 (1.
Even for 7 <Z ≦ 2), when the value is close to 1.7, some color may be exhibited.

Further, the transparent vapor-deposited film of the present invention can be formed by the plasma CVD method similarly to the above, and the same effect is exhibited.

The transparent vapor deposition film of the present invention will be described with reference to specific examples.

Example 1 A polyethylene terephthalate film (hereinafter referred to as a PET film) having a thickness of 12 μm was used as a base material 2, and an oxygen partial pressure on the surface thereof was 3.7 × 10.
^The surface of the substrate 2 was plasma-treated by exposing it to oxygen plasma obtained by supplying a high frequency power of ^-4 Torr and 400 W for 3 seconds. Further, on the surface of the base material 2 after this plasma treatment, a SiO _x layer having a thickness of 52 nm was formed using SiO as a vapor deposition material.

The vapor-deposited film of the obtained transparent vapor-deposited film was analyzed from the composition in the film thickness direction by photoelectron spectroscopy to analyze Si-2p, C
-1s and O-1s were measured and found to be 46n from the surface of the deposited film.
PE as the base material 2 having an average O / Si ratio up to m of 1.9 and further subjected to argon ion beam etching.
Analysis of the vicinity of the T film interface revealed that SiC and Si
Mixing layer composed of O _Y (Y ≦ 2) is 6 nm
It was found to have been formed. This mixing layer
At least a part of SiO _Y (Y ≦ 2) has a Si—C bond.

The oxygen transmission rate of this transparent vapor-deposited film was measured by an oxygen transmission rate measuring device (Mo by Modern Control Co., Ltd.).
conOxtran) under an atmosphere of 27 ° C.-75% RH, and a transparent vapor deposition film of 190-80.
The light transmittance in the wavelength region of 0 nm was also measured, and the transmittance at a wavelength of 350 nm was used as an index of the coloring degree of the deposited film. The results and evaluation are shown in Table 1.

As is clear from the results, this vapor-deposited film is a colorless and transparent vapor-deposited film having an oxygen permeability of 1.5 cc / m / day / atm, a very high gas barrier property, and high transparency without coloring.

Comparative Example 1 PET under the same conditions as in Example 1
Using the film as a substrate, a film was similarly formed using SiO as a vapor deposition material except that the oxygen plasma treatment was not performed, and the same measurement was performed. The results and evaluation are shown in Table 1. When the ratio of Si and O was analyzed in the same manner as in Example 1, the average O / S
The i ratio was 1.7, and when the vicinity of the interface of the PET film was analyzed, the presence of a mixing layer composed of SiC and SiO _Y (Y ≦ 2) was not recognized, and the color of the vapor deposition film was colored light yellow. Had.

Comparative Example 2 PET under the same conditions as in Example 1
Using the film as a substrate, oxygen gas was introduced into the chamber at the time of vapor deposition of SiO, high frequency power was applied to form a film while forming oxygen plasma, and the same measurement was performed. The results and evaluation are shown in Table 1. When the ratio of Si and O was analyzed in the same manner as in Example 1, the average O / Si ratio from the outer layer to 51 nm was 1.9. When the vicinity of the interface of the PET film was analyzed, SiC and SiO _Y (Y ≦ The mixing layer composed of 2) was formed with a thickness of 0.9 nm, and the vapor deposition film was colorless and transparent, but had an oxygen permeability of 3
It showed a large value of 0.5 cc / m / day / atm.

Comparative Example 3 PET under the same conditions as in Example 1
By using a film as a base material to deposit SiO while introducing oxygen gas, a so-called reactive vapor deposition method
A SiO _x film was formed to have a film thickness of 1 nm, and the same measurement was performed. The results and evaluation are shown in Table 1. When the ratio of Si and O was analyzed in the same manner as in Example 1, the average O / Si
The ratio was 1.9, and when the vicinity of the interface of the PET film was analyzed, the presence of a mixing layer composed of SiC and SiO _Y (Y ≦ 2) was not recognized, and the color of the vapor-deposited film was light yellow. Had.

Comparative Example 4 PET under the same conditions as in Example 1
After using the film as a base material to similarly form a mixing layer, a mixture of Si and SiO ₂ was used as a vapor deposition material to form a film, and the same measurement was performed. The results and evaluation are shown in Table 1.
Shown in. When the ratio of Si and O was analyzed in the same manner as in Example 1, the average O / Si ratio from the outer layer to 45 nm was 1.7, and when the vicinity of the interface of the PET film was analyzed, S
Mixing layer composed of iC and SiO _Y is 6 nm
However, the vapor-deposited film had a pale yellow color. The oxygen permeability was 1.6 cc / m / day / atm, which was large in gas barrier property, but the light transmittance was 66%.

Example 2 A vapor deposition film was formed in the same manner as in Example 1 except that the discharge gas used in the plasma treatment was 50/50 Vol% of carbon dioxide and oxygen and the treatment time was 1 second. The same measurement was performed. The results and evaluation are shown in Table 1. When the ratio of Si and O was analyzed in the same manner as in Example 1, the average O / Si ratio from the outer layer to 51 nm was 1.
No. 9, and the vicinity of the interface of the PET film was analyzed, and it was found that a mixing layer composed of SiC and SiO _Y was formed with a thickness of 2 nm, and the vapor deposition film had an oxygen permeability of 2.0 cc / m / day. It is a colorless and transparent vapor-deposited film having a very high gas barrier property of / atm and high transparency without coloring.

[Embodiment 3] The discharge gas used in the plasma treatment of Embodiment 1 is 50/50 Vo of methane and oxygen.
1%, the treatment time was 0.01 seconds, and then Comparative Example 2
Similarly to the above, oxygen gas was introduced into the chamber at the time of vapor deposition of SiO, high frequency power was applied to form a film while forming oxygen plasma, and the same measurement was performed. The results and evaluation are shown in Table 1.
Shown in. When the ratio of Si and O was analyzed in the same manner as in Example 1, the average O / Si ratio from the outer layer to 32 nm was 1.9, and when the vicinity of the interface of the PET film was analyzed, S
20n mixing layer composed of iC and SiO _Y
Although it was formed with a thickness of m, the vapor-deposited film is a colorless and transparent vapor-deposited film having a very high gas barrier property with an oxygen permeability of 1.3 cc / m / day / atm and high transparency without coloring. .

[0039]

[Table 1]

[0040]

As described above, the transparent vapor deposition film of the present invention has a SiO _x film (0 <X ≦ 2) on the base film.
The transparent vapor-deposited film in which the SiO 2 film is formed is formed by mixing the SiO _X film from the base film interface with SiC and SiO _Y (Y ≦ 2) and the SiO _Z layer (1.7 <Z ≦
By being composed of 2), it is excellent in gas barrier properties such as moisture proof, fragrance proof, and anti-oxidant, has high heat resistance, strength, and flexibility and is colorless and transparent. That is, compared with the conventional vapor-deposited film of silicon oxide showing a light yellow color, it is possible to realize both colorless transparency and gas barrier property.
Due to the realization of this colorless transparency, the vapor-deposited film does not show a light yellow color, so the color reproducibility at the time of surface decoration and printing processing by multicolor printing is high, and packaging with excellent decoration that enables more beautiful printing. A vapor-deposited film that can be used as a film for use can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating the configuration of a transparent vapor deposition film of the present invention.

FIG. 2 is a SiO _x vapor deposition film (0
It is a graph showing oxygen transmittance (cc / m ² / day) and light transmittance% (λ = 350 nm) of <X ≦ 2.

FIG. 3 Oxygen permeability (cc / m) with respect to mixing layer thickness
² is a graph showing ² / day) and light transmittance% (λ = 350 nm).

[Explanation of symbols]

1 Transparent Vapor Deposition Film 2 Base Material 3 Mixing Layer 4 SiO _Z Layer (1.7 <Z ≦ 2)

Claims (4)

[Claims] 1. A SiO _x film (0 <X ≦ is formed on a base film.
In the transparent vapor-deposited film formed by 2), the SiO _x film is formed from the interface of the base film with SiC and SiO.
A mixing layer composed of _Y (Y ≦ 2) and SiO _Z
A transparent vapor-deposited film, which is formed by sequentially laminating layers (1.7 <Z ≦ 2). 2. The transparent vapor deposition film according to claim 1, wherein the layer thickness of the mixing layer is 2 to 20 nm. 3. The mixing layer is SiO _Y (Y ≦ 2)
At least one part of this has a Si-C bond, The transparent vapor deposition film of Claim 1 characterized by the above-mentioned. 4. The transparent vapor deposition film according to claim 1, wherein the content of SiC constituting the mixing layer is continuously changed from the interface of the base film.