JPH01297237A - Vapor deposition film - Google Patents

Abstract

PURPOSE:To obtain a vapor deposition film having an excellent oxygen barrier property and high transparency, by providing a membrane layer consisting of magnisium fluoride and calcium fluoride to at least the single surface of a base material composed of a polymer film in a vacuum system. CONSTITUTION:A plastic film being a base material is a non-stretched film or sheet having an arbitrary draw ratio obtained from one or more kind of a resin such as polyethylene or polypropylene and pref. composed of polyethylene terephthalate or polyethylene naphthylate having transparency and heat resistance. A membrane composed of magnesium fluoride and calcium fluoride is considered to be a mixed state of Mg, MgF, MgF2, MgO, Mg(OH)2, MgCO2, Mg(OH)2, 3H2O, Ca, CaF, CaF2, CaO and Ca(OH)2 and the proper film thickness thereof is 300-3,000Angstrom . By providing the membrane layer consisting of magnesium oxide, calcium oxide or the like on the base material in a vacuum system by a PVD method such as vapor deposition, sputtering or ion plating, a vapor deposition film having high transparently, an excellent oxygen barrier property, showing no curling at all and having excellent workability is obtained.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a highly transparent vapor-deposited film in which a metal fluoride thin film is provided on a base material made of a polymer film, and in particular, a vapor-deposited film with excellent gas barrier properties. Regarding vapor deposited films.

<Prior art and its problems> In the field of pharmaceutical and food packaging, materials used for packaging are required to have various physical properties in order to enhance the protection of contents.
These required physical properties are becoming increasingly desirable.

Oxygen barrier properties and water vapor barrier properties are indispensable for packaging materials, especially from the viewpoint of protecting the contents from deterioration and oxidation. -S, and packaging materials are being designed from this perspective.

In general, from the perspective of oxygen barrier properties, ethylene vinyl alcohol copolymers, polyvinyl alcohol formal compounds (vinylon), biaxially oriented polyamides (ON
y), unstretched polyamide (CNy), cellophane, etc. are excellent.

In addition, from the perspective of water vapor barrier properties, biaxially oriented polypropylene (OPP) and unoriented polypropylene (o
pp) etc. are excellent.

On the other hand, those with both oxygen and water vapor barrier properties are so-called films coated with polyvinylidene resin, polyvinylidene-polyacrylic acid copolymer resin, etc.
There are K cellophane, KOP 5KPET SKOIJy, and K vinylon.

However, these materials are inferior to aluminum foil in terms of light-shielding and fragrance-retaining properties, and although each of the above materials has its own advantages, it is not possible to have all the physical properties by itself.
By laminating two or more different materials, it can be used as a laminate with multiple functions.

Aluminum foil has extremely good water vapor and oxygen barrier properties, and has a display effect in terms of gloss, but
Below 0μ, PET, ONy, Opp, cp are recently used from the point of view of pinhole resistance and cost.
A vapor-deposited film in which aluminum (AL) is vacuum-deposited on a base material such as aluminum is actively used for its moisture-proofing, oxygen barrier, light-shielding, and fragrance-retaining display effects.

However, when such a metallized film is used as a packaging material, the contents cannot be confirmed, and it cannot be heated in a microwave oven. The adhesion between the film and the vapor deposited layer was insufficient.

In addition, a vapor-deposited film has been proposed that is transparent and has moisture-proofing and oxygen barrier properties by providing a thin film of silicon oxide, magnesium oxide, or aluminum oxide on a polymer film instead of the AI vapor-deposited layer. (Japanese Patent Publication No. 53-12953, Japanese Patent Application Laid-open No. 61-51332, Japanese Patent Application Laid-open No. 62-179935, etc.) However, the above-mentioned vapor-deposited thin films of silicon oxide, magnesium oxide, aluminum oxide, etc. all have the following drawbacks: The performance is insufficient. In other words, the silicon oxide vapor deposited film is
Although the barrier evaluation was good, the vapor deposition itself was brownish and the transparency was insufficient.

Regarding the magnesium oxide vapor-deposited film, the magnesium oxide that is the vapor-deposited layer gradually reacts with CO□ in the air over time and becomes magnesium carbonate, etc., resulting in loss of water resistance and a decrease in barrier properties.

Furthermore, aluminum oxide vapor-deposited films have insufficient barrier properties.

In addition, any of the above vapor-deposited films also curled badly.
There were major problems such as extremely poor workability during post-processing such as lamination with other base materials and printing of letters and designs on the vapor-deposited surface.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the above-mentioned conventional drawbacks.
By providing a novel vapor deposited film on a base material, the objective is to provide a highly transparent vapor deposited film that has no curling and has excellent oxygen barrier properties.

<Means for Solving the Problems> The present invention provides magnesium fluoride,
It is a vapor deposited film with a thin layer of calcium fluoride.

Specifically, the base plastic film used in the present invention is unstretched, obtained from one or more resins such as polynyletine, polypropylene, polyamide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, etc., at any stretching ratio, It is a film or sheet that has a thin layer, and may contain additives to provide surface smoothness and stability. , a film made of resin containing as few additives as possible,
Sheets are preferred, and polyethylene terephtate (PET), polyethylene naphthylate (PEN), etc., which are transparent and heat resistant, are particularly preferred.

The transparent thin film referred to in the present invention refers to general vacuum evaporation methods using resistance heating, high frequency fusion heating, electron beam heating method, magnetron sputtering such as radio frequency sputtering (RF), and even ion sputtering in a vacuum system. The thin film may be obtained by any method such as brating.

Ion blating and sputtering are superior in terms of adhesion to the substrate, but vapor deposition is the most advantageous from an economical point of view, as it can be processed at high speed in a rolled form.

Furthermore, the physical properties of the resulting vapor-deposited film are also sufficiently satisfactory.

Magnesium fluoride according to the present invention obtained by the above method,
and calcium fluoride thin film are Mg
, AgF, MgFz, MgO, Mg (OH) z, AgcOt+Mg(0■) z + 3t(t Or C
a, CaF + CaFt + CaO+ Ca
It is considered to be a mixed state of (O)I) t ), and the content ratio of each varies depending on the degree of vacuum in the vacuum system, water vapor partial pressure, residual oxygen partial pressure, substrate temperature, etc. when producing 'Fii#.

The transparent thin film referred to in the present invention is characterized in that the above-mentioned thin film components are composed of an arbitrary composition, and in addition, Li, B
e,B,Na+Mg+AI,St,'P,CI,ni,T
i, Cr, Mn, Fe.

Even if it is contained as an inorganic substance such as Co, Ni, Cu, Zn, Pb, etc., it may be contained in an amount of 10% by weight or less as long as it does not affect the physical properties.

When the content of both metals increases, the water resistance of the deposited film decreases due to metal components with low ionic energy, causing deterioration of barrier properties, so it is preferable that the content of both metals is 5% by weight or less.

Further, in order to provide wavelength absorption in the near ultraviolet region, by controlling the peff+ concentration in the thin film, it is also possible to absorb wavelengths in the near ultraviolet region accordingly.

The appropriate thin film thickness is 300 Å to 3000 Å, and 3
If it is less than 00 Å, a uniform thin film will not be formed on the base material,
As a result, barrier properties become insufficient. If the thickness exceeds 3000 Å, cracks will occur in the thin film and the barrier properties will drop sharply. For this reason, 500 to 1000 people is preferable.

In addition, by extrusion coating a heat-sealable resin such as polyethylene or polypropylene on the vapor-deposited film of the present invention, or by laminating a film made of the above-mentioned resin as a sealing layer and laminating it with the vapor-deposited film, it is possible to create a barrier packaging material. used as

In particular, when used as a so-called retort packaging barrier material for sterilizing the contents of foods and the like by retorting, polyethylene terephthalate, two-wheel oriented polypropylene, two-wheel oriented polypropylene, etc., with a printed layer of letters, designs, etc. on the outer layer of the vapor-deposited film are used. It is preferable to use a composite film in which at least one layer of material that can be used as an outer layer film such as axially oriented nylon is provided, the outer layer film is laminated with the non-deposited side of the vapor-deposited film, and an olefin that can be used as a sealant is provided in the innermost layer. .

Under retort conditions, the packaging material undergoes considerable heat and stress due to heating and pressurization, causing some elongation at least in the outermost layer.Also, due to rapid cooling, cracks occur at the interface between the base material and the evaporation layer, as described above, and the evaporation layer The adhesion becomes insufficient, and in the worst case, the deposited layer will peel off.

For this reason, it is desirable that the vapor deposition layer be provided as close as possible to the innermost olefin layer side and laminated.

In addition, the means for forming the transparent thin film in the present invention may be any of the methods mentioned above, but in terms of high-speed productivity and economy, common resistance heating, high-frequency induction, and electron beam methods are suitable. Vacuum deposition using heating means is preferred.

Sputtering, ion blating, etc. can be used to form a vapor deposited film on a base material, so these methods can be used when adhesion is important.

In addition, when forming a thin film layer on a substrate, the substrate does not require any specific treatment, but discharge treatment under 104 to several Torr with gases such as Ox + Nz + Ar + lle, Ne, etc., so-called low-temperature plasma treatment, By sputtering charged objects, clumps, etc. with an inert gas and performing ion bombardment treatment to clean the surface, a thin film layer with better adhesion to the base material is formed.

Furthermore, a thermosetting resin layer can be provided on the base material.

<Function> The present invention provides a highly transparent film by forming a thin film layer of 300 Å to 3000 Å made of magnesium oxide, calcium oxide, etc. on a substrate using a PVD method such as vapor deposition sputtering or ion blating in a vacuum system. A vapor-deposited film with a certain oxygen barrier property, no curling, and excellent workability during post-processing was obtained.

<Example-1> Using a two-wheeled stretched polyester film 12 μm (NS Film manufactured by Kijin) as a base material, the following was performed on one side using a winding type vapor deposition sputtering device (SPW-020 special model, Japan Vacuum Technology Model) using electron beam heating. About 500 magnesium fluoride thin films were continuously applied under the following conditions to obtain a transparent vapor-deposited film.

<Vapor deposition conditions> Vapor deposition material MgFz (99% UP manufactured by Kojundo Science Institute)
) Vacuum degree 3 The film thickness was measured using a stylus method (Dectak U,
Japan Vacuum Technology Type) 500 people ± 2 in the width direction of the film
It was within 0%.

When the oxygen barrier properties and water vapor barrier properties of the vapor-deposited film obtained here were measured, they were each 5.
[cc/rh, day, atm] 22561
Oxygen barrier properties were good at 1100%+11.35 [g/day].

In addition, in order to evaluate transparency, a spectrophotometer 700-40
When we measured the transmittance at 0nm wavelength, it was 8 in all ranges.
At 5% or more, the transmittance at a wavelength of 550 nm is 90%,
It had extremely high transparency.

Next, when looking at the degree of curl, there was no curling at all, and the appearance was no different from that of the untreated base material.

Furthermore, a two-component curable urethane adhesive was applied to the vapor deposition surface of this vapor-deposited film, and a composite film was obtained by laminating it with unstretched polypropylene 60μ (Show Aroma-AT, manufactured by Showa Denko) under the following conditions. .

Processing conditions> ・Adhesive AD1050EIADRT-10/NC401=100
/4.5 /22.7 (TNV30%) ・Plate 135 μm 751 grid ・Nip pressure 4 kg
/C+Trine speed 20m/win ・Drying temperature 70"-80'-80"C ・Tension Unwinding 6-7 kg/cm Oven
6kg/c11 Winding 5kg/cn+ ・Impression pressure 3-5 kg 7cm ・Heat roll temperature 75℃ <Example-2> 1 Implemented except that the line speed was changed to make the deposited film thickness 1000 ± 20% A composite film was obtained in the same manner as in Example-1.

<Example-3> Using the same apparatus as in <Example-1> and <Example-2>, a vapor-deposited film was obtained under the following conditions.

Vapor deposition material MgFz/CaFt=1/1 (weight ratio) (manufactured by Kojundo Science Institute) Vacuum degree 2.4 monitor MgF2 component) Beam power 6K
V-50a+A Cooling roll temperature -10゛C Note that the deposited film thickness component is [! After checking with PMA,)'
Both Ig and Ca were confirmed, and their intensity ratios were almost the same.

<Example 4.5> Under the same conditions as Example-1, the film thickness was changed to 300 and 300, respectively.
A composite film of 1,000 ml was obtained.

The measurement results of the above Examples and Comparative Examples are shown in Table 1.

Comparative Examples-1 to 3> SiO (manufactured by Osaka Titanium), Mg0 (manufactured by Kojundo Kagaku Kenkyusho, 99.9% or more), and AIzOs (manufactured by Kojundo Kagaku Kenkyusho) were each deposited, and the resulting vapor deposition Films were similarly evaluated.

The above results are shown in Table-1.

(Ichi, #, (:l) <Effect> 300 yen on a substrate made of a transparent polymer film
By providing a transparent thin film layer of magnesium fluoride and calcium fluoride of ~3000 Å, conventional PVDC,
KOP SKP [! It has oxygen barrier properties better than T film and does not have a brown color like the above films.
A vapor-deposited film with extremely excellent transparency was obtained, and furthermore, there was no problem of extremely poor workability due to curling during secondary processing, and a highly practical vapor-deposited film with highly transparent oxygen barrier properties was obtained.

Claims (4)

[Claims] (1) A highly transparent vapor-deposited film in which a thin film layer of 300 Å to 3000 Å of either magnesium fluoride, calcium fluoride, or a mixture thereof is formed on at least one side of a substrate made of a transparent polymer film. (2) The vapor-deposited film according to claim (1), wherein the thin film layer is made of either magnesium fluoride, calcium fluoride, or a mixture thereof to which 10% by weight or less of an inorganic substance is added. (3) Claim (1) in which a sealing layer is laminated on the vapor deposited layer side.
Or the vapor-deposited film of (2). (4) The vapor-deposited film according to claim (3), wherein an outer layer film is provided on the opposite side of the vapor-deposited layer of the base material.