JPH09216653A - Package film having excellent oxygen-barrier properties and package film laminate body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve compatibility between colorless transparency and high oxygen-barrier properties suitably used in food packaging, medicine packaging, cigarette packaging, electronic-material packaging, cosmetic packaging, industrial-material packaging, and so on. SOLUTION: This laminate body is obtained by forming a thin film layer (B), comprising a silicon oxide and an alkaline-earth metal fluoride, onto one or both sides of a polyvinyl alcohol film (A) by a vacuum thin layer formation technique. Further, an adhesive layer (C) and a plastic layer (D), as needed, are bonded onto a package film having 85% or more visible light transmission based on the 100% visible light transmission of the polyvinyl alcohol film (A), and the thin film layer (B) of the package film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a packaging film and a packaging film laminate used for food packaging, pharmaceutical packaging, tobacco packaging, electronic material packaging, cosmetic packaging, industrial material packaging and the like. In particular, it relates to a packaging film and a packaging film laminate having colorless transparency and a high oxygen gas barrier property.

[0002]

2. Description of the Related Art Currently, in the packaging field centering on food,
A vapor-deposited film of silicon oxide has been developed as a "high gas barrier film" and has been disclosed up to now.
69, JP 59-51051 A, JP 6
As described in JP-A-133936, JP-A-61-279134, JP-A-62-103139 and the like, many inventions have been made on vapor deposited films of silicon oxide. The thin film layer of silicon oxide is an inorganic barrier layer and has a high oxygen gas barrier property and a high water vapor barrier property. As a highly versatile transparent barrier film, PVDC (polyvinylidene chloride), EVOH (ethylene vinyl alcohol copolymer), PVA (polyvinyl alcohol), PAN (polyacrylonitrile), etc. other than vapor-deposited films of silicon oxide can be used. Organic barrier films are mentioned, but the barrier performance of these organic barrier films is obviously inferior to the total barrier performance of the vapor deposition film of silicon oxide. In other words, among the versatile transparent barrier films, the vapor deposition film of silicon oxide is a highly balanced high barrier film having both high oxygen and water vapor barrier properties.

The vapor-deposited film of silicon oxide is not opaque like aluminum foil and aluminum vapor-deposited film, and is transparent to visible light and microwaves, so that it is used as a packaging material for showing the contents and as a packaging material for microwave-applied foods. It has been put to practical use. This vapor-deposited film is also in the spotlight because it does not generate hydrogen chloride gas that causes acid rain unlike PVDC even when it is incinerated at the time of disposal. PVD (physical vapor deposition method: for example, vacuum vapor deposition, sputtering, ion plating, etc.) is generally used as a method for obtaining a vapor deposited film of silicon oxide.

However, when vapor deposition of silicon oxide is carried out by PVD, in most cases, the thin film layer is colored yellow to brownish. Therefore, in vapor deposition by PVD, the film itself is colored no matter how thin the film is made, and a certain amount of film thickness is required to maintain high barrier properties. Since this is not possible, coloring of the vapor deposition film is unavoidable. The cause of coloring of the thin film layer is its composition. Since SiO ₂ is colorless and transparent, and SiO is brown, the thin film layer is colored like SiO _2.
SiO _x (X = 1.
2 to 1.9), the thin film layer is always colored.

The reason why the composition of the thin film layer is not completely oxidized by PVD and becomes an oxygen deficient state is as follows. For a vacuum vapor deposition method, raw material is SiO ₂ alone if colorless transparent thin film layer can be obtained, since the SiO ₂ alone does not evaporate difficult evaporation rate is obtained, the raw material is SiO alone or Si and SiO
_It has to be a mixture of _two . Further, in the case of sputtering, although it is easy to evaporate the SiO ₂ raw material, reduction occurs during vapor deposition, and the composition of the thin film layer is not SiO ₂ and is reduced to about SiO _1.9 . In any case, even if oxygen is introduced for the purpose of oxidizing the thin film layer in the oxygen-deficient state, the film is not completely oxidized and the desired barrier property is further deteriorated.

In the field of packaging, coloring of vapor-deposited films causes various problems. Particularly prominent are the food packaging, pharmaceutical packaging, and tobacco packaging fields. The yellow coloring of the vapor-deposited film in these packaging fields looks like "rot" or "discoloration" of the foods, medicines and cigarettes which are contents. In particular, general consumers are more sensitive than necessary to the discoloration of the contents, and the appearance of "rot" or "discoloration" leads to a reduction in the image of the product. In addition, there is also a problem that it is not possible to judge whether the contents of the packaging film colored yellow are really yellow. In other words, when the contents are foods, if the packaging film is colored yellow, it is easy to overlook the discoloration when "rotation" really occurs, and if troubles occur due to it, the image of the product will be reduced. When used as a sealing material for solar cells other than food packaging, there is a problem in that the conversion efficiency from sunlight to electricity is reduced if there is yellow coloring.

Japanese Unexamined Patent Publication (Kokai) No. 1-297237 discloses a transparent vapor-deposited film in which a thin film layer made of either magnesium fluoride or calcium fluoride or a mixture thereof is formed on a polymer film. There is. However, although this vapor-deposited film is highly transparent, it has the drawback of poor barrier properties. In addition, JP-A-5-23
In Japanese Patent No. 9622, (A) sodium, magnesium, aluminum, potassium, calcium, titanium, chromium, and (A) are formed on at least one surface of a plastic film (A).
A vapor deposition film provided with a thin film layer containing at least one element selected from the group consisting of nickel and indium, (B) silicon and (C) oxygen as main components, and a method for making the vapor deposition film transparent. It is disclosed. However, although this vapor-deposited film is excellent in barrier performance, it has a drawback that it is not necessarily colorless and transparent and exhibits a slight brown color.

Further, when a very high oxygen barrier property is required, the performance is insufficient when the plastic film is polyester. JP-A-1-95038, JP-A-1-156054, JP-A-1-16554
34, JP-A-1-184127, JP-A-1
JP-A-267032 and JP-A-1-283135 disclose inventions in which a thin film layer of silicon oxide is formed on a polyvinyl alcohol film or an EVOH film, but all of them have excellent oxygen barrier properties. However, the film itself was colored brown, and it could not have both the oxygen barrier property and the colorless and transparent property. On the other hand, the market demanded a film having both a high oxygen barrier property and a colorless and transparent property.

[0009]

The object of the present invention is colorless transparency and high oxygen barrier property, which are preferably used for food packaging, pharmaceutical packaging, tobacco packaging, electronic material packaging, cosmetic packaging, industrial material packaging and the like. The purpose of the present invention is to provide a packaging film and a packaging film laminate that satisfy both requirements.

[0010]

The object of the present invention is to provide a polyvinyl alcohol film (A) on one side or both sides,
When a thin film layer (B) made of silicon oxide and a fluoride of an alkaline earth metal is formed by a vacuum thin film forming technique, and the transmittance of visible light of the polyvinyl alcohol film (A) is 100%. Visible light transmittance of 8
This can be achieved with a packaging film that is 5% or more. Also,
The object of the present invention can be achieved by a packaging film laminate obtained by laminating an adhesive layer (C) on the thin film layer (B) of the packaging film.

In the packaging film of the present invention, the visible light transmittance of the polyvinyl alcohol film (A) is 100%.
In that case, the visible light transmittance is 85% or more, and more preferably 95% or more. The visible light transmittance of the packaging film of the present invention is usually 110.
Do not exceed%. Visible light transmittance of the packaging film is 85
If it is less than%, it may have a coloring that can be felt with the naked eye,
As described above, there is a problem in terms of discoloration of the contents. Further, when the white color is directly printed on the thin film layer of the packaging film, it is a slightly colored white, which is a problem.
The visible light is a light in the wavelength range of 380 to 780 nm.

In the present invention, examples of the polyvinyl alcohol film (A) include a polyvinyl alcohol film and an ethylene vinyl alcohol copolymer film. The ethylene vinyl alcohol copolymer is usually
It is obtained by saponifying an ethylene vinyl acetate copolymer. Among these, as the polyvinyl alcohol film (A), from the viewpoint of heat resistance and price, a heat-fixed film, particularly a biaxially stretched film is preferable, and a biaxially stretched polyvinyl alcohol film and a biaxially stretched ethylene vinyl alcohol copolymer A united film is preferably used.

Polyvinyl alcohol film (A)
May be previously corona-treated, plasma-treated, or flame-treated to impart adhesiveness, or may be pre-coated with an organic easy-adhesive such as a surfactant-based or polyelectrolyte-based. I do not care. The thickness of the polyvinyl alcohol-based film (A) varies depending on the application and is 6 to 50 μm.
However, the range of 12 to 25 μ is particularly desirable.

As a vacuum thin film forming technique for forming the thin film layer (B), a method generally called PVD such as vacuum vapor deposition, ion plating and sputtering can be applied. The heating method for vacuum vapor deposition is not particularly limited as long as it does not cause vapor deposition droplets called splash during vapor deposition and is small enough to be removed without trouble, and conventional methods such as high frequency induction heating, resistance heating, and electron beam heating are used. A known heating method can be used. The PVD method for forming the thin film layer (B) on one surface or both surfaces of the polyvinyl alcohol film (A) may be either a continuous winding method or a single-wafer method. A general crucible system may be used as an evaporation source for vacuum vapor deposition, but it is disclosed in Japanese Patent Laid-Open No. 1-25276.
The method of continuously supplying and discharging the evaporation raw material, which is disclosed in JP-A-8, can also be applied.

The silicon oxide constituting the thin film layer (B) is not particularly limited as long as it is within the range represented by SiO _x (X = 1.0 or more and less than 2.0), and SiO, Si
₂ O ₃ , Si ₃ O _4, etc. are included. Further, magnesium oxide, aluminum oxide, and a co-oxide of magnesium oxide and silicon oxide called forsterite or steatite may be included as long as the physical properties are not adversely affected. When the silicon oxide is used in combination with magnesium oxide or a co-oxide of silicon oxide and magnesium oxide, the mixing ratio is silicon oxide / magnesium oxide or co-oxide = 99.5-80. Mol% / 0.5 mol%
It is about 20 mol%.

Examples of the alkaline earth metal fluoride constituting the thin film layer (B) include one or more selected from magnesium fluoride, calcium fluoride, strontium fluoride and barium fluoride. Among these, magnesium fluoride and calcium fluoride are particularly desirable. The composition ratio of silicon oxide / fluoride of alkaline earth metal constituting the thin film layer (B) is 99.5 to 8 respectively.
The range of 0 mol% / 0.5 to 20 mol% is desirable, and the range of 95 to 90 mol% / 5 to 10 mol% is particularly desirable.

When the thin film layer (B) is in the state of a thin film, it is sufficient that the silicon oxide and the fluoride of the alkaline earth metal are almost combined as a result, and the raw material of the film to be formed is Either an inorganic compound such as silicon oxide, an alkaline earth metal fluoride, silicon, or an organic silicon compound, or an organic compound may be used alone or as a mixture. That is, even if the thin film layer (B) is directly formed on the polyvinyl alcohol-based film (A) by using a mixture of silicon oxide and a fluoride of an alkaline earth metal as a raw material by a method such as vacuum deposition, a metal or metal or A thin film layer (B) may be formed by vacuum deposition while oxidizing or fluorinating a compound containing a metal such as an organometallic compound, or a fluoride of an alkaline earth metal and silicon may be vacuum deposited on the polyvinyl alcohol film (A). It is also possible to form the thin film layer (B) by subjecting the deposited layer to a thin film layer (B) by oxidizing the deposited layer in a later step. The oxidation method is not particularly limited as long as it is a method of performing the treatment within the usable temperature range of the polyvinyl alcohol film (A), and an oxygen gas introduction method during vapor deposition, an electric discharge treatment method, an oxygen plasma method, a thermal oxidation method, etc. Can be given.

The thickness of the thin film layer (B) is selected according to the polyvinyl alcohol film (A) to be used, but is preferably 50 to 1500 angstroms. More preferably, it is 100 to 1000 angstroms, and 300 to 600 angstroms is particularly desirable.
The thin film layer (B) to be formed may be double-layered or multi-layered as long as the required function of the finally obtained layer is obtained,
Different kinds of silicon oxides or fluorides of alkaline earth metals may be laminated.

An example of analysis of the thin film layer (B) of the present invention will be given. As a typical example, when the surface of a vapor deposition film obtained by vacuum vapor deposition using silicon oxide and magnesium fluoride as raw materials is analyzed using ESCA, the binding energies of Mg 2p orbitals are 48.0 ev and 47. 1 ev. Of these, 48.0 ev is the peak of Mg—F, and 47.1 ev is M of Si—O—Mg bond.
This is the peak of the g-O bond (this 47.1 ev matches the peak of forsterite (SiO2 .2MgO)). Further, since the peak intensities indicating the amounts of bonds between Mg-F and Si-O-Mg are similar, Mg-F and Si
It is presumed that -O-Mg is bonded to form a Si-O-Mg-F bond. From this fact, most of the thin film layer (B) is not a Si—O bond alone, but a part of the three-dimensional network structure of Si—O is Si—O—Mg—F. It can be seen that it is a complex compound of magnesium iodide.

The packaging film of the present invention comprising a polyvinyl alcohol film (A) and a thin film layer (B) comprising a silicon oxide and a fluoride of an alkaline earth metal, has a high visible light transmittance, Although it has a high oxygen barrier property, the reason why these effects are obtained will be described below. First, the reason why the packaging film of the present invention has a high visible light transmittance will be described in terms of a transparent region of a light wavelength of a substance. Silicon oxides and fluorides of alkaline earth metals each have a transparent region depending on the light wavelength, and in the case of SiO, which is a silicon oxide, is 500 nm to 8 μm, and is less than 500 nm including a wavelength showing yellow to brown. Is in the opaque region. That is, the thin film layer of SiO and the powder show yellow to brown. On the other hand, in the case of fluoride of alkaline earth metal, the transparent region is widened, and in the case of magnesium fluoride, it is 210 nm to 10 μm. That is, it is presumed that the light transmissivity of less than 500 nm is improved by forming a film in which silicon oxide is mostly combined with a fluoride of an alkaline earth metal into a thin film layer. The wavelength region showing brown or yellow which is a problem in the present invention is about 380 to 400 nm.

Next, the reason why the packaging film of the present invention has a high oxygen barrier property will be described. The amorphous thin film layer made of silicon oxide alone is formed of a Si—O random network structure, and the network structure has physical defects (holes) due to randomness. It is presumed that oxygen molecules permeate the slight physical defects. On the other hand, the thin film layer made of silicon oxide and the alkaline earth metal fluoride is in an amorphous state, but since the alkaline earth metal fluoride is bonded to the silicon oxide, a random network structure is formed. It is considered that the number of defective portions is smaller. for that reason,
It is estimated that the oxygen barrier property will be higher.

The packaging film of the present invention is made into a packaging film laminate by laminating the adhesive layer (C) on the thin film layer (B) and, if necessary, the plastic (D) thereon. You can A printing ink layer used for general packaging materials may be provided between the thin film layer (B) and the adhesive layer (C) or between the adhesive layer (C) and the plastic (D). Good.

The adhesive layer (C) is referred to as an adhesive for dry lamination, an adhesive for wet lamination, an anchor coating agent for extrusion extrusion of polyolefin, a heat seal agent or an adhesive which is used in general packaging fields. There is no particular limitation as long as it is one. Specifically, in the case of a dry laminating adhesive or a wet laminating adhesive, any type of solvent type, high solid content coating type, alcohol type, solventless type, water-based type may be used, and one-component curing Type,
Any of two or more curing types may be used. Further, any of those based on polyester resin, those based on polyether resin and those based on acrylic resin may be used, and the curing agent thereof may be any of aliphatic isocyanate, aromatic isocyanate and epoxy amine.
For example, an adhesive obtained by reacting a hydroxyl group with an isocyanate or an epoxy with an amine is naturally included in the adhesive layer (C) of the present invention.

As the anchor coating agent for polyolefin extrusion laminate, titanate type, imine type,
Either butadiene type or urethane type may be used. The heat sealing agent is not particularly limited as long as it is generally used for packaging, and its composition can be the same as that of the adhesive for dry lamination. Examples of the adhesive include acrylics. As a method of applying the adhesive layer (C),
Examples include roll coating, gravure coating, reverse coating, and bar coater coating.

The coating amount of the adhesive is about 0.8 to 5.0 g / m ² (after drying) in the case of the adhesive for dry lamination, and 5 to 10 g / in the case of the adhesive for wet lamination.
It is about m ² (undried state), and in the case of the anchor coating agent for polyolefin extrusion lamination, 0.01 to 1.
It is about 0 g / m ² (after drying). In the case of a pressure-sensitive adhesive, it is about 5 to 50 g / m ² (after drying), and in the case of a heat-sealing agent, it is about 1 to 10 g / m ² (after drying).

As the plastic (D), a polyolefin having a heat sealing property is desirable, but it is not particularly limited. Typical examples are polyethylene, polypropylene, polystyrene, ethylene-vinyl acetate copolymer resin (EVA), ethylene-acrylic copolymer resin, ionomer resin, polyethylene terephthalate, polyethylene-2,6-naphthalate, nylon, polyvinyl alcohol, ethylene vinyl. Alcohol copolymer (EVO
H), polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyacrylonitrile, polyimide and the like.

The plastic (D) may be film-processed in advance, and may be laminated on the packaging film by dry lamination or wet lamination via the adhesive layer (C). Alternatively, the plastic (D) may be melted and extruded to be laminated on a packaging film via an anchor coating agent by using a laminating process. Alternatively, the molten plastic (D) may be formed into a film and then laminated on the packaging film via the adhesive layer (C) as in the nilam processing.

[0028]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to the following examples. In addition, the test method in an Example is as follows. Light transmittance: spectrophotometer ("U-best" manufactured by JASCO Corporation)
30 ") was used, and the transmittance was measured at a wavelength of 400 nm as a film used for vapor deposition as a reference (unvaporized). Oxygen gas permeability: According to ASTM D 3985, "OXTRAN-TWIN" manufactured by US Modern Control Co.
Was used to measure the oxygen gas permeability.

[Example 1] A continuous winding type resistance heating type vacuum vapor deposition system for continuously supplying and discharging an evaporation raw material described in JP-A-1-252768 was used, and a thickness of 14 μm was used.
On one side of the biaxially stretched polyvinyl alcohol film ("Bovlon" manufactured by Nigo Film Co., Ltd.), a mixture of silicon, silicon dioxide and magnesium fluoride (mixing ratio 44 mol%: 4)
4 mol%: 12 mol%) was vacuum-deposited by heating at 1350 ° C. (thickness: about 600 Å) to obtain a packaging film. The degree of vacuum at that time was 3 × 10 ⁻⁴ torr.

Example 2 Using the vapor deposition apparatus used in Example 1, a mixture of silicon, silicon dioxide, and magnesium fluoride (mixing ratio 44 mol%) was formed on both sides of the same polyvinyl alcohol film as in Example 1. : 44 mol%: 12 mol%) was vacuum-deposited by heating at 1350 ° C. (thickness is about 600 angstrom per side) to obtain a packaging film. The degree of vacuum at that time was 3 × 10 ⁻⁴ torr.

Example 3 Using the vapor deposition apparatus used in Example 1, a biaxially stretched ethylene vinyl alcohol copolymer film having a thickness of 12 μ (“Eval EF-X manufactured by Kuraray Co., Ltd.”
L ”), a mixture of silicon monoxide and magnesium fluoride (mixing ratio 98 mol%: 2 mol%) is vacuum-deposited by heating at 1300 ° C. (thickness is about 300 angstrom per side) to obtain a packaging film. It was The vacuum degree at that time is 4
× 10 ^-4 torr.

Example 4 The heating system of the evaporation source of the vacuum vapor deposition apparatus used in Example 1 was changed from the resistance heating system to the electron beam heating system, and a 25 μm thick biaxially stretched polyvinyl alcohol film (Nihon Film) was used. Silicon and silicon dioxide and forsterite (SiO) on both sides of the company's "Boblon"
₂ · 2MgO: co-oxidation of silicon dioxide and magnesium oxide) and mixtures of magnesium fluoride (mixing ratio 42 mol%: 42 mol%: 4 mol%: 12 mol%) and 1350 ° C.
Was vacuum-deposited by heating (the thickness is about 200 angstrom per one side) to obtain a packaging film. The degree of vacuum at that time is
It was 3 × 10 ⁻⁴ torr.

Example 5 Using the vapor deposition apparatus used in Example 1, a mixture of silicon, silicon dioxide and calcium fluoride (mixed) was formed on both sides of the same ethylene vinyl alcohol copolymer film as in Example 3. Ratio 48 mol%: 48 mol%:
4 mol%) was vacuum-deposited by heating at 1330 ° C. (thickness is about 800 angstrom per side) to obtain a packaging film. The degree of vacuum at that time was 4 × 10 ⁻⁴ torr.

Example 6 Using the vapor deposition apparatus used in Example 1, a mixture of silicon monoxide and strontium fluoride (mixing ratio 60 mol%: 40) was formed on both sides of the same polyvinyl alcohol film as in Example 1. (Mol%) was vacuum-deposited by heating at 1370 ° C. (thickness is about 1000 angstrom per side) to obtain a packaging film. The degree of vacuum at that time is 3
× 10 ^-4 torr.

Example 7 Using the vapor deposition apparatus used in Example 1, a mixture of silicon monoxide and barium fluoride (mixing ratio 95 mol%: 5) was formed on both sides of the same polyvinyl alcohol film as in Example 1. (Mol%) was vacuum-deposited by heating at 1350 ° C. (thickness is about 1000 angstrom per side) to obtain a packaging film. The degree of vacuum at that time is 3 × 1
It was 0 ^-4 torr.

[Comparative Example 1] Using the vapor deposition apparatus used in Example 1, a mixture of silicon and silicon dioxide (mixing ratio: 50) was formed on both sides of the same polyvinyl alcohol film as in Example 1.
Mol%: 50 mol%) was vacuum-deposited by heating at 1400 ° C. (thickness is about 500 angstrom per side) to obtain a packaging film. The degree of vacuum at that time is 5 × 10 ^-4 torr
r.

Comparative Example 2 Using the vapor deposition apparatus used in Example 1, a mixture of silicon, silicon dioxide and magnesium fluoride (mixing ratio 44 mol%: 44 mol) was formed on both sides of a polyethylene terephthalate film having a thickness of 12 μm. %: 12 mol%) was vacuum-deposited by heating at 1350 ° C. (thickness is about 600 angstrom per side) to obtain a packaging film. The degree of vacuum at that time was 3 × 10 ⁻⁴ torr.

Comparative Example 3 Using the vapor deposition apparatus used in Example 1, silicon monoxide alone was vacuum-deposited on both sides of the same polyvinyl alcohol film as in Example 1 at 1300 ° C. (thickness per side). (About 500 Å),
A packaging film was obtained. The degree of vacuum at that time is 2 × 10 ^-4 t
orr.

Comparative Example 4 Using the vapor deposition apparatus used in Example 1, magnesium fluoride alone was vacuum-deposited by heating at 1300 ° C. on both sides of the same polyvinyl alcohol film as in Example 1 (thickness is about one side). A packaging film was obtained. The degree of vacuum at that time is 2 × 1
It was 0 ^-4 torr.

With respect to the packaging films obtained in Examples and Comparative Examples, light transmittance and oxygen gas transmittance (25 ° C.)
-0% RH) was measured. Further, a heat sealant (“Q092 (S1)” manufactured by Toyo Ink Mfg. Co., Ltd.) was coated on the thin film layer on one surface of the obtained packaging film at 3 g / m ² (after drying) using a bar coater. A heat-sealing agent laminate was prepared and the oxygen gas permeability (25 ° C., 100% RH) was measured. In addition, an adhesive (“AD506S / CA” manufactured by Toyo Morton Co., Ltd. was formed on the thin film layer on one surface of the obtained packaging film.
T-RT1 ") is coated with a bar coater at 3 g / m ² (after drying), and an unstretched linear rhodity polyethylene film having a thickness of 60 μm (“ TU manufactured by Tohcello Co., Ltd. ”
X-FCD ”) was dry laminated to form a film laminate, and the oxygen gas permeability (25 ° C., 100% RH) was measured.

The results are shown in Table 1.

[Table 1]

[0042]

Industrial Applicability According to the present invention, a packaging film having both a high oxygen barrier property and a very high visible light transmittance (excellent colorless transparency) can be obtained. The packaging film of the present invention has a visible light transmittance equivalent to that of the polyvinyl alcohol film before forming the thin film layer.

Claims (7)

[Claims] 1. A thin film layer (B) comprising a silicon oxide and a fluoride of an alkaline earth metal is formed on one or both sides of a polyvinyl alcohol film (A) by a vacuum thin film forming technique. A packaging film having a visible light transmittance of 85% or more when the visible light transmittance of the alcohol-based film (A) is 100%. 2. The packaging film according to claim 1, wherein the polyvinyl alcohol film (A) is a biaxially stretched film. 3. The packaging film according to claim 1, wherein the polyvinyl alcohol film (A) is a polyvinyl alcohol film or an ethylene vinyl alcohol copolymer film. 4. The alkaline earth metal fluoride of the thin film layer (B) is one or more selected from magnesium fluoride, calcium fluoride, strontium fluoride and barium fluoride. The packaging film according to item 1. 5. The composition ratio of the silicon oxide and the alkaline earth metal fluoride constituting the thin film layer (B) is 99.
It is 5 to 80 mol% and 0.5 to 20 mol%.
4. The packaging film according to any one of 4 above. 6. A packaging film laminate obtained by laminating an adhesive layer (C) on the thin film layer (B) of the packaging film according to any one of claims 1 to 5. 7. A plastic (D) on the adhesive layer (C).
A packaging film laminated body obtained by laminating.