JP2000071379A - Transparent gas barrier film, packaging material using the film, and package using the packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silicon oxide compd. mainly having barrier properties to oxygen or steam and having sufficient flexibility hardly generating a crack at a time of post-processing or practical use by allowing the fine structure of a silicon oxide compd. layer to enter a predetermined range prescribed from the permeabilities of a plurality of inert gases different in molecular size. SOLUTION: A transparent gas barrier film is formed by laminating a silicon oxide compd. layer to at least the single surface of a base layer comprising a transparent polymer. In this case, the permeability of Ne gas of the laminated film is set to 0.05 times or less the permeability only of the base layer and the permeability of He gas of the laminated film is set to 0.02-0.15 times the permeability only of the base layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent gas barrier film having a silicon oxide compound layer laminated on a transparent polymer film, and more particularly, to a transparent gas barrier film which is suitable for practical packaging of foods and pharmaceuticals. The present invention relates to a transparent gas barrier film having both gas barrier properties and flexibility, a packaging material using the same, and a package using the same.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate (P)
A silicon oxide compound layer is formed on a transparent polymer film such as an ET) or a biaxially oriented polypropylene (OPP) film by a physical vapor deposition method (PVD) such as a vacuum vapor deposition method or a chemical vapor deposition method (CVD). The provided laminated film has been suitably used as a packaging material for foods and pharmaceuticals because of its excellent gas barrier properties and transparency. More recently, PVD
In addition to the fact that chlorine-based gas burrs such as C are repelled from environmental problems, expectations for silicon oxide compound laminated films are increasing.

[0003]

However, such a silicon oxide compound laminated film also has a problem. If the silicon oxide compound layer is too dense, the gas barrier properties of the laminated film itself will be excellent, but since the silicon oxide compound layer is not flexible, printing and laminating are performed to form a practical package. There is a possibility that cracks may occur during the processing process or handling after packaging, and there is a limitation that it cannot be used for applications such as applying a protective coat on the silicon oxide compound layer or applying excessive stress such as bending. Was.

[0004]

Therefore, according to the present invention, the fine structure of the silicon oxide compound layer falls within a suitable range defined by the transmittance of a plurality of inert gases (He, Ne) having different molecular diameters. Accordingly, it is intended to provide a silicon oxide compound having gas barrier properties mainly against oxygen and water vapor, and sufficient flexibility that is unlikely to be generated during post-processing or practical use.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described.

According to the present invention, in a transparent gas barrier film having a silicon oxide compound layer laminated on at least one surface of a base layer made of a transparent polymer, the Ne gas permeability of the laminated film is less than the Ne gas permeability of only the base layer. A transparent gas barrier film, wherein the transmittance of He gas of the laminated film is 0.01 times or more and 0.15 times or less of the transmittance of He gas of only the base layer; And a package using the same.

The present invention will be described below with reference to a formula. A transparent gas barrier film comprising a silicon oxide compound layer laminated on at least one surface of a transparent polymer base layer,
The ratio of the transmittance P (s) of the gas A of the base layer only to the transmittance P (f) of the gas A of the laminated film is represented by P (A) = P (f) / P
(S), P (Ne) ≦ 0.05, P (H
e) characterized by simultaneously satisfying 0.02 to 0.15.

Here, the transparent polymer used as the base layer is:
Polymer materials commonly used as packaging materials, such as polyethylene terephthalate (PET), biaxially oriented polypropylene (OPP), and biaxially oriented nylon (ON
y) It has mechanical strength and dimensional stability, etc., which are processed into a film and used. Further, a film having excellent smoothness and a small amount of the additive is preferable.
The surface of the transparent polymer may be subjected to a corona treatment, a low-temperature plasma treatment, an ion bombardment treatment as a pretreatment in order to improve the adhesiveness of the thin film, and a chemical treatment, a solvent treatment, etc. May be applied.

Although the thickness is not particularly limited, the thickness is preferably in the range of 5 to 100 μm in consideration of suitability as a packaging material and workability in forming a silicon oxide compound layer. Further, in consideration of mass productivity, it is desirable to use a long film so that a silicon oxide compound layer can be continuously formed.

Means for providing a silicon oxide compound layer on the base layer as a packaging material include PVD methods such as sputtering and ion plating in addition to vacuum evaporation.
And TMDSO (tetramethyldisiloxane) and HM
CVD using an organic silicon compound gas such as DSO (hexamethyldisiloxane) or a silane gas and an oxygen gas as raw materials
A sol-gel method utilizing the hydrolysis and polymerization of silicon alkoxide compounds such as TEOS (tetraethoxysilane) is used, and the method is not limited, but it is important to use helium gas. And the neon gas transmittance satisfy the following relationship.

P (Ne) ≦ 0.05, P (He) = 0.
02-0.15

Here, P (Ne) is the transmittance of Ne gas in the transparent polymer film used alone as the base material and the transparent gas barrier obtained by the present invention obtained by laminating a silicon oxide compound layer on the transparent polymer film. Similarly, P (He) is the ratio of the He gas transmittance of the transparent polymer alone to the He gas transmittance of the transparent gas barrier film obtained in the present invention. Ratio.

Here, the fact that P (Ne) is larger than 0.05 means that the number of defects large enough to allow Ne molecules having a molecular diameter of 2.60 ° to pass is increased, and as a result, oxygen barrier properties and water vapor are increased. The barrier properties become insufficient as a packaging material.

On the other hand, the fact that P (He) is 0.02 or less means that the gas is so dense that even He gas having a molecular diameter of 2.16 ° is almost impervious. The transparent gas barrier film provided with
Although the gas barrier properties of the laminated film itself are excellent, the silicon oxide compound layer loses its flexibility, so that the film may be cracked during the process of printing or laminating into a practical package or handling after packaging. May occur, and the intended use is restricted. On the other hand, when P (He) is 0.15 or more, the number of fine gaps becomes too large, and the basic gas barrier performance as a packaging material is the same as when P (Ne) is larger than 0.05. Become inferior to

The thickness of such a silicon oxide compound is not particularly limited, and the preferred thickness varies depending on the film forming method and the film forming conditions.
In the range of 1500 °, P (He) and P (N
The value of e) tends to fall within the range defined by the present invention. That is, if the thickness is less than 50 °, the silicon oxide layer often becomes an island shape instead of a film shape, and if the thickness is more than 1500 °, cracks are easily generated due to the internal stress.

As described above, He and Ne are used as evaluation gases.
The reason why the rare gas is used is that the chemical reaction does not occur to the extent that it can be considered, and it is preferable to measure the gas permeability purely. It is not necessary to consider the change.

At least one of the protective layer side and the base film side of the coated film of the present invention is laminated with a sealant material which is a heat-sealable thermoplastic material as shown below via a barrier adhesive if necessary. It can be used as a heat sealable resin.

Specifically, a non-stretched polypropylene film, a polyethylene film and the like can be exemplified.

Although the optimum thickness of the heat-sealable resin varies depending on the use, it is preferably in the range of 10 to 100 μm.

The heat-sealing temperature of the heat-sealing resin can be appropriately selected depending on the material used.
The method for forming the heat-sealable resin on the protective layer is not particularly limited, and examples thereof include a method of coating with a coater and a method of laminating an extrusion coating molten film via an adhesive.

As the supporting base material layer, a base material such as paper and polyethylene can be used. The thickness is not particularly limited.

The printing may be performed directly on the transparent gas barrier film itself, but may be provided on the supporting base material layer.
It may be performed partially or not at all.

<Method of measuring P (He) and P (Ne)>
Hereinafter, the method of measuring P (He) and P (Ne) used in the present invention will be described. However, it is understood that the method of measuring P (He) and P (Ne) is not limited to the method described here. It is clear from the nature of

In the measurement of P (He) and P (Ne) in the present invention, a differential pressure type transmittance measuring device GTR-30X manufactured by Yanaco Analytical Industry Co., Ltd. using a gas chromatography as a detector.
T was used. FIG. 1 shows a schematic view of the transmission cell section of the apparatus.
The principle of measuring the gas permeability will be described with reference to FIG.

The transmission cell is divided into an upper cell 1 and a lower cell 2 by a sample film, and each is evacuated by a vacuum pump.

A gas for measuring the transmittance (test gas) can be introduced into the upper cell at a constant pressure, and a calibration tube 3 (capacity: 3995 μl) is arranged on the lower cell side. Vacuum pump 5 inside the calibration tube
To exhaust or to connect to the column 6 of gas chromatography.

As a measurement procedure, first, the sample film 7 is set on the lower cell using the vacuum grease 8,
After setting the upper cell in contact with the sample with the O-ring 9, both the upper and lower ends are evacuated, and then the measurement gas is supplied into the upper cell at a pressure of ² kgf / cm ² .
At this time, the lower cell side is kept evacuated. The pressure of the measurement gas applied to the upper cell can be arbitrarily changed, but in the present invention, the measurement was performed by unifying the above values.

Then, after several hours have passed, after the permeation of the measurement gas through the sample film reaches a steady state, only the valve 10 on the lower side of the calibration tube is closed, and the gas permeating the sample is stored in the calibration tube. Here, the time required to reach the steady state and the time required to accumulate gas in the calibration tube differ depending on the types of the sample film and the gas to be measured. The respective times used in the present invention are described below.

Measurement gas Time to steady state Time to store in calibration tube Helium 120 min 2 min Neon 300 min 15 min

After a lapse of a predetermined time, the upper valve 11 of the calibration tube is closed, the lower valve 10 is opened, and the three-way valve is switched to the gas chromatography side so that the gas stored in the calibration tube is removed from the gas chromatography column. Lead to.

From the intensity measured by gas chromatography, the amount of permeated gas was calculated using a previously prepared calibration curve.

The actual calculation of P (He) and P (Ne) is performed by measuring the transmittance of He and Ne of only the base film, measuring the transmittance of the silicon oxide compound laminated film, and determining the ratio between them. I went by taking.

In addition, evaluations of oxygen barrier properties, water vapor barrier properties, and flexibility, which are practically important as other packaging materials, were performed by the following methods.

<Oxygen Barrier Property> MOCON OXTRA
The measurement was performed in an atmosphere of 30 ° C. and 70% RH using an N 10 / 50A oxygen gas permeability measuring device (manufactured by Modern Control).

<Water vapor barrier property> JIS Z-0208
Was measured in an atmosphere of 40 ° C. and 90% RH according to the cup method described above.

The flexibility was evaluated by measuring the tensile resistance and the kneading resistance described below.

<Tensile Resistance> Using a tensile tester (Tensilon SS-207-EB manufactured by Toyo Baldwin Co., Ltd.), the oxygen permeability after 6% tension was measured to determine the tensile resistance.

<Kneading resistance> An unstretched polypropylene (C) having a thickness of 60 μm was applied via an adhesive having a coating amount of 4.0 g / m ^2.
PP) A film laminated with a film and a dry laminate was rubbed five times using a rubbing tester (Gerboflex tester manufactured by Rigaku Kogyo Co., Ltd.), and then the oxygen permeability was measured to determine the rubbing resistance.

[0039]

The present invention will be described more specifically with reference to the following examples.

Example 1 FIG. 2 shows an embodiment of the transparent gas barrier film of the present invention. The base is a polyethylene terephthalate film (Toray P-6).
0) A silicon oxide compound thin film is formed on one side of a thickness of about 12 μm) 12.

The silicon oxide compound thin film is formed by using particulate silicon monoxide (SIMOX manufactured by Sumitomo Citix) as an evaporation source, changing the degree of vacuum to 2 × 10 ^{−5 to} 3 × 10 ⁻³ Torr, Changing the emission current and the winding speed by heating the heater to increase the evaporation speed to 50 to 1;
It was performed by changing within the range of 000 ° / sec.
P (He), P of the obtained transparent gas barrier film
Table 1 shows the measurement results of (Ne) and the evaluation results of the oxygen barrier property, the water vapor barrier property, and the flexibility.

[0042]

[Table 1]

<Comparative Example 1> As in Example 1, the electronic beam
P (He)
And P (Ne) measurement, oxygen and water vapor barrier properties,
The flexibility was evaluated. The results are shown in Table 1 at the same time. As can be seen from the results, there was a problem with the oxygen and water vapor barrier properties or flexibility.

Example 2 A silicon oxide compound was prepared in the same manner as in Example 1, except that the transparent polymer film serving as the base was changed to biaxially oriented polypropylene (FOK thickness: 20 μm, manufactured by Mimura Nimura). The thin film was formed by vacuum evaporation, and its P (He), P (Ne) and other performance evaluations were performed. The results are shown in Table 1.

<Comparative Example 2> As in Example 2, the electronic beam
P (He)
And P (Ne) measurement, oxygen and water vapor barrier properties,
The flexibility was evaluated. The results are shown in Table 1 at the same time. As can be seen from the results, there was a problem with the oxygen and water vapor barrier properties or flexibility.

[0046]

According to the present invention, on a base layer made of a transparent polymer film,
The ratio of the transmittance P (s) of the gas A of the base layer only to the transmittance P (f) of the gas A of the laminated film is represented by P (A) = P (f) / P
(S), P (Ne) ≦ 0.05, P (H
e) By providing a silicon oxide compound layer that simultaneously satisfies 0.02 to 0.15, it has gas barrier properties mainly against oxygen and water vapor, and has sufficient flexibility to prevent cracking during post-processing and practical use. It is intended to provide a transparent gas barrier film.

[0047]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a gas permeability measuring device.

FIG. 2 is a partially enlarged sectional view of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper cell 2 Lower cell 3 Calibration tube 4, 5 Three-way electromagnetic bubble 6 Column of liquid chromatography 7 Inspection object (sample film) 8 Vacuum grease 9 O-ring 10 Upper valve of calibration tube 11 Lower valve of calibration tube 12 Base layer 13 Oxidation Silicon compound layer

Continued on front page F-term (reference) 3E086 AD01 BA04 BA15 BA40 BB01 BB22 BB51 BB90 CA01 CA28 4F006 AA12 AA35 AA38 AB13 AB67 AB76 BA00 BA05 BA13 CA07 DA01 DA04 EA01 4F100 AA20B AK02A AK41 AR00C AT00D BA03 BA10 BA06 BA06 BA06 BA06 GB66 HB31E JD03 JD04 JK07 JK13 JL12C JN01 JN01A YY00A YY00B YY00E 4K029 AA11 AA25 BA46 BC00 BD00 GA03 4K030 AA06 BA44 CA07 CA12 DA08 LA00 LA24

Claims (4)

[Claims] 1. A transparent gas barrier film comprising a silicon oxide compound layer laminated on at least one side of a base layer made of a transparent polymer, wherein the Ne gas permeability of the laminated film is lower than the Ne gas permeability of only the base layer. .05 times or less,
And the permeability of He gas of the laminated film is He of only the base layer.
A transparent gas barrier film having a gas transmittance of 0.02 times or more and 0.15 times or less. 2. The transparent gas barrier film according to claim 1, further comprising a heat sealing layer provided on the silicon oxide compound layer as a base layer of the transparent gas barrier film. 3. A transparent gas barrier film according to claim 1, wherein a support substrate layer is provided on the side opposite to the base layer of the transparent gas barrier film with or without an adhesive layer. 4. A package formed by using the transparent gas barrier film of claim 1, 2 or 3, and printed as required.