JP3267741B2 - Gas barrier film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for packaging foods, electronic parts, pharmaceuticals and the like, and more particularly to a film having improved properties such as gas barrier properties, moisture permeability and aroma resistance. The present invention relates to a packaging film having excellent mechanical properties including characteristics.

[0002]

2. Description of the Related Art Films having excellent gas barrier properties include those obtained by laminating aluminum on a plastic film and those coated with vinylidene chloride or ethylene vinyl alcohol copolymer. Also,
As a device using an inorganic thin film, a device obtained by laminating a silicon oxide, an aluminum oxide thin film, or the like is known.

[0003]

However, such a conventional gas barrier film has the following problems. Aluminum laminates are economical and have good gas barrier properties.However, they are opaque, making it difficult to use microwave ovens because they do not allow the contents to be seen during packaging and do not transmit microwaves. is there. Those coated with vinylidene chloride or ethylene vinyl alcohol copolymer do not have sufficient gas barrier properties against water vapor, oxygen, etc., and the decrease is remarkable especially at high temperature treatment. In addition, with respect to vinylidene chloride, there is generation of chlorine gas at the time of incineration, and there is also a concern about the influence on the global environment. On the other hand, visible contents, as a gas barrier film that can be used in the microwave oven, in JP-B-51-48511, a gas barrier film formed by depositing a Si _x O _y (e.g., SiO ₂₎ in the synthetic resin surface is proposed Has good gas barrier properties
The iO _x system (x = 1.3 to 1.8) has a slightly brown color and is insufficient as a transparent gas barrier film.

[0004] Some of those mainly composed of aluminum oxide are found in Japanese Patent Application Laid-Open No. 62-101428, but they have a problem that their oxygen barrier properties are insufficient and their mechanical properties are not so high. Also, Al ₂ O ₃ .SiO ₂
As an example of the system, there is one proposed in Japanese Patent Application Laid-Open No. 2-194944, which is a laminate of Al ₂ O ₃ and SiO ₂ , and requires a large-scale manufacturing apparatus. The initial gas barrier properties of these gas barrier films are also excellent, but care must be taken when handling them, that is, gas barrier properties due to post-processing such as laminating and printing or handling before laminating. The problem is that the deterioration is large. Thus, it has sufficient oxygen barrier properties and water vapor barrier properties,
In addition, at present, there is no transparent gas barrier film with little deterioration of the barrier property against mechanical deformation due to a post-process or handling.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas barrier film having excellent gas barrier properties and excellent mechanical properties such as bending resistance. That is, the present invention relates to a gas barrier film in which a thin film containing an aluminum oxide silicon oxide thin film as a main component is formed on at least one surface of a plastic film, and a peak intensity P1 around 1060 cm-1 in an infrared absorption spectrum of the thin film. And the peak intensity P2 around 1170 cm-1
A gas barrier film, wherein 2 / P1 satisfies the following expression. P2 / P1 = B-0.00195W where P
1: Peak intensity around 1060 cm @ -1 of infrared absorption spectrum of thin film P2: 1170 cm of infrared absorption spectrum of thin film
-1 peak intensity W: weight% of aluminum oxide in the thin film B: peak intensity ratio of the thin film not containing aluminum oxide 0.35 ≦ B ≦ 0.77 P 2 / P 1 ≧ 0 A gas barrier film according to claim 1 provided with a gas barrier layer, and a packaging or gas barrier film using the gas barrier film according to claim 1 or 2.

[0006] The plastic film referred to in the present invention is:
A film obtained by melt-extruding an organic polymer and stretching, cooling, and heat setting in the longitudinal direction and / or the width direction as necessary. Examples of the organic polymer include polyethylene, polypropylene, and polyethylene terephthalate. , Polyethylene-2,6-naphthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, wholly aromatic polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, Examples include polyphenylene sulfide and polyphenylene oxide. These (organic polymer) organic polymers may be copolymerized or blended in small amounts with other organic polymers.

Further, known additives such as an ultraviolet absorber, an antistatic agent, a plasticizer, a lubricant, and a coloring agent may be added to the organic polymer, and the transparency thereof is not particularly limited. However, when used as a transparent gas barrier film, those having a transmittance of 50% or more are preferred. The plastic film of the present invention may be subjected to corona discharge treatment, glow discharge treatment, or other surface roughening treatment prior to laminating the thin film layer, as long as the object of the present invention is not impaired. ,Also,
Known anchor coat treatment, printing, and decoration may be applied. The thickness of the plastic film of the present invention is preferably in the range of 5 to 500 μm, more preferably 8 to 300 μm. The product of the present invention may be used as it is, or may be used by laminating or coating another organic polymer film or a thin layer.

It is considered that the aluminum oxide silicon oxide thin film is composed of a mixture or a compound of aluminum oxide and silicon oxide. The aluminum oxide here is composed of a mixture of various aluminum oxides such as Al, AlO, and Al ₂ O ₃ , and the content of each of the aluminum oxides in the aluminum oxide differs depending on the production conditions. Silicon oxide is considered to be composed of Si, SiO, SiO _{2 and the} like, and their ratios also differ depending on the preparation conditions. The ratio of aluminum oxide in the thin film in the present invention is not particularly limited, but is preferably 1% by weight or more and 80% by weight or less, more preferably 3 to 75% by weight, and more preferably 6 to 65% by weight. is there. Also, this component may contain a trace amount (up to 2% of all components) of other components as long as the characteristics are not impaired. As the thickness of the thin film,
Although not particularly limited, it is preferably 50 to 8000 °, more preferably 70 to 5000 °, from the viewpoint of gas barrier properties and flexibility. Further, the crystallinity of the thin film is not particularly limited as long as the characteristics are not impaired, but it is more preferable that the thin film is in an amorphous state. Such an aluminum oxide / silicon oxide based thin film is formed by a PVD method such as a vacuum evaporation method, a sputtering method, and ion plating.
Method (physical vapor deposition) or CVD (chemical vapor deposition)
And the like are appropriately used. For example, in a vacuum deposition method, Al ₂ O ₃ and SiO ₂ or Al and S
A mixture of iO _{2 and} the like are used, and as a heating method, resistance heating, high-frequency induction heating, electron beam heating, or the like can be used. Further, oxygen, nitrogen, water vapor, or the like may be introduced as a reactive gas, or reactive vapor deposition using means such as ozone addition or ion assist may be used. Also,
Apply DC voltage, AC voltage, high frequency voltage to the board,
The production conditions may be changed as long as the object of the present invention is not impaired, such as raising the substrate temperature or cooling. For example, to increase the peak intensity ratio P ₂ / P ₁ of the infrared absorption spectrum of the thin film, the substrate temperature may be increased,
It is effective to increase the high frequency voltage applied to the substrate, increase the power of the electron beam, and the like. Sputtering method and CV
The same applies to other creation methods such as the D method.

In the present invention, the infrared absorption spectrum is
Absorbance for infrared rays of 400 to 4000 cm ^-1 , which can be measured by an infrared spectrophotometer. Measurement methods include transmission method, reflection method, total reflection method (ATR method),
There are photoacoustic spectroscopy (PAS method) and the like, although not particularly limited, but preferably a reflection method and an ATR method. In addition, in order to obtain an infrared absorption spectrum of only the thin film layer, the spectrum can be observed more accurately by taking a difference spectrum between the film on which the thin film is formed and the substrate only on which the thin film is not formed. . From the infrared absorption spectrum, the chemical bonding state between atoms can be known, and here, the bonding state of silicon, aluminum, and oxygen can be observed. 10
The peak near 60 cm ^-1 is absorption due to asymmetric stretching motion of Si-O-Si. On the other hand, the peak near 1170 cm ^-1 indicates the non-uniformity of the SiO ₂ network structure or
This is considered to indicate the degree of structural distortion. Also, 117
Absorption peak in the vicinity of 0 cm ^-1 is by the ratio of the aluminum oxide, but shifts the range of 1190～1150Cm ^-1, which is believed to be due to an increase in Si-O-Al bond.

In the infrared absorption spectrum of the thin film thus obtained, the peak intensity P near 1060 cm -1 is obtained.
The ratio of the peak intensity P2 around 1 to 1170 cm-1 P2 /
The relation between P1 and the mass% of aluminum oxide in the thin film is expressed by the formula P2 / P1 = B-aW (W: mass% of aluminum oxide in the thin film, B: peak intensity ratio of the thin film not containing aluminum oxide). In the region where the value of B is larger than 0.77, the strain in the thin film is large and sufficient gas barrier properties cannot be obtained. However, the B value is 0.35
In the smaller region, the structural relaxation due to the strain is reduced, so that the mechanical characteristics such as the gelbo characteristics tend to be somewhat inferior, but this is not a level that causes a practical problem.
For the above reasons, the peak intensities P1 and 1170c around 1060 cm @ -1 in the infrared absorption spectrum of aluminum oxide and silicon oxide thin films which are preferable as gas barrier films
The ratio P2 / P1 of the peak intensity P2 near m-1 is expressed by the relationship between the composition ratio of aluminum oxide in the thin film and P2 / P1 = B-
0.00195 WW: mass% of aluminum oxide in thin film B: peak intensity ratio of thin film not containing aluminum oxide P2 / P1 ≧ 0 When expressed by a relational expression, the B value is 0.1.
35 to 0.75 . The gas barrier film of the present invention has excellent mechanical properties including gelling properties, so that there is little deterioration in the laminating process, the printing process, the manufacturing process, and even after the bag is formed, it is unnecessarily necessary for its handling. No attention is required. The use state of the gas barrier film of the present invention includes bags, lid materials, cups, tubes, standing bags, trays, and the like, and the contents include snacks, crackers, dried foods such as sprinkles, pickles, soy sauce, mayonnaise, and the like. Aquatic foods, frozen goods such as vegetables, fish, meat, etc .;
Electronic components such as C and LSI, and pharmaceuticals such as infusion bags, and are not limited thereto. Next, the present invention will be described with reference to examples.

(Embodiment 1) As an evaporation source, particulate Al ₂ O ₃ (purity 99.9%) having a size of about 3 to 5 mm and S
iO using ₂ (purity 99.9%), electron beam - in beam evaporation method, 12 [mu] m thick PET film (Toyobo (Ltd.): E
5007), a silicon oxide gas barrier thin film containing aluminum oxide was formed. The deposition materials are mixed without mixing.
Al ₂ O ₃ and SiO ₂ were separately placed in two water-cooled hearths, and each of the Al ₂ O ₃ and SiO ₂ was heated in a time-sharing manner using one electron gun (hereinafter referred to as an EB gun) as a heating source. At that time, the emission current of the EB gun was set to 3.0 A, the heating ratio of Al ₂ O ₃ to SiO ₂ was changed from 10:10 to 80:10, and the composition was changed. Further, a DC voltage of -200 V was applied to the chill roll. The temperature of the chill roll was + 10 ° C. The film thickness is 600
It was fixed at Å. (Table 1) Examples 1-1 to 5 The infrared absorption spectra of the films thus obtained were measured with an infrared spectrophotometer. Further, an unstretched polypropylene film (OPP film) having a thickness of 40 μm was dry-laminated with a two-component curable polyurethane-based adhesive (thickness of 3 μm) on the composite film on PET.
A plastic film for packaging according to the present invention was obtained. The packaging film is retorted (120 degrees x 3
0 minutes) or after the gelbo treatment, the oxygen barrier properties were measured.

Next, a measuring method and a processing method will be described. -Oxygen transmission rate measurement method The oxygen transmission rate of the prepared gas barrier film is measured by an oxygen transmission rate measuring apparatus (OX-TRANS manufactured by Modern Controls).
100). -Measurement method of water vapor transmission rate The water vapor transmission rate of the prepared gas barrier film was measured using a water vapor transmission rate tester (L80-4000, manufactured by RISSI). Measurement method of infrared absorption spectrum Using an infrared spectrophotometer (FTS-80 manufactured by Bio-Rad), an infrared absorption spectrum at 400 to 4000 cm ^-1 was measured by the ATR method. In addition, in order to measure the surface layer as much as possible, germanium having a relatively short penetration length of infrared light into the sample was used as a high refractive material. At this time, the incident angle was 45 °.

Test method for bending fatigue resistance (hereinafter referred to as gelbo property) The bending fatigue resistance was evaluated using a so-called gelbo flex tester (manufactured by Rigaku Corporation). The conditions are (MIL-B131H) 11.2 inches × 8 inches
The sample piece of the channel is cylindrical with a diameter of 3 (1/2) inch, the both ends are held, the initial holding interval is 7 inches, and the stroke is 3 (1/2) inch and a twist of 400 degrees is applied. Reciprocating motion 40 times / m
The test was conducted at a speed of 20 ° C. and a relative humidity of 65%. The oxygen transmittance measured in this way was as excellent as about 1 cc. The results after the retort and the gelbo test were also increased by about 1 cc, and a gas barrier film having excellent overall characteristics was obtained. (Comparative Example 1) A packaging film was prepared in the same manner as in Example 1 using a silicon oxide-based gas barrier film formed by evaporating a SiO material by an EB evaporation method, and the oxygen barrier properties were measured.
At the same time, the PET film substrate was also measured. (Comparative Example 1-1
5) The silicon oxide-based gas barrier film was excellent in gas barrier properties, but exhibited a brown color and was not colorless and transparent.

(Embodiment 2) As an evaporation source, an electron beam is used by using particulate Al ₂ O ₃ (purity 99.9%) and SiO ₂ (purity 99.9%) having a particle size of about 3 to 5 mm. 12 µm thick PET film (Toyobo Co., Ltd .: E
5007), a silicon oxide gas barrier thin film containing aluminum oxide was formed. The deposition materials were heated without mixing, using one EB gun each as a heating source. The emission current was set to 0.2 to 3.5 A, respectively, and the heating power ratio was changed to 1: 1 to 10: 1. Further, an AC voltage of 200 V is applied to the chill roll, and the chill roll temperature is +5.
To + 50 ° C. Film feed speed 60-210m
/ Min, and formed a film having a thickness of 150 to 2000 mm ((Table 2) Examples 2-1 to 4, (FIG. 1)). The peak intensity ratio and the barrier property of the infrared absorption spectrum of the obtained film were measured in the same manner as in Example 1. The oxygen transmittance measured in this way was very excellent, 1 cc or less. Further, the results after the retort and gelbo tests were also around 2 cc, and a gas barrier film having excellent overall characteristics was obtained.

Comparative Example 2 In the same manner as in Example 2, an aluminum oxide silicon oxide-based gas barrier thin film was formed by EB heating evaporation. At this time, the emission current of the EB gun is 0.
The voltage was 5 to 3.0 A, an AC voltage of 200 V was applied to the chill roll, and the chill roll temperature was -15C. The peak intensity ratio of the infrared absorption spectrum and the oxygen transmittance were measured for the obtained sample (Comparative Examples 2-1 to 4 in Table 2 and FIG. 2) in the same manner as in Example 2. As a result, one of the oxygen barrier properties, retort, and gelbo properties became insufficient.

[0016]

As described above, in a gas barrier film in which an aluminum oxide silicon oxide-based thin film is formed on at least one surface of a plastic film, the infrared absorption spectrum of the thin film has peak intensities P1 and 117 near 1060 cm ^-1.
The relationship between the ratio P ₂ / P ₁ to the peak intensity P ₂ near 0 cm ⁻¹ and the mass% of the aluminum oxide in the thin film is expressed as P ₂ / P ₁ =
When expressed by a relational expression of B−0.00195 W (W: weight% of aluminum oxide in the thin film, B: peak intensity ratio of the thin film not containing aluminum oxide), B ≦ 0.77;
By setting the range of P ₂ / P ₁ ≧ 0, it is possible to provide an aluminum oxide silicon oxide-based gas barrier film having excellent gas barrier properties and excellent mechanical properties such as flexibility and overall excellent practical properties. .

[0017]

[Table 1]

[0018]

[Table 2]

[Brief description of the drawings]

FIG. 1 is an example of an infrared absorption spectrum of a thin film obtained in Example 2 according to the present invention. The ratio of aluminum oxide in this sample is 40% by weight.

FIG. 2 is an example of an infrared absorption spectrum of a thin film obtained in Comparative Example 2. The ratio of this sample aluminum oxide is 40% by weight.

[Explanation of symbols]

P ₁ is the peak intensity around 1060 cm ⁻¹ . P ₂ is the peak intensity around 1170 cm ⁻¹ .

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Kotani 2-1-1 Katata, Otsu-shi, Shiga Toyo Spinning Co., Ltd. (72) Inventor Hiromi Goto 2-1-1 Katata, Otsu-shi, Shiga (72) Inventor Noriko Takahashi 2-1-1 Katata, Otsu-shi, Shiga Prefecture Toyo Spinning Co., Ltd. (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu-shi, Shiga Prefecture Examiner Hiroaki Hirai in the Research Laboratory of Toyobo Co., Ltd. (56) References JP-A-3-23934 (JP, A) JP-A-4-99165 (JP, A) JP-A-60-23037 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (3)

(57) [Claims] 1. A gas barrier film having aluminum oxide and silicon oxide as main components formed on at least one surface of a plastic film, wherein a peak intensity P ₁ near 1060 cm ⁻¹ in an infrared absorption spectrum of the thin film is obtained. And the ratio P ₂ / P ₁ of the peak intensity P ₂ around 1170 cm ⁻¹
Satisfies the following formula: P ₂ / P ₁ = B−0.00195 W where P ₁ is 1060 cm ^{−1 in} the infrared absorption spectrum of the thin film
Near peak intensity P ₂ : Peak intensity near 1170 cm ^{−1 in} infrared absorption spectrum of thin film W: Weight% of aluminum oxide in thin film 0.35 ≦ B ≦ 0.77 P ₂ / P ₁ ≧ 0 2. A gas barrier film, wherein a heat seal layer is provided on the thin film layer according to claim 1. 3. A film for packaging or gas shielding using the gas barrier film according to claim 1 or 2.