JPS6246629B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a synthetic resin body having moisture permeability resistance. Conventionally, moisture permeable materials have been used in the packaging of foods, medicines, and chemical products to avoid deterioration of the contents, and in the electronic industry to protect EL elements. For example, in Japanese Patent Application Laid-open No. 51-114483, aluminum is vapor-deposited on a polyester film.
If aluminum is vapor-deposited, the transparency will naturally be impaired and the adhesion strength will be relatively low, so it can only be used for limited purposes. Also, special public service in 1977-
In Publication No. 12953, SixOy is applied to plastic film.
Although transparency was maintained by providing a thin film layer, the moisture permeation resistance was insufficient. The present invention was obtained as a result of intensive studies to eliminate the above-mentioned conventional drawbacks, and does not impair transparency.
Furthermore, the present invention provides a synthetic resin body having extremely good moisture permeability resistance. In the present invention, transparent synthetic resin bodies such as polyvinyl chloride, polystyrene, polyvinyl butyral, polyethylene, polypropylene, polyester, polyamide, and cellophane are used as the base material. Furthermore, the transparent synthetic resin body is a highly flexible film-like body, which is convenient for use in packaging or stacking. However, the present invention is not limited to those in which the base material is a film-like body, but can be applied to synthetic resin molded products such as plate-like bodies and lens bodies, and can prevent deterioration and deterioration of synthetic resin bodies due to moisture permeation. It can be prevented. The film-like transparent synthetic resin body has a thickness of 5 to 300 μm and is highly flexible, preferably 5 to 100 μm. In order to vapor-deposit an oxide composition on a film-like transparent synthetic resin body, a winding process using a cooling roll is normally required, but if the film-like transparent synthetic resin body has a thickness of less than 5 μm If so, wrinkles and cracks are likely to occur, and if the thickness exceeds 300 μm, flexibility becomes poor and continuous winding becomes difficult. A transparent thin film layer is formed on at least one side of the transparent synthetic resin body. The transparent thin film layer is made of SiO ₂ , B ₂ O ₃ ,
Consisting of BaO, Al ₂ O ₃ , in molar ratio (SiO ₂ ):
(B ₂ O ₃ ): (BaO + Al ₂ O ₃ ) = 2-4:1-2:0.3
~1. BaO _{and Al2O3}
may not include substantially one of them. If a large amount of alkali metal oxides such as Na ₂ O are included in the above composition of the transparent thin film layer, the moisture permeability will be impaired due to its hydrophilic nature, and even if vacuum evaporation is performed, the composition will easily fluctuate. arise. Furthermore, if the molar ratio of the transparent thin film layer is out of the above range, layer separation tends to occur and moisture permeation resistance decreases. When the amount of B ₂ O ₃ increases, the moisture permeability deteriorates due to its reactivity with water, and (BaO +
As the amount of Al ₂ O ₃ ) decreases, water resistance tends to deteriorate. The most preferable method for forming the above oxide composition on the surface of a transparent synthetic resin body is sputtering, and by setting the sputtering target to the above composition, it is possible to form a transparent thin film layer having almost the same composition. can. Further, a transparent thin film layer having the above composition can also be formed by a vacuum evaporation method or an ion plating method. In the case of vacuum evaporation, it is said to be difficult to form a thin film layer using mixed substances having different vapor pressures with the same composition. However, the present inventors have confirmed that if the above composition is melted in advance in an electric furnace and vitrified, then used as an evaporator and evaporated using an electron gun heating method, a deposited film with approximately the same composition can be obtained. did. Further, a deposited film having the above composition can also be formed by a flash deposition method which is generally used when vacuum depositing a mixture. In the present invention, the adhesiveness of the transparent thin film layer to the transparent synthetic resin body of the base material of the transparent thin film layer is good, and the transparency is also good, regardless of whether the vacuum evaporation method, the ion plating method, or the sputtering method is used. Another feature of the present invention is that curling does not pose a major problem in a film-like transparent synthetic resin body in which a transparent thin film layer is formed by a vacuum evaporation method or the like. This is probably because the system of the present invention (SiO ₂ , B ₂ O ₃ , BaO, Al ₂ O ₃ ) has less residual stress in the transparent thin film layer than the conventional SixOy. Forming a transparent thin film layer by vacuum evaporation, ion plating, or sputtering is usually carried out in a vacuum atmosphere of 2×10 ^-3 torr or less, but in order to avoid deterioration in performance due to contamination with impurities, It is preferable to carry out under a vacuum atmosphere of 5×10 ⁻⁴ torr or less. The thickness of the transparent thin film layer is preferably in the range of 100 to 5,000 Å, more preferably in the range of 500 to 2,500 Å in order to have good flexibility and adhesion. Even if the thickness of the transparent thin film layer exceeds 5000 Å, the transparency will not be impaired, but the curling property of the film-like transparent synthetic resin body may become a problem, and cracks and peeling may occur easily. Also, the thickness of the transparent thin film layer is
When the thickness is less than 100 Å, the film may form an island-like structure, resulting in insufficient moisture permeation resistance. When the moisture permeable synthetic resin body of the present invention is used as a packaging body, it is desirable to impart heat sealability to it. In that case, (SiO ₂ , B ₂ O ₃ , BaO,
By laminating a synthetic resin film having heat-sealing properties on a transparent thin film layer made of threads of Al ₂ O ₃ ), heat-sealing properties can be imparted to the moisture permeable synthetic resin body of the present invention. Examples of the synthetic resin film having heat-sealing properties include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-based ionomer, etc., which do not lose transparency. To laminate synthetic resin films having heat-sealing properties, there are a method using an adhesive (dry lamination method) and a method of melt-extruding a synthetic resin into a film and pressing it onto a base material (extrusion lamination method). In the dry lamination method, the adhesive used varies depending on the synthetic resin film, but isocyanate-based adhesives are generally used. In the extrusion lamination method, the transparent thin film layer exhibits an anchoring effect, so that the usual anchoring treatment using an organic titanate-based, isocyanate-based, or polyethyleneimine-based anchoring agent is not necessary. Therefore, there is no need to use conventional organic solvents, and there is no need to degrade the manufacturing work environment or leave organic solvents in the product. Examples of the present invention are shown below. Example 1 The molar ratio of SiO ₂ , B ₂ O ₃ , BaO, and Al ₂ O ₃ was 3:1:
A mixture of oxides with a ratio of 0.67:0.33 was melted in an electric furnace and vitrified, then heated and evaporated using an electron gun heating method under a vacuum of 5 × ^-5 torr and deposited on a polyethylene terephthalate (PET) film (15 μm thick).
A transparent thin film layer with a thickness of 1000 Å was formed. The thickness of the transparent thin film layer was measured using a crystal oscillation type monitor. The composition of the transparent thin film layer was analyzed using an x-ray microanalyzer and was found to be approximately the same as the composition of the initial mixture. The adhesion of the formed transparent thin film layer was checked using JIS D0202 and was found to be very good. Further, the light transmittance of the film on which the transparent thin film layer was formed was approximately the same as that of the undeposited film, and the transparency was good. Moisture permeability is JIS at 40℃ and relative humidity 90%RH.
It was measured using Z0208 (gravimetric method using cup) and hygrometer method, and both values were approximately the same. Example 2 In Example 1, the thickness of the transparent thin film layer was set to 2000 Å.
And so. Examples 3 and 4 Biaxially oriented polypropylene (OPP) film (25 μm thick) was used instead of the PET film in Example 1.
It was used. Examples 5 to 8 In place of the mixture composition of Example 1, the compositions shown in the table were used to form transparent thin film layers. Comparative Examples 1 and 2 In place of the mixture composition of Example 1, a transparent thin film layer was formed using a mixture having a molar ratio composition outside the range of the present invention. Comparative Examples 3 and 4 SiO forming a conventionally known moisture-resistant transparent thin film layer
and SiO ₂ to form a transparent thin film layer. Comparative Example 5 An Al thin film layer, which is opaque but is said to have good moisture permeability, was formed on a PET film.

[Table] As detailed above, the transparent synthetic resin body of the present invention can obtain extremely good moisture permeability, which has not been available in the past, without impairing transparency, and can be used as packaging bodies for foods and medicines. It can be used as a protector for EL elements.

Claims (1)

[Claims] 1. On at least one side of the transparent synthetic resin body,
SiO ² , B ₂ O ₃ , BaO, Al ₂ O ₃ in molar ratio, (SiO ₂ );
( _B2O3 ); (BaO _{+ Al2O3} )= _2-4 ;1-2:0.3
1. A synthetic resin body having moisture permeability, characterized in that it is formed with a transparent thin film layer of a composition of 1 to 1. 2 The transparent synthetic resin body is a highly flexible film-like body with a thickness of 5 to 300 μm, and the transparent thin film layer has a thickness of 5 to 300 μm.
A synthetic resin body having moisture permeability resistance according to claim 1, which has a moisture permeability of 100 to 5000 Å. 3. A synthetic resin body having moisture permeability resistance according to claim 1 or 2, wherein the transparent thin film layer is formed by a vacuum evaporation method, an ion plating method, or a sputtering method.