JPH0432147B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a synthetic resin body having moisture permeability resistance. (Prior art) Moisture-resistant transparent synthetic resin bodies have traditionally been used in the packaging of foods, drugs, and chemical products to avoid deterioration of the contents, and in the electronics field to protect EL elements. ing. For example, JP-A-51-114483 proposes a polyester film with metal aluminum vapor-deposited, but if aluminum is vapor-deposited, the transparency will naturally be lost and the adhesion strength will be relatively low, so there are limitations. It can only be used for specified purposes. Furthermore, Japanese Patent Publication No. 53-12953 proposes a plastic film coated with a thin layer of SixOy to maintain transparency, but the moisture permeation resistance was insufficient. (Problems to be Solved by the Invention) The present invention has been made for the purpose of eliminating the above-mentioned conventional drawbacks, and providing a transparent synthetic resin body that does not impair transparency and has extremely good moisture permeability resistance. It is. (Means for Solving the Problems) In the present invention, the transparent synthetic resin body of the base material is a transparent synthetic resin body such as polyvinyl chloride, polystyrene, polyester, polyvinyl butyral, polyethylene, polypropylene, polyamide, cellophane, etc. used. Furthermore, it is convenient for the transparent synthetic resin body to be a flexible film-like body for packaging or laminating. However, the present invention is not limited to those in which the base material is a film-like body, but can be applied to, for example, synthetic resin molded products such as plate-like bodies and lens bodies. Deterioration and deformation can be prevented. The film-like transparent synthetic resin body preferably has a flexibility of 5 to 300 μm, and more preferably has a thickness of 5 to 100 μm. In order to deposit an oxide composition onto a film-like transparent synthetic resin body, a winding process using a cooling roll is usually required, but if the thickness of the film-like transparent synthetic resin body is less than 5 μm, 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 , Al ₂ O ₃ ,
The molar ratio of MO (M represents alkaline earth metals such as Ca, Sr, Ba, etc.) is (SiO ₂ ): (Al ₂ O ₃ ): (MO) =
2-9; 1-5; 1-5. When the molar ratio of the transparent thin film layer is out of the above range, phase separation tends to occur and moisture permeation resistance decreases. The above composition contains impurities such as PbO, ZrO ₂ ,
If the content of oxides such as B ₂ O ₃ is 5% by weight or less, no extreme deterioration in moisture permeability will be observed, and when producing the transparent synthetic resin body having moisture permeability resistance of the present invention, impurities such as those mentioned above will not be observed. It is desirable to set the range. A method for forming a transparent thin film made of an oxide having the above composition may be a known method such as a vacuum evaporation method, an ion plating method, or a sputtering method. The formation method will be explained in detail below. The most preferred method for forming the above-mentioned oxide composition film on a plastic substrate is sputtering, and by setting the sputtering target to the above-mentioned composition, a transparent thin film layer having substantially the same composition can be formed. 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 a deposited film having approximately the same composition can be obtained by melting and solidifying the above composition in advance in an electric furnace and using it as an evaporator and evaporating it using an electron gun heating method. . Further, a vapor deposited film having the above composition can also be formed by a flash vapor deposition method which is generally used when a mixture is vacuum vapor deposited. In the present invention, the adhesion of the transparent thin film layer to the transparent synthetic resin body of the base material is good and the transparency is also good, regardless of whether the vacuum evaporation method, ion plating method or 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 vacuum evaporation or the like. This is the traditional SixOy
This is thought to be due to the fact that the system of the present invention (SiO ₂ , Al ₂ O ₃ , MO) has less residual stress in the transparent thin film layer than in the system of the present invention. Forming a transparent thin film layer by vacuum evaporation method or ion plating method is usually carried out under a vacuum atmosphere of 2×10 ^-3 torr or less. It is preferable to carry out under a vacuum atmosphere of ^-4 torr or less. The transparent thin film layer preferably has a thickness in the range of 0.01 μm to 0.5 μm, more preferably in the range of 0.05 to 0.3 μm, in order to have good flexibility and adhesion. The thickness of the transparent thin film layer is 0.01μm
Otherwise, it will not be possible to form a uniform continuous film.
0.01 μm or more is required. In addition, if the thickness of the thin film exceeds 0.5 μm, the transparency will not be impaired, but curling of the film-like transparent synthetic resin body may become a problem.
Cracks and peeling of the transparent film may occur easily. (Function) 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, by laminating a synthetic resin film with heat-sealing properties on a transparent thin film layer consisting of (SiO ₂ , Al ₂ O ₃ , MO) system, the transparent synthetic resin body with moisture permeability of the present invention can be made. Can provide heat sealability. Examples of synthetic resin films having heat-sealing properties include polyethylene, polypropylene, ethylene-vinyl acetate copolymers, and ethylene-based ionomers, which do not compromise 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
Generally, isocyanate-based adhesives are used. In the extrusion lamination method,
(SiO ₂ , Al ₂ O ₃ , MO) has an anchoring effect in the transparent thin film layer, which eliminates the need for anchor treatment using organic titanate, isocyanate, or polyethyleneimine anchor agents. . 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. (Example) Examples of the present invention are shown below. <Example 1> A mixture of oxides with a molar ratio of SiO ₂ , Al ₂ O ₃ , and CaO of 5:3:3 was melted in an electric furnace and solidified, and then heated with electrons under a vacuum of 5×10 ^-5 torr. Polyethylene terephthalate (PET) is produced by heating and vaporizing it using a gun heating method.
A 0.1 μm transparent thin film layer was formed on the film (15 μm thick). 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 initial mixture. The adhesion of the formed transparent thin film layer was checked using JIS D0202 and was found to be very good. Furthermore, 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 Z at 40℃ and relative humidity 90%.
0208 (gravimetric method using a cup) and a 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 0.2 μm.
And so. <Example 3, 4> Instead of the PET film in Examples 1 and 2, a biaxially oriented polypropylene (OPP) film (25 μm
thickness) was used. <Examples 5 to 10> 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 to 4> In place of the mixture composition of Example 1, a mixture having a molar ratio outside the range of the present invention was used to form a transparent thin film layer. <Comparative Examples 5, 6> SiO forming a conventionally known moisture permeable transparent thin film layer
and SiO ₂ were used to form a transparent thin film layer. <Comparative Example 7> An Al thin film layer, which is opaque but is said to have good moisture permeability, was formed on a PET film.

【table】

[Table] (Effects of the Invention) As detailed above, the transparent synthetic resin body having moisture permeability resistance of the present invention can obtain extremely good moisture permeation resistance that has not been obtained conventionally, without impairing transparency. It can be used as packaging for food and medicine, and as a protector for EL elements.

Claims (1)

[Claims] 1. SiO ₂ ,
The molar ratio of Al ₂ O ₃ and MO (M represents alkaline earth metals such as Ca, Sr, and Ba) is (SiO ₂ ); (Al ₂ O ₃ );
A transparent synthetic resin body having moisture permeability, characterized in that a transparent thin film layer of a composition having (MO)=2-9; 1-5; 1-5 is formed. 2 The transparent synthetic resin body is a 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 transparent synthetic resin body having moisture permeability resistance according to claim 1, which has a moisture permeability of 0.01 to 0.5 μm. 3. A transparent 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.