JPH0625448A - Production of ultraviolet-barrier film - Google Patents

Abstract

PURPOSE:To produce a film excellent in performances such as ultraviolet-barrier properties and transparency by forming a plasma-polymerized film of an ultraviolet absorber good in adhesion to a base film. CONSTITUTION:An ultraviolet absorber 10a and 10b is plasma-polymerized to form a plasma-polymerized film of the ultraviolet absorber 10a and 10b on the surface of a plastic base 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ultraviolet shielding film. More specifically, the present invention relates to a method for producing an ultraviolet shielding film having excellent performances such as ultraviolet shielding property and transparency by forming a plasma-polymerized film of an ultraviolet absorbent having good adhesion to a base film. Is.

[0002]

2. Description of the Related Art A wavelength of about 10 to 400 nm in sunlight
The ultraviolet light included in the region has a larger energy than visible light or infrared light having a long wavelength, and has an energy intensity equivalent to that of exciting or cutting a molecular bond such as plastic or an organic compound. In particular, it is known that short-wavelength ultraviolet light has a large energy. For this reason, ultraviolet rays cause discoloration and fading of various industrial products such as decorative steel plates, signboards, color photographs, and polymer materials, and also cause a decrease in their strength.

In order to block such ultraviolet rays and protect industrial products, an ultraviolet shielding film having an ultraviolet absorber provided on the surface of a substrate such as plastic or glass has been conventionally used. This ultraviolet shielding film is usually a method of forming a film by mixing an organic ultraviolet absorber and a base resin, a method of applying the organic ultraviolet absorber to the surface of the base film, and dissolving the organic ultraviolet absorber. A method of immersing a base material film in a solution to absorb the ultraviolet absorbent in the film, or a method of mixing the inorganic ultraviolet absorbent and a base resin to form a film, and the inorganic ultraviolet absorbent as a base material. It is manufactured by a method such as coating on the film surface.

[0004]

However, among the conventional methods for producing an ultraviolet light shielding film, the method using an organic ultraviolet light absorbing agent is described in order to obtain an ultraviolet light shielding effect. It is necessary to increase the addition amount and the coating amount, and there is a problem that the ultraviolet absorber bleeds on the surface of the film due to a change with time, the shielding effect does not continue, and the transparency decreases.

When an inorganic ultraviolet absorber is used, the transparency of the ultraviolet absorber itself is not good,
There is a drawback in that the transparency of the manufactured ultraviolet shielding film is also halved. The present invention has been made in view of the above circumstances, eliminates the drawbacks of the conventional method for producing an ultraviolet shielding film, a new method for producing an ultraviolet shielding film by forming a plasma polymerized film of an ultraviolet absorber, It is intended to be provided.

[0006]

In order to solve the above-mentioned problems, the present invention is characterized in that an ultraviolet absorbent is plasma-polymerized to form a plasma-polymerized film of the ultraviolet absorbent on the surface of a plastic substrate. A method for manufacturing an ultraviolet shielding film is provided. Ultraviolet absorbers are classified into inorganic type and organic type. Examples of the inorganic ultraviolet absorber include zinc oxide, titanium oxide, carbon black and the like. On the other hand, as the organic UV absorber, phenyl salicylate, p-tert-butylphenyl salicylate,
Salicylic acid compounds such as p-octylphenyl salicylate, 2,
4-dihydroxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2 Benzophenone series such as -hydroxy-4-methoxy-5-sulfobenzophenone, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy
-5'-tert-butylphenyl) benzotriazole, 2-
(2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-3'-5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 '-
tert-Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2' -Hydroxy-3 ', 5'-di-tert-aminophenyl) benzotriazoles such as benzotriazole, 2-ethylhexyl-2-cyano 3,3'-diphenyl acrylate, ethyl-2-cyano
Examples thereof include cyanoacrylates such as -3,3'-diphenylacrylate.

In the present invention, for example, the ultraviolet absorber exemplified above is formed on a plastic substrate by plasma polymerization to produce an ultraviolet shielding film. As the plastic substrate, for example, a transparent film of polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyether ether ketone, polycarbonate, polymethylmethacrylate, polystyrene, polyvinyl chloride, polypropylene or the like can be used. A plasma polymerized film of an organic UV absorber alone on these plastic substrates, or a composite plasma polymerized film obtained by simultaneously plasma polymerizing an organic UV absorber and an inorganic UV absorber, or sequentially laminating these polymer films. To form.

Further, in the present invention, an organic binder component may be used. For example, a transparent film forming substance such as an acrylic compound or a fluorine-containing compound may be used as a binder, and this may be used to simultaneously perform plasma polymerization. Furthermore, in any case, in order to improve the adhesiveness, the plastic substrate surface may be subjected to plasma bombardment treatment prior to film formation.

When forming a plasma polymerized film on a plastic substrate, for example, an inductive coupling type electrode or a capacitive coupling type electrode such as a coil electrode (4) is provided in a vacuum container (1) as shown in FIG. A high frequency excitation type ion plating device can be used. In plasma polymerization, the exhaust pipe (2) is driven by the vacuum pump (12).
A non-polymerizable inorganic gas such as argon or nitrogen is introduced into the vacuum container (1) through the gas introduction valve (3) under a reduced pressure atmosphere exhausted through the chamber, and a high frequency power source is supplied to the electrode (4). From (6), a high frequency voltage is applied to generate discharge. Further, the organic ultraviolet absorber (10a) and the inorganic ultraviolet absorber (10b) filled in the evaporation sources (9a) and (9b) are heated and vaporized by applying a voltage from the resistance heating power source (11), respectively, and plasma is generated. Upon excitation, the polymerized thin film is formed on the plastic substrate (8) supported by the substrate support (7). In this case, the plasma polymerization of the ultraviolet absorbers (10a) and (10b) on the plastic substrate (8) is preferably carried out at a gas pressure of 10 ^-2 to 10 ^-5 torr. When the gas pressure is higher than 10 ^-2 torr, the energy of accelerating particles (ions and electrons) becomes small, and a uniform film is not formed even though the total number of accelerating particles is large. On the other hand, when the gas pressure is lower than 10 ⁻⁵ torr, the energy of the accelerated particles increases, but the total number of the accelerated particles reaching the plastic substrate (8) decreases, and the film formation rate decreases.

The high frequency power source (6) is usually several hundred K
It is possible to use one with a frequency of Hz to several tens of MHz,
13.56 MHz is illustrated as a suitable example. Further, the high frequency power may be in the range of 10 to 200 W. Further, the film thickness of the polymer film of the ultraviolet absorbers (10a) (10b) plasma-polymerized on the plastic substrate (8) is not particularly limited, but is usually 500 to 5000Å
It is preferable to appropriately select the one having the highest light transmittance in the thickness.

[0011]

EXAMPLES The following is a more detailed description of the method for producing the ultraviolet shielding film of the present invention, showing examples. Example 1 Using the ion plating apparatus illustrated in FIG. 1, a plasma-polymerized film of an ultraviolet absorber was formed on a polyethylene terephthalate (PET) film by the steps shown below. First, the PET film was set on the substrate support (7) in the vacuum container (1), and then the pressure inside the apparatus was reduced to 1 × 10 ⁻⁶ torr or less by the vacuum pump (12) connected to the exhaust pipe (2). . After that, the gas introduction valve (3) is opened to introduce argon gas, and the atmospheric pressure is adjusted to 1 × 10 ⁻⁴ torr.
It was adjusted to and discharged. And gas pressure 1 × 10 ^-3 tor
Under the conditions of r and high-frequency power of 50 W, a plasma-polymerized film of 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, an organic ultraviolet absorber, filled in a resistance heating type evaporation source (9a) was used. A film was formed on the surface of the PET film for 10 seconds. When the film thickness was repeatedly measured by a reflection interferometer, it was 1200Å.

With respect to the ultraviolet shielding film thus obtained, its ultraviolet shielding effect was measured by using a spectrophotometer.
Continuously measure the light transmittance in the range of 200-900 nm,
350, 380 n, which is a guide for the wavelength of UV deterioration of polymer materials
The light transmittance at 550 nm, which is a measure of the transparency in the m and visible light regions, was determined. Moreover, the haze value (JIS K-6714) was determined by a haze meter.

Furthermore, the adhesion between the PET film and the plasma-polymerized film of the ultraviolet absorber is checked by a cross-cut test (JIS K-
5400) was tested by peeling off the tape. Table 1 summarizes the above measurement results. As is clear from comparison with the comparative example described later, wavelengths of 350 nm and 380 n
The transmittance of ultraviolet light at m was significantly reduced to 1.6% and 36.2%, and it was confirmed that the ultraviolet ray shielding effect was excellent. In addition, the transmittance of visible light and the haze value at a wavelength of 550 nm were about the same as those of the comparative example, and had good transparency. Adhesion between the formed plasma polymerized film and the base film was good.

Example 2 In the same manner as in Example 1, a film was formed for 15 seconds. The film thickness at this time was 1330Å. The light transmittance was extremely excellent as shown in Table 1. Example 3 As in Example 1, the atmospheric pressure in the vacuum container (1) was set to 1 ×.
After adjusting to 10 ⁻⁴ torr and discharging the introduced argon gas, 2- (2′-hydroxy-5′-tert-octyl which is an organic ultraviolet absorber filled in the resistance heating evaporation source (9a). Phenyl) benzotriazole and the inorganic ultraviolet absorber ZnO filled in another evaporation source (9b) under the gas pressure of 1 × 10 ⁻³ torr, O ₂ pressure of 7 × 10 ⁻⁴ torr, and high frequency power of 50 W. Plasma polymerization was performed on the PET film surface for 10 minutes.

The same measurement as in Example 1 was performed on the obtained ultraviolet shielding film. The results are also shown in Table 1. As is clear from comparison with Comparative Examples described later, it was confirmed that the performance of the ultraviolet shielding film produced by the method of the present invention was superior to that of the conventional product.
The film thickness of the ultraviolet absorber was 2100Å.

Example 4 As in Example 1, the atmospheric pressure in the vacuum vessel (1) was set to 1 ×.
After adjusting the pressure to 10 ⁻⁴ torr and discharging the introduced argon gas, 2- (2′-hydroxy-5′-tert-octylphenyl) which is an organic ultraviolet absorber filled in the resistance heating evaporation source (9a). ) Benzotriazole was plasma-polymerized on the surface of the PET film for 2 minutes under the conditions of gas pressure of 1 × 10 ⁻³ torr and high frequency power of 50 W. Next, on this plasma-polymerized film, another inorganic source UV absorber ZnO filled in the evaporation source (9b) was applied under the conditions of gas pressure of 1 × 10 ⁻³ torr (O ₂ pressure) and high-frequency power of 100 W. The film was formed in minutes.

The same measurement as in Example 1 was performed on the obtained ultraviolet shielding film. The results are also shown in Table 1. As is clear from comparison with Comparative Examples described later, it was confirmed that the performance of the ultraviolet shielding film produced by the method of the present invention was superior to that of the conventional product.
The film thickness of the ultraviolet absorber was 1550Å.

Comparative Example 1 1% by weight of an organic ultraviolet absorber 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole was added to a polyester resin [Vylon 200 manufactured by Toyobo Co., Ltd.],
A solution dissolved in a mixed solvent of toluene / methyl ethyl ketone was applied to a PET film having a thickness of 100 μm with a Meyer bar.

With respect to the ultraviolet shielding film thus produced, the light transmittance at wavelengths of 350 nm, 380 nm and 550 nm and the haze were measured. The results are also shown in Table 1. The ultraviolet ray transmittance was high and the ultraviolet ray shielding effect was low. The coating thickness of the dried ultraviolet absorber was 3 μm, which was 10 times or more than the film thickness of Examples 1 to 4.

Comparative Example 2 Coating was conducted in the same manner as in Comparative Example 1 except that 5% of 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, an organic ultraviolet absorber, was added, and ultraviolet rays were applied. A shielding film was manufactured.

The results are also shown in Table 1. The ultraviolet light shielding effect was low.

[0022]

[Table 1]

Of course, the present invention is not limited to the above examples. It goes without saying that various aspects are possible in terms of details such as the types of the plastic substrate and the ultraviolet absorber, discharge and reaction conditions.

[0024]

As described in detail above, according to the present invention, the transmittance in the visible light region is about the same as that of the base film,
An ultraviolet shielding film can be obtained by forming a plasma-polymerized film of an ultraviolet absorber having a thin film thickness of about 1/10 or less as compared with the coating type and having a good ultraviolet shielding effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an ion plating device that can be used in the method for manufacturing an ultraviolet shielding film of the present invention.

[Explanation of symbols]

 1 vacuum container 2 exhaust pipe 3 gas introduction valve 4 coil electrode 5 matching box 6 high frequency power supply 7 substrate support 8 plastic substrate 9a, 9b evaporation source 10a organic ultraviolet absorber 10b inorganic ultraviolet absorber 11 resistance heating power source 12 vacuum pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Noboru Sakaushi No. 2 No. 2 Hiraide Industrial Park, Utsunomiya City, Tochigi Prefecture Oji Kako Co., Ltd. Product Research Laboratory

Claims (5)

[Claims] 1. A method for producing an ultraviolet shielding film, which comprises polymerizing an ultraviolet absorber by plasma to form a plasma polymerized film of the ultraviolet absorber on the surface of a plastic substrate. 2. The method according to claim 1, wherein the plasma polymerized film is formed by using an organic ultraviolet absorber alone or a composite of an organic ultraviolet absorber and an inorganic ultraviolet absorber. 3. The method according to claim 1, wherein the plasma polymerized film of the ultraviolet absorber is formed by high frequency excitation type ion plating. 4. The method according to claim 1, 2 or 3, wherein plasma polymerization is carried out within a gas pressure range of 10 ^-2 to 10 ^-5 torr. 5. The thickness of the plasma-polymerized film of the ultraviolet absorber
Claim 1, 2, 3 or 4 within the range of 500-5000Å
Manufacturing method.