JP2902884B2 - Reflector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for reflectors such as flat mirrors or curved mirrors used in optical equipment including laser equipment, vehicle lighting devices such as headlights and fog lights, and indoor / outdoor lighting devices. Related to the reflector.

[0002]

2. Description of the Related Art A reflector which forms an aluminum film by a vacuum deposition method and serves as a reflection film is known. Further, there is a reflector in which a silver film is formed by a vacuum deposition method and used as a reflection film in order to improve the reflectance. However, since the reflector directly exposes the metal film to the outside air, the surface of the reflection film is corroded.

As a solution to this problem, a reflector which forms a transparent film such as a silicon oxide, aluminum oxide, titanium oxide, magnesium fluoride film or the like on the surface of the reflective film by a vacuum deposition method to serve as a corrosion protective film, or a reflective film There is a reflector that applies an organic paint to the surface to form a protective film. In addition, Japanese Patent Publication No. 62-4
No. 2994 reports that an aluminum-zirconium alloy reflecting film is formed to prevent corrosion.

[0004]

In recent years, the demand for low power cost, high illuminance lighting equipment and the like has been increasing, so that a reflector having a reflection film having a higher reflectance than a conventional reflection film is required. ing. Aluminum is used for most reflective films of conventional products, but the reflectance of aluminum is up to 9
It is about 2%, and no further increase in reflectance can be expected.

[0005] Silver has a high reflectance, but when exposed to the open air, silver is blackened by sulfurization or becomes cloudy by chloride. In order to prevent corrosion of the silver film, there is a reflector with a transparent protective film of oxide or fluoride formed by vacuum evaporation, but silver has a very weak adhesion with the protective film compared to aluminum, so it is easy to peel off In addition, the interface between the protective film having poor adhesion and the silver film becomes very unstable electrochemically, which is a factor to promote silver corrosion. Reflector coated with organic paint
It overcomes the corrosion of silver, but requires more labor to handle organic paints and has environmental health problems. Also, this reflector,
The appearance of the product is poor because the unevenness of the surface of the reflective film is conspicuous. The aluminum-zirconium alloy reflection film reported in JP-B-62-42994 has better corrosion resistance than the aluminum reflection film, but has a lower reflectance than the aluminum reflection film.

Accordingly, an object of the present invention is to provide a reflector having a reflective film having high reflectance and excellent corrosion resistance.

[0007]

Means for Solving the Problems In order to solve the above problems, a reflector according to the present invention comprises an alloy layer reflecting film containing a platinum group metal containing silver as a main component formed on a substrate. Examples of the substrate include glass, metal, and resin substrates. Further, a substrate on which an organic film base layer is formed by performing a pretreatment for the purpose of smoothness on these substrates may be used.

The reflection film of the present invention is not particularly limited, but is preferably made of an alloy containing 70% by weight or more of silver. The alloy forming the reflective film is not limited to the following, except for incidental impurities, but includes, for example, a combination of silver and palladium, silver and platinum, silver, palladium and platinum, and the like. Increasing the palladium content of the silver-palladium alloy reflective film improves the corrosion resistance, but tends to reduce the reflectivity. Therefore, the palladium content is preferably 1 to 30% by weight. Increasing the platinum content of the silver-platinum alloy reflective film improves the corrosion resistance in the same manner as described above, but lowers the reflectivity, though not as much as palladium. Further, since platinum is expensive, the platinum content is preferably 1 to 30% in consideration of reflectance, corrosion resistance, and cost. For the same reason, the total content of palladium and platinum in the silver-palladium-platinum alloy reflection film is preferably 1 to 30% by weight.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Pure silver has a high reflectance, but is inferior in corrosion resistance. On the other hand, platinum group metals such as palladium and platinum have excellent corrosion resistance. The reflector of the present invention has a high reflectance and excellent corrosion resistance because an alloy reflection film composed of a combination of silver and palladium, silver and platinum, and silver, palladium and platinum is formed.

[0010]

1 and 2 schematically show an embodiment of a reflector according to the present invention. In the embodiment of FIG. 1, an alloy reflection film 2 is formed on a substrate 1. In the embodiment shown in FIG. 2, an organic base film 3 is formed as a pretreatment on a substrate 1, and an alloy reflection film 2 is formed thereon. Hereinafter, how to make this reflector will be described.

A silver-palladium alloy is prepared by placing silver (99.9% purity) and palladium (99.9% purity) in a boron nitride crucible and heating at 1500 ° C. in an argon atmosphere (1 atm). did. In the same manner, silver and platinum were heated at 1800 ° C. to produce a silver-platinum alloy. At this time, since the evaporation rates of the individual metals are different, the addition amounts of palladium and platinum were determined in consideration of the evaporation rates of the individual metals. A substrate having an aluminum surface coated with an epoxy-based organic film was used. The vapor deposition of the alloys was performed using an electron beam heating vapor deposition method.
A film was formed at a thickness of μm to obtain a reflector .

The obtained reflector was evaluated by analyzing the composition ratio of the film using an X-ray microanalyzer (XMA), measuring the reflectance after film formation (wavelength range 400 to 800 nm), performing a corrosion test by spraying with salt water, and after a corrosion test. Of reflectance of light (wavelength range 40
0-800 nm). The salt spray corrosion resistance test was performed for 48 hours, and the evaluation was judged by the appearance of the film. A: A state in which there is no discoloration or peeling of the film due to corrosion and the appearance is good.

B: A state in which no peeling of the film is present but the color is slightly discolored. C: Discoloration and peeling of the film due to corrosion are observed. Table 1 shows the evaluation results of the reflector formed with the silver-palladium alloy reflection film, and Table 2 shows the evaluation results of the reflector formed with the silver-platinum alloy reflection film.

[0014]

[Table 1]

[0015]

[Table 2]

As shown in Tables 1 and 2, the reflector formed with a pure silver reflective film shows a very high reflectance before the salt spray test, but becomes cloudy due to chloride after the salt spray test. And film peeling were observed, indicating that silver alone did not exhibit satisfactory behavior as a reflective film. On the other hand, when silver contains palladium or platinum, there is no clouding or film peeling due to salt water spray, and it can be said that the corrosion resistance of the reflective film is improved when silver contains a platinum group metal. However, as the content of the platinum group metal increases, the reflectance of the film decreases, so that the content of the platinum group metal of 30% by weight or more is not preferable.

[0017]

According to the reflector of the present invention, a reflection film having a higher reflectance than the aluminum film and excellent in corrosion resistance is formed. Power consumption can be reduced. Also,
Since there is no need to form a protective film on the surface of the silver film, the number of steps and costs can be reduced, and the appearance as a reflector is beautiful.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a reflector according to the present invention.

FIG. 2 is a sectional view showing a configuration of a reflector according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 substrate 2 alloy reflective film 3 organic base film formed by applying organic paint

Continuation of front page (56) References JP-A-49-90545 (JP, A) JP-A-53-6315 (JP, A) JP-A-61-136670 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) G02B 5/08-5/10 G02B 1/10

Claims (6)

(57) [Claims] 1. A reflector comprising an alloy layer reflection film containing a platinum group metal containing silver as a main component formed on a substrate. 2. The reflector according to claim 1, wherein the substrate is subjected to a pretreatment for the purpose of improving the adhesion between the substrate and the reflection film and smoothing the reflector. 3. The reflector according to claim 2, wherein an organic film is formed as a pretreatment. 4. The reflection film is formed of an alloy layer containing silver and palladium, wherein the content of silver in the alloy is 70% by weight or more and the content of palladium is 30% by weight or less. The reflector according to any one of the above. 5. The reflection film is formed of an alloy layer containing silver and platinum, wherein the silver content in the alloy is 70% by weight or more and the platinum content is 30% by weight or less. The reflector according to any one of the above. 6. The reflection film is formed of an alloy layer containing silver, palladium and platinum, and the silver content of the alloy is 70% by weight or more and the total content of palladium and platinum is 30% by weight or less. The reflector according to claim 1.