JP2780174B2 - Manufacturing method of metal reflector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a metal reflector, and more particularly, to a method for manufacturing a metal reflector having excellent corrosion resistance.

2. Description of the Related Art Metal reflectors are formed by depositing an aluminum metal or the like on a glass substrate or a resin substrate surface. A protective film made of silicon monoxide or silicon dioxide and having a thickness of about 0.5λ ₀ (λ ₀ represents a design dominant wavelength) is formed thereon. However, to use a planar or nearly so shaped as substrate, a metal reflecting mirror to form a aluminum deposition layer and a thickness of about 0.5 [lambda ₀ protective film in accordance with conventional methods on its surface scratch resistance an object and Corrosion resistance is obtained, but on a roof-type substrate as shown in FIG.
The aluminum deposited layer is provided, further a metal reflector provided with a protective layer having a thickness of 0.5 [lambda ₀ is a problem in the corrosion resistance of the aluminum, the corrosion particularly pronounced at high temperature and high humidity.

Regarding the prevention of corrosion, for example, Japanese Patent Application Laid-Open No. 54-24046 is known. The above technique solves the problem of corrosion by depositing a substance with a high filling rate between the air and the metal layer, and is different from the present application in which corrosion is prevented by an aluminum oxide film.

Problems to be Solved by the Invention The present invention solves the above-mentioned problems, and provides scratch resistance and corrosion resistance even when a metal reflector is formed using a roof-shaped substrate using a conventional vapor deposition apparatus or the like. An object of the present invention is to provide a metal reflecting mirror having excellent properties.

The above object is achieved by extremely thin compared to the thickness of the protective layer provided on the vapor-deposited aluminum layer on a conventional approximately 0.5 [lambda _0.

Means for Solving the Problems A step of depositing aluminum on a substrate so that a mechanical film thickness is 500 to 2000 °; and an optical film for the design dominant wavelength (λ ₀ ) on the aluminum layer. the method for producing a metal reflector comprising; thickness depositing an oxide or magnesium fluoride of silicon such that 0.03λ ₀ ~0.15λ _0.

The metal reflecting mirror of the present invention is provided with at least two layers of an aluminum deposited layer and a silicon oxide or magnesium fluoride deposited layer on a substrate in that order. In the present invention, the first layer is a silicon oxide or magnesium fluoride deposited layer on the air side, and the second layer is an aluminum deposited layer.

The material of the substrate is not particularly limited,
For example, various types of glass or resin substrates can be used, and a second layer and a first layer are provided on such a substrate.

The second layer is formed by evaporating aluminum metal so that the mechanical thickness becomes 500 to 2000 mm. If the film thickness is less than 500 mm, light is transmitted and the reflectance is reduced,
If it is thicker than 0 °, cracks are likely to occur.

The first layer is formed by depositing silicon oxide such as silicon monoxide or silicon dioxide or magnesium fluoride. These substances are used for the first layer because the decrease in reflectance is small particularly in relation to the second layer.

The first layer 0.03~0.15λ ₀ (λ ₀ represents a design primary wavelength) provided so as to be as an optical film thickness. The thickness of the first layer is 0.
Thin and surface hardness is insufficient than 03λ _0, easily scratched on the surface of the metal reflector. On the other hand, the film thickness is formed of the oxide film of aluminum with a thick the aluminum metallized layer surface of the second layer than 0.15Ramuda ₀ is inhibited, the resulting metal reflector becomes inferior in corrosion resistance.

For the first and second vapor deposition layers, a known vapor deposition method and a known vapor deposition apparatus can be used. In this case, attention should be paid to the incident angle of the vaporized substance vaporized by the resistance heating method to the substrate. It is important to. For example, the case of vapor deposition on a flat substrate will be described with reference to FIG. In FIG. 2, (1) indicates a substrate on which a vapor deposition layer is to be formed, and arrow (2) indicates the incident direction of the substance vaporized by means such as resistance heating on the substrate (1). And the normal (3) to the substrate is defined as the incident angle θ of the deposition material.

As the incident angle θ of the deposition material approaches 0 °, a film having a higher packing density is formed on the substrate, and as the incident angle θ approaches 90 °, a film having a lower filling density is formed. Therefore, when the first layer is formed under the condition that the incident angle θ is close to 0 degree, the obtained vapor-deposited film is a film having a high packing density, so that the first layer is formed by the vapor deposited on the second aluminum vapor-deposited layer. Of the second aluminum deposition layer can be prevented. Further, a decrease in reflectance due to deterioration of the aluminum vapor deposition layer is prevented.

However, as the incident angle θ gradually increases and approaches 90 degrees, particularly when the incident angle is 20 degrees or more, the filling rate of the vapor deposition layer decreases, similar to a vapor deposition layer formed with a high filling rate. Excellent properties, especially corrosion resistance, cannot be expected. According to conventional methods, the thickness is about 0.50λ _0, lower first layer formed by filling ratio than oxygen permeability, probably because the water easily passes, particularly in high temperature and high humidity The It is notable that the water vapor that has passed through one layer penetrates the second layer of aluminum and corrodes the aluminum. Therefore, as a result of various investigations to prevent such corrosion, as described above, by making the thickness of the first layer significantly smaller than in the past, a metal reflector having excellent corrosion resistance and scratch resistance is obtained. be able to. This makes the penetration of oxygen through the first layer on the surface of the aluminum layer of the second layer easier than that of water vapor, which oxygen combines with aluminum and is corrosive to water vapor. It is considered that aluminum oxide is coated on the surface of the second layer.

According to the present invention, a metal reflector excellent in corrosion resistance and scratch resistance can be obtained using a complicated substrate such as a roof shape shown in FIG. Conventionally, when fabricating a metal reflector having a complicated shape such as a roof shape, a metal reflector having a simple shape such as a flat plate was produced and fabricated by assembling it. Even a metal reflector having such a complicated shape can be vapor-deposited with the shape as it is, and a metal reflector excellent in scratch resistance and corrosion resistance can be manufactured, and a conventional assembling process is not required.

In the metal reflecting mirror of the present invention, a third layer made of silicon monoxide may be further provided below the second layer to improve the adhesion between the substrate and the deposited film.

Hereinafter, the present invention will be described with reference to Comparative Examples and Examples.

Comparative Example A polycarbonate resin substrate of the shape shown in FIG.
3) using the vapor deposition apparatus shown in FIG.
A layer, a second layer and a first layer were formed.

In FIG. 3, reference numeral (7) denotes a vacuum chamber having an exhaust pipe (6), and the inside of the vacuum chamber is evacuated through the exhaust pipe. (4) and (5) are resistance heating electrodes, and resistance heating containers (10) and (11), which also serve as containers for the deposition material, are mounted between the electrodes. The resistance heating vessel (1
0) and (11) are supplied with power from the electrodes (4) and (5) to heat and vaporize the deposition material in the resistance heating vessels (10) and (11). A rotatable rotating dome (8) is provided over the resistance heating vessels (10) and (11), and a substrate (9) as an object to be deposited is placed on the rotating dome (8).
The rotating dome rotates during the deposition operation to form a uniform deposited film on the substrate surface.

Using the vapor deposition apparatus having the above configuration, the following first to third vapor deposition layers were formed on the substrate to obtain a metal reflector.

The third layer has an optical thickness of 0.25λ at a degree of vacuum of 1 × 10 ^-4 Torr.
₀ (λ ₀ (design primary wavelength) is 650 nm; the same applies hereinafter). A layer of silicon monoxide was formed by vapor deposition on the substrate surface. Mechanical layer thickness of 1000 at 2 × 10 ^-5 Torr vacuum as the second layer
A layer of aluminum was formed by vapor deposition on the third layer. First
A layer of silicon monoxide optical film thickness 0.50Ramuda ₀ at a vacuum degree 2.5 × 10 ^-4 Torr was vapor deposited on the second layer as a layer.

Example Using the same apparatus and substrate as those used in the above comparative example, a metal reflector having the following first to third layers was obtained.

The third layer has an optical thickness of 0.25λ at a degree of vacuum of 1 × 10 ^-4 Torr.
A layer of silicon monoxide ₀ formed deposited on the substrate surface. Mechanical layer thickness of 1000 at 2 × 10 ^-5 Torr vacuum as the second layer
A layer of aluminum was formed by vapor deposition on the third layer. First
A layer of silicon monoxide optical film thickness 0.09Ramuda ₀ at a vacuum degree 2.5 × 10 ^-4 Torr was vapor deposited on the second layer as a layer.

Evaluation The following tests were performed on the metal reflectors obtained in the above comparative examples and examples.

a) Solvent resistance test: Use lens wipes (silbon paper) soaked with a mixed solution of CFC-solve and alcohol, and
Rubbing was performed 10 times at a pressure of 11 kg / cm ^{2, and} the surface of the metal reflector was examined for any abnormalities such as scratches. The results are shown in Table 1.

 In the table, ○ indicates that no change was observed after the test.

b) Temperature and humidity resistance test: The sample was left in a thermostat adjusted to a temperature of 70 ° C. and a humidity of 80% for 100 hours, and the reflectance of the metal reflecting mirror was examined. The results are shown in Table 1.

 In the table, ○ indicates that no change was observed after the test.

c) A cycle test was carried out 10 times continuously from a temperature of −30 ° C. to an atmosphere of 70 ° C. The results are shown in Table 1.

 In the table, ○ indicates that no change was observed after the test.

 Table 1 shows the test results.

It can be seen that the present invention has provided a metal reflecting mirror having better durability against temperature and humidity than the conventional one.

Effect of the Invention According to the present invention, by forming the first layer on the air side as an extremely thin vapor-deposited layer, a metal reflector excellent in scratch resistance and corrosion resistance can be obtained, and a metal reflector having a complicated shape can be easily formed. Can be prepared.

[Brief description of the drawings]

FIG. 1 is a diagram showing the shape of the substrate used in the examples and comparative examples. FIG. 2 is a diagram for explaining an incident angle of a deposition material. FIG. 3 is a diagram showing the schematic configuration of one example of a vapor deposition apparatus.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 5/00-5/136 C23C 14/00-14/58

Claims (2)

(57) [Claims] 1. A step of depositing aluminum on a substrate so as to have a mechanical thickness of 500 to 2000 °; and forming an optical thickness on the aluminum layer with respect to a design dominant wavelength (λ ₀ ). method for producing a metal reflector made of; 0.03 ₀ oxides of silicon such that ～0.15Ramuda ₀ or depositing a magnesium fluoride. 2. The method according to claim 1, wherein, in the vapor deposition step, an incident angle between a direction in which the vapor-deposited substance is incident on the substrate to vapor-deposit and a normal to the substrate is 0 ° or more and less than 20 °. Manufacturing method of metal reflector.