JPH03239203A - Surface high reflecting mirror - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high surface reflection mirror having a surface reflection multilayer film used in optical products such as cameras, telescopes, and microscopes.

[Conventional technology]

Silver, which has a high reflectance in the visible to near-infrared range, is generally used as a reflective material for high-surface reflectance mirrors used in optical products. However, when using silver, there is a problem that a single layer film is inferior in terms of film adhesion, moisture resistance, sulfidation resistance, etc. For this reason, a multilayer film structure is used in which a base layer and a protective layer are formed on a single layer film of silver, thereby imparting film adhesion, moisture resistance, sulfidation resistance, etc.

For example, as shown in FIG.
An oxide base layer 2e made of aluminum oxide is formed on the oxide base layer 2e, a reflective layer 4e made of silver is formed on the oxide base layer 2e, and an aluminum oxide layer 5e and an aluminum dioxide layer 5e are further formed as a protective layer on the reflective layer 4e. An example in which silicon layers 6e and silicon layers 6e are sequentially formed ("Reflectance and durabi")
lity of Ag m1rrors coated
with thin 1ayers of/d120
3plus reactively deposit
d 5ilicon oxide, ”Appl, o
pt6.14 (1975), 2639).

Further, as shown in FIG. 4, in a six-layer structure, a base layer 2f made of copper is formed on the substrate lf, a reflective layer 4f made of silver is formed on the base layer 2f, and a protective layer 4f is further formed on the reflective layer 4f. An example in which an aluminum oxide layer 5f, a tantalum oxide layer 6f, a silicon dioxide layer 7f, and a tantalum oxide layer 8f are sequentially formed as layers ('"Progress 1nthe
development of a durable
5ilver-based hlgh-reflec
tance coating f'or astron
musical telescopes, ”Appl.
Opt., 24 (1985), 1164)
There is.

All of the above methods are effective when glass is used as the substrate of the high surface reflection mirror.

[Problem to be solved by the invention]

In recent years, the technology for molding plastics such as polycarbonate and polyester acrylic resins has developed, and because plastics have the advantage of being easier to mold into complex shapes than glass, the scope of their use as optical members has expanded. For example, it is desired that pentaprisms used in cameras be made of plastic to reduce costs.
Products with a reflective film formed on the surface of a hollow penta-shaped molded product are also beginning to be used. However, when the substrate is made of plastic such as polycarbonate, polyester, or acrylic resin, the same film structure as described above has poor film adhesion, moisture resistance, etc. compared to when the substrate is made of glass. There is a problem that it is inferior in terms of.

Therefore, an object of the present invention is to provide a high surface reflection mirror that has excellent film adhesion, moisture resistance, etc. even when the substrate is made of plastic such as polycarbonate, polyester, or acrylic resin.

[Means to solve the problem]

As a result of intensive research in view of the above objectives, the present inventors have found that even when the substrate is made of plastic such as polycarbonate, polyester, or acrylic resin, film adhesion and
In order to obtain a high surface reflection mirror with excellent moisture resistance, etc., it is sufficient to strengthen the adhesion between the substrate and the reflective layer made of silver. It was discovered that the adhesion force could be strengthened by forming a reflective layer on top of the reflective layer, and came up with the present invention.

That is, the high surface reflection mirror of the present invention includes (a) an oxide base layer formed on the substrate surface, (a) a sulfide base layer formed on the oxide base layer, and (c) the sulfide base layer. It is characterized by having a reflective layer made of silver formed on the base layer, and (6) a protective layer formed on the reflective layer.

[Effect]

In high-reflection mirrors, even when the substrate is made of plastic such as polycarbonate, polyester, or acrylic resin, an oxide base layer with high adhesion to the substrate is formed on the substrate. By forming a sulfide underlayer thereon and forming a reflective layer made of silver on the sulfide underlayer, the film adhesion between the substrate and the reflective layer made of silver is strengthened. As a result, a highly reflective mirror with high film adhesion and moisture resistance can be obtained.

〔Example〕

FIG. 1 schematically shows a high surface reflection mirror according to an embodiment of the invention. This high surface reflection mirror has a four-layer structure, and each layer is formed by vacuum evaporation, sputtering, or the like.

In this embodiment, a case is shown in which the high surface reflection mirror is formed on a substrate IC made of plastic such as polycarbonate, polyester, or acrylic resin, but it goes without saying that it can also be formed on a glass substrate.

A base layer 2C made of sulfide is formed on the substrate IC, a sulfide base layer 3C made of sulfide is formed on the oxide base layer 2C, and a reflective layer 4C made of silver is formed on the sulfide base layer 3C.
is formed, and a protective layer 5C is further formed on the reflective layer 4C.

The oxide base layer 2C is formed of an oxide with high adhesion to the substrate IC made of the above-mentioned plastic material and the sulfide base layer 3C made of sulfide, but the sulfide base layer 3C is made of zinc sulfide. 1.1', such oxides are preferably aluminum oxide, niobium oxide, cobalt oxide, and titanium oxide. Among such oxides, niobium oxide and cobalt oxide are preferable [7F c. The thickness of the acid 1-monoelectric layer 2C is lQ
nm or more, especially 15 =, -1'i (l rl
It is preferable to use m. Gland f of oxide base layer 2C
When i fi < i 0 nm 3, sufficient adhesion can be obtained and the 9-sulfide underlayer 3C has a bond between the oxide underlayer and the reflective layer 4C made of silver. Zinc sulfide or microsulfide sulfide is preferred in combination with an oxide base q2C in which the formation of sulfides with high adhesion is continuous.The thickness of the sulfide base layer 3C The thickness of the sulfide underlayer 3C is preferably iQnm or more, particularly preferably 15 to 5Qnm.If the thickness of the sulfide underlayer 3C is less than 1Qnm, sufficient adhesion cannot be obtained.

Reflective layer 4C made of silver formed on sulfide base layer 3C
preferably has a film thickness of 45 nm or more, particularly 1
It is preferable to set it as 00-200 nm. Film thickness is 45n
If it is less than m, complete reflection will not occur and /'%-fumirrization will occur, which is not preferable.

Finally, the protective layer 5C formed on the reflective layer 4C is preferably made of aluminum oxide, and has a thickness of 2
It is preferably Qnm or more, especially 20 to 1100n,
stomach. If the film thickness is less than 3 Q nm, the protective effect of the reflective layer 4C is insufficient.

FIG. 2 schematically shows a high surface reflection mirror according to another embodiment of the invention. In this embodiment, the protective layer 5d is made of a multilayer film including an aluminum oxide layer and a layer made of a transparent material.
Other layers (oxide base layer 2d.

Regarding the sulfide base 113d and the reflective layer 4d), the first
This is the same as the embodiment shown in the figure.

Transparent materials include zirconium oxide, tantalum oxide,
Dielectric materials such as titanium oxide, cerium oxide, niobium oxide, silicon dioxide, and magnesium fluoride may be mentioned, and the film thickness thereof is preferably 20 nm or more, particularly 20 to 1 oonm.

The aluminum oxide layer and the transparent material layer may be one layer at a time, or they may be stacked alternately.

In the case of lamination, each layer is preferably about 2 to 5 layers.

The present invention will be explained in further detail by the following examples.

Examples 1 to 6 In order to create a high surface reflection mirror having the configuration shown in Figure 1, first, a layer of the oxide shown in Table 1 below was deposited to a thickness of 15 nm on a substrate IC made of polycarbonate by vacuum evaporation. was formed to form an oxide base layer 2C. This oxide base layer 2C
A sulfide layer was formed thereon to a thickness of 15 nm by vacuum evaporation according to the combinations shown in Table 1 below, and the sulfide base layer 3
4. On this sulfide base layer 3C, a reflective layer 4C made of silver with a thickness of IQQna+ was formed as a reflective material by vacuum evaporation method.
A protective layer 5C made of 0n aluminum oxide was formed by vacuum evaporation to form a high surface reflection mirror.

Table 1 This high surface reflection mirror was left in a constant temperature room with a temperature of 40° C. and a humidity of 95% RH, and a peel test using cellophane tape was performed every 24 hours until 216 hours had elapsed to perform a moisture resistance test. Note that in consideration of actual use, the time required for peeling is preferably 200 hours or more. The results are shown in Table 3.

In addition, for Example 1, the temperature was 45° before and after the above moisture resistance test.
The spectral reflectance of the incident light was measured.

The results are shown in Figure 6. According to this result, the spectral reflectance of 45° incident light hardly changes before and after the moisture resistance test.
Further, even after the moisture resistance test, a high reflectance of 97% or more was obtained in the visible wavelength range of 10430 to 700 nm.

Example 7 In order to create a high surface reflection mirror having the configuration shown in FIG. 2, a multilayer film of a transparent material including an aluminum oxide layer was formed as the protective layer 5d, and the other conditions were the same as in Examples 1 to 6. A high-reflection mirror was formed on the surface. Note that the protective layer 5d has a thickness [i5
It consists of two layers: a 55 nm thick aluminum oxide layer and a 55 nm thick dielectric layer made of zirconium oxide. Example 1
As a result of testing in the same manner as in Examples 1 to 6, the film adhesion and moisture resistance were the same as in Examples 1 to 6.

Comparative Examples 1 to 8 Examples 1 to 8 except that the oxide base layer and sulfide base layer were formed using the combinations of oxides and sulfides shown in Table 2 below.
A high surface reflection mirror was formed under the same conditions as in Example 6, and the same moisture resistance test as in Examples 1 to 6 was conducted.

The results are shown in Table 3.

Table 2 Comparative Example 9 In order to create a high surface reflection mirror with a four-layer structure as shown in FIG.
e is formed by a vacuum evaporation method, and a film thickness of 11 is formed on the base layer 2e.
A reflective layer 4e made of 00n silver is formed by vacuum evaporation, and a protective layer is further formed on the reflective layer 4e to a thickness of 30 nm.
An aluminum oxide layer 5e with a thickness of 15 Qnm and a silicon dioxide layer 6e with a thickness of 15 Qnm were successively formed by vacuum evaporation. The same moisture resistance test as in Examples 1 to 6 was conducted on the obtained high surface reflection mirrors. The results are shown in Table 3.

Comparative Example 10 As shown in FIG. 4, substrate I made of polycarbonate
Copper is formed on f by vacuum evaporation to a thickness of 40 nm,
The base layer was 2f. On this base layer 2f, a reflective layer 4f made of silver with a thickness of 1100 nm is formed as a reflective material by vacuum evaporation, and further on the reflective layer 4f, as a protective layer, an aluminum oxide layer 5f with a thickness of 6 Q nm and an aluminum oxide layer 5f with a thickness of 75 nm are formed. a tantalum oxide layer 6f and a silicon oxide layer 7 with a thickness of 75 nm.
f and a tantalum oxide layer 8f having a film thickness of 75 nm were sequentially formed by vacuum evaporation. The same moisture resistance test as in Examples 1 to 6 was conducted on the obtained high surface reflection mirrors. The results are shown in Table 3.

Comparative Examples 11 to 12 In order to create a high surface reflection mirror with a three-layer structure as shown in FIG. The layer 12) was formed to a thickness of 15 nm by vacuum evaporation to form the sulfide base layer 31. A reflective layer 4 made of silver with a thickness of 1100 nm is formed on this sulfide base layer 31 as a reflective material.
1 was formed by a vacuum evaporation method. Furthermore, a protective layer 5I made of aluminum oxide with a thickness of 1100 nm was formed on the reflective layer 41 by vacuum evaporation. The same moisture resistance test as in Examples 1 to 6 was conducted on the obtained high surface reflection mirrors. The results are shown in Table 3.

13-14- As is clear from Table 3 and above (in the high surface reflection mirror of the present invention, aluminum oxide, niobium oxide, cobalt oxide,
It can be seen that the oxide base layer made of at least one material of titanium oxide is particularly excellent in film adhesion to the substrate and the sulfide base layer made of zinc sulfide. It is also found that the oxide underlayer made of at least one of niobium oxide and conoylt oxide has particularly excellent film adhesion to the substrate and the sulfide underlayer made of antimony sulfide.

〔Effect of the invention〕

As detailed above, in the high surface reflection mirror of the present invention, an oxide base layer and a sulfide base layer are sequentially formed between the substrate and the reflective layer made of silver.

Therefore, even when the substrate is made of plastic such as polycarbonate, polyester, or acrylic resin, the adhesion between the substrate and the reflective layer is strengthened, resulting in excellent film adhesion, moisture resistance, etc.

Although the case where the reflective mirror is formed on a plastic substrate has been described above, the present invention is not limited thereto, and good effects can also be achieved when the reflective mirror is formed on a glass substrate.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a high surface reflection mirror according to an embodiment of the present invention, FIG. 2 is a sectional view showing a high surface reflection mirror according to another embodiment of the invention, and FIG. FIG. 4 is a sectional view showing an example of a conventional high surface reflection mirror; FIG. 4 is a sectional view showing another example of a conventional high surface reflection mirror; FIG. FIG. 6 is a cross-sectional view showing an example, and FIG.
It is a graph showing the spectral reflectance of 45° incident light before and after a time-moisture resistance test. 1c, 1d, 1e, 1f, li 1 - Substrate 2c, 2
d, 2e...Oxide base layer 2f...
・Copper base layer 3c, 3d, 3i...Oxide base layer 4c, 4
14e, 4f, 4i...reflection layer red, 5d, 5e,
5f, 5i, 6f, 7f, 8f ・Protective layer

Claims (3)

[Claims] (1) In the surface high reflection mirror, (a) an oxide base layer formed on the substrate surface, (b) a sulfide base layer formed on the oxide base layer, and (c) the sulfide base layer. A high surface reflection mirror comprising: a reflective layer made of silver formed on a base layer; and (d) a protective layer formed on the reflective layer. (2) In the surface high reflection mirror according to claim 1, the oxide base layer is made of at least one material of aluminum oxide, niobium oxide, cobalt oxide, and titanium oxide, and the sulfide base layer is made of zinc sulfide. A high-reflection mirror with a surface. (3) The high surface reflection mirror according to claim 1, wherein the oxide base layer is made of at least one of niobium oxide and cobalt oxide, and the sulfide base layer is made of antimony sulfide. Reflector.