JPH02234101A - Production of multilayred antireflection material - Google Patents

Abstract

PURPOSE:To form two antireflection layers which are in contact with each other and are different in refractive index from each other by using the same material and forming the low-refractive index layer of the antireflection layers in such a manner that a transparent base material is disposed diagonally with an evaporating source and is subjected to vapor deposition. CONSTITUTION:The evaporating source 1 and the transparent base material 2 are so disposed that the angle theta between both 1 and 2 attains 90 deg.. The 1st antireflection layer 3 is formed by vapor deposition on the surface of the transparent base material 1. The angle theta is then so adjusted as to attain about 20 to 60 deg. and the 2nd antireflection layer 4 is formed by vapor deposition on the 1st antireflection layer by using the same evaporating source 1 as the evaporating source used for forming the 1st antireflection layer 3. The multilayered antireflection material to be obtd. in such a manner is laminated successively with the high-refractive index layer 3 and the low-refractive index layer 4 on the transparent base material 2. The formation of the high-refractive index layer 3 and the low-refractive index layer 4 in contact with each other of the same material is possible in this way and the laborious operation of changing the evaporating source 1 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to a novel method for producing multilayer antireflective materials in which two or more antireflective layers are formed on a transparent base surface.

(Prior art) Antireflection materials used in computer displays, cathode ray tubes, etc., include those provided with a single antireflection layer on a transparent substrate, or those with one or more antireflection layers having different refractive indexes. A type with a length of 7 m is known.

Anti-reflection performance is generally high! Those having an antireflection rating of 1 J- are superior to single-layer types and are preferable.

and. As for the manufacturing method of the antireflection material having this multilayer antireflection layer. ZrOt I& (high refractive index layer) as a first anti-reflection layer and Si02+1111 (low refractive index layer) as a second anti-reflection layer on the transparent substrate.
of. A method of sequentially using WtIC is known.

(Problem to be solved by the invention) However. In the case of using the above method, it is necessary to prepare two kinds of materials to form a high refractive index layer and a low refractive index layer of 1 m. After forming the high refractive index layer. Once the evaporation equipment leaked. Work such as cleaning the evaporation equipment and changing the evaporation source must be performed, and then the low refractive index JrlJ must be formed. There is a problem that not only is it inferior to L1LT, but productivity is also poor.

Therefore, an object of the present invention is to provide a method of forming two antireflection layers that are in contact with each other and have different refractive indexes using the same material.

(Means for Solving the Problems) In order to solve the above-mentioned problems of the prior art, the inventors of the present invention have made extensive studies and found that, in the case of evaporation, the transparent substrate is tilted to the evaporation source. Compared to the case of vapor deposition without tilting,
The inventor discovered that the refractive index of the antireflection layer formed on the base soil was lowered, leading to the present invention.

That is, the method for manufacturing a multi-jt4 antireflection material according to the present invention has at least two antireflection layers on the surface of a transparent base material, and one of the antireflection layers and one antireflection layer in contact with it are made of the same material. A method for manufacturing a multilayer antireflection material having different refractive indexes, in which the low refractive index I1 of these antireflection rd is vapor-deposited by arranging a transparent substrate obliquely to the evaporation source. It is characterized by being formed by.

below. Examples of the present invention will be described with reference to the drawings. Figure 1 shows an example of the method of the present invention. First of all. As shown in Figure 1(a), the conventional method. That is. Angular change θ formed by the evaporation source 1 and the transparent base material 2 (perpendicular line a extending from the evaporation source toward the transparent base material
The first antireflection layer is formed on the surface of the transparent substrate 1 by vapor deposition.

Note that the transparent base material 2 may be a glass plate, a plastic plate, or
plastic film. Plastic molded products etc. can be used.

Then, as shown in Figure 1(b), θ is approximately 20 to 6.
Rotate g4 so that the angle is 0' (normally, adjust the angle by moving the transparent base material). using the same evaporation source as the first antireflection layer. '＃． A second antireflection layer is formed on the first antireflection layer by vapor deposition (hereinafter, vapor deposition in which θ is approximately 20 to 60°KL is referred to as oblique vapor deposition).

The multi-layer antireflection material thus obtained is shown in Figure 2. High refractive index layers 1 to 3 and low refractive index layers 4 are sequentially laminated on the surface of the transparent base material 2 to form a structure M.

The refractive index of both /d3.4 depends on the type of evaporation source, the low refractive index a
t may vary depending on θ at the time of formation. When ZrOz is used as the evaporation source. The refractive index of the high refractive index layer and the low refractive index I layer is usually 1.8 to 2.4 for the former and 1.4 to 1.4 for the latter.
It is 55. Note that, if other conditions are the same, the refractive index of the low refractive index layer increases as θ increases. Mat. The thickness of both layers is. The optical film thickness is appropriately set to effectively prevent reflection of external light. Generally, each is about 800 to 1500A.

The refractive index for oblique deposition is . Although it is not necessarily clear why it is lower than when θ is set to 90°. The thin film formed by this method has low density. This seems to be related to the large unevenness of the thin film surface and the large scattering of incident light on the thin film surface.

The above is an example in which a high refractive index layer is first formed on the surface of a transparent substrate, and then a low refractive index layer is formed on it. form the rate III,
A high refractive index layer made of the same material can then be formed. In this case, a third antireflection ttA having a lower refractive index than the low refractive index layer is further provided on the high refractive index layer (the material is high refractive index 1-
(which may be the same or different) has been found to be preferable.

for example. Zr02 is used as the evaporation source and θ is 20 to 6 as described above.
0°, a low refractive index layer with a refractive index of 1.6 to 1.9 is formed on the surface of the transparent substrate by oblique vapor deposition, then θ is set to 90°, and the layer is made of ZrO* with a refractive index of 1.8 to 2.4. High refractive index of 1
1 by vapor deposition, and the refractive index 1 obtained from Sif2.
．． A third antireflection angle of 4 to 1.55 degrees can be accommodated.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 100μ thick transparent polyethylene terephthalate (
Hereinafter, PET) film is set in a pressure-resistant container,
Adjust the atmospheric pressure to 2 x 10 Torr K.

The Zr02t evaporation source is used as an evaporation source, and the angle θ between this and the PET film is 90°. EB evaporation (40mA.IOKV
) to form a high refractive index j- with a thickness of 120 OA and a refractive index of 2.05 on one side of the PET film.

Next, by diagonal steaming using the same dovetail as above except that θ was set to 30°. A low refractive index ItI with a thickness of 90 OA and a refractive index of 1.48 was formed on the high refractive index layer to obtain a multilayer antireflection material.

Incident light of this anti-reflection material (to wavelength 400 -7oonm)
The average reflectance was 0.75%.

Example 2 Same as Example 1 except that θ was set to 50°. PET
on one side of the film. A low refractive index layer made of Zr(h) with a thickness of 80 OA and a refractive index of 1.9 is formed by oblique vapor deposition.

next. Same as above except that θ is 90°. Z with a thickness of 1200A and a refractive index of 2.05 on low refractive index skin
Form the high refractive index layer to be cut from r02.

Next, proceed as above except for changing the second evaporation source to SiO2 (90° to θ). on the Zr02 high refractive index layer. A SiOz layer with a thickness of 90 OA and a refractive index of 1.48 was formed to obtain a multilayer antireflection material.

The average reflectance ri of this antireflection material for incident light (wavelength 400 to 700 nm) was 0.65%.

(Effects of the Invention) According to the present invention, the high refractive index layer and the low refractive index layer that are in contact with each other can be formed of the same material. When forming these two J- onto a transparent substrate surface. There is no need for troublesome work such as changing the evaporation source. Multilayer antireflection materials can be efficiently produced.

[Brief explanation of the drawing]

FIG. 1(a) and FIG. 1(b) are explanatory diagrams showing an example of the method for manufacturing a multilayer antireflection material according to the present invention. FIG. 2 is a front view showing an example of a multi-l1 antireflection material obtained by the method of the present invention. 1... Evaporation source 2... Transparent base material 3...
High refractive index no 4...Low refractive index layer

Claims (1)

[Claims] having at least two antireflection layers on the surface of the transparent base material,
A method for producing a multilayer antireflection material in which one of the antireflection layers and one antireflection layer in contact with it are made of the same material and have different refractive indexes, and the low refractive index layer of these antireflection layers is 1. A method for producing a multilayer antireflection material, characterized in that the transparent substrate is formed by evaporation by arranging the transparent substrate obliquely to an evaporation source.