JPS60130704A - Antireflection film for plastic substrate - Google Patents

Abstract

PURPOSE:To increase the substrate reinforcing effect of an antireflection film and the antireflection effect in the visible light region independently of the kind of plastic substrate by forming a multilayered antireflection film having a specified composition on a plastic substrate. CONSTITUTION:A multilayered antireflection film is formed on a plastic substrate 1 by successively laminating an SiO film as the 1st layer of 0.13lambda-lambda optical thickness (lambda is the wavelength of light), an SiO2 film as the 2nd layer 3 of 0.13lambda-lambda thickness, a film of Ta2O5, TiO, TiO2 or a mixture of two or more among them or a multilayered film consisting of two or more among them as the 3rd layer 4 of 0.05lambda-0.06lambda thickness, a film of Al2O3, SiO or a mixture of them or a multilayered film consisting of them as the 4th layer 5 of 0.05lambda-0.06lambda thickness, a film of Ta2O5, TiO, TiO2 or a mixture of two or more among them or a multilayered film consisting of two or more among them as the 5th layer 6 of 0.07lambda-0.09lambda thickness, a film of Al2O3, SiO or a mixture of them or a multilayered film consisting of them as the 6th layer 7 of 0.05lambda-0.06lambda thickness, a film of Ta2O5, TiO, TiO2 or a mixture of two or more among them or a multilayered film consisting of two or more among them as the 7th layer 8 of 0.2lambda-0.3lambda thickness, and a film of SiO2, MgF2 or a mixture of them or a multilayered film consisting of them as the 8th layer 9 of 0.23lambda-0.28lambda thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer anti-reflection 1L coating for a synthetic resin substrate such as a synthetic resin lens.

In recent years, synthetic resin optical parts, especially lenses, have come into use due to their ease of molding and light weight, but problems still remain with the antireflection coatings of these optical parts.

Conventionally, the following are known as such antireflection films, for example. That is, in JP-A No. 56-18922, a first layer of silicon dioxide (SIQ2) with a thickness of several μm, which is sufficient to supplement mechanical strength, is formed on a synthetic resin substrate, and a film is then formed on the first layer. A second layer consisting of a yttrium oxide (Y2O2) film with a thickness of 0.15λ to 0.25λ [λ (wavelength of light) = 450 to 550 nm: l, on which a zirconium oxide (ZrO2) film with a film thickness of 0165λ to 0.45λ
) film, and further a film on the sixth layer. Japanese Patent Application Laid-Open No. 50-67147 discloses that silicon monoxide (S i 0 ) is coated at 1/2 as the first layer on a synthetic resin substrate. 4
Vapor deposited to a thickness of λ dimension or 1/2λ (λ-5111m),
It is disclosed that silicon dioxide is then deposited as a second layer to a thickness of 1/4λ to form a multilayer antireflection coating.

In Japanese Unexamined Patent Publication No. 56-121001, d1 is a silicon monoxide film with a thickness of 2Q+un as a first layer on a synthetic resin substrate, and an alumina film with a thickness of less than 50λ as a second layer thereon. , further on top of that is a sixth layer with a film thickness of 0.25λ~
A plastic optical component is disclosed in which 0.60λ magnesium/ium fluoride (Mg"2) films are sequentially laminated.

Furthermore, JP-A No. 58-60701 discloses a multilayer anti-reflection film composed of a vapor-deposited film of silicon monoxide having a refractive index, and A film is disclosed, specifically a substrate having a jtN refractive index of 1.
60 to 1.68, a first layer made of silicon monoxide with an optical thickness of λ/4, a refractive index of 1.75 to 1.83,
A second layer made of silicon monoxide with an optical thickness of λ/4, and a second layer with a refractive index of 1.50 to 1.55. A multilayer antireflection film is disclosed in which a sixth layer of silicon monoxide film having an optical thickness of λ/4 is laminated in j order. At this time, the refractive index of -silicon oxide can be changed by changing the oxygen gas pressure under conditions where the deposition rate is constant, or by changing the deposition rate under conditions where the depletion oxygen force pressure is constant. Disclosed.

Among these multilayer antireflection coatings, JP-A-56-1892
The one disclosed in No. 2 uses diethylene glycol bisallyl carbonate (C1(・-69
) is a multilayer anti-reflection coating developed for eyeglasses, and when the above-mentioned constituent films are applied to an injection or cast molded substrate, cracks occur in the first layer of silicon dioxide film. In addition, although the films disclosed in JP-A-50-67147 and JP-A-56-121001 do not cause cracks in the film, they have low anti-reflection effects in the i1J visual field and have poor adhesion. There is no need for this.

Furthermore, since the material disclosed in Q4 1986-60701 is composed only of -silicon oxide, if left in the atmosphere it will be affected by oxygen and will approach silicon dioxide, resulting in spectral reflection over time. The disadvantage is that the characteristics change.

An object of the present invention is to provide an antireflection film for a synthetic resin substrate that improves the reinforcing effect of the substrate and the antireflection effect in the visible light region, regardless of the type of synthetic resin substrate.

One objective of the present invention is to achieve good color balance and
The object of the present invention is to provide an antireflection film that has high adhesion to a substrate and also has good solvent resistance, abrasion resistance, and environmental resistance.

The synthetic resin-based antireflection film according to the present invention is formed on a synthetic resin substrate with an optical film thickness of 0.16λ to λ[λ(
A first layer made of a silicon oxide film of -450 to 550 former 1) (wavelength of light), and a second layer made of a silicon dioxide film with an optical thickness of 0.16λ to λ formed on the first layer. layer, an optical film thickness formed on the second layer 0.05λ to 0.06
λ tantalum pentoxide, titanium itide, titanium dioxide-
or a film of a mixture of two or more of these, or a sixth layer consisting of a multilayer film of two or more of tantalum oxide, -titanium oxide, and titanium dioxide; The optical film thickness formed on J is 0.05λ~0. A fourth layer consisting of a film of O12 alumina, -silicon oxide or a mixture thereof, or a multilayer film of alumina and silicon monoxide, an optical film formed on the fourth layer having an optical thickness of 0. Tantalum pentoxide from O7λ to 0.09λ, -
A fifth layer consisting of a film of titanium oxide, titanium dioxide or a mixture of two or more thereof, or a multilayer film of two or more of tantalum pentoxide, -titanium oxide and titanium dioxide, and an optical film formed on the fifth layer. A sixth layer consisting of a film of alumina, -silicon oxide, or a mixture thereof, or a multilayer film of alumina and silicon monoxide, with a film thickness of 0.05 to 0.06λ, and a sixth layer formed on the sixth layer. Optical film thickness 0.2λ~0.6
tantalum pentoxide of λ, - a film of titanium oxide, titanium dioxide or a mixture of two or more thereof, or tantalum pentoxide,
- A seventh layer consisting of a multilayer film of two or more of titanium oxide and titanium dioxide, and silicon dioxide or magnesium fluoride with an optical thickness of 0626λ to 0.28λ formed on the seventh layer - or a mixture thereof. or an eighth layer consisting of a multilayer film of silicon dioxide and magnesium fluoride.

In the present invention, it is preferable that the second to eighth layers are formed by activated reaction vapor deposition in order to improve the adhesion between each layer. Here, "activated reactive vapor deposition" means vapor deposition in an active gas turned into plasma, such as oxygen gas.

Examples of the synthetic resin substrate in the present invention include synthetic resin lenses used in lens constructions intended for aspherical lenses used particularly in small camera lenses, video camera lenses, copier lenses, and the like. These synthetic resin substrates are made of, for example, diethylene glycol bisallyl carbonate 1, an acrylic face plate formed by casting/in-extension molding, polycarbonate resin, or styrene resin.

Vacuum deposition,
Although known means such as electron beams can be used, it is preferable to stack the second to eighth layers 1 by the above-mentioned activated reaction vapor deposition, since this increases the adhesion between the layers. Since the first layer of amorphous silicon film has good adhesion to the synthetic resin, activation reaction vapor deposition is not necessary.

In the multilayer antireflection film according to the present invention, the first layer made of a -silicon oxide film and the second layer made of a silicon dioxide film have not only an antireflection function but also a substrate reinforcing function.

EXAMPLES The present invention will be explained and explained in more detail with reference to Examples below.

Example 1 The present invention will be described in detail with reference to FIG.

FIG. 1 is an enlarged sectional view of a part of the antireflection film of this example. On the surface of the injection-molded acrylic resin substrate 1, silicon monoxide is vacuum-deposited at a deposition rate of 2 A/sec (constant) at a vacuum degree of 1×10 Torr by resistance heating to a film thickness of 0.5λ (λ=450 to 550 nm).
A first layer 2 is formed. At this time, the refractive index of the first layer is 1
．． 60 to 1.68.

Silicon dioxide is deposited on the first layer using an electron beam to form a second layer 3 having a thickness of 0.5λ.

The second layer has a refractive index of 1.45 to 1.46. The first layer and the second layer also have the effect of reinforcing the substrate.

On the second layer, tantalum pentoxide is deposited using an electron beam to form a sixth layer 4 having a thickness of 0.06λ. The refractive index of the sixth layer is 2.0 to 2.1.

Next, alumina is deposited on the sixth layer using an electron beam to form a fourth layer 5 having a thickness of 0.06λ. The refractive index of the fourth layer is 1.59 to 1.62.

On the fourth layer, a fifth layer having a film thickness of 0.08λ and a refractive index of 20 to 2.1 is formed by vapor-depositing pentoxide tank with an electron beam.

On the fifth layer, alumina is deposited using an electron beam to form a sixth layer with a film thickness of 0.06λ and a refractive index of 1.59 to 1.62.
Form layer 7.

On the sixth layer, tantalum pentoxide is deposited using an electron beam to form a seventh layer with a film thickness of 0.26λ and a refractive index of 2.0 to 2.1.
Form layer 8.

Next, silicon dioxide is deposited on the seventh layer using an electron beam to give a film thickness of 0.25λ and a refractive index of 1.45 to 1.4.
An eighth layer 9 of No. 6 is formed.

The spectral reflectance characteristics of the antireflection film thus obtained are as shown in FIG. As is clear from FIG. 2, this antireflection film has good spectral reflectance characteristics in the town festival light area.

The following tests were conducted on this antireflection film.

(1) Adhesion test 2 After adhering cellophane Teso to the surface of the anti-reflection film obtained as above, a test was repeated 15 times to remove it quickly at an angle perpendicular to the surface. However, no peeling of the deposited film occurred.

(2) Solvent Resistance Test 2 The surface of the antireflection film was wiped with lens wiping paper (Silbon paper) moistened with an ether alcohol mixture, but no abnormalities were observed.

(3) Abrasion resistance test: 6 to 4 kg/cr using lens wiping paper (Silbon paper) on one spot on the surface of the anti-reflection film.
I rubbed it 50 times with a pressure of 1 liter, but no abnormality was found.

(4) Environmental resistance test Two anti-reflection coatings at 45℃, relative humidity 9
It was left in a constant temperature and humidity chamber of section 5 for 1000 hours, and then a thermal shock test (60°C e-60°C) was repeated 5 times, but no abnormality was observed.

Example 2 The second layer 6 to the eighth layer 9 in Example 1 were vacuumed to '7X1.
High frequency (15,5
Activated deposition in 6MI(z) oxygen plasma.

The antireflection film obtained in this example showed substantially the same spectral reflection characteristics as the antireflection film obtained in Example 1, and no peeling of the film was observed even after 20 repetitions of the adhesion test. Further, the solvent resistance was equivalent to or better than that of the antireflection film of Example 1.

In this example, the 61st layer 4, the 5th layer 6 and the 7th layer
In place of the tantalum pentoxide film of layer 8, a part titanium film, a part titanium film, a film of a mixture of two or more of tantalum pentoxide, -titanium oxide and titanium dioxide, or two or more of these films can be used.
In place of the above multilayer film, the alumina film of the fourth layer 5 and the sixth layer 7, a partially silicon film, a film of a mixture of alumina and a part of arsenic, or a multilayer film thereof, and/'
-! In place of the silicon dioxide film in the eighth layer 9, antireflection films made using a magnesium/umium fluoride film, a film of a mixture of silicon dioxide and magnesium fluoride, or a multilayer film thereof have excellent adhesion, It was excellent in solvent resistance, abrasion resistance and environmental resistance.

According to the present invention, regardless of the type of synthetic resin and the molding method, it has both a reinforcing effect for the synthetic resin substrate and a good antireflection effect in the visible light region, and also has good adhesion, solvent resistance,
The anti-reflection coating on the synthetic resin substrate has excellent wear resistance and environmental resistance.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of a part of an antireflection film according to an embodiment of the present invention, and FIG. 2 is a graph showing the spectral reflectance characteristics of the antireflection film. 1... Substrate 2 - 1st layer 6 2nd layer 4 6th layer 5 4th layer 6 ・5th layer 7 6th layer 8... 7th layer 9... 8th layer

Claims (1)

[Claims] 1. Optical film thickness Q formed on a synthetic resin substrate, 16λ
~λ [λ [wavelength of light] = 450-550 nn]] A first layer made of a silicon monoxide film, and a silicon dioxide film formed on the first layer with an optical thickness of 0.16λ to λ. a second layer, an optical thickness of 0.05λ formed on the second layer;
~0. A sixth layer consisting of two or more multilayer films of O12 tantalum pentoxide, -titanium oxide, and tan, alumina, -silicon oxide, or these with an optical thickness of 0905λ to 0.06λ formed on the sixth layer. A fourth layer consisting of a mixture film or a multilayer film of alumina and silicon monoxide; tantalum pentoxide, -titanium oxide, and dioxide having an optical thickness of 0.07λ to 0.09λ formed on the fourth layer. A fifth layer consisting of a film of titanium or a mixture of two or more thereof, or a multilayer film of two or more of tantalum pentoxide, -titanium oxide, and titanium dioxide, and an optical film formed on the fifth layer has an optical thickness of 0. 05λ~0.
A sixth layer consisting of a film of alumina, -silicon oxide or a mixture thereof, or a multilayer film of alumina and silicon monoxide, and an optical film formed on the sixth layer with an optical thickness of 06λ
．． 2λ to 0.6λ film of tantalum pentoxide, -titanium oxide, titanium dioxide or 1 or a mixture of two or more of these, or 2 of tantalum pentoxide, -titanium oxide and titanium dioxide
A seventh layer consisting of the following multilayer film, and a film of silicon dioxide, magnesium fluoride, or a mixture thereof having an optical thickness of 0.26λ to 0.28λ formed on the seventh layer,
Alternatively, an anti-reflection film on a synthetic resin substrate is characterized by comprising an eighth layer made of a multilayer film of silicon dioxide and magnesium fluoride. 2. The anti-reflection 1F film according to claim 1, wherein the second to eighth layers are formed by activated reaction vapor deposition.