JPH07253501A - Optical product having antireflection layer - Google Patents

Abstract

PURPOSE:To obtain excellent antireflection performance and to suppress generation of interference pattern by forming a single layer or multilayer precoating layer between the surface of a substrate and a hard coating layer. CONSTITUTION:A hard coating layer comprising an inorg. material is formed on a plastic base body and a single layer or multilayer antireflection layer is formed on the hard coating layer. A single or multilayer precoating layer is formed between the surface of the base body and the hard coating layer. It is preferable that the refractive index of this precoating layer is between the refractive index of the plastic base body and the refractive index of the hard coating layer. By forming the precoating layer, reflection of light caused by the difference of the refractive indices between the hard coating layer and the plastic base body can be decreased. Therefore, the influence of the interference pattern produced by the interference of the reflected light from the interface between the plastic base body and the hard coating layer and the reflected light from the interface between the hard coating layer and the antireflection layer can be decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, for spectacle lenses, camera lenses, optical filters,
The present invention relates to an optical article having an antireflection layer.

[0002]

2. Description of the Related Art Conventionally, plastic has attracted attention as an optical member which can be replaced with glass because it is lighter in weight than glass, has excellent workability and impact resistance, and has useful advantages such as easy dyeing. ing.

For example, since plastic lenses are lighter than conventional glass lenses, plastic lenses improved according to the purpose of use have been proposed one after another as an alternative to the glass lenses. Recently, a large number of plastic lenses having a high refractive index and low chromatic aberration have been proposed to make the lenses thinner.

Generally, plastics have many useful advantages as mentioned above, but on the other hand, they have insufficient hardness and are easily scratched, easily attacked by solvent, and electrostatically adsorb dust. It also has drawbacks such as insufficient heat resistance, and is practically unsatisfactory as compared with glass for practical use as an optical member such as a spectacle lens or a camera lens. Therefore, in general, a plastic base material used for an optical member is provided with a coating layer on its surface to cover the defects of the plastic base material according to the purpose.

As an example thereof, there is a plastic lens having a hard coat layer of SiO ₂ film of about 0.5 to 5.0 μm formed in order to improve hardness. Further, in order to suppress the surface reflection of the plastic lens having the hard coat layer formed thereon, a plastic lens having an antireflection layer formed of an inorganic material on the hard coat layer has also been proposed and put into practical use.

For example, in JP-A-56-116003, a hardened layer for improving the durability and scratch resistance of the surface of a synthetic resin substrate has a SiO.sub.2 of 0.5 to 5.0 .mu.m on the substrate surface. subjected to ₂ film, further, subjected to a ZrO ₂ film is an antireflection film thereon, further, a SiO ₂ film is an antireflection film thereon, alternating with the ZrO ₂ film and the SiO ₂ film and so on A synthetic resin optical component formed by vacuum deposition is disclosed.

As another example, JP-A-56-7420
No. 2 discloses an optical element in which at least one surface of a synthetic resin molded body is provided with an organic hard coat layer, and an inorganic coating film is further formed thereon.

[0008]

For example, when a lens is manufactured using plastic, if the lens to be manufactured is made thin, the refractive index of the plastic base material must be increased in terms of optical design. However, when a hard coat layer is formed on the surface of a thin plastic substrate having a high refractive index to improve the hardness, the difference between the refractive index of the plastic substrate and the refractive index of the hard coat layer is reduced. Because of the large difference, reflected light is generated due to the difference between the refractive index of the hard coat layer and the refractive index of the plastic substrate.

Further, generally, in order to suppress the surface reflection of the plastic lens on which the hard coat layer is formed, an antireflection layer is further formed by an inorganic material. However, even at the boundary between the hard coat layer and the antireflection layer. There is reflected light. Therefore, the reflected light resulting from the difference between the refractive index of the hard coat layer and the plastic substrate described above,
The reflected light generated at the boundary between the hard coat layer and the antireflection layer interferes with each other, and ripples are generated in the spectral reflection characteristic, so that the antireflection performance is inferior.

Generally, the hard coat layer is formed of an organic material, but a dipping method, a spin coating method or the like is used as a method for forming a film.
With these methods, it is difficult to make the film thickness uniform on the lens surface, so ripples appear as interference fringes,
Not only the antireflection performance is deteriorated, but also the appearance is remarkably deteriorated.

Therefore, conventionally, there has been proposed a method for making such interference fringes less visible. For example, JP-A-4
-366801 has a plastic base material and an organic base.
A plastic lens has been proposed in which an organic primer layer having a thickness of λ / 4 is sandwiched between the plastic layer and the doctrine layer. This is to provide a plastic lens having excellent impact resistance after antireflection coating and good weather resistance, but to form a thin layer film of λ / 4 with an organic substance. Is very difficult, and this invention is of little practicality.

The present invention is intended to solve such problems, and a hard coat layer and an antireflection layer are formed on the surface of a plastic substrate (plastic substrate having a high refractive index). When it is made to have excellent anti-reflection performance,
An object of the present invention is to provide an optical article that suppresses the generation of interference fringes.

[0013]

[Means for Solving the Problems] In order to achieve the above object,
The present invention of claim 1 is an optical article having a hard coat layer made of at least an inorganic material on a plastic substrate and a single-layer or multi-layer antireflection layer on the hard coat layer, and the surface of the substrate and the hard coat. It is provided with a single-layer or multi-layer precoat layer between the layers.

The present invention according to claim 2 is the optical article according to claim 1, characterized in that the precoat layer is made of an inorganic material.

Further, the present invention according to claim 3 provides the optical article according to claim 2, wherein the precoat layer is one or more selected from oxides, fluorides, silicides and sulfides of metals or semimetals. It is characterized by being composed of the substance of.

According to a fourth aspect of the present invention, in the optical article according to the first to third aspects, the optical article having the antireflection layer is a plastic lens.

Further, the present invention according to claim 5 is based on claims 1 to 4.
In the optical article described in ( ₁₎ above, when the refractive index of the plastic substrate is n ₁ , the refractive index of the hard coat layer is n ₂ , and the design center wavelength is λ, the precoat layer is
A refractive index with a _{(n 1 × n 2) 1} /2, in which the film thickness is equal to or is a lambda / 4.

[0018]

Since the present invention is constructed as described above,
The following effects are achieved. The present invention according to claim 1 is an optical article having a hard coat layer made of at least an inorganic substance on a plastic substrate and a single-layer or multilayer antireflection layer on the hard coat layer, and the surface of the substrate and the hard coat. A single-layer or multi-layer precoat layer is provided between the layers.

This precoat layer preferably has a refractive index between the refractive index of the plastic substrate and the refractive index of the hardcoat layer. By providing such a layer, it is possible to reduce the generation of reflected light due to the difference between the refractive index of the hard coat layer and the refractive index of the plastic substrate, and between the plastic substrate and the hard coat layer. It is possible to reduce the influence of interference fringes generated due to interference between the generated reflected light and the reflected light generated between the hard coat layer and the antireflection layer.

Further, by forming the precoat layer as a single layer or a multilayer, the precoat layer can be freely adjusted so as to have a refractive index effective for preventing the generation of the reflected light. For example, two or more kinds of substances having different refractive indexes are mixed and adjusted so as to have a refractive index of a value between the refractive index of the plastic substrate and the refractive index of the hard coat layer. You may form as.

As another example, a precoat layer having a desired refractive index as a whole is formed by forming a thin film made of a low refractive index substance and a thin film made of a high refractive index substance or a medium refractive index substance into multiple layers. It may be formed. When the precoat layer is formed in multiple layers in this manner, dispersion is reduced, which is preferable.

By forming the precoat layer in multiple layers,
For example, there is no practical substance having a refractive index between the refractive index of the hard coat layer and the refractive index of the plastic substrate, or it is difficult to obtain the precoat layer formed by one layer. Even if it is difficult to do so, the precoat layer can be easily obtained at a low cost by using an available material.

An optical article obtained by providing a hard coat layer and an antireflection layer on the precoat layer thus formed does not cause ripples in the spectral reflection characteristics and is optically excellent. To be The optical article is not particularly limited as long as it is an optical article that can be constructed with a plastic material such as a plastic lens, a plastic mirror, and a plastic prism.

According to the present invention of claim 2, the precoat layer is made of an inorganic material. In general, when a thin film made of an organic material is formed, it is difficult to make the film thickness uniform on the surface. Therefore, ripples appear as interference fringes. When forming a thin layer film, the film thickness on the surface can be made uniform more easily than when forming a thin film of an organic material.

As a method for forming a thin film of an inorganic material, the selected inorganic material is dissolved in a solvent, and the solution is applied to the surface of the substrate by spray coating, brush coating or dipping, and then the solvent is removed. A method of removing and forming a film,
The selected inorganic substance is dissolved in a solvent (or as it is), and the selected inorganic substance is vapor-deposited while rotating the substrate in a closed container under pressure such that the inorganic substance (or inorganic substance) in this solution becomes vapor. The method is not particularly limited as long as it is a method generally used for forming a thin film and the formed film is uniform, such as a method for forming a film.

However, it is difficult to make the surface of the formed film uniform and extremely thin by the dip coating method such as the dipping method, the surface coating method such as the spray method and the spin coating method as described above. It is preferable to use the vapor deposition methods such as the vacuum vapor deposition method, the ion plating method and the sputtering method as described in the latter. Further, in the vacuum vapor deposition method, a film having higher durability can be obtained by using the ion assist method together.

Further, the precoat layer made of an inorganic material thus formed has sufficient optical properties to reduce the generation of reflected light due to the difference between the refractive index of the hard coat layer and the refractive index of the plastic substrate. In addition to providing the characteristics, the film thickness on the surface is uniform, so that the occurrence of ripples can be prevented and an optical article having a good appearance can be obtained.

Further, in the present invention of claim 3, the precoat layer is made of one or more substances selected from metal or metalloid oxides, fluorides, silicides and sulfides. Specific examples are SiO ₂ and MgF ₂ as the low refractive index substance, and as the medium refractive index substance,
Al ₂ O ₃ , SiO _x , and ZrO as a high refractive index substance
₂ , TiO ₂ , Ta ₂ O ₅ , CeO ₂ , HfO ₂ , Pr
₆ O ₁₁ , Y ₂ O ₃ , ZnS, etc., or a mixture thereof can be mentioned.

Further, in the present invention of claim 4, the optical article having the antireflection layer is a plastic lens. That is, the optical article of the present invention can be used as an alternative to a glass lens or a conventionally used plastic lens.

That is, a case where a hard coat layer or a hard coat layer and an antireflection layer are formed on the precoat layer by forming a precoat layer made of an inorganic material on the surface of the plastic lens substrate. Also, the reflected light due to the difference between the refractive index of the lens substrate and the refractive index of the hard coat layer formed thereon can be prevented.

Therefore, there is no problem that the reflected light and the reflected light generated between the hard coat layer and the antireflection layer interfere with each other and appear as interference fringes, and a plastic lens having good optical characteristics is not present. Can be obtained.

Further, the precoat layer is preferably formed by vapor-depositing an inorganic substance, whereby a precoat layer having a uniform film thickness on the surface can be easily obtained and the film thickness is not uniform. Since there is no ripple due to this, this ripple does not appear as interference fringes,
It is possible to obtain an optically good plastic lens.

Further, in claim 5 of the present invention, when the refractive index of the plastic substrate is n ₁ , the refractive index of the hard coat layer is n ₂ , and the design center wavelength is λ, the precoat layer is: The refractive index is (n ₁ × n ₂ ) ^1/2 and the film thickness is λ / 4.

That is, since the refractive index of the precoat layer is determined in accordance with the refractive index of the lens substrate and the hardcoat layer, the lens substrate and the hardcoat layer having any refractive index are A precoat layer having an optimum refractive index is selected and provided at an appropriate time.

By providing such a layer, it is possible to prevent generation of reflected light due to the difference between the refractive index of the hard coat layer and the refractive index of the plastic substrate.
Eliminates interference fringes that occur due to interference between the reflected light generated between the plastic substrate and the hard coat layer and the reflected light generated between the hard coat layer and the antireflection layer. It is possible to obtain not only a plastic lens but also a plastic lens having good optical characteristics.

[0036]

EXAMPLES The present invention will be described in detail below with reference to examples. [Example 1] As a lens substrate, a refractive index nd = 1.60
A commercially available plastic lens was prepared, and a thin film was formed by a vacuum deposition method with a designed central wavelength λ of λ = 535 nm. As the conditions at this time, the lens base material is set in a rotating dome in a vacuum container in which the pressure in the vacuum container is always adjusted to 1.0 × 10 ⁻⁵ torr, and the hard coat is sequentially applied from the precoat film. The film and the antireflection film were vacuum-deposited.

A precoat film is first formed on the surface of this lens substrate, and this precoat film is a film for preventing reflection between the lens substrate and the hard coat film. In Example 1, as the precoat film, SiO _{2 was used.}
A film having a two-layer structure composed of a layer and an Al ₂ O ₃ layer is formed. The SiO ₂ layer is a layer that corresponds to the first layer when counted in order from the lens substrate side, has a refractive index of 1.47, and was vacuum-deposited until the optical film thickness becomes 0.09λ.

After forming the SiO ₂ layer, an Al ₂ O ₃ layer, which is a layer corresponding to the second layer, was formed in order from the lens substrate side. This Al ₂ O ₃ layer had a refractive index of 1.62 and was vacuum-deposited until the optical film thickness became 0.07λ.

Further, a hard coat film is formed after forming the precoat film, and this hard coat film is a film for increasing the surface hardness of the plastic lens. To increase the surface hardness, a film thickness of about 0.5 to 5.0 μm is necessary. This is because when the film thickness is 0.5 μm or less, sufficient hardness cannot be obtained, and when the film thickness is 5.0 μm or more, the temperature of the lens rises during film formation, causing problems such as deformation and cracks.

In general, a plastic lens is weak to heat, and therefore, as the hard coat layer, it is necessary to select a substance which has high hardness even when formed at a low temperature and which does not increase in temperature during the film formation. Therefore, SiO ₂ is suitable as a material used for this layer, and S 1 is also used in the first embodiment.
iO ₂ is used as a hard coat film.

The SiO ₂ layer, which is a hard coat film, is the third layer when counted from the lens substrate side in order, and has a refractive index of 1.47 and a physical film thickness of 1.0 μm. It was vacuum-deposited.

Further, an antireflection film for preventing reflection between the hard coat film and air is formed on the hard coat film. Although the antireflection film may have any structure, a film having a large number of layers is not preferable in view of durability of the antireflection film. Preferably, the optical film thickness is
λ / 4, λ / 2, λ / 4 or λ / 4, λ / 4, λ /
4 is preferable. In this case, the medium refractive index λ /
Often, the four layers are replaced with two to three layers of equivalent films composed of a low refractive index material and a high refractive index material.

In Example 1, as the antireflection film, Si was used.
A film having a four-layer structure in which O ₂ layers and ZrO ₂ layers are alternately provided is formed. First, a layer corresponding to the fourth layer, counted from the lens substrate side, was vacuum-deposited with ZrO ₂ having a refractive index of 2.00 until the optical film thickness became 0.12λ.

Further, SiO ₂ having a refractive index of 1.47 was vacuum-deposited thereon as a fifth layer until the optical film thickness became 0.06λ. The sixth layer is ZrO with a refractive index of 2.00
₂ is vacuum-deposited until the optical film thickness becomes 0.25λ,
The seventh layer was formed by vacuum-depositing SiO ₂ having a refractive index of 1.47 until the optical film thickness became 0.25λ.

FIG. 1 shows the spectral reflectance characteristics of the plastic lens of Example 1 thus obtained. Figure 1
, The vertical axis represents the spectral reflectance (%) and the horizontal axis represents the wavelength (n
m).

[Example 2] As a lens substrate, a refractive index n
A commercially available plastic lens having d = 1.60 was prepared, and a thin film was formed by a vacuum vapor deposition method with a designed central wavelength λ of λ = 535 nm. The condition at this time is to set the lens base material in the rotating dome in a vacuum container in which the pressure in the vacuum container is always adjusted to 1.0 × 10 ⁻⁵ torr, and to apply the hard coat in order from the precoat film. The film and the antireflection film were vacuum-deposited.

A precoat film is first formed on the surface of this lens substrate, and this precoat film is a film for preventing reflection between the lens substrate and the hard coat film. In Example 2, as the precoat film, SiO _{2 was used.}
A film having a three-layer structure composed of a layer and an Al ₂ O ₃ layer is formed.

The layer corresponding to the first layer when counted from the lens substrate side is an Al ₂ O ₃ layer having a refractive index of 1.62,
Vacuum deposition was performed until the optical film thickness became 0.50λ. The second layer was a SiO ₂ layer having a refractive index of 1.47 and was vacuum-deposited until the optical film thickness became 0.09λ. Further, the third layer is an Al ₂ O ₃ layer having a refractive index of 1.62 and was vacuum-deposited until the optical film thickness became 0.07λ. The above first to third layers are the precoat film of the second embodiment.

After forming the precoat film, a hardcoat film is formed. This hardcoat film is the fourth layer counted from the lens base material side, and the S having a refractive index of 1.47.
It was a layer composed of io ₂ and was vacuum-deposited until the physical film thickness became 1.0 μm. Furthermore, on the hard coat film,
An antireflection film is formed to prevent reflection between the hard coat film and air.

In the second embodiment, Si is used as the antireflection film.
A film having a four-layer structure in which O ₂ layers and ZrO ₂ layers are alternately provided is formed. First, a layer corresponding to the fifth layer, counted from the lens substrate side, was vacuum-deposited with ZrO ₂ having a refractive index of 2.00 until the optical film thickness became 0.12λ.

Further, a sixth layer of SiO ₂ having a refractive index of 1.47 was vacuum-deposited thereon until the optical film thickness became 0.06λ. The seventh layer is ZrO with a refractive index of 2.00
₂ is vacuum-deposited until the optical film thickness becomes 0.25λ,
The eighth layer was formed by vacuum-depositing SiO ₂ having a refractive index of 1.47 until the optical film thickness became 0.25λ.

FIG. 2 shows the spectral reflectance characteristics of the plastic lens of Example 2 thus obtained. Figure 2
, The vertical axis represents the spectral reflectance (%) and the horizontal axis represents the wavelength (n
m).

[Example 3] As a lens substrate, a refractive index n
A commercially available plastic lens having d = 1.60 was prepared, and a thin film was formed by a vacuum vapor deposition method with a designed central wavelength λ of λ = 535 nm. As the conditions at this time, the lens base material is set in a rotating dome in a vacuum container in which the pressure in the vacuum container is always adjusted to 1.0 × 10 ⁻⁵ torr, and the hard coat is sequentially applied from the precoat film. The film and the antireflection film were vacuum-deposited.

A precoat film is first formed on the surface of this lens substrate, and this precoat film is a film for preventing reflection between the lens substrate and the hard coat film. In Example 3, as the precoat film, SiO _{2 was used.}
A film having a two-layer structure composed of a layer and an Al ₂ O ₃ layer is formed.

The layer corresponding to the first layer when counted from the lens substrate side was a SiO ₂ layer having a refractive index of 1.47 and was vacuum-deposited until the optical film thickness became 0.10λ. The second layer was an Al ₂ O ₃ layer having a refractive index of 1.62 and was vacuum-deposited until the optical film thickness became 0.05λ.

Further, a hard coat film is formed after the precoat film is formed. This hard coat film is a layer corresponding to the third layer counting from the lens base material side, and has a refractive index of 1.4.
It is a layer composed of SiO ₂ and has a physical film thickness of 1.0 μm.
It was vacuum-deposited until it reached m.

Further, an antireflection film for preventing reflection between the hard coat film and air is formed on the hard coat film. In the second embodiment, SiO is used as the antireflection film.
A four-layer structure film in which _two layers and ZrO ₂ layers are alternately provided is formed. First, a layer corresponding to the fifth layer, counted from the lens substrate side, was vacuum-deposited with ZrO ₂ having a refractive index of 2.00 until the optical film thickness became 0.12λ.

[0058] Furthermore, thereon, the refractive index as the fifth layer was vacuum deposited to a SiO ₂ of 1.47 optical film thickness becomes 0.06. The sixth layer is ZrO with a refractive index of 2.00
₂ is vacuum-deposited until the optical film thickness becomes 0.25λ,
The seventh layer was formed by vacuum-depositing SiO ₂ having a refractive index of 1.47 until the optical film thickness became 0.25λ.

FIG. 3 shows the spectral reflectance characteristics of the plastic lens of Example 3 thus obtained. Figure 3
, The vertical axis represents the spectral reflectance (%) and the horizontal axis represents the wavelength (n
m).

[Comparative Example 1] As a lens substrate, a refractive index n
A commercially available plastic lens having d = 1.60 was prepared, and a thin film was formed by a vacuum vapor deposition method with a designed central wavelength λ of λ = 535 nm. As the conditions at this time, the lens substrate is set in a rotating dome in a vacuum container in which the pressure in the vacuum container is always adjusted to 1.0 × 10 ⁻⁵ torr, and the hard coat film is vacuum-deposited. After that, vacuum deposition of the antireflection film was performed.

A hard coat film is first formed on the surface of this lens substrate, and this hard coat film is a film for increasing the surface hardness of the plastic lens. The hard coat film, which is the first layer counting from the lens substrate side, is a layer made of SiO ₂ having a refractive index of 1.47, and was vacuum-deposited until the physical film thickness became 1.0 μm.

Further, an antireflection film for preventing reflection between the hard coat film and air is formed on the hard coat film. Also in Comparative Example 1, as in the case of Example 1, Example 2 and Example 3 described above, Si was used as the antireflection film.
A film having a four-layer structure in which O ₂ layers and ZrO ₂ layers are alternately provided is formed. First, a layer corresponding to the second layer counted from the lens substrate side was vacuum-deposited with ZrO ₂ having a refractive index of 2.00 until the optical film thickness became 0.12λ.

Further thereon, SiO ₂ having a refractive index of 1.47 was vacuum-deposited as a third layer until the optical film thickness became 0.06λ. The fourth layer is ZrO with a refractive index of 2.00
₂ is vacuum-deposited until the optical film thickness becomes 0.25λ,
The fifth layer was formed by vacuum-depositing SiO ₂ having a refractive index of 1.47 until the optical film thickness became 0.25λ.

The spectral reflectance characteristics of the plastic lens of this Comparative Example 1 obtained in this way are shown in FIG. Figure 4
, The vertical axis represents the spectral reflectance (%) and the horizontal axis represents the wavelength (n
m).

[Comparative Example 2] As a lens substrate, a refractive index n
A commercially available plastic lens with d = 1.56 was prepared, and a thin film was formed by a vacuum vapor deposition method with a designed central wavelength λ of λ = 535 nm. As the conditions at this time, the lens substrate is set in a rotating dome in a vacuum container in which the pressure in the vacuum container is adjusted to always be 1.0 × 10 ⁻⁵ torr, and vacuum deposition of the hard coat film is performed. After that, vacuum deposition of the antireflection film was performed.

A hard coat film is first formed on the surface of this lens substrate, and this hard coat film is a film for increasing the surface hardness of the plastic lens. The hard coat film, which is the first layer counting from the lens substrate side, is a layer made of SiO ₂ having a refractive index of 1.47, and was vacuum-deposited until the physical film thickness became 1.0 μm.

Further, an antireflection film for preventing reflection between the hard coat film and air is formed on the hard coat film. Also in Comparative Example 2, as in the case of Example 1, Example 2 and Example 3 described above, Si was used as the antireflection film.
A film having a four-layer structure in which O ₂ layers and ZrO ₂ layers are alternately provided is formed. First, a layer corresponding to the second layer counted from the lens substrate side was vacuum-deposited with ZrO ₂ having a refractive index of 2.00 until the optical film thickness became 0.12λ.

Further thereon, SiO ₂ having a refractive index of 1.47 was vacuum-deposited as a third layer until the optical film thickness became 0.06λ. The fourth layer is ZrO with a refractive index of 2.00
₂ is vacuum-deposited until the optical film thickness becomes 0.25λ,
The fifth layer was formed by vacuum-depositing SiO ₂ having a refractive index of 1.47 until the optical film thickness became 0.25λ.

The spectral reflectance characteristics of the plastic lens of Comparative Example 2 thus obtained are shown in FIG. In FIG. 5, the vertical axis represents the spectral reflectance (%) and the horizontal axis represents the wavelength (nm).
Is.

As is clear from FIGS. 1 to 5 shown above, the plastic lenses of Examples 1, 2 and 3 of the present invention did not generate ripples in the spectral reflection characteristics, and the comparative examples The plastic lenses of Comparative Example 1 and Comparative Example 2 all have ripples in the spectral reflection characteristics.

As described above, when the hard coat layer and the antireflection layer are formed on the surface of the plastic lens (thin plastic lens having a high refractive index), the plastic lens of the present invention forms the precoat layer. Therefore, the antireflection performance is excellent and the occurrence of interference fringes is suppressed.

[0072]

As described above, according to the present invention, when a hard coat layer and an antireflection layer are formed on the surface of a plastic substrate (plastic substrate having a high refractive index), the antireflection performance is improved. It is possible to obtain an optical article that is excellent in the generation of interference fringes.

[Brief description of drawings]

FIG. 1 is a diagram showing a spectral reflectance characteristic of a plastic lens in a first embodiment of the present invention.

FIG. 2 is a diagram showing a spectral reflectance characteristic of a plastic lens according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a spectral reflectance characteristic of a plastic lens according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a spectral reflectance characteristic of a conventional plastic lens given as a comparative example 1.

5 is a diagram showing a spectral reflectance characteristic of a conventional plastic lens given as a comparative example 2. FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuki Ohashi 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation (72) Inventor Shigeo Itagaki 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Ceremony Company Nikon

Claims (5)

[Claims] 1. An optical article having a hard coat layer made of at least an inorganic substance on a plastic substrate and a single-layer or multi-layer antireflection layer on the hard coat layer, comprising: a surface of the substrate and the hard coat layer; An optical article having an antireflection layer, comprising a single-layer or multi-layer precoat layer between them. 2. The optical article according to claim 1, wherein the precoat layer is made of an inorganic material. 3. The optical article according to claim 2, wherein the precoat layer is made of one or more substances selected from oxides, fluorides, silicides, and sulfides of metals or semimetals. 4. The optical article according to claim 1, wherein the optical article having the antireflection layer is a plastic lens. 5. The refractive index of the plastic substrate is n ₁ ,
When the refractive index of the hard coat layer is n ₂ and the design center wavelength is λ, the precoat layer has a refractive index of (n ₁ × n ₂ ) ^1/2
And the film thickness is λ / 4, and the optical article according to any one of claims 1 to 4.