JPH11183705A - Optical member having reflection preventing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical member in which a reflection preventing film excellent in durability where a reflection color becomes a green reflection color and easy in the control of its film thickness is formed on a plastic lens base material. SOLUTION: This optical member made of a plastic and its provided with a reflection preventing film constituted of a base material in which a refractive index is >=1.45 and <1.58, a 1st layer having a refractive index in the range of 1.37 to 1.48 and optical film thickness in the range of 0.60 to 1.25λ (provided that λis a value in the range of 400 to 650 nm), a 2nd layer having a refractive index in the range of 1.90 to 2.10 and optical film thickness in the range of 0.20 to 0.40λ, a 3rd layer having a refractive index in the range of 2.15 to 2.30 and optical film thickness in the range of 0.15 to 0.35λ and a 4th layer having a refractive index in the range of 1.37 to 1.48 and optical film thickness in the range of 0.20 to 0.35λ which are successively laminated from the side of the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection film provided on an optical member, in particular, a synthetic resin substrate used for an eyeglass lens or the like.

[0002]

2. Description of the Related Art Synthetic resins such as plastics are lighter in weight, more excellent in workability and impact resistance than glass, and have properties of being easily dyed. For this reason, plastics have recently attracted attention as a material for optical members that replace glass, such as eyeglass lenses.

[0003] However, since this plastic has a lower hardness than glass, it is easily damaged. In addition, there are disadvantages such as being easily attacked by a solvent, being charged and adsorbing dust, and having low heat resistance. Therefore, for use as an optical member, a film that compensates for these drawbacks is formed on a plastic substrate.

For example, in a spectacle lens, a primer layer for improving impact resistance, a hard coat layer for protecting the substrate surface, and an antireflection film for suppressing surface reflection of the lens are provided on a plastic lens substrate. Is formed.

It is desirable that the antireflection film also be a film that makes up for the above-mentioned disadvantages of plastic. For example, in an optical article having a multilayer antireflection film disclosed in Japanese Patent Publication No. 6-85001, a multilayer antireflection film consisting of four layers is provided on the upper side of a plastic transparent substrate, and is sequentially arranged from the substrate side. The first layer is a layer mainly containing zirconium oxide, the second layer is a layer mainly containing silicon dioxide, the third layer is a layer mainly containing titanium oxide, and the fourth layer is a layer mainly containing titanium oxide. The layer is a layer containing silicon dioxide as a main component. According to this, an antireflection film having particularly excellent adhesion strength and durability can be obtained.

[0006]

However, among the layers constituting the antireflection film, a layer having a thickness of 0.15λ or less is included (λ represents a set wavelength, and here, 450 to 550 nm. There.) When the thickness of the layer is small, it is difficult to control the thickness of the layer when manufacturing the antireflection film. As a result, the productivity of the optical member itself may be reduced.

In addition, in an antireflection film formed on an inexpensive plastic lens substrate having a low refractive index of 1.45 or more and less than 1.58, scratch resistance, chemical (solvent) resistance, and antistatic properties There has not been anything that can compensate for the drawbacks of plastics, such as poor heat resistance and durability.

In recent years, it has been desired to enhance the fashionability of spectacle lenses and to give a high-quality appearance to camera lenses. In general, the reflection color of lenses is made green. It is preferred.

Therefore, the refractive index is 1.45 or more and 1.58 or more.
The emergence of an optical member provided with an anti-reflection film having excellent durability, a green reflection color, and easy control of the thickness of a layer constituting the film on a plastic lens substrate having a value of less than Was desired.

[0010]

SUMMARY OF THE INVENTION Therefore, an optical member according to the present invention is an optical member comprising a plastic base material and an antireflection film formed on the base material. The value of the refractive index is in the range of 1.45 or more and less than 1.58, and the antireflection film is a first layer, a second layer, a third layer, and a fourth layer sequentially laminated from the base material side. Including the first
The layer has a refractive index value in the range of 1.37 to 1.48 and an optical film thickness of 0.60λ to 1.25λ (provided that
λ is a design center wavelength, and a value within a range of 400 nm to 650 nm. ), And the second layer has a refractive index value in the range of 1.90 to 2.10 and an optical film thickness in the range of 0.20λ to 0.40λ. A third layer having a refractive index value in the range of 2.15 to 2.30 and an optical film thickness in the range of 0.15λ to 0.35λ; Means that the value of the refractive index is 1.37
１1.48 and the optical film thickness is 0.20
The layer is characterized by being in the range of λ to 0.35λ.

Among the layers constituting the antireflection film, the first
Of the layers from the layer to the fourth layer, the thickness of the layer having the smallest optical film thickness can be 0.15λ or more. Therefore, it is possible to easily control the film thickness when the film is formed on the substrate made of the synthetic resin. For this reason, the productivity of the optical member can be improved.

When the material constituting the first and fourth layers having a refractive index in the range of 1.37 to 1.48 is SiO ₂ among the layers constituting the antireflection film,
Since SiO ₂ is a material having high hardness, an antireflection film having excellent scratch resistance can be formed.

Further, by forming the anti-reflection film as described above, the reflection color of the optical member can be made green.

Preferably, a hard coat layer or a primer layer and a hard coat layer are provided between the substrate and the antireflection film.

If the hard coat layer is provided, the scratch resistance of the optical member can be further improved. Also,
If the primer layer is provided, the impact resistance of the optical member can be further improved. For this reason, the durability of the optical member can be improved.

The second layer is made of ZrO ₂ and Ta ₂ O.
_It is preferable to use one of the _five materials or a mixture of both materials.

The material constituting the second layer is ZrO ₂
Besides or _{Ta 2 O 2, HfO 2,} CeO 2, Al 2 O
₃ , metal oxides such as La ₂ O ₃ and Nd ₂ O ₃ can be used. However, in order to improve the durability of the optical member, it is preferable to use ZrO ₂ and Ta ₂ O ₅ .

The material constituting the third layer is TiO ₂
Only, a binary mixture of TiO ₂ and ZrO ₂ or Ta ₂ O ₅ , or TiO ₂ , ZrO ₂ and Ta ₂
It is preferable to use a mixture of three components of O ₅ . The material constituting the third layer is a high refractive index material having a refractive index of 2.15. In consideration of the durability of the antireflection film and the optical member, the above-described materials are preferably used.

[0019]

Embodiments of the present invention will be described below.

The optical member of the present invention is an optical member comprising a base made of plastic and an antireflection film formed on the base. The value of the refractive index of the substrate is in the range of 1.45 or more and less than 1.58. Further, the antireflection film includes a first layer, a second layer, a third layer, and a fourth layer sequentially laminated from the side of the base material.

Examples of the polymer compound used as the material of the plastic base material include, for example, a copolymer of an epoxy resin, an acrylate ester and / or a methacrylate ester (including a copolymer with another vinyl monomer. .), Polyamide, polyester (including so-called alkyd resin and unsaturated polyester resin), various amino resins (including urea resin), urethane resin, polyvinyl acetate, polyvinyl alcohol, transparent vinyl chloride resin, and cellulose resin And ethylene glycol bisallyl carbonate polymer (CR39).

The first layer of the antireflection film has a refractive index value of 1.
It is in the range of 37 to 1.48, and the optical film thickness is 0.4.
The layer is in the range of 60λ to 1.25λ. here,
λ is a design center wavelength, and a value within a range of 400 nm to 650 nm. The second layer has a refractive index value of 1.90-2.
10 and the optical film thickness is 0.20λ-
The third layer has a refractive index value in the range of 2.15 to 2.30 and an optical film thickness in the range of 0.15λ to 0.35λ. And the fourth layer has a refractive index value in the range of 1.37 to 1.48 and an optical film thickness in the range of 0.20λ to 0.35λ.

Here, if the material constituting the first layer and the fourth layer is SiO ₂ , since SiO ₂ is a material having high hardness, an antireflection film having excellent scratch resistance can be formed.

The second layer is made of ZrO ₂ and Ta ₂ O.
_It is preferable to use one of the _five materials or a mixture of both materials.

The material constituting the second layer is ZrO ₂
Besides or _{Ta 2 O 2, HfO 2,} CeO 2, Al 2 O
₃ , metal oxides such as La ₂ O ₃ and Nd ₂ O ₃ can be used. However, in order to improve the durability of the optical member, it is preferable to use ZrO ₂ and Ta ₂ O ₅ .

The material constituting the third layer is TiO ₂
Only, a binary mixture of TiO ₂ and ZrO ₂ or Ta ₂ O ₅ , or TiO ₂ , ZrO ₂ and Ta ₂
It is preferable to use a mixture of three components of O ₅ . The material constituting the third layer is a high refractive index material having a refractive index of 2.15. In consideration of the durability of the antireflection film and the optical member, the above-described materials are preferably used.

A hard coat layer or a primer layer and a hard coat layer are preferably provided between the substrate and the antireflection film.

If the hard coat layer is provided, the scratch resistance of the optical member can be further improved. Also,
If the primer layer is provided, the impact resistance of the optical member can be further improved. For this reason, the durability of the optical member can be improved.

The hard coat film is preferably an organosilicon compound represented by the following general formula (I) or a hydrolyzate thereof.

Formula (I): R ¹ _a R ² _b Si (OR ³ ) _{4- (a + b) wherein} R ¹ is a functional group or an unsaturated double bond having 4 to 4 carbon atoms. 14 organic groups, and R ² has 1 to 1 carbon atoms.
6 is a hydrocarbon group or a halogenated hydrocarbon group, R ³ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group or an acyl group, a and b are each 0 or 1,
And a + b is 1 or 2.

Of the compounds of the general formula (I), those in which R ¹ has an epoxy group as a functional group are preferably used.

Each of the compounds represented by the above general formula has an epoxy group, and is therefore also called epoxysilane.

Specific examples of epoxysilane include, for example, γ-glycidoxypropyltrimethoxysilane, γ
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriacetoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane , Β- (3,4-
Epoxycyclohexyl) ethyltriethoxysilane and the like.

Further, among the compounds of the general formula (I), R ¹
Examples of compounds other than those having an epoxy group as a functional group (including those having a = 0) include, for example, the following. Methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-methacryloxypropyltrimethoxysilane, aminomethyltrimethoxysilane, 3
-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3,3,3-trifluoropropyl Various trialkoxysilanes such as trimethoxysilane, trisiloxysilane or trialkoxyalkoxysilane compounds.

The above-mentioned compounds of the general formula (I) are all trifunctional examples (a + b = 1) having three OR ³ groups bonded to a Si atom, but have two OR ³ groups. Certain (b = 2) bifunctional equivalents can of course also be used. Examples of bifunctional equivalent compounds include dimethyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, methylvinyldimethoxysilane, dimethyldiethoxysilane, and the like.

The compounds of the general formula (I) may be used alone or in combination of two or more according to the purpose.

In particular, when a bifunctional compound is used, it is preferable to use it in combination with a trifunctional compound. When they are used together, 2> a + b> 1 on average.

Further, it is also possible to use a compound corresponding to tetrafunctional of a + b = 0 in combination. Examples of tetrafunctional equivalents include methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate, n-butyl silicate, t-butyl silicate, s
ec-butyl silicate and the like.

When these compositions are used, it is possible to add inorganic fine particles for controlling the refractive index, improving the hardness, preventing interference fringes, and imparting an antistatic effect. In addition, various solvents such as water, lower alcohol, acetone, ether, ketone, and ester can be used in order to improve the flowability at the time of coating and improve the smoothness of the cured film.

Examples of the above inorganic fine particles include zinc oxide, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, beryllium oxide, antimony oxide, tungsten oxide, cerium oxide, iron oxide, tin oxide and tungsten oxide. Fine particles of inorganic fine particles such as composite fine particles can be used.

These fine particles can be used not only alone, but also in a mixture or a solid solution of two or more kinds, if necessary. The mixture in the present invention refers to a state in which a plurality of different substances are present while maintaining the structure of each substance, and a solid solution is different from a plurality of different substances. It refers to what exists by forming a chemical bond.

In particular, titanium oxide, antimony oxide,
Tungsten oxide, cerium oxide, zirconium oxide,
When tin oxide is used, the refractive index of the composition can be increased, and when a substrate having a high refractive index is used and a film is formed thereon, interference fringes can be suppressed. Becomes possible.

The particle diameter of the fine particles is preferably from 1 to 200 nm, particularly preferably from 5 to 100 nm. If it is smaller than this, the production is difficult, the stability of the fine particles themselves is poor, and the effect is small. If it is larger than this, the stability of the coating composition, the transparency and the smoothness of the coating film, etc. will be reduced.

The method of applying the hard coat layer includes brush coating,
Conventional coating methods such as dipping, roll coating, spray coating, and flow coating can be used. At this time, the application conditions are determined mainly by the properties of the vehicle.

By forming the hard coat layer on the base material and forming the antireflection film of the present invention on the hard coat layer, the scratch resistance of the optical member can be further improved.

Further, heretofore, it has been formed by a wet method in which a liquid polymer (hard coat liquid) containing an organosilicon compound as a main component as a hard coat as described above as a main component is applied to the lens substrate surface. Instead of such a wet method, the hard coat layer can be formed by a CVD method which is a dry method.

The hard coat layer formed by the CVD method is formed of a material containing Si and O. Preferably, the CV contains at least one of a Si-based compound and / or a Ti-based compound, and has a refractive index changing in a thickness direction.
It is preferable that the modified layer formed by the method D is formed on a lens substrate. Further, a modified layer whose refractive index is changed in the thickness direction is provided on the base material, has a relatively thicker film than the modified layer, and has a constant refractive index. A hard coat layer containing Si and O can be formed by a CVD method. Organic compounds containing Si used in the production process of the modified layer and the hard coat layer include tetraethoxysilane, dimethoxysilane,
Methylmethoxysilane, tetramethoxysilane, ethyltrimethoxysilane, diethoxydimethylsilane, methyltriethoxysilane and the like are preferably used.

The organic compounds containing Ti used in the first step include tetramethoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, tetra-n
-Titanium propoxy, tetra-n-butoxytitanium, tetraisobutoxytitanium, tetra-sec-butoxytitanium, tetra-t-butoxytitanium, tetradiethylaminotitanium and the like are preferably used.

One of these organic compounds containing Si and Ti may be used alone, or two or more thereof may be used in combination.

The thickness of the hard coat layer is preferably larger than 0.4 μm and smaller than 5 μm. The thickness of the denatured layer is preferably larger than 100 nm and smaller than 900 nm. Chemical vapor deposition is a method of discharging by applying thermal energy and electric energy to a source gas, promoting a reaction in a non-thermal equilibrium state in a plasma atmosphere, and depositing a thin film on a substrate.
Commonly used types include a parallel plate electrode type, a capacitive coupling electrode type, and an inductive coupling type. In particular, in the present invention, it is preferable to form by a plasma enhanced CVD method in which an electric field and a magnetic field are applied in parallel to the main plane of the substrate.

The modified layer which may be provided on the substrate of the optical member of the present invention is a layer which is formed on the surface of the substrate and whose refractive index gradually changes in the thickness direction from the substrate side. And the composition ratio of the substance in the modified layer is changed. Further, it has been confirmed that the impact resistance is improved by providing the modified layer. This is due to the fact that the internal stress of the hard coat layer was increased because the thickness of the conventional hard coat layer was 3 μm or more, but the modified layer as in the present invention was placed between the substrate and the hard coat layer. By providing this, the internal stress remaining in the hard coat layer can be reduced. Therefore, in order to reduce internal stress,
There is an effect that cracks and the like caused by heat resistance can be avoided.

By forming the hard coat layer on the base material by the CVD method and forming the anti-reflection film of the present invention on the hard coat layer, it is possible to obtain a more preferable reflection color only by the dry method and to obtain an excellent resistance to light. An optical member having abrasion properties can be obtained.

Further, if a primer layer for improving adhesion and impact resistance is formed between the plastic substrate and the hard coat layer, a plastic lens having more excellent impact resistance can be obtained. As a material of the primer layer, a polyurethane resin, an epoxy resin, a polyacetal resin, or the like is preferable.

The composition of the primer layer comprising a urethane solution comprises an active hydrogen-containing compound and a polyisocyanate.

Here, the urethane solution may be a mixture of an active hydrogen-containing compound and a polyisocyanate, or a polymer. Further, an emulsion containing urethane as a main component may be used.

It is also possible to form a primer layer made of polyvinyl acetal or cross-linked polyvinyl acetal. The primer layer made of polyvinyl acetal dissolves polyvinyl acetal as a main component, a hydrolyzable organosilane compound or a hydrolysis condensate thereof, an aluminum or titanium alkoxide compound or an aluminum or titanium alkoxide diketonate compound, and a curing catalyst. It can be formed by applying the primer composition thus obtained to the surface of a plastic lens and subjecting it to heat treatment.

The thickness of the primer layer is 0.1 to 5 μm, preferably 0.2 to 3 μm at the stage after thermosetting. If the thickness of the primer layer is less than 0.1 μm, the impact resistance is not sufficiently improved, and if it is more than 5 μm, there is no problem in terms of the impact resistance, but the heat resistance and surface accuracy are reduced.

The primer solution may contain inorganic fine particles as added to the hard coat layer. The average particle diameter of the inorganic fine particles or the composite of these inorganic oxides is 1 to 300 nm, preferably 1 to 50 nm. If the average particle diameter exceeds 300 nm, fogging of the lens occurs due to light scattering.

The amount of the inorganic oxide fine particles to be added in the primer composition is 0.1 to 30% by weight as a solid content, but the refractive index of the cured primer film matches or is very close to the refractive index of the plastic lens. The type and the amount of the inorganic oxide fine particles are adjusted so as to be as follows.

The thickness of the primer layer is from 0.01 to
It is preferably 30 μm. Particularly preferably, 1-2
0 μm.

The method of applying the resin for forming the primer layer is appropriately selected from known methods such as a spinner method, a dipping method and a spray method, and can be formed by a dry method such as a vacuum evaporation method.

On the antireflection film of the present invention, a drainage preventing layer can be formed. As the material, an organic polysiloxane-based polymer or an organic-containing cured product made of a polymer obtained by polymerizing a perfluoroalkyl base material-containing compound is preferably used, and a mono- to tri-functional silazane compound having a fluorine atom and a siloxazan compound having a fluorine atom are preferably used. And an alkoxy compound having a fluorine group. As a forming method, a vacuum evaporation method or a CVD method, which is an immersion method or a dry method,
It can be formed by a sputtering method or the like.

By forming the anti-reflection film on the anti-reflection film of the present invention as described above, it is possible to prevent the lens surface from being stained and to prevent water droplets from adhering, thereby making the reflection color more vivid. It is possible to maintain a high-quality reflection color for a long period of time.

In one embodiment of the optical member of the present invention, when the value of the refractive index of the substrate is 1.45 and the design center wavelength λ is 480 nm, the refractive index of the first layer is There composed of SiO ₂ is 1.47, the optical thickness of the first layer and 0.75?, the refractive index of the second layer 2.
The second layer is made of ZrO ₂ having a thickness of 0.000.
The third layer is made of Ti having a refractive index value of 2.25.
Composed of O _2, the thickness of the third layer and 0.20Ramuda, and a fourth layer composed of SiO ₂ and the refractive index is 1.47, the thickness of the fourth layer 0. One having an antireflection film formed as 27λ can be mentioned.

In this optical member, an antireflection film having excellent antireflection characteristics and scratch resistance can be provided on the substrate. When forming an anti-reflection film, a vacuum evaporation method is usually used. However, since the thickness of the layer constituting the film is 0.20λ even at the thinnest, control of the film thickness is easier than before. It can be carried out. With such a configuration, the reflection color of the optical member can be green.

Further, the value of the refractive index of the substrate is set to 1.50,
When the design center wavelength λ is 480 nm, the first layer is made of SiO ₂ having a refractive index value of 1.47, the thickness of the first layer is 1.00λ, and the second layer is the refractive index. Is made of ZrO ₂ whose value is 2.00, the thickness of this second layer is 0.32λ, and the third layer is made of TiO ₂ whose refractive index value is 2.25. The fourth layer has a thickness of 0.18λ, and the fourth layer has a refractive index value of 1.47.
Constituted by _2, or an optical member having an antireflection film formed with the film thickness of the fourth layer as 0.27Ramuda.

Also in this optical member, an antireflection film having the above-described characteristics can be provided on the substrate. In addition, since the thinnest layer among the layers constituting the anti-reflection film can be made thicker than in the related art, the thickness can be easily controlled when the anti-reflection film is formed. Therefore, a stable film can be formed with good reproducibility. Further, the reflection color of the optical member having such a configuration is also green.

Further, the value of the refractive index of the substrate is set to 1.56,
When the design center wavelength λ is 520 nm, the first layer is made of SiO ₂ having a refractive index value of 1.47, the thickness of the first layer is 1.00λ, and the second layer is the refractive index. Is made of ZrO ₂ whose value is 2.00, the thickness of this second layer is 0.30λ, and the third layer is made of TiO ₂ whose refractive index value is 2.25. The fourth layer has a thickness of 0.16λ, and the fourth layer has a refractive index of 1.47.
_The optical member may be made of 2 and provided with an antireflection film having a thickness of the fourth layer of 0.26λ.

Also in this optical member, an antireflection film having the above-described characteristics can be provided on the substrate. In addition, a stable antireflection film with good reproducibility can be formed more easily than before. Also in the case of this configuration, the reflection color of the optical member can be green.

[0070]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 As Example 1, a specific example of the optical member of the present invention will be described. In this example, the optical member is a lens used for spectacles or the like.

First, a cleaned plastic lens substrate (CR-39) having a refractive index of 1.45 is set in a vacuum chamber, and the degree of vacuum in the chamber is set to 1.0 × 10 ⁻⁵ To.
Exhaust until rr.

Under the condition of a vacuum degree of 1.0 × 10 ⁻⁵ Torr, SiO ₂ was deposited on the lens substrate by electron beam.
Deposit to a thickness of 450 ° to form a first layer.
The thickness of this layer is such that the design center wavelength λ is 480 nm,
The thickness is set to 0.75λ.

Next, oxygen or air is introduced into the chamber to reduce the degree of vacuum to 5.0 × 10 ⁻⁵ Torr, and then ZrO ₂ is deposited on the first layer by an electron beam to a thickness of 720 °. A second layer of (0.30λ) is formed.

Oxygen is further introduced into the chamber to make the degree of vacuum in the chamber 1 × 10 ⁻⁴ Torr. After this, the second
A layer is formed on the upper side of the layer while oxidizing Ti ₃ O ₅ using an electron beam. This allows the thickness to be 430 mm (0.2
A third layer of TiO ₂ (0λ) is formed.

Next, the introduction of oxygen was stopped, and the chamber was evacuated until the degree of vacuum in the chamber became 1.0 × 10 ⁻⁵ Torr or less. Then, SiO ₂ was formed on the third layer using an electron beam. Is deposited until the thickness becomes 880 ° (0.27λ) to form a fourth layer.

As a result, an optical member having an antireflection film composed of four layers on the lens substrate is obtained.

FIG. 1 shows the spectral reflection characteristics of this optical member. Here, since the purpose is to use this optical member as a spectacle lens, the reflection characteristics from 400 nm to 700 nm, which is the wavelength range in which the spectacle lens is used, are measured by using a spectrophotometer (trade name: U- 400
0). FIG. 1 shows the obtained results.
In the graph, the horizontal axis represents the wavelength, and the vertical axis represents the reflectance.

According to this characteristic curve, the reflectance in the wavelength range of about 420 nm to about 650 nm can be suppressed to 1% or less. Also, within this wavelength range, 50
One peak was observed near the wavelength of 0 nm, and this peak portion had a reflectance of about 1%. Therefore, it was confirmed that the antireflection film obtained in Example 1 had preferable antireflection characteristics when used as a spectacle lens.

In this wavelength range, 500n
One peak was observed near the wavelength of m, and this peak portion had a reflectance of about 1%. In addition, 500
A wavelength near nm indicates green light. Therefore, when the reflectance of the film has a peak wavelength in the wavelength range around 500 nm, the reflection color is green.

The reflection color was green when visually observed.

2. Example 2 In Example 2, an antireflection film formed on a lens substrate using a plastic lens substrate having a higher refractive index than the plastic lens substrate used in Example 1 and changing the thickness of each layer. An example of a film will be given. Hereinafter, points different from the first embodiment will be described, and detailed description of the same points as the first embodiment will be omitted.

A plastic lens substrate having a refractive index of 1.50, for example, CR39 (trade name, manufactured by PPG) was set in a vacuum chamber, and the degree of vacuum in the chamber was 1. It is evacuated to 0 × 10 ^{over 5} Torr.

Thereafter, the center wavelength λ of the design is placed on the lens substrate.
Is set to 480 nm, and the first to fourth layers are sequentially deposited on the lens substrate using an electron beam.

In this example, the degree of vacuum in the chamber is set to 1.0
At 10 × 10 ⁻⁵ Torr, the first layer of SiO ₂ is formed to have a thickness of 3270 ° (design center wavelength λ is 480 nm and optical layer thickness is 1.00λ). The second layer is
As in Example 1, under a vacuum of 5.0 × 10 ⁻⁵ Torr,
A ZrO ₂ layer is formed with a thickness of 770 ° (0.32λ). The third layer has a degree of vacuum of 1.0 × 10 ⁻⁴ Torr and T
An iO ₂ layer is formed with a thickness of 385 ° (0.18λ). In the fourth layer, the degree of vacuum is returned to 1.0 × 10 ⁻⁵ or less, and S
An iO ₂ layer is formed with a thickness of 880 ° (0.27λ).

Thus, the optical member of the second embodiment is obtained.

FIG. 2 shows the spectral reflection characteristics of this optical member. According to FIG. 2, the reflectance in the wavelength range from about 420 nm to about 650 nm can be suppressed to within 1%. One peak is observed around the wavelength of 500 nm, and this peak portion shows a reflectance of about 1% or more. It can be confirmed that the antireflection film obtained in Example 2 has preferable antireflection characteristics when used as a spectacle lens.

The reflection color of the optical member of Example 2 visually confirmed was green.

3. Example 3 Example 3 is an example of an antireflection film using a plastic lens substrate having a larger refractive index than the plastic lens substrates used in Examples 1 and 2 and changing the center wavelength of the design. I will.

MCR10, a plastic lens substrate having a refractive index of 1.56 (trade name, manufactured by Mitsubishi Rayon Co., Ltd.)
Is set in a vacuum chamber, and the chamber is evacuated until the degree of vacuum in the chamber reaches 1.0 × 10 ⁻⁵ Torr.

Thereafter, in the same manner as in Examples 1 and 2, an antireflection film consisting of four layers is formed on the lens substrate in order.

First, the degree of vacuum in the chamber is 1.0 × 10
It is evacuated to ^{over 5} Torr.

Thereafter, the designed center wavelength λ is placed on the lens substrate.
Is set to 520 nm, and the first to fourth layers are sequentially deposited on the lens substrate by using an electron beam.

In this example, the degree of vacuum in the chamber is set to 1.0
The first layer of SiO ₂ is formed at a thickness of 3540 ° (at an optical layer thickness of 1.00λ) at × 10 ^-5 Torr. The second layer is 5.0 × 10 ⁻⁵ Torr as in the first embodiment.
Under a vacuum degree, a layer of ZrO ₂ is formed to a thickness of 780 ° (0.
30λ). The third layer has a vacuum degree of 1.0 × 10
^-4 Torr, a layer of TiO _{2 with} a thickness of 370 ° (0.1
6λ). The fourth layer has a degree of vacuum of 1.0 × 10 ^−5.
Returning to the following, the layer of SiO ₂ is 920 ° thick (0.26 °).
λ).

As a result, the optical member of the third embodiment is obtained.

FIG. 3 shows the spectral reflection characteristics of this optical member. According to FIG. 3, the reflectance in the wavelength range from about 420 nm to about 670 nm can be suppressed to within 1%. One peak is observed near the wavelength of 480 nm, and this peak portion indicates a reflectance of about 1% or more. Thereby, it can be confirmed that the antireflection film obtained in Example 3 has preferable antireflection characteristics when used as an eyeglass lens.

Further, the reflection color of the optical member of Example 3 visually confirmed was green.

4. Example 4 In Example 4, the plastic lens substrate used in Example 2, CR39 having a refractive index of 1.50 (trade name)
An anti-reflection film is formed on a structure in which a primer layer for improving the impact resistance of the optical member is formed on the upper surface of the optical member, and a hard coat layer for improving the scratch resistance of the optical member is formed on the primer layer. An optical member obtained by providing is described as an example.

First, after a primer layer is formed on the surface of the lens substrate (CR39) by dipping, an organic silicon-based hard coat layer is formed on the primer layer by dipping. After this, 11
Heat treatment is performed for 4 hours at a temperature of 0 ° C. to cure the structure.

Thereafter, the structure is set in a vacuum chamber and the chamber is evacuated until the degree of vacuum in the chamber reaches 1.0 × 10 ⁻⁵ Torr.

Next, the upper surface of the structure was irradiated with Ar gas using a Kauffman-type ion beam at 300 V for 20 m.
A ion beam irradiation is performed at A for 60 seconds. Thereby, the adhesion between the hard coat layer on the surface of the structure and the antireflection film provided in the next step can be improved.

The degree of vacuum in the chamber is set to 1.0 × 10 ⁻⁵ Torr
Then, SiO ₂ is deposited on the hard coat layer with an electron beam to a thickness of 3270 ° (the design center wavelength λ is 480 nm, and the thickness of the set layer is 1.00λ) to form the first layer. Form.

Next, oxygen is introduced into the chamber, the degree of vacuum is adjusted to 5.0 × 10 ⁻⁵ Torr, and ZrO ₂ is formed on the first layer by an electron beam to a thickness of 770 ° (0.32λ). Deposit to form a second layer.

Further, oxygen is introduced into the chamber, the degree of vacuum is set to 1.0 × 10 ⁻⁴ Torr, and Ti ₃ O ₅ is oxidized and deposited by using an electron beam, whereby a thickness of 385 is obtained.
Forming a third layer of TiO ₂ in Å (0.18λ).

The introduction of oxygen into the chamber is stopped, and the chamber is evacuated until the degree of vacuum becomes 1.0 × 10 ⁻⁵ or less. Thereafter, a thickness of 880 ° (0.2 mm) is formed on the third layer by using an electron beam.
7λ) to form a fourth layer.

Thus, a four-layer antireflection film can be formed. On the antireflection film, a drainage prevention layer is formed by using a resistance heating evaporation method.

Thus, the optical member of the fourth embodiment is obtained.

FIG. 4 shows the spectral reflection characteristics of this optical member. According to FIG. 4, the reflectance in the wavelength range from about 420 nm to about 680 nm can be suppressed to within 1%.

One peak is observed near the wavelength of 500 nm, and this peak portion indicates a reflectance of about 1%. Therefore, it can be confirmed that the antireflection film obtained in Example 4 has preferable antireflection characteristics when used as a spectacle lens.

Further, the reflection color of the optical member of Example 4 visually confirmed was green.

Further, in Example 4, since a primer layer, a hard coat layer and a drainage preventing layer were provided in addition to the lens substrate and the antireflection film, the impact resistance, the scratch resistance and the water resistance were further improved. An optical member excellent in quality can be obtained.

Further, several durability tests were performed on the optical member of Example 4 for the optical member.

First, the abrasion resistance is determined by observing the surface of the anti-reflection film by reciprocating the surface of the anti-reflection film 10 times with # 0000 steel wool and visually rubbing the surface according to the following criteria. A state with almost no damage was designated as A rank, a state with slight damage as B rank, and a state with noticeable damage as C rank.

Next, the adhesion is evaluated by a cross-cut tape test according to JIS-Z-1522. Use a knife to cut 10 grids on the surface of the anti-reflection coating.
After making zero pieces and strongly pressing a cellophane adhesive tape on this square, the tape is suddenly pulled and peeled off.
The operation of pressing and peeling the tape is performed five times, and the number of squares in which the antireflection film is completely left is counted.

The heat resistance was evaluated by placing the structure in an oven at 80 ° C., allowing the structure to stand for 5 minutes, removing the structure, and visually observing the presence or absence of cracks and the state of peeling of the film.

The structure was placed in warm water at 80 ° C., left for 5 minutes, taken out, and the presence or absence of cracks and the state of peeling of the film were visually observed.

As a result, it was confirmed that the optical member of Example 4 had an abrasion resistance of rank A, and had excellent characteristics.

Further, as a result of the cross cut tape test, 1
Since all 100 of the 00 cells remained, it was confirmed that the adhesion was excellent.

Further, since no change in the state of the antireflection film was observed after the heat resistance test and the hot water resistance test, the heat resistance and the hot water resistance were also excellent.

Here, as a comparative example with respect to Example 4,
Three examples are given. These examples are antireflection films designed to have a reflection color of green, and the film configuration is changed from that of the antireflection film of the present invention.

[0120] 5. Comparative Example 1 As Comparative Example 1, the refractive index was 1.5 as in Example 4.
An anti-reflection film having a four-layer structure is formed on a plastic lens having a hard lens layer of an organic silicon system provided on the surface of CR39, which is a plastic lens substrate having a thickness of 0, under the same vapor deposition conditions and using the same material as in Example 4. To form In addition, 4
The optical thickness of each of the first to third layers in the layer structure is a value outside the range of the optical thickness of the present invention.

Here, the center wavelength λ of the design is set to 500 nm.
The refractive index of the hard coat layer is made of SiO ₂ having a refractive index of 1.47, and the thickness of the layer is 1840 ° (0.54
a first layer is a lambda), the refractive index is composed of ZrO ₂ of 2.00, a second layer thickness of the layer is 530Å (0.21λ), the refractive index is composed of TiO ₂ of 2.25 A third layer having a thickness of 800 ° (0.36λ) and a refractive index of 1.
47 SiO _{2 with} a layer thickness of 920 ° (0.2
7λ) to form a four-layer antireflection film.

The characteristics (scratch resistance, adhesion, heat resistance, hot water resistance) of the obtained antireflection film of Comparative Example 1 were measured in the same manner as in Example 4.

First, the scratch resistance rank of Comparative Example 1 was B, and it was found that the scratch resistance was inferior to that of Example 4.

The results of adhesion, heat resistance and hot water resistance were the same as those of the optical member of Example 4.

As a result, it was confirmed that the abrasion resistance was changed by changing the thickness of the layer constituting the antireflection film.

6. Comparative Example 2 In Comparative Example 2, a five-layer antireflection conventionally used on a plastic lens similar to that of Example 4 (a hard coat layer is provided on the surface of CR39 having a refractive index of 1.50). Form a film. The vapor deposition conditions are the same as in Example 4, and the central wavelength λ of the design is 510 nm.

In this example, S was sequentially formed on the hard coat layer.
a first layer made of iO ₂ and having a layer thickness of 1750 ° (optical thickness is set to 0.50λ); and a second layer made of ZrO ₂ and having a layer thickness of 380 ° (0.15λ). Layer and SiO ₂ , and the thickness of the layer is 175 ° (0.05%).
λ) and ZrO _{2 having} a thickness of 6
A fourth layer having a thickness of 40 ° (0.25λ) and a fifth layer made of SiO ₂ and having a thickness of 870 ° (0.25λ) are laminated.

The properties (scratch resistance, adhesion, heat resistance, hot water resistance) of the obtained antireflection film of Comparative Example 2 were measured in the same manner as in Example 4.

As a result, the scratch resistance rank was B,
It is slightly inferior to Example 4. The same results as in Example 4 were obtained for the adhesiveness, heat resistance and hot water resistance.

The antireflection film of Comparative Example 2 has excellent antireflection characteristics. However, the same degree of scratch resistance as in Example 4 cannot be obtained. In forming the antireflection film, it was difficult to control the thickness of the third layer in particular because the optical thickness was 0.05λ. Therefore, the productivity is lower than that of the optical member of the fourth embodiment.

7. Comparative Example 3 In Comparative Example 3, an antireflection film having a five-layer structure was formed on the same plastic lens as in Example 4. In this example, the first to third layers of the five-layer structure form a laminated structure of a layer made of a low-refractive-index material and a layer made of a high-refractive-index material, so that a medium- The layers are equivalent layers. The total thickness of the first to third layers is λ / 4. Therefore, the outermost layer (fifth layer) is made of a material having a low refractive index, and has an optical film thickness of λ / 4.
Layer) made of a high-refractive-index substance and having an optical thickness of λ / 4, and three layers (first to third layers) inside the fourth layer.
Layer) is substantially composed of a medium refractive index material, and has an optical thickness of λ /
Since this is the fourth layer, the film configuration has an ideal anti-reflection effect that is well known in the art.

In this example, S was sequentially formed on the hard coat layer.
a first layer made of iO ₂ and having an optical film thickness of 0.05λ; a second layer made of ZrO ₂ having a refractive index of 2.00 and having an optical film thickness of 0.15λ; 47 SiO
₂ , a third layer having an optical film thickness of 0.05λ and ZrO ₂ having a refractive index of 2.00 and an optical film thickness of 0.2
A fourth layer having a wavelength of 5λ and a fifth layer made of SiO ₂ having a refractive index of 1.47 and having an optical thickness of 0.25λ are laminated.

The characteristics (scratch resistance, adhesion, heat resistance, hot water resistance) of the obtained antireflection film of Comparative Example 3 were measured in the same manner as in Example 4.

As a result, the rank indicating the scratch resistance was C, and it was found that this antireflection film was a film having poor scratch resistance. In addition, the same results as those of the optical member of Example 4 were obtained in terms of adhesion, heat resistance, and hot water resistance.

As a result, the antireflection film of Comparative Example 3 was excellent in antireflection properties, but was inferior in scratch resistance.
In forming this antireflection film, it was difficult to control the film thickness of the first layer and the third layer, particularly, since the optical thickness was 0.05λ. Therefore, it was confirmed that the optical member of Comparative Example 3 was inferior in productivity to the optical member of Example 4.

The durability of the optical members of Examples 1 to 3 was excellent in abrasion resistance as in Example 4. By providing these optical members with a primer layer, a hard coat layer, and the like as in Example 4, a member having more excellent durability such as adhesion can be obtained.

[0137]

As is apparent from the above description, according to the optical member of the present invention, an antireflection film is provided as a four-layer structure film on a synthetic resin base material. The thickness of the layer having the smallest optical thickness among the first to fourth layers constituting the antireflection film can be set to 0.15λ or more.

For this reason, it is possible to easily control the film thickness when forming a film on a substrate made of a synthetic resin.
Therefore, the productivity of the optical member can be improved.

Further, the antireflection film has excellent antireflection characteristics and also has excellent durability such as scratch resistance.

Further, since the reflection color is green, a favorable appearance can be obtained by using the optical member having the antireflection film for an eyeglass lens or a camera lens. Therefore, the fashionability of a product using this lens can be enhanced, and a sense of quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a spectral reflection characteristic diagram of an optical member according to a first embodiment.

FIG. 2 is a spectral reflection characteristic diagram of an optical member according to a second embodiment.

FIG. 3 is a spectral reflection characteristic diagram of an optical member according to a third embodiment.

FIG. 4 is a spectral reflection characteristic diagram of the optical member of Example 4.

Claims (2)

[Claims] 1. An optical member comprising a base material made of plastic and an antireflection film formed on the base material, wherein the base material has a refractive index value of 1.45 or more and less than 1.58. Wherein the antireflection film is sequentially laminated from the side of the substrate,
The first layer includes a first layer, a second layer, a third layer, and a fourth layer, wherein the first layer has a refractive index value in a range of 1.37 to 1.48 and an optical thickness of 0.3. 60λ to 1.25λ
(However, λ is a design center wavelength, 400 nm to 650 n
The value is within the range of m. ), Wherein the second layer has a refractive index value in the range of 1.90 to 2.10 and an optical film thickness in the range of 0.20λ to 0.40λ. A third layer having a refractive index value in the range of 2.15 to 2.30 and an optical film thickness in the range of 0.15λ to 0.35λ; and The fourth layer is a layer having a refractive index value in a range of 1.37 to 1.48 and an optical film thickness in a range of 0.20λ to 0.35λ. Optical members. 2. The optical member according to claim 1, wherein a hard coat layer is provided between the base material and the antireflection film.
Alternatively, an optical member provided with a primer layer and a hard coat layer.