JP2010140008A - Optical article and method for manufacturing the same - Google Patents

Abstract

A transparent optical article excellent in antistatic property, antireflection property and chemical resistance and a method for producing the same are provided.
An eyeglass lens includes a lens substrate, a hard coat layer provided on the surface of the lens substrate, and an antireflection film provided on the hard coat layer. Configured. The antireflection film 130 includes a low refractive index layer 131, 133, 135, 138 having a refractive index in the visible light region of 1.3 to 1.5, and a high refractive index having a refractive index of 1.8 to 2.60. The layers 132, 134, and 136 and the amorphous silicon layer 137 are formed.
[Selection] Figure 1

Description

  The present invention relates to an optical article having an antireflection film having antistatic properties and a method for producing the same.

Conventionally, an optical article such as a spectacle lens has been provided with an antireflection film on the surface of a lens base material in order to prevent ghost and flicker. The antireflection film is formed as a so-called multilayer antireflection film formed by alternately laminating substances having different refractive indexes on the surface of the lens substrate on which the hard coat layer is laminated.
In order to further impart antistatic properties, lenses in which a conductive layer is included in a part of the antireflection film have been proposed (for example, Patent Documents 1 and 2). In particular, an indium tin oxide (ITO) layer is preferably used as such a conductive layer.

JP 2002-031701 A Japanese Patent Laid-Open No. 2004-341052

  However, although the indium tin oxide (ITO) layer is excellent in transparency and conductivity, there is a problem that it is easily attacked by chemicals such as acid and alkali. For example, human sweat is a salty acid, which may erode the ITO layer.

  Accordingly, an object of the present invention is to provide a transparent optical article excellent in antistatic property, antireflection property and chemical resistance and a method for producing the same.

The optical article of the present invention is an optical article comprising an antireflection film in which a low refractive index layer and a high refractive index layer are alternately laminated on the surface of a transparent substrate, and the antireflection film includes: An amorphous silicon layer is included.
According to the optical article of the present invention, since the antireflection film includes an amorphous silicon layer having conductivity, an antistatic effect can be exhibited. Furthermore, the amorphous silicon layer contained in the antireflection film hardly inhibits the transparency and antireflection properties of the antireflection film. The amorphous silicon layer is excellent in durability against erodible substances such as acids and alkalis.
Therefore, according to the present invention, an optical article excellent in antistatic property, antireflection property and chemical resistance can be provided. When the low refractive index layer is a SiO ₂ layer, it is not an impurity because the main component of the amorphous silicon layer is the same Si, and is excellent in interlayer adhesion. Furthermore, even if the amorphous silicon layer becomes an oxide due to a change with time, it is only an SiO ₂ layer although there is a decrease in conductivity, and no problem is caused in terms of optical and quality.

In the present invention, the total thickness of the amorphous silicon layer is preferably 1 nm or more and 10 nm or less, and more preferably 2 nm or more and 7 nm or less. Here, the amorphous silicon layer does not need to be a single layer (single layer), and may be a plurality of layers.
According to the present invention, since the total thickness of the amorphous silicon layer is 1 nm or more, sufficient conductivity can be exhibited, and since the total thickness of the amorphous silicon layer is 10 nm or less, the antireflection effect is adversely affected. Never give.

In the present invention, the sheet resistance is preferably 5 × 10 ¹² Ω / □ or less, more preferably 1 × 10 ¹² Ω / □ or less, and further preferably 1 × 10 ¹¹ Ω / □ or less. .
According to this invention, since the sheet resistance of the optical article is 5 × 10 ¹² Ω / □ or less, a sufficient antistatic effect can be expected.

In the present invention, the substrate is preferably plastic or glass.
According to this invention, since the base material is plastic or glass, it is possible to provide an optical article that is transparent, excellent in antireflection properties and antistatic properties, and hardly affected by chemicals such as acids and alkalis.

In the present invention, the optical article is preferably a lens.
According to the present invention, it is possible to provide various optical lenses that have excellent antireflection properties and antistatic properties and are less susceptible to chemicals such as acids and alkalis. Examples of such optical lenses include spectacle lenses, telescope lenses, microscope lenses, camera lenses, and optical window materials.

The optical article manufacturing method of the present invention is any of the optical article manufacturing methods described above, wherein the antireflection film is formed on the surface of the substrate by vacuum deposition.
According to the manufacturing method of the present invention, since the antireflection film is formed by vacuum deposition including the conductive layer contained therein, an optical article having the effects described above can be manufactured with a simple apparatus and method. Further, when the low refractive index layer is an SiO ₂ layer, Si grains as a material can be commonly used in the vacuum vapor deposition machine, so that the formation of the amorphous silicon layer is very simple. Even when the SiO ₂ layer is formed using SiO ₂ grains, it is simple because it is only necessary to separately prepare Si grains as a material.
In addition, when depositing the amorphous silicon layer in the present invention, oxygen, water, hydrogen, or the like may be included as a residual gas in the vacuum deposition apparatus. Therefore, the amorphous silicon layer may be amorphous silicon containing some oxidation or hydrogen due to reaction with the residual gas. In addition, when forming an amorphous silicon layer, oxygen may be introduced into the chamber in some cases. At this time, the surface of the amorphous silicon layer may undergo an oxidation reaction. The amorphous silicon layer may be sandwiched between oxide layers such as a TiO ₂ layer and a SiO ₂ layer. Therefore, the amorphous silicon layer may be slightly oxidized due to oxygen diffusion at the multilayer film interface.
Thus, even in the case of amorphous silicon containing some oxidation or hydrogen, the effect of the present invention is obtained and is within the scope of the present invention.

1 is a cross-sectional view of a spectacle lens according to an embodiment of the present invention. The schematic diagram of the vapor deposition apparatus used for manufacture of the anti-reflective film in the said embodiment. (A) Sectional drawing which shows the state which made the metal electrode contact | abut to a plastic lens, (B) The top view which shows the state which made the metal electrode contact | abut to a plastic lens. The graph which shows the relationship between the film thickness of an amorphous silicon layer and sheet resistance in a present Example. Schematic which shows the apparatus for giving a damage | wound to the lens surface in order to perform the chemical-resistance test in a present Example. Schematic which shows the driving | running state of the apparatus for providing a damage | wound on the said lens surface. Schematic which shows the determination method of the swelling in a present Example. (A) A schematic diagram showing a state without swelling on the lens surface, (B) A schematic diagram showing a state with swelling on the lens surface. The graph which shows the spectral reflectance in each thickness of the amorphous silicon layer in a present Example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a spectacle lens is described as an example of an optical article, but the present invention is not limited to this.
FIG. 1 is a cross-sectional view of the spectacle lens of the present embodiment.
In FIG. 1, a spectacle lens 100 includes a lens base 110, a hard coat layer 120 provided on the surface of the lens base 110, and an antireflection film 130 provided on the hard coat layer 120. Configured.
The hard coating layer 120 may be omitted, and the antireflection film 130 may be formed directly on the lens substrate 110. Further, in order to improve impact resistance, the lens substrate 110 and the hard coating layer 120 A primer layer may be provided at the interface. A water repellent layer or a layer having antifogging properties may be formed on the antireflection film 130 as necessary.

(1. Lens substrate)
The lens substrate 110 is not particularly limited, but includes (meth) acrylic resin, styrene resin, polycarbonate resin, allyl resin, allyl carbonate resin such as diethylene glycol bisallyl carbonate resin (CR-39), vinyl resin, polyester resin. , Polyether resins, urethane resins obtained by reaction of isocyanate compounds with hydroxy compounds such as diethylene glycol, thiourethane resins obtained by reacting isocyanate compounds with polythiol compounds, and having one or more disulfide bonds in the molecule (thio ) A transparent resin obtained by curing a polymerizable composition containing an epoxy compound can be exemplified.

(2. Hard coat layer)
The hard coat layer 120 only needs to improve the scratch resistance, which is the original function. For example, examples of the material used for the hard coat layer 120 include melamine resins, silicone resins, urethane resins, acrylic resins, and the like, but a hard coat layer using a silicone resin is most preferable. For example, a hard coat layer is provided by applying and curing a coating composition comprising metal oxide fine particles and a silane compound. This coating composition may contain components such as colloidal silica and a polyfunctional epoxy compound.
Specific examples of the metal oxide fine particles include SiO ₂ , Al ₂ O ₃ , SnO ₂ , Sb ₂ O ₅ , Ta ₂ O ₅ , CeO ₂ , La ₂ O ₃ , Fe ₂ O ₃ , ZnO, WO ₃ and ZrO _2. Fine particles made of metal oxides such as In ₂ O ₃ and TiO ₂ or composite fine particles made of two or more kinds of metal oxides are colloidally dispersed in a dispersion medium such as water, alcohol or other organic solvent. Can be raised.
As a method for forming such a hard coat layer 120, the composition of the hard coat layer 120 is applied by a dipping method, a spinner method, a spray method, or a flow method, and then heated and dried at a temperature of 40 to 200 ° C. for several hours. The method of doing can be illustrated.

(3. Antireflection film)
The anti-reflective film 130 alternates between a low refractive index layer having a refractive index of 1.3 to 1.5 and a high refractive index layer having a refractive index of 1.8 to 2.60 in the visible light region (550 nm). Are laminated. The antireflection film 130 includes a first layer 131, a second layer 132, a third layer 133, a fourth layer 134, a fifth layer 135, and a sixth layer 136 that are arranged in order from the lens substrate 110 side to the outside. The seventh layer is composed of an amorphous silicon layer 137 and an eighth layer 138, of which the first layer 131, the third layer 133, the fifth layer 135 and the eighth layer 138 are low refractive index layers, The second layer 132, the fourth layer 134, and the sixth layer 136 are high refractive index layers.

The first layer 131, the second layer 132, the third layer 133, the fourth layer 134, the fifth layer 135, the sixth layer 136, and the eighth layer 138 which are the low refractive index layer and the high refractive index layer of the antireflection film 130. Examples of inorganic substances used in the above are SiO ₂ , ZrO ₂ , TiO ₂ , TiO, Ti ₂ O ₃ , Ti ₂ O ₅ , Al ₂ O ₃ , TaO ₂ , Ta ₂ O ₅ , NbO, Nb ₂ O _3. NbO ₂ , Nb ₂ O ₅ , CeO ₂ , Y ₂ O ₃ , SnO ₂ , MgF ₂ , WO ₃ , HfO ₂ , or a mixture thereof. These inorganic substances are used alone or in a mixture of two or more. For example, the first layer 131, the third layer 133, the fifth layer 135, and the eighth layer 138 are SiO ₂ layers, and the second layer 132, the fourth layer 134, and the sixth layer 136 are TiO ₂ layers. Can do.
The low refractive index layer made of silicon dioxide (SiO ₂ ) has a refractive index n in the visible light region of 1.40 to 1.50. The high refractive index layer made of titanium oxide (TiO ₂ ) has a refractive index in the visible light region (550 nm) of 2.10 to 2.60.

As a material used for the amorphous silicon layer 137 which is the seventh layer, so-called amorphous silicon is used.
The thickness of the amorphous silicon layer 137 is preferably in the range of 1 nm to 10 nm, more preferably 2 nm to 7 nm. If the thickness of the amorphous silicon layer 137 is less than 1 nm, a sufficient antistatic effect cannot be obtained. Further, even if the thickness of the amorphous silicon layer 137 exceeds 10 nm, the antistatic property cannot be improved so much, and the transparency may be deteriorated.
Further, the amorphous silicon layer 137 may not be formed continuously as a whole, and may be, for example, a layer formed in a discontinuous island shape. In this case, the average thickness of the whole layer should just be in said range.
The amorphous silicon layer 137 may be formed at any position of the antireflection film 130 that is a multilayer film. Desirably, a position that does not become the outermost layer of the antireflection film 130 is desirable to prevent oxidation on the surface. For example, an amorphous silicon layer may be formed in the high refractive index layer 136.

  In this embodiment, the antireflection film 130 is not necessarily limited to eight layers. For example, the first layer 131 is on the lens substrate side, and the low refractive index layer and the high refractive index are provided. Other layers may be used as long as the layers are alternately arranged. For example, the first layer, the second layer, the third layer, the fourth layer, and the fifth layer may be composed of six layers of an amorphous silicon layer and a sixth layer.

In the present embodiment, the first layer 131, the third layer 133, the fifth layer 135, and the eighth layer 138 that are low refractive index layers include SiO ₂ , the second layer 132 that is a high refractive index layer, the fourth layer 134, and TiO ₂ was used for the sixth layer 136, and amorphous silicon was used for the amorphous silicon layer 137.

In order to form each layer of the antireflection film 130, a normal ion assist (IAD) vapor deposition method is preferably used. However, it may be determined appropriately whether or not ion assist is performed.
FIG. 2 is a schematic diagram of the vapor deposition apparatus 10 used for manufacturing the antireflection film 130 of the present embodiment.
In FIG. 2, the vapor deposition apparatus 10 is a so-called electron beam vapor deposition apparatus including a vacuum vessel 11, an exhaust device 20, and a gas supply device 30.

  The vacuum vessel 11 is a base material support on which an electron gun 17 for heating and dissolving (evaporating) the evaporation material of the evaporation sources (crucibles) 12 and 13 in which the evaporation material is set in the vacuum vessel 11 and the lens substrate 110 are placed. A base 15, a substrate heating heater 16 for heating the lens substrate 110, an ion gun 18 for performing ion assist, and the like are provided. Further, a cold trap for removing moisture remaining in the vacuum vessel 11 and an apparatus for managing the film thickness are provided as necessary. As an apparatus for managing the film thickness, for example, an optical film thickness meter, a crystal resonator film thickness meter, or the like can be used.

The evaporation sources 12 and 13 are crucibles in which a vapor deposition material is set, and are disposed at the lower part of the vacuum vessel 11. As the evaporation material, it is for TiO ₂ deposition TiO _Y particle (0 ≦ Y ≦ 2), SiO
₂ SiO ₂ grains or Si grains are preferably used for film formation, and Si grains are preferably used for amorphous silicon film formation.

  The base material support base 15 is a support base on which a predetermined number of lens base materials 110 are placed, and is disposed in the upper part of the vacuum container 11 facing the evaporation sources 12 and 13. The base material support 15 preferably has a rotation mechanism in order to ensure the uniformity of the antireflection film formed on the lens base material 110 and to improve mass productivity.

The substrate heating heater 16 is formed of, for example, an infrared lamp, and is disposed on the upper portion of the substrate support 15 or on the lower portion (not shown). The substrate heating heater 16 heats the lens substrate 110 to degas or remove moisture from the lens substrate 110, thereby improving the adhesion with the film formed on the surface of the hard coat layer 120.
As the base material heater 16, a resistance heater or the like may be used in addition to the infrared lamp.

The exhaust device 20 is a device that exhausts the inside of the vacuum vessel 11 to a high vacuum, and includes a cryopump or a turbo molecular pump 21 and a pressure control valve 22 that keeps the pressure inside the vacuum vessel 11 constant.
The gas supply device 30 includes a gas container 310 containing a gas such as Ar, N ₂ , and O ₂ and a flow rate control device 320 that controls the flow rate of the gas. The gas built in the gas container 310 is introduced into the vacuum container 11 via the flow rate control device 320.
The pressure gauge 50 detects the pressure in the vacuum vessel 11. Based on the pressure value detected by the pressure gauge 50, the pressure control valve of the exhaust device 20 is controlled by a control signal from a control unit (not shown), and the pressure in the vacuum vessel 11 is maintained at a predetermined pressure value.

The lens substrate 110 on which the hard coat layer 120 is formed is placed on the substrate support 15 in the vacuum container 11 described above, and the vapor deposition apparatus 10 is operated.
Here, in forming the second layer 132, the fourth layer 134, and the sixth layer 136 constituting the high refractive index layer, the film forming conditions are that the acceleration voltage is 5 to 10 kV and the current value is 50 to 50 with an electron gun. The material in the crucible is heated and evaporated at 500 mA to form a thin film. During film formation, ion assist is performed by the ion gun 18 at an acceleration voltage of 200 to 1000 V and a current value of 100 to 500 mA.
In order to form the first layer 131, the third layer 133, the fifth layer 135, and the eighth layer 138 to be low refractive index layers, a crucible with an acceleration voltage of 5 to 10 kV and a current value of 50 to 500 mA by an electron gun. The material inside is heated and evaporated to form a thin film. Although ion assist is not performed here, ion assist may be performed in a timely manner as in the case where the high refractive index layer is configured.

Next, the manufacturing process will be described.
First, a lens base material 110 (hereinafter referred to as a lens base material 110) coated with a hard coat layer 120 is mounted on the base material support base 15, and heat treatment is performed with the base material heater 16, so that the lens base material 110. Evaporate water adhering to.
Next, ion cleaning using an oxygen ion beam is performed on the surface of the lens substrate 110. Specifically, the ion gun 18 is used to irradiate the surface of the lens substrate 110 with an energy of several hundreds eV to remove organic substances adhering to the surface of the lens substrate 110. By this method, the adhesion of the film formed on the surface of the lens substrate 110 can be strengthened. Note that the same treatment may be performed using an inert gas such as argon (Ar), xenon (Xe), or nitrogen (N ₂ ) instead of the oxygen ion beam, or irradiation with oxygen radicals or oxygen plasma. Also good.

Then, after the inside of the vacuum vessel 11 is sufficiently exhausted by the exhaust device 20, the antireflection film 130 is formed. Specifically, SiO ₂ grains, TiO ₂ grains, and Si grains, which are vapor deposition materials, are set in the evaporation sources 12 and 13 when each layer is formed, and the vapor deposition material is heated by irradiating the vapor deposition material with an electron gun (not shown). Evaporate and deposit on the surface of the lens substrate 110.
Each layer is formed while measuring the film thickness, and the evaporation is stopped when the desired film thickness is reached.
In addition, in order to form each layer, you may use normal vacuum evaporation, ion plating, sputtering, etc. besides this.
Each layer is formed as described above to form the antireflection film 130.

(4. Effects of this embodiment)
According to the present embodiment described above, the following operational effects can be obtained.
In the above embodiment, since the amorphous silicon layer 137 made of amorphous silicon is provided on a part of the antireflection film 130, the antistatic effect can be sufficiently obtained without impairing the antireflection effect and transparency. Moreover, the amorphous silicon layer 137 is amorphous silicon, and can sufficiently exhibit resistance to chemicals having high reactivity (erosion) such as acid and alkali. In particular, when the thickness of the conductive layer is 1 to 10 nm, more preferably 2 to 7 nm, these effects can be exhibited more preferably.

(5. Modifications)
The best configuration, method, and the like for carrying out the present invention have been disclosed above, but the present invention is not limited to this.

  For example, in the above embodiment, the amorphous silicon layer 137 is a single layer, but may be a plurality of layers. For example, it may be formed between the fifth layer 135 and the sixth layer 136 or between the fourth layer 134 and the fifth layer 135. In that case, what is necessary is just to set so that the thickness of the whole amorphous silicon layer may be set to 1-10 nm. Furthermore, the antireflection film 130 including the amorphous silicon layer 137 may be provided not only on one side of the lens substrate 110 but also on both sides.

  Moreover, there is no restriction | limiting in the formation method of the amorphous silicon layer 137, It is possible to select suitably according to various conditions, such as a composition and thickness, of an amorphous silicon layer. For example, besides ion-assisted deposition, CVD (low pressure CVD, plasma CVD, etc.), high-frequency sputtering, direct current sputtering, ion plating, molecular beam deposition (MBE), and ion beam sputtering can be used. . Furthermore, you may combine 2 or more types of methods among these.

  In the above embodiment, an antifouling layer made of an organosilicon compound containing fluorine may be formed on the antireflection film 130 for the purpose of improving the water / oil repellency of the lens surface. As the organosilicon compound containing fluorine, for example, a fluorine-containing silane compound can be preferably used. The fluorine-containing silane compound can be applied on the organic antireflection film by using a water repellent treatment solution dissolved in an organic solvent and adjusted to a predetermined concentration. As a coating method, a dipping method, a spin coating method, or the like can be used. It is also possible to form the antifouling layer by using a dry method such as vacuum deposition after filling the water repellent liquid into the metal pellet. Although the film thickness of an antifouling layer is not specifically limited, 0.001-0.5 micrometer is preferable. More preferably, it is 0.001-0.03 micrometer. If the antifouling layer is too thin, the water and oil repellency effect will be poor, and if it is too thick, the surface will be sticky, which is not preferable. In addition, when the antifouling layer becomes too thick, the above-mentioned range is preferable because not only the antireflection effect is lowered but also the sheet resistance is increased.

  Furthermore, in the above embodiment, the optical article has been described as an eyeglass lens, but the optical article of the present invention may be other than an eyeglass lens, for example, a camera lens, a telescope lens, a microscope lens, various optical lenses, and an optical window material. Alternatively, an optical element such as a prism may be used.

  Next, examples of the present invention will be described. The present invention is not limited to the following examples, but includes modifications and improvements as long as the object of the present invention can be achieved.

[Examples 1-8, Comparative Examples 1-6, Reference Example]
First, the following plastic lenses for eyeglasses (hereinafter also simply referred to as “lenses”) were produced. Specifically, Seiko Super Sovereign (manufactured by Seiko Epson Corporation) was used as a lens substrate with a hard coat layer, and an antireflection film was formed by (ion-assisted) vapor deposition as follows.
After the lens substrate with a hard coat layer was washed with acetone, heat treatment at about 70 ° C. was performed in a vacuum chamber to evaporate water adhering to the lens substrate with a hard coat layer.
Next, ion cleaning was performed on the surface of the lens substrate with a hard coat layer (see the embodiment). After completion of the ion cleaning, the film was sufficiently evacuated, and an antireflection film (including an amorphous silicon layer) was formed to have a film thickness shown in Table 1 by an electron beam vacuum deposition method. The film forming conditions for each layer are as follows. The film thickness was measured at the time of film formation using an optical film thickness meter. In Example 8, only white glass (B270) was used as a base material, and the film was formed in the same process.

(Deposition of low refractive index layer)
Ion assist was not performed, and the first layer, the third layer, the fifth layer, and the eighth layer were formed as low refractive index layers (SiO ₂ layers) by vacuum deposition. The film formation rate was 2.0 nm / sec.

(Deposition of high refractive index layer)
Ion-assisted deposition was performed while introducing oxygen gas, and the second layer, the fourth layer, and the sixth layer were formed as high refractive index layers (TiO ₂ layers). The film formation rate was 0.4 nm / sec.

(Formation of amorphous silicon layer)
The seventh layer was formed as an amorphous silicon layer.
<Amorphous silicon layer: Examples 1 to 8>
Film formation was performed by vacuum deposition without performing ion assist. The film formation rate was 0.1 nm / sec.
<ITO layer: Comparative Examples 1-6>
It is an ITO layer for comparison, and was formed as a seventh layer by ion-assisted vacuum deposition. Specifically, film formation was performed under the following conditions. The acceleration voltage of the electron gun was 7 kV, the current value was 50 mA, and the ITO material was heated and evaporated. During the deposition, ion assist is performed to promote the oxidation of the ITO layer. Oxygen gas was introduced into the ion gun at a rate of 35 cc per minute and discharged within the ion gun to irradiate an oxygen ion beam with an acceleration voltage value of 500 V and an ion beam current value of 250 mA. At this time, 15 cc of oxygen gas was introduced into the vacuum vessel per minute.
As a reference example, a lens on which an antireflection film including neither an amorphous silicon layer nor an ITO layer was formed was also manufactured (the thickness of the seventh layer was zero).

The materials used for forming each of the layers described above are as follows.
SiO ₂ : Granular SiO ₂
TiO ₂ : granular TiO ₂
Si: Granular Si
ITO: Sintered material in which 5% by mass of tin oxide (SnO ₂ ) is mixed with indium oxide (InO ₂ ) The refractive index of each layer is almost determined by the film material, and the refractive index at a wavelength of 550 nm is SiO ₂ is 1.46 and TiO ₂ is 2.43.

The lenses of Examples 1 to 8, Comparative Examples 1 to 6, and Reference Example were evaluated for transparency, antistatic properties, chemical resistance, and moisture resistance by the following methods.
(transparency)
I looked at each lens through the fluorescent light. And the difference with the lens of a reference example was evaluated by the following references | standards. The results are shown in Table 2.
○: The same transparency as the lens of the reference example. Δ: A slight decrease in transparency is observed compared to the lens of the reference example. ×: The transparency is inferior to the lens of the reference example.

(Antistatic property)
The sheet resistance of each lens surface was measured using the metal electrodes shown in FIGS. 3 (A) and 3 (B). FIG. 3A is a cross-sectional view showing a state in which the metal electrode is in contact with the lens 1, and FIG. 3B is a top view showing a state in which the metal electrode is in contact with the lens 1.
As shown in FIGS. 3A and 3B, the metal electrode 61 is brought into contact with the convex surface 1A of the lens 1, a voltage of 1 kV is applied between the electrodes, and the value of the electric resistance at this time is measured to measure the sheet. It was resistance. This sheet resistance is a measure of the antistatic property, and if it is 5 × 10 ¹² Ω / □ or less, a temporary antistatic property is recognized, and if it is 1 × 10 ¹¹ Ω / □ or less, there is a considerably excellent antistatic property. It can be said. The measurement results are shown in FIG. ◆ (a-Si) is Examples 1 to 8, ■ (ITO) is Comparative Examples 1 to 6, and ▲ is a reference example without a conductive layer. Further, Table 2, wherein the sheet resistance of 1 × 10 ¹¹ Ω / □ of the following lenses ◎, a 5 × 10 ¹² Ω / □ or less of the lens than this value ○, × lenses exceeds this value As shown. MITSUBISHI CHEMICAL CORPORATION HIRESTA-UP MCP-HT450 was used as a measuring instrument.

(chemical resistance)
The lens surface was scratched as follows, and then chemical immersion was performed. And the chemical resistance was evaluated according to the following criteria by observing the presence or absence of peeling (film peeling) of the antireflection film 130 on the treated lens. The evaluation results are shown in Table 2.
○: The antireflection film 130 is not peeled. ×: The antireflection film 130 is severely peeled. (1) Scratch method The lens 1 for evaluation is attached to the drum tube 2 as shown in FIGS. Affix four on the inner wall and put the nonwoven fabric 3 and sawdust 4 for scratching. Then, after covering, the drum tube 2 is rotated at 30 rpm for 30 minutes as shown in FIG.
(2) Method of immersion in chemical solution While maintaining a chemical solution imitating human sweat (a solution of 50 g of lactic acid and 100 g of sodium chloride in 1 L of pure water) at 50 ° C., the lens after the step (1) is immersed for 100 hours. .

(Moisture resistance)
The produced lens was left in an environment of constant temperature and humidity (60 ° C., 98% RH) for 8 days, and the presence or absence of swelling was determined by the following method. In Table 2, “no swelling” is indicated by ○, and “swelling” is indicated by ×.
<Method of judging swelling>
Observe the light reflected from the front or back of the lens. Specifically, the reflected light of the fluorescent lamp 71 on the convex surface 1A of the lens 1 is observed as shown in FIG. 7, and the contour of the image of the reflected light 72 is clearly observed as shown in FIG. If it is possible, it is determined that there is no swelling, and as shown in FIG. 8B, if the contour of the image of the reflected light 73 is blurred or can be observed, it is determined that there is swelling.

〔Evaluation results〕
From the results in Table 2, it can be seen that the lenses of Examples 1 to 5 and 8 having an amorphous silicon layer thickness of 1 to 6 nm are excellent in transparency and are not inferior to those of the reference example. In Examples 6 and 7 in which the thickness of the amorphous silicon layer is 8 nm and 10 nm, the transparency is slightly inferior to that of the reference example, and there is no practical problem.
From FIG. 4, it can be seen that the lenses of Examples 2 to 8 have extremely low sheet resistance of 1 × 10 ¹¹ Ω / □ or less. Therefore, it can be said that the lenses of Examples 2 to 8 have excellent antistatic properties. In addition, it should be noted that the sheet resistance is about 5 × 10 ¹² Ω / □ even when the thickness of the amorphous silicon layer is 1 nm, as in Example 1, which is a level at which an antistatic effect can be expected. Moreover, from the results in Table 2, it can be seen that the lenses of Examples 1 to 8 are all excellent in chemical resistance and moisture resistance and have durability. On the other hand, in all the lenses of Comparative Examples 1 to 6, the ITO layer was eroded by the acid, the antireflection film 130 was severely peeled off, and the antireflection function was also deteriorated. Moreover, when the film thickness of the ITO layer is 10 nm or more as in Comparative Examples 5 and 6, swelling is severe and it is understood that moisture resistance deteriorates.

  Moreover, in order to confirm that there was no change in the optical characteristic of the plastic lens produced in Examples 1-8, the spectral reflectance was measured and the spectral reflectance curve shown in FIG. 9 was obtained. As can be seen from FIG. 9, when Examples 1 to 8 (the thickness of the amorphous silicon layer is 1 nm to 10 nm) and the reference example (the thickness of the amorphous silicon layer is 0 nm) are compared, the thickness of the amorphous silicon layer is large. Even if it became, there was no big difference regarding a reflectance and it has confirmed that there was no problem in an optical characteristic. In addition, it can be seen from Example 8 that the same effect can be obtained even when glass is used as the lens substrate instead of plastic.

  The present invention can be used not only for eyeglass lenses but also for various optical lenses, optical window materials, etc., including camera lenses, telescope lenses, and microscope lenses.

  DESCRIPTION OF SYMBOLS 110 ... Lens base material, 120 ... Hard coat layer, 130 ... Antireflection film, 131 ... 1st layer (low refractive index layer), 132 ... 2nd layer (high refractive index layer), 133 ... 3rd layer (low refraction) Index layer), 134 ... fourth layer (high refractive index layer), 135 ... fifth layer (low refractive index layer), 136 ... sixth layer (high refractive index layer), 137 ... seventh layer (amorphous silicon layer) 138: Eighth layer (low refractive index layer)

Claims (6)

An optical article comprising an antireflection film in which a low refractive index layer and a high refractive index layer are alternately laminated on the surface of a transparent substrate,
An optical article, wherein the antireflection film contains an amorphous silicon layer. The optical article according to claim 1.
An optical article, wherein the total thickness of the amorphous silicon layer is 1 nm or more and 10 nm or less. The optical article according to claim 1 or 2,
An optical article having a sheet resistance of 5 × 10 ¹² Ω / □ or less. In the optical article according to any one of claims 1 to 3,
An optical article, wherein the substrate is plastic or glass. An optical article according to any one of claims 1 to 4, wherein the optical article is a lens. A method for manufacturing an optical article according to any one of claims 1 to 5,
A method for producing an optical article, wherein the antireflection film is formed on a surface of the substrate by vacuum deposition.

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