JP2010072635A - Optical article and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical article excellent in antistatic effect, antireflection property and endurance, and to provide a method for manufacturing the optical article. <P>SOLUTION: An eyeglass lens includes: a lens base 110; a hard coat layer 120 disposed on the surface of the lens base 110; and an antireflection layer 130 disposed on the hard coat layer 120. The antireflection layer 130 is prepared by successively laminating 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 2.4. The antireflection layer 130 is composed of a first layer 131, a second layer 132, a third layer 133, a fourth layer 134, a fifth layer 135, a first transparent conductive layer 136 as a sixth layer, a seventh layer 137, a second transparent conductive layer 138 as an eighth layer and a ninth layer 139 which are arranged in the order outward from the lens base 110 side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plastic optical article and a method for manufacturing the same.

Conventionally, an optical article such as a spectacle lens is provided with an antireflection layer on the surface of a lens base material in order to prevent ghost and flicker. The antireflection layer is formed as a so-called multilayer antireflection layer 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 addition, lenses in which a transparent conductive layer is included in a part of the antireflection layer to prevent charging are disclosed (for example, Patent Documents 1, 2, and 3).

Japanese Patent Laid-Open No. 2004-341052 Japanese Patent Laid-Open No. 11-149063 JP-A-4-50801

However, as described in Patent Documents 1, 2, and 3, the transparent conductive layer is usually formed of indium tin oxide (ITO) or the like with a thickness of about 20 nm or more, and these materials include gas and moisture. However, although the antistatic effect can be obtained, the surface is swollen and the reflected light on the lens surface appears to be distorted. Here, the swelling is a state in which the outline of the reflected light image is blurred or blurred when the reflected light on the surface of the lens is observed (see FIG. 7B).
Furthermore, there is also a problem that the durability of the lens is lowered due to worsening of swelling.

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

  The optical article of the present invention is an optical article provided with an antireflection layer in which a low refractive index layer and a high refractive index layer are alternately laminated on the surface of a lens substrate, and the antireflection layer is a transparent conductive layer. It has at least two layers, and the total thickness of the transparent conductive layer is 5 nm or more and 14 nm or less.

  In the present invention, at least two transparent conductive layers are included in a part of the antireflection layer composed of the low refractive index layer and the high refractive index layer. The transparent conductive layer is a layer that reduces electrical resistance and is excellent in antistatic properties, and the total thickness of each layer of the transparent conductive layer is determined in the range of 5 nm to 14 nm. If the total thickness of each layer of the transparent conductive layer is less than 5 nm, a sufficient antistatic effect may not be obtained. Moreover, when the sum total of the thickness of each layer of a transparent conductive layer exceeds 14 nm, swelling will generate | occur | produce and there exists a possibility that durability may deteriorate.

Here, the inventors infer the reason why swelling occurs when the thickness is equal to or greater than a predetermined value as follows.
Even if a thick film is formed as the transparent conductive layer, there are minute defects in the film, and the defects are scattered. Therefore, moisture and the like enter from the surface of the thick film to the lens substrate side through this defect. As a result, moisture and the like are present in the vicinity of the defect, and the moisture and the like enter the lens as a whole. On the other hand, when the total thickness of each layer of the transparent conductive layer is 14 nm or less, the entire film is in a rough state, that is, moisture or the like enters through the entire film. As a result, moisture and the like enter the entire lens, and the entire lens becomes uniform.
This swelling mainly occurs when the lens base material is a material whose refractive index changes due to moisture absorption, such as plastic.

Thus, by including a transparent conductive layer with a some layer, since the thickness of each layer can be made thin, generation | occurrence | production of swelling can be prevented. Moreover, since the thickness of each layer of the transparent conductive layer is 5 nm or more and 14 nm or less, the antistatic effect can be sufficiently ensured.
Therefore, an optical article excellent in antistatic properties and durability can be provided.

  In the optical article of the present invention, the thickness of each layer of the transparent conductive layer is preferably 3 nm or more and 9 nm or less.

When the thickness of the transparent conductive layer is less than 3 nm, an antistatic effect cannot be obtained. On the other hand, if the thickness of the transparent conductive layer exceeds 9 nm, the gas and moisture permeability becomes insufficient and swelling occurs, which may deteriorate durability. In addition, the more preferable range of the thickness of each layer of a transparent conductive layer is 3.5 nm or more and 7 nm or less.
That is, an optical article excellent in durability and antistatic properties can be provided.

  In the optical article of the present invention, the transparent conductive layer is preferably formed of a material containing indium tin oxide (ITO).

  In this invention, since the transparent conductive layer is made of a material containing ITO, the antistatic effect is excellent.

  The optical article manufacturing method of the present invention is the above-described optical article manufacturing method, wherein the antireflection layer is formed on the surface of the lens substrate by vacuum deposition.

  In the present invention, an optical article capable of achieving the above-described effects can be easily realized by a conventionally performed method called vacuum deposition.

1 is a cross-sectional view of a spectacle lens according to a first embodiment of the present invention. The schematic diagram of the vapor deposition apparatus used for manufacture of the reflection preventing layer in 1st Embodiment. Sectional drawing of the spectacle lens concerning 2nd Embodiment of this invention. The graph which shows the relationship between the thickness of the ITO film | membrane and a reflectance in a present Example. (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. 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 relationship between the thickness of the ITO film | membrane and sheet resistance value in a present Example. The graph which shows the spectral reflectance 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.
(1. First embodiment)
FIG. 1 is a cross-sectional view of the spectacle lens of the first 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 layer 130 provided on the hard coat layer 120. Configured.
In the present embodiment, the hard coating layer 120 may be omitted and the antireflection layer 130 may be formed directly on the lens substrate 110. Further, the adhesion between the lens substrate 110 and the hard coating layer 120 is improved. In order to obtain, a primer layer may be provided at the interface between the lens substrate 110 and the hard coat layer 120. Then, a water repellent layer or an antifogging layer may be formed on the antireflection layer 130 as necessary.

(1-1. 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.

(1-2. 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 composed of metal oxides such as In ₂ O ₃ and TiO ₂ or composite fine particles composed 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.

(1-3. Antireflection layer)
The antireflection layer 130 is formed by sequentially laminating a low refractive index layer having a refractive index of 1.3 to 1.5 in a visible light region and a high refractive index layer having a refractive index of 1.8 to 2.4. It is. The antireflection layer 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 that are sequentially arranged from the lens base 110 side toward the outside. The first transparent conductive layer 136, the seventh layer 137, the second transparent conductive layer 138, which is the eighth layer, and the ninth layer 139, of which the first layer 131, the third layer 133, and the fifth layer 135 are included. The ninth layer 139 is a low refractive index layer, and the second layer 132, the fourth layer 134, and the seventh layer 137 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 seventh layer 137, and the ninth layer 139 which are the low refractive index layer and the high refractive index layer of the antireflection layer 130. examples of inorganic substances used _{for, SiO 2, SiO, 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 Examples include O ₃ , NbO ₂ , Nb ₂ O ₅ , CeO ₂ , MgO, Y ₂ O ₃ , SnO ₂ , MgF ₂ , and WO ₃ . These inorganic materials 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 ninth layer 139 are made of SiO ₂ , and the second layer 132, the fourth layer 134, and the seventh layer 137 are made of TiO _2. Can do.
The low refractive index layer made of silicon dioxide (SiO _2), the refractive index n in the visible light region is 1.40 to 1.50. The high refractive index layer made of titanium oxide (TiO ₂ ) has a refractive index n of 2.10 to 2.40 in the visible light region.

As a material used for the first transparent conductive layer 136 as the sixth layer and the second transparent conductive layer 138 as the eighth layer, for example, an inorganic oxide containing at least one of indium, tin, and zinc is used. In particular, indium tin oxide (ITO) is preferably used.
The thickness of the first transparent conductive layer 136 and the second transparent conductive layer 138 is preferably 5 nm or more and 14 nm or less when these two layers are combined. If the total thickness of the two layers is less than 5 nm, sufficient antistatic properties cannot be obtained. On the other hand, if the total thickness of the two layers exceeds 14 nm, gas and moisture permeability may be reduced and swelling may occur. A more preferable range of the total thickness of the two layers is 10 nm or more and 14 nm or less.

Moreover, it is preferable that the thickness of each layer of the 1st transparent conductive layer 136 and the 2nd transparent conductive layer 138 is 3 nm or more and 9 nm or less. When the thickness of each layer is less than 3 nm, the effect of antistatic properties cannot be sufficiently obtained. In addition, if the thickness of each layer exceeds 9 nm, swelling occurs on the surface of the spectacle lens, which may deteriorate durability. A more preferable range of the thickness of each layer is 3.5 nm or more and 7 nm or less.
In the present embodiment, the thickness of the first transparent conductive layer 136 is 4 nm, and the thickness of the second transparent conductive layer 138 is 6 nm.

The first transparent conductive layer 136 and the second transparent conductive layer 138 are provided as a part of the high refractive index layer. In this embodiment, it is provided adjacent to the seventh layer 137 and contributes to antireflection properties as a part of the seventh layer 137. Therefore, the refractive indexes of the first transparent conductive layer 136 and the second transparent conductive layer 138 are preferably 1.8 to 2.4.
The first transparent conductive layer 136 and the second transparent conductive layer 138 may be formed at any position from the second layer 132 to the eighth layer 138 as long as the first transparent conductive layer 136 and the second transparent conductive layer 138 do not become the outermost layers of the antireflection layer 130. Among these positions, it is preferable to form the sixth layer 136 and the eighth layer 138 with the seventh layer 137 being the highest refractive index layer farthest from the lens substrate 110.

  In the present embodiment, the antireflection layer 130 is not necessarily limited to one composed of nine layers. For example, the first layer 131 is on the lens substrate 110 side, and the high refractive index layer and the high refractive index layer are high. Other layer configurations may be used as long as the refractive index layers are alternately arranged and the outermost layer is formed of a low refractive index layer. For example, the first layer 131, the second layer 132, the third layer 133, the first transparent conductive layer 134 as the fourth layer, the fifth layer 135, the second transparent conductive layer 136 and the seventh layer 137 as the sixth layer. It may be composed of seven layers.

In the present embodiment, the first layer 131, the third layer 133, the fifth layer 135, and the ninth layer 139 that are low refractive index layers are made of SiO ₂ , the second layer 132 that is a high refractive index layer, the fourth layer 134, and the like. TiO ₂ was used for the seventh layer 137 and ITO was used for the first transparent conductive layer 136 and the second transparent conductive layer 138.

In order to form each layer of the antireflection layer 130, a normal ion assist (IAD) electron beam evaporation apparatus is preferably used.
FIG. 2 is a schematic diagram of the vapor deposition apparatus 10 used for manufacturing the antireflection layer 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 includes a heating unit 14 that heat-dissolves (evaporates) the vapor deposition material of the evaporation sources (crucibles) 12 and 13 in which the vapor deposition material is set in the vacuum vessel 11, and a substrate support on which the lens substrate 110 is placed A base 15, a substrate heating heater 16 for heating the lens substrate 110, a filament 17, and an ion gun 18 for ionizing and accelerating the introduced gas to irradiate the lens substrate 110 are provided. Further, a cold trap for removing moisture remaining in the vacuum vessel 11 and an apparatus for managing the layer thickness are provided as necessary. As a device for managing the layer thickness, for example, a reflection type 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. The metal used for coloring is mixed in advance with a metal oxide or fluoride.
The heating means 14 performs so-called electron beam evaporation, in which thermionic electrons generated by the heat generated by the filament 17 are accelerated and deflected by an electron gun (not shown) and irradiated to the evaporation material set in the evaporation sources 12 and 13 to evaporate. Is called.

  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 substrate support 15 preferably has a rotation mechanism in order to ensure the uniformity of the antireflection layer 130 formed on the lens substrate 110 and to increase mass productivity.

The substrate heating heater 16 is made of, for example, an infrared lamp, and is disposed on the substrate support 15. The substrate heating heater 16 heats the lens substrate 110 to degas or remove moisture from the lens substrate 110 to ensure the adhesion of the layer formed on the surface of the lens substrate 110.
In addition to the infrared lamp, a resistance heater or the like can be used as the substrate heating heater 16. However, when the material of the lens substrate 110 is plastic, it is preferable to use an 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 turbo molecular pump 21 and a pressure adjustment 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 adjustment valve 22 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 first transparent conductive layer 136 and the second transparent conductive layer 138, and the second layer 132, the fourth layer 134, and the seventh layer 137 constituting the high refractive index layer, the film formation conditions are as follows: The acceleration voltage of the electron gun is 5 to 10 kV, the current value is 50 to 500 mA, the voltage value of the ion gun 18 is 200 to 1000 V, and the current value is 100 to 500 mA.
Here, when the current value of the electron gun is increased, the evaporation rate of low boiling point components in the ITO material increases, and the transparency of the ITO film tends to decrease. Therefore, the current value of the electron gun is more preferably 100 mA or less.
In order to form the first layer 131, the third layer 133, the fifth layer 135, and the ninth layer 139 constituting the low refractive index layer, the above-described ion assist method may be used, but other methods, for example, Alternatively, a method of melting / vaporizing a deposition material by energizing a resistor such as tungsten (so-called resistance heating deposition), a method of irradiating a material to be vaporized with high energy laser light, or the like may be employed.

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 subjected to a heat treatment with a base material heating heater 16, whereby the lens base material 110. Evaporate water adhering to. Since the heat resistance temperature of a normal plastic material is around 100 ° C., the temperature of the lens substrate 110 is maintained at 80 ° C. or lower when forming the antireflection layer 130.
Next, ion cleaning 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 oxygen ions, or irradiation with oxygen radicals or oxygen plasma may be performed. Good.

Then, after the inside of the vacuum vessel 11 is sufficiently exhausted by the exhaust device 20, the antireflection layer 130 is formed. Specifically, SiO ₂ , TiO _2, and ITO, 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 and evaporated by irradiating the vapor deposition material with an electron gun (not shown). Then, vapor deposition is performed on the surface of the lens substrate 110. In particular, when depositing TiO ₂ and ITO, it is preferable to perform ion-assisted deposition in which an oxygen ion beam is irradiated from the ion gun 18 to the lens substrate 110.
Specifically, as the ITO material, a sintered body material in which 5% by mass of tin oxide (SnO ₂ ) is mixed with indium oxide (InO ₂ ) is used, and this material is heated and evaporated by an electron gun in a vacuum. Then, a thin film is formed while irradiating the ion gun 18 with an oxygen ion beam.
Each layer is formed while measuring the layer thickness, and the deposition is stopped when the desired layer thickness is reached.
Each layer is formed as described above to become the antireflection layer 130.
In addition, in order to form each layer, you may use normal vacuum evaporation, ion plating, sputtering, etc. besides this.

(1-4. Effects of First Embodiment)
According to the first embodiment described above, the following operational effects can be obtained.
In the above embodiment, the first transparent conductive layer 136 and the second transparent conductive layer 138 are provided on a part of the antireflection layer 130, the thickness of the first transparent conductive layer 136 is 4 nm, and the thickness of the second transparent conductive layer 138 is set. The thickness was 6 nm.
Therefore, since the total thickness of the first transparent conductive layer 136 and the second transparent conductive layer 138 is 10 nm, a sufficient antistatic effect can be obtained.
In addition, since the first transparent conductive layer 136 and the second transparent conductive layer 138 are formed thin, they have excellent gas and moisture permeability, can prevent swelling, and have excellent durability. Yes.

  In the above embodiment, the vacuum deposition method is used for forming each layer of the antireflection layer 130. In particular, since the first transparent conductive layer 136 and the second transparent conductive layer 138 are formed by ion-assisted deposition, the first transparent conductive layer 136 and the second transparent conductive layer formed of ITO are used. The degree of oxidation of 138 is promoted, and the transparency can be improved.

(2. Second Embodiment)
Next, a second embodiment of the present invention will be described below.
FIG. 3 is a cross-sectional view of the spectacle lens of the second embodiment.
In FIG. 3, the spectacle lens 200 includes a lens base 210, a hard coat layer 220 provided on the surface of the lens base 210, and an antireflection layer 230 provided on the hard coat layer 220. Configured.
In the second embodiment, since the configuration of the antireflection layer 230 is the same as that of the first embodiment except that the configuration of the antireflection layer 230 is different from that of the first embodiment, only the antireflection layer 230 will be described in detail here.

(2-1. Antireflection layer)
The antireflection layer 230 is formed by sequentially laminating a low refractive index layer having a refractive index of 1.3 to 1.5 in a visible light region and a high refractive index layer having a refractive index of 1.8 to 2.4. It is. The antireflection layer 230 is a first transparent conductive layer that is a first layer 231, a second layer 232, a third layer 233, a fourth layer 234, and a fifth layer, which are arranged in order from the lens base 210 side to the outside. A layer 235, a sixth layer 236, a seventh transparent conductive layer 237 as a seventh layer, an eighth layer 238, a third transparent conductive layer 239 as a ninth layer, and a tenth layer 240. The layer 231, the third layer 233, the sixth layer 236, and the tenth layer 240 are low refractive index layers, and the second layer 232, the fourth layer 234, and the eighth layer 238 are high refractive index layers.

As an example of the inorganic material used for the low refractive index layer and the high refractive index layer of the antireflection layer 230, the same materials as those exemplified in the first embodiment can be used. In the present embodiment, for example, the first layer 231, the third layer 233, the sixth layer 236, and the tenth layer 240 are SiO ₂ layers, and the second layer 232, the fourth layer 234, and the eighth layer 238 are TiO _2. Layer.
The low refractive index layer made of silicon dioxide (SiO ₂ ) has a refractive index n of 1.40 to 1.50 in the visible light region. The high refractive index layer made of titanium oxide (TiO ₂ ) has a refractive index n of 2.10 to 2.40 and a compressive stress of 150 to 250 MPa in the visible light region.

Examples of materials used for the first transparent conductive layer 235 that is the fifth layer, the second transparent conductive layer 237 that is the seventh layer, and the third transparent conductive layer 239 that is the ninth layer include indium, tin, and zinc. Among these, an inorganic oxide containing at least one kind is used, and indium tin oxide (ITO) is particularly preferably used.
The thicknesses of the first transparent conductive layer 235, the second transparent conductive layer 237, and the third transparent conductive layer 239 are formed so that the total thickness of these three layers is 5 nm or more and 14 nm or less. When the total thickness of the three layers is smaller than 5 nm, the antistatic effect is insufficient. On the other hand, if the total thickness of the three layers exceeds 14 nm, swelling may occur and durability may decrease. A more preferable range of the total thickness of the three layers is 10 nm or more and 14 nm or less.
Moreover, it is preferable that the thickness of each layer of the 1st transparent conductive layer 235, the 2nd transparent conductive layer 237, and the 3rd transparent conductive layer 239 is 3 nm or more and 9 nm or less. If the thickness of each layer is less than 3 nm, the antistatic effect cannot be obtained. In addition, if the thickness of each layer exceeds 9 nm, swelling occurs on the surface of the spectacle lens, which may deteriorate durability. A more preferable range of the thickness of each layer is 3.5 nm or more and 7 nm or less.
In the present embodiment, the thickness of the first transparent conductive layer 235 is 3 nm, the thickness of the second transparent conductive layer 237 is 3.5 nm, and the thickness of the third transparent conductive layer 239 is 4.5 nm.

  The first transparent conductive layer 235, the second transparent conductive layer 237, and the third transparent conductive layer 239 are formed at any position from the second layer 232 to the ninth layer 239 as long as the position is not the outermost layer of the antireflection layer 230. May be. Among these positions, it is preferably formed on the side farthest from the lens substrate 210.

  Note that in the present embodiment, the antireflection layer 230 is not necessarily limited to a layer composed of 10 layers. For example, the first layer 231 is on the lens base 210 side, and the low refractive index layer and the high layer are high. Other layer configurations may be used as long as the refractive index layers are alternately arranged and the outermost layer is formed of a low refractive index layer. For example, the first layer 231, the second layer 232, the first transparent conductive layer 233 that is the third layer, the fourth layer 234, the second transparent conductive layer 235 that is the fifth layer, the sixth layer 236, and the seventh layer It may be composed of eight layers of a third transparent conductive layer 237 and an eighth layer 238.

In the present embodiment, the first layer 231, the third layer 233, the sixth layer 236, and the tenth layer 240 that are low refractive index layers are made of SiO ₂ , the second layer 232 that is a high refractive index layer, the fourth layer 234, and TiO ₂ was used for the eighth layer 238, and ITO was used for the first transparent conductive layer 235, the second transparent conductive layer 237, and the third transparent conductive layer 239.

  In order to form each layer of the antireflection layer 230, a normal ion assist (IAD) electron beam evaporation apparatus is preferably used as in the first embodiment.

(2-2. Effects of Second Embodiment)
According to the second embodiment described above, it is possible to provide an optical article having the same effect as that of the first embodiment and having a higher antistatic effect.

(3. Modified examples)
In addition, although the structure, method, etc. for implementing this invention are disclosed by the above description, this invention is not limited to this.

  For example, an antifouling layer made of an organosilicon compound containing fluorine may be formed on the antireflection layer 130 or the antireflection layer 230 for the purpose of improving the water and oil repellency of the lens surface in the above embodiment. . 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 layer 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. The layer thickness of the antifouling layer is not particularly limited, but is preferably 0.001 to 0.5 μm. More preferably, it is 0.001-0.03 micrometer. If the antifouling layer is too thin, the water and oil repellency is poor, and if it is too thick, the surface becomes sticky, which is not preferable. On the other hand, if the antifouling layer is thicker than 0.03 μm, the antireflection effect is lowered, which is not preferable.

  Moreover, there is no restriction | limiting in the formation method of the antireflection layer 130 or the antireflection layer 230, In addition to an ion assist vapor deposition method, various things, such as high frequency sputtering method, direct current | flow sputtering method, CVD method (chemical vapor deposition method) ion plating method, are various. This method can be adopted.

  Furthermore, although the optical article has been described as an eyeglass lens in the above embodiment, the optical article of the present invention may be various optical lenses such as a camera lens and a microscope lens other than a spectacle lens, or an optical element such as a prism. It is good also as an element.

  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.

First, plastic lenses for spectacles shown in the following examples and comparative examples were produced.
As a lens substrate with a hard coat layer, Seiko Super Sovereign (manufactured by Seiko Epson Corporation) was used.
Next, an antireflection layer was formed as follows by ion-assisted vapor deposition.
First, 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, each layer was formed to have a film thickness as shown in Table 1 below by a vacuum evaporation method in which the material was sufficiently evacuated and heated to evaporate the material with an electron beam to obtain a thin film. The film formation rate when forming the low refractive index layer (SiO ₂ ) and the high refractive index layer (TiO ₂ ) is 2 nm / sec, and the film formation rate when forming the transparent conductive layer (ITO). Was 0.1 nm / sec.
The materials used for each layer are as follows.
SiO ₂ : Granular SiO ₂ material.
TiO ₂ : Granular TiO ₂ material.
ITO: A sintered body material in which 5% by mass of tin oxide (SnO ₂ ) is mixed with indium oxide (InO ₂ ).
The refractive index of each layer was determined by the film material. The refractive index at a wavelength of 500 nm was 1.462 for SiO ₂ , 2.431 for TiO ₂ , and 2.1 for ITO.

  The ITO film was formed under the following conditions. The acceleration voltage of the electron gun was 7 kV, the current value was 50 mA, and in order to promote the oxidation of the ITO film, 15 ml of oxygen gas was introduced into the vacuum vessel to create an oxygen atmosphere. Further, an oxygen gas of 35 milliliters per minute was introduced into the ion gun, and the oxygen ion beam was irradiated with a voltage value of 500 V and a current value of 250 mA. As the oxygen gas, a total of 50 milliliters of oxygen gas was introduced per minute. The temperature of the lens substrate was about 60 ° C. The extinction coefficient indicating the light absorption characteristic was 0.001 at 550 nm.

The film thickness was measured at the time of film formation using an optical film thickness meter.
The case of a transparent conductive layer (ITO film) will be specifically described.
When an ITO film is deposited as a thin film on a glass substrate (white glass) as λ / 4, the reflected light of light at a wavelength of 550 nm changes as shown in FIG. FIG. 4 is a graph showing the relationship between the thickness of the ITO film and the reflectance.
Assuming that the initial reflectivity is 20%, when ITO is deposited, the reflectivity reaches a maximum value of 61.7% when the optical film thickness λ / 4 is deposited. For example, when it is desired to deposit 5 nm, the film formation may be stopped at a reflectance of 20.74%. If it is desired to deposit 10 nm, the film formation is stopped at a reflectance of 22.9%. In this manner, a layer having a desired film thickness can be formed by performing film formation while monitoring the reflectance.
The film thickness was measured in the same manner for the other layers.
Note that the measurement may be performed in the same manner using a quartz crystal film thickness meter as well as the optical film thickness meter. In the case of forming a film using a sputtering apparatus, the film thickness can be adjusted by controlling the film formation time.

Next, a fluorine-based water repellent layer was formed on the antireflection layer.
Then, the vacuum chamber was opened to the atmosphere, the lens base material was inverted, and an antireflection layer was formed in the same process as described above, thereby producing a plastic lens having antireflection layers formed on both surfaces of the lens base material.

The sheet resistance, charging effect, and presence / absence of swelling of the plastic lenses produced in the above examples and comparative examples were measured by the following methods.
(Measuring method of sheet resistance)
Sheet resistance is measured using the metal electrodes shown in FIGS. FIG. 5A is a cross-sectional view illustrating a state in which the metal electrode is in contact with the plastic lens, and FIG. 5B is a top view illustrating a state in which the metal electrode is in contact with the plastic lens.
As shown in FIGS. 5A and 5B, the metal electrode 61 was brought into contact with the convex surface 1A of the plastic lens 1, a voltage of 1 kV was applied between the electrodes, and the sheet resistance at this time was measured.

(Evaluation method of charging effect)
On the surface of the plastic lens, a spectacle lens wipe was rubbed 10 times with a vertical load of 1 kg, and the presence or absence of dust due to static electricity generated at this time was examined. When there is no dust adhesion, the charging effect is excellent, and when there is dust adhesion, the charging effect is inferior.

(Judgment method of swelling)
Observe the light reflected from the front or back surface of the plastic lens. Specifically, as shown in FIG. 6, the reflected light of the fluorescent lamp 71 on the convex surface 1A of the plastic lens 1 is observed, and the contour of the image of the reflected light 72 is clearly and clearly shown in FIG. If the image can be observed, it is determined that there is no swelling. If the contour of the image of the reflected light 73 is blurred or blurred as shown in FIG. 7B, it is determined that there is swelling.
The measurement results are shown in Table 2 below and FIG. In addition, the thickness of the horizontal axis ITO in FIG. 8 represents the thickness of each layer.

As can be seen from Table 2 and FIG. 8, in Examples 1 to 4 having two ITO layers, the sheet resistance value is lower than that of Comparative Examples 1 and 2 and there is no adhesion of dust. Are better. Moreover, since the thickness of each layer of the ITO layer is thin, swelling is not generated.
In Examples 5 and 6 having three ITO layers, the sheet resistance value is lower than in Comparative Examples 1 and 2, and the antistatic property is excellent. Moreover, since the thickness of each layer of the ITO layer is thin, swelling is not generated.
On the other hand, in Comparative Example 8, since the total thickness of the ITO layer and the thickness of each layer are large, swelling occurs and the durability is inferior.

Moreover, in order to confirm that there was no change in the optical characteristics of the plastic lenses produced in Examples 2 and 6 and Comparative Example 3, the reflectance of each plastic lens was measured using a spectrophotometer generally used. (Figure 9).
As can be seen from FIG. 9, even when Examples 2 and 6 and Comparative Example 3 were compared, there was no significant difference in reflectance, and it was confirmed that there was no problem in optical characteristics.

  The present invention can be used not only for eyeglass lenses but also for various optical lenses including camera lenses.

  DESCRIPTION OF SYMBOLS 110 ... Lens base material, 120 ... Hard coat layer, 130 ... Antireflection layer, 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 ... first transparent conductive layer (sixth layer), 137 ... seventh layer (high refractive index) Layer), 138... Second transparent conductive layer (eighth layer), 139... Ninth layer (low refractive index layer).

Claims (4)

An optical article including an antireflection layer in which a low refractive index layer and a high refractive index layer are alternately laminated on the surface of a lens substrate,
The antireflection layer has at least two transparent conductive layers,
An optical article having a total thickness of the transparent conductive layer of 5 nm to 14 nm. The optical article according to claim 1.
The thickness of each layer of the said transparent conductive layer is 3 nm or more and 9 nm or less, The optical article characterized by the above-mentioned. The optical article according to claim 1 or 2,
The said transparent conductive layer is formed with the material containing indium tin oxide (ITO), The optical article characterized by the above-mentioned. It is a manufacturing method of the optical article according to any one of claims 1 to 3,
The method for producing an optical article, wherein the antireflection layer is formed on a surface of the lens substrate by vacuum deposition.

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