JP2009217018A - Optical article and method for manufacturing optical article - Google Patents

Abstract

An optical article having improved heat resistance and hardness of an antireflection layer is provided.
A first layer 31, a third layer 33, a fifth layer 35, and a seventh layer 37, which are low refractive layers, and a second layer 32, a fourth layer, which are high refractive layers, are formed on the surface of a lens substrate 1. 34 and the sixth layer 36 are alternately laminated, the high refractive layer is made of tantalum pentoxide (Ta ₂ O ₅ ) and has a refractive index of 2.10 to 2.30. The compressive stress is 150 to 250 MPa. Heat resistance and hardness are improved by setting the refractive index of the high refractive layer to 2.10 to 2.30 and the compressive stress to 150 to 250 MPa.
[Selection] Figure 1

Description

    The present invention relates to spectacle lenses, other optical articles, and a method for manufacturing the optical articles.

Some spectacle lenses and other optical articles are provided with an antireflection layer on the surface of a substrate.
Conventionally, in a plastic lens in which a primer layer is formed on the surface of a lens substrate, a hard coat layer is formed on the primer layer, and an antireflection layer is formed on the hard coat layer, There are layers formed by alternately laminating low refractive layers made of silicon and high refractive layers made of one material selected from zirconia dioxide, niobium pentoxide and ditantalum pentoxide (Patent Documents 1 and 2) .

Japanese Patent Laying-Open No. 2005-294938 (refer to the claims) Japanese Patent Laying-Open No. 2005-266685 (see claims)

In the conventional examples shown in Patent Documents 1 and 2, silicon dioxide is used for the low refractive layer, and titanium dioxide, zirconia, niobium pentoxide or tantalum pentoxide is used for the high refractive layer. The heat resistance of the material constituting the refractive layer is not always satisfactory, and when the heat is applied, some trouble may occur in the lens.
Further, since the material constituting the high refractive layer is not sufficiently hard, there is a possibility that the outermost surface may be damaged due to rough handling or carelessness of the lens user.

  An object of the present invention is to provide an optical article and an optical article manufacturing method in which the heat resistance and hardness of the antireflection layer are improved.

The optical article of the present invention is an optical component in which low refractive layers and high refractive layers are alternately laminated on the surface of a substrate, and the high refractive layer is formed of tantalum pentoxide (Ta ₂ O ₅ ). In addition, the refractive index is 2.10 to 2.30, and the compressive stress is 150 to 250 MPa.

In the invention of this configuration, since the refractive index of tantalum pentoxide constituting the high refractive layer is 2.10 to 2.30 and the compressive stress is 150 to 250 MPa, it functions as an antireflection layer and has heat resistance. Hardness is improved.
In other words, in order to set the refractive index of tantalum pentoxide to 2.10 to 2.30, the compressive stress must be 150 to 250 MPa or more. When the compressive stress is set to a large value in this way, the density of the high refractive layer is increased and the hardness is increased. And, when heat is applied to the base material, it expands, but if the high refractive layer of the antireflection layer provided on the base material has a large compressive stress, the compressive stress and the base material expansion will be balanced. Thus, the optical article can withstand high temperatures. On the other hand, if the refractive index of tantalum pentoxide is set to a value exceeding 2.30, the compressive stress will be too large, and the antireflection layer will not function as an antireflection layer such as a black film.

In the present invention, the low refractive layer is preferably silicon dioxide, has a refractive index of 1.40 to 1.50, and a compressive stress of 150 to 250 MPa.
In the invention of this configuration, the optical article can be easily manufactured by using the low refractive layer having the same configuration as the conventional configuration.

The optical article of the present invention is preferably a spectacle lens.
The invention with this configuration can provide a spectacle lens capable of producing the effects described above.

In the method of manufacturing an optical component according to the present invention, the film formation condition of the high refractive layer is an ion-assisted deposition method, the current value of the electron gun is 300 to 350 mA, the voltage value of the ion gun is 400 to 600 V, and the current value is 200 to 350 mA. It is characterized by being.
The invention of this configuration is a condition suitable for forming an antireflection layer having the above-described effects, and an optical article can be easily manufactured under this condition.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of the spectacle lens of the present embodiment.
In FIG. 1, the spectacle lens includes a lens substrate 1, a hard coat layer 2 provided on the surface of the lens substrate 1, and an antireflection layer 3 provided on the hard coat layer 2. It is configured.
In the present embodiment, the hard coat layer 2 may be omitted and the antireflection layer 3 may be formed directly on the lens substrate 1, and the adhesion between the lens substrate 1 and the hard coat layer 2 may be improved. In order to obtain, a primer layer may be provided at the interface between the lens substrate 1 and the hard coat layer 2. Then, a water repellent layer or a layer having antifogging properties may be formed on the antireflection layer 3 as necessary.

The lens substrate 1 includes an acrylic resin, thiourethane resin, methacrylic resin, allyl resin, episulfide resin, polycarbonate, polystyrene, diethylene glycol bisallyl carbonate (CR-39), polyvinyl chloride, which is a transparent plastic, A halogen-containing copolymer and a sulfur-containing copolymer are preferably used.
The refractive index of the lens substrate 1 is preferably 1.6 or more in order to match the refractive index of the hard coat layer 2 containing titanium oxide. In particular, allyl carbonate resin, acrylate resin, methacrylate resin, and thiourethane resin are preferable.

The hard coat layer 2 is formed of a single organic material, a single inorganic material, or a composite material thereof, but a composite material is preferable from the viewpoint of obtaining hardness and adjusting the refractive index.
By adjusting the refractive index of the hard coat layer 2 to the same degree as the refractive index of the lens base material 1, it is possible to prevent interference fringes and a decrease in transmittance caused by reflection at the interface between the hard coat layer 2 and the lens base material 1. .
Specifically, the hard coat liquid for forming the hard coat layer 2 includes an organic silicon compound and inorganic oxide particles containing titanium oxide having a rutile crystal structure.

The rutile-type titanium oxide particles preferably have a particle size of 1 to 200 μm. From the viewpoint of adjusting the refractive index, in addition to these particles, metal oxide particles of silicon, tin, zirconium, antimony having a particle size of 1 to 200 μm, or a composite material of these composite oxide particles is used as a composite material as a hard coat layer. It is good to form.
Further, when titanium is used as the inorganic material, the light resistance of the hard coat layer 2 and the lens base material 1 is reduced due to the photoactivity (specifically, the transmittance is reduced due to yellowing or the interface is deteriorated). In order to prevent the occurrence of peeling of the layer, it is preferable to use titanium oxide having a rutile crystal structure or composite oxide particles having a structure in which silicon dioxide surrounds titanium oxide. The thickness of the hard coat layer 2 is preferably several μm from the viewpoint of being hard to be damaged.

The antireflection layer 3 has a first layer 31, a second layer 32, a third layer 33, a fourth layer 34, a fifth layer 35, a sixth layer 36, and a seventh layer from the lens substrate 1 toward the objective side. It is composed of layer 37.
The first layer 31, the third layer 33, the fifth layer 35, and the seventh layer 37 constitute a low refractive layer made of silicon dioxide (SiO ₂ ), and the refractive index n of the low refractive layer is 1.40. 1.50 and the compressive stress is 150 to 250 MPa.
The second layer 32, the fourth layer 34, and the sixth layer 36 constitute a high refractive layer made of tantalum pentoxide (Ta ₂ O ₅ ), and the high refractive layer has a refractive index n of 2.10 to 2. .30 and the compressive stress is 150 to 250 MPa.
In the present embodiment, the antireflection layer 3 is not necessarily limited to one composed of seven layers. For example, the first layer 31 is on the lens substrate side, and a low refractive layer and a high refractive layer are provided. As long as it is composed of odd layers alternately arranged, other layer configurations may be used. For example, the first layer 31, the second layer 32, the third layer 33, the fourth layer 34, and the fifth layer 35 may be used.

In order to form at least the high refractive layer of the antireflection layer 3, a normal ion assist (IAD) electron beam evaporation apparatus is preferably used.
FIG. 2 is a schematic view of a vapor deposition apparatus 100 used for manufacturing the antireflection layer 3 of the present embodiment.
In FIG. 2, the vapor deposition apparatus 100 is a so-called electron beam vapor deposition apparatus that includes a vacuum vessel 11, an exhaust device 20, and a gas supply device 30.

  The vacuum vessel 11 includes a heating unit 14 for heating and dissolving (evaporating) 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 1 is placed. A base 15, a substrate heating heater 16 for heating the lens substrate 1, a filament 17, and an ion gun 18 that ionizes and accelerates the introduced gas to irradiate the lens substrate 1. 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.

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 1 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 layer formed on the lens base material 1 and to improve 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 1 to degas or remove moisture from the lens substrate 1 to ensure adhesion of the layer formed on the surface of the lens substrate 1.
In addition to the infrared lamp, a resistance heater or the like can be used. However, when the material of the lens substrate 1 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 control valve 22 that keeps the pressure inside the vacuum vessel 11 constant.
The gas supply device 30 includes a gas cylinder 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 cylinder 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 1 on which the hard coat layer 2 is formed is placed on the substrate support 15 in the vacuum container 11 described above, and the vapor deposition apparatus 100 is operated.
Here, in forming the second layer 32, the fourth layer 34, and the sixth layer 36 constituting the high refractive layer, the film formation conditions are as follows: the current value of the electron gun is 300 to 350 mA, and the voltage value of the ion gun is 400. It is -600V and the electric current value is 200-350mA.
In order to form the first layer 31, the third layer 33, the fifth layer 35, and the seventh layer 37 constituting the low refractive layer, the above-described ion assist method may be used. For example, 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, 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. [Example 1]
In Example 1, a hard coat layer 2 is formed on a lens substrate 1, and an antireflection layer 3 having a seven-layer structure is formed on the hard coat layer 2. Among these, the low refractive layer is formed of SiO ₂ having a refractive index n of 1.45 and a compressive stress of 175 MPa, and the high refractive layer is formed of a refractive index n of 2.15 and a compressive stress of 215 MPa. It is formed from Ta ₂ O ₅ . The thickness of the first layer 31 constituting the low refractive layer is 25 nm, the thickness of the third layer 33 is 195 nm, the thickness of the fifth layer 35 is 30 nm, the thickness of the seventh layer 37 is 100 nm, The thickness of the second layer 32 constituting the highly refractive layer is 5 nm, the thickness of the fourth layer 34 is 25 nm, and the thickness of the sixth layer 36 is 35 nm.
In Example 1, the second refractive layer 32, the fourth layer 34, and the sixth layer 36 are formed by an ion assist method. This ion assist method was performed under the conditions that the electron gun current value was 325 mA, the ion gun voltage value was 500 V, and the ion gun current value was 250 mA. The low refractive layers of the first layer 31, the third layer 33, the fifth layer 35, and the seventh layer 37 use an electron beam evaporation method with an electron gun current value of 100 mA, but do not use an ion assist method.
Tables 1 and 2 show the experimental conditions of Example 1 described above.

[Example 2]
The second embodiment is different from the first embodiment in the refractive index n and compressive stress of the high refractive layer. That is, in Example 2, the high refractive layer is formed of Ta ₂ O ₅ having a refractive index n of 2.11 and a compressive stress of 198 MPa, and the low refractive layer has the same configuration as that of Example 1. is there. The thickness of each layer is the same as that in the first embodiment.
In Example 2, the antireflection layer 3 is formed in the same manner as in Example 1. However, unlike Example 1, the ion assist method for forming the high refractive layer is different in that the electron gun current value is 300 mA. To do.
The experimental conditions of Example 2 are shown in Tables 1 and 2.

[Example 3]
Example 3 differs from Example 1 in the refractive index n and compressive stress of the high refractive layer. That is, in Example 2, the high refractive layer is formed of Ta ₂ O ₅ having a refractive index n of 2.28 and a compressive stress of 239 MPa, and the low refractive layer has the same configuration as that of Example 1. is there. The thickness of each layer is the same as that in the first embodiment.
In Example 3, the antireflection layer 3 is formed by an ion assist method under the same conditions as in Example 1.
Tables 1 and 2 show the experimental conditions of Example 3 described above.

[Comparative Example 1]
Comparative Example 1 is different from Example 1 in that the material constituting the high refractive layer is titanium dioxide (TiO ₂ ), which is the same as the conventional one. This titanium dioxide has a refractive index n of 2.4 and a compressive stress of 125 MPa. In Comparative Example 1, the low refractive layer has the same configuration as that of Example 1. The thickness of each layer is the same as that in the first embodiment.
In Example 3, the antireflection layer 3 is formed in the same manner as in Example 1.
In Example 3, the antireflection layer 3 is formed in the same manner as in Example 1. However, unlike Example 1, in the ion assist method for forming the high refractive layer, the electron gun current value is 280 mA.
Tables 1 and 2 show the experimental conditions of Example 3 described above.

[Comparative Example 2]
Comparative Example 2 differs from Example 1 in the refractive index n and compressive stress of the high refractive layer. That is, in Comparative Example 2, the high refractive layer is formed of Ta ₂ O ₅ having a refractive index n of 1.94 and a compressive stress of 105 MPa, and the low refractive layer has the same configuration as that of Example 1. is there. The thickness of each layer is the same as that in the first embodiment.
In Example 2, an electron beam evaporation method is used with an electron gun current value of 325 mA when forming a highly refractive layer, but an ion assist method is not used.
The experimental conditions of Comparative Example 2 are shown in Tables 1 and 2.

[Comparative Example 3]
Comparative Example 3 differs from Example 1 in the refractive index n and compressive stress of the high refractive layer. That is, in Comparative Example 3, the high refractive layer is formed of Ta ₂ O ₅ having a refractive index n of 2.37 and a compressive stress of 220 MPa, and the low refractive layer has the same configuration as that of Example 1. is there. The thickness of each layer is the same as that in the first embodiment.
In Comparative Example 3, the antireflection layer 3 is formed in the same manner as in Example 1. However, unlike Example 1, in the ion assist method for forming the highly refractive layer, the electron gun current value is 450 mA, and the ion gun The difference is that the voltage value is 750 V and the ion gun current value is 375 mA.
The experimental conditions of Comparative Example 3 are shown in Tables 1 and 2.

About the above Examples 1-3 and Comparative Examples 1-3, experiment of AR function, hardness, and heat resistance was conducted.
The AR function is a test of whether or not it functions as an antireflection layer. In Table 3, o indicates that the AR function is present, and x indicates that the AR function is absent.
In Comparative Example 3, the antireflection layer was a black film, and the film had absorption in the visible light region. The other Examples 1 to 3 and Comparative Examples 1 to 2 have the AR function without the inconvenience as in Comparative Example 3. Since Comparative Example 3 does not have an AR function, experiments on hardness and heat resistance were not performed.

The hardness experiment was performed by the Bayer test. This Bayer test is an abrasion resistance test using a Bayer testing machine (manufactured by COLTS Laboratories). A spectacle lens specimen is reciprocated 600 times with 500 g of media and scratched at the same time. The haze value is measured, and the Bayer value R (Bayer Ratio) is calculated based on the following formula.
R = (H _STB -H _STA ) / (H _SAB -H _SAA )
H _STB : Haze value of standard lens (after test) H _STA : Haze value of standard lens (before test) H _SAB : Haze value of test piece lens (after test) H _SAA : Haze value of test piece lens (before test) The larger the value of R, the better the scratch resistance.
In the heat resistance test, the test piece lens was heated, and the temperature at which cracks or scratches were found on the surface was regarded as the heat resistance temperature.
The above experimental results are shown in Table 3.

As can be seen from Table 3 above, the Bayer value in the Bayer test is 6.8 to 10.8 in Examples 1 to 3, whereas it is 3.2 to 3.5 in Comparative Examples 1 and 2. Thus, the examples have better scratch resistance by the Bayer test than the comparative examples.
And heat resistance is 75-80 degreeC in Examples 1-3 and the comparative example 2, whereas it is 70 degreeC in the comparative example 1, and it turns out that heat resistance is low.
As described above, Examples 1 to 3 have a function as an antireflection layer and exhibit good values for both the Bayer value and the heat resistance.

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. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but it is not intended to depart from the technical concept and scope of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.
For example, the formation method of the antireflection layer 3 is not limited, and various methods such as a high frequency sputtering method, a direct current sputtering method, a CVD method (chemical vapor deposition method) and an ion plating method can be employed in addition to the electron beam evaporation method. .

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

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

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 an antireflection layer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lens base material, 2 ... Hard-coat layer, 3 ... Antireflection layer, 31 ... 1st layer (low refractive index layer), 32 ... 2nd layer (high refractive index layer), 33 ... 3rd layer (low refraction) Index layer), 34 ... 4th layer (high refractive index layer), 35 ... 5th layer (low refractive index layer), 36 ... 6th layer (high refractive index layer), 37 ... 7th layer (low refractive index layer) )

Claims (4)

An optical component in which low refractive layers and high refractive layers are alternately laminated on the surface of a substrate,
The optical component, wherein the high refractive layer is made of tantalum pentoxide, has a refractive index of 2.10 to 2.30, and a compressive stress of 150 to 250 MPa. 2. The optical article according to claim 1, wherein the low refractive layer is silicon dioxide, has a refractive index of 1.40 to 1.50, and a compressive stress of 150 to 250 MPa. parts.   The optical article according to claim 1 or 2 is an eyeglass lens. A method for manufacturing the optical component according to any one of claims 1 to 3,
The production conditions of the high refractive layer are ion-assisted deposition, and the current value of the electron gun is 300 to 350 mA, the voltage value of the ion gun is 400 to 600 V, and the current value is 200 to 350 mA. Method.

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