JP4060898B2 - Synthetic resin spectacle lens manufacturing method - Google Patents

Description

【００４９】
【発明の効果】
本発明によれば、合成樹脂製眼鏡レンズの反射防止膜として好適な、屈折率が低く光吸収のないフッ化物膜をスパッタリング法により高速で形成でき、これにより反射防止膜付き合成樹脂製眼鏡レンズを得ることができる。
【００５０】
また本発明によれば、膜強度が高く、屈折率が低く光吸収のないフッ化物膜をスパッタリング法により高速で形成でき、これにより反射防止膜付き合成樹脂製眼鏡レンズを得ることができる。
【００５１】
また、さらに本発明によれば、帯電防止効果を有し、汚れの付着しにくい反射防止膜付き合成樹脂製眼鏡レンズを得ることができる。
【図面の簡単な説明】
【図１】 本発明に用いる成膜装置の断面図である。
【図２】 実施の形態１における顆粒の表面温度と基板への成膜速度との関係を示す特性図である。
【図３】 比較例１における顆粒の表面温度と基板への成膜速度との関係を示す特性図である。
【図４】 本実施の形態１の分光反射率特性図である。
【図５】 本実施の形態３の分光反射率特性図である。
【図６】 本実施の形態４の分光反射率特性図である。
【図７】 本実施の形態５の分光反射率特性図である。
【図８】 本実施の形態６の分光反射率特性図である。
【図９】 本実施の形態７の分光反射率特性図である。
【図１０】 本実施の形態８の分光反射率特性図である。
【図１１】 本実施の形態９の分光反射率特性図である。
【図１２】 本実施の形態１の分光反射率特性図である。
【図１３】 本実施の形態１における顆粒の表面温度が７００℃の場合の吸収係数の特性図である。
【図１４】 本実施の形態１における顆粒の表面温度が６００℃の場合の吸収係数の特性図である。
【図１５】 本実施の形態１における顆粒の表面温度が５００℃の場合の吸収係数の特性図である。
【図１６】 本実施の形態１における顆粒の表面温度が４５０℃の場合の吸収係数の特性図である。
【図１７】 本発明に用いる別の成膜装置の断面図である。
【符号の説明】
１ 真空槽
２ 基板
３ 顆粒
４ 石英皿
５ カソード
６ マッチングボックス
７ 高周波電源
８ 冷却水
９ ガス導入口
１０ シャッター[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a synthetic resin spectacle lens having an optical thin film, particularly an antireflection film, at high speed by a sputtering method.To the manufacturing methodRelated.
[0002]
[Prior art]
  In the case of forming an antireflection film for a synthetic resin spectacle lens, a vacuum deposition method has been often used in view of easiness of the method and a high film formation speed. This antireflection film is generally a multilayer film composed of a combination of a low refractive index layer having a low refractive index of 1.50 or less and a high refractive index layer having a high refractive index of 1.60 or more, or It is composed of a single layer film made of a low refractive index layer. It is widely known that the lower the refractive index layer, the better the antireflection effect can be obtained as the refractive index is lower. For this reason, in the antireflection film on the glass substrate, a stable low refractive index of 1.38 can be obtained by vacuum deposition by heating the substrate temperature to around 300 ° C.₂Is produced as a low refractive index layer.
[0003]
  On the other hand, when the substrate is a synthetic resin, the substrate temperature cannot be increased due to the characteristics of the substrate. Further, in the film forming method in which the substrate is not heated, since the film hardness is insufficient and the film is easily damaged, the characteristics as in the case of performing heat evaporation cannot be obtained. For example, as disclosed in Japanese Patent Application Laid-Open No. 3-129301, no ion assisted vapor deposition method has been obtained that can withstand practical use. For this reason, in the formation of an antireflection film on a synthetic resin substrate, SiO is used as a low refractive index layer.₂Is used. In this publication, SiO₂MgF by forming a multilayer film composed of a film mainly composed of₂An antireflection film having characteristics equivalent to those of a single layer film is obtained. However, even with this method, MgF having a refractive index of about 1.38.₂It is not possible to obtain an antireflection film having a low reflectance such as a multilayer film using MgF.₂Is not a solution to the inability to use.
[0004]
  Thus, in order to solve the problems of insufficient heat resistance and antireflection effect when the substrate is not heated, JP-A-4-191801 discloses a hard coat containing an organic silicon compound in advance in a synthetic resin spectacle lens. A Ta layer is provided as a high refractive index layer.₂O₅And TiO₂Etc. are formed by oxygen ion beam assisted vapor deposition, and SiO as a low refractive index layer.₂Is formed by a normal vacuum deposition method.
[0005]
  On the other hand, in recent years, film formation by a sputtering method effective in terms of automation, labor saving, and applicability to a large area substrate has been performed. The thin film formed by this sputtering method has a high film packing density and a high hardness even when the film is formed without heating the substrate, compared to a thin film formed by a normal vacuum deposition method. .
[0006]
  However, the sputtering method has the disadvantage that the film formation rate is slower than the vacuum evaporation method, and even if it is a practical level in the case of a metal film, the film formation rate is extremely slow in the case of other films. Industrial spread is delayed. MgF₂Sputtering fluoride such as Mg dissociates into Mg and F, and there is a problem that large absorption of visible light occurs due to insufficient F in the film. It was a big obstacle.
[0007]
[Problems to be solved by the invention]
  As described above, the antireflection film formed on the synthetic resin spectacle lens has a higher reflectance than the film formed on the glass lens, that is, the antireflection effect is low, and compared with the glass substrate on which heat deposition is performed. Since the film hardness is low, there is a problem that the film is easily scratched. Further, when the antireflection film is composed of only a complete derivative film, the synthetic resin spectacle lens is easily charged, so that it has a problem that it easily becomes dirty due to adhesion of dust or the like.
[0008]
  The present invention has been made in view of such problems, and is suitable as an antireflection film for synthetic resin spectacle lenses, and is a fluoride film having high film strength, low refractive index and no light absorption. The object is to provide a method of forming at high speed by sputtering..
[0009]
  In order to achieve the above object, the invention of claim 1 is a granular MgF having a particle size of 0.1 to 10 mm.₂As a film raw material, while introducing one or more gases selected from oxygen, nitrogen, or hydrogen into the vacuum chamber, AC power is supplied and MgF₂Plasma is generated on the top, and this plasma causes MgF₂While maintaining the surface at a temperature of 450 to 600 ° C., MgF₂By sputtering with positive ions of the introduced gas.₂At least a part of the molecular state, and MgF in this molecular state₂Thus, a film is formed on the substrate of the spectacle lens.
[0010]
  In the conventional sputtering method, when an ion collides with the target, it is necessary to break the interatomic bond in the target and eject the atom from the target, and part of the energy of the accelerated ion breaks the interatomic bond. As a result, the sputtering yield is lowered, and as a result, the film forming speed is lowered. On the other hand, in the present invention, by increasing the temperature of the film raw material, the bonding force is weakened in advance, and in this state the ions collide with the target, so that most of the energy of the accelerated ions is sputtered. Can be used. For this reason, the sputtering yield is increased, and as a result, the film formation rate can be remarkably increased as compared with the conventional method.
[0011]
  In addition, in the conventional sputtering method, the interatomic bond is broken and the atoms jump out of the target, whereas in the present invention, by increasing the temperature of the film raw material, a portion having strong and weak bonding force due to thermal vibration. In this case, the form of the particles that jump out becomes a molecule. Here, the molecule includes not only a single molecule but also a multimolecule that forms an aggregate in a cluster shape. And it can be considered that the form of the molecule jumping out of the target is almost the same as the molecule evaporated by heat.
[0012]
  In the present invention, by applying an alternating current to the electrode on which the film material is placed, the electrode is set to a negative potential, and the film material is sputtered with positive ions on the same principle as the generally known high-frequency sputtering. Is based. The alternating current referred to here includes a so-called high frequency of 13.56 MHz and a medium frequency of several tens of kHz. In the present invention, since plasma is generated on the electrode by applying an alternating current to the electrode on which the film material is placed for sputtering, the film material can be heated by this plasma. In particular, when the film raw material is granular, it can be easily heated due to poor heat conduction or concentration of an electric field / magnetic field at a large amount of the edge portion.
[0013]
  At this time, if the size of the granule is too small, it rises in the vacuum chamber and becomes particles, so that the particle size is preferably 0.1 mm or more, and more preferably 0.5 mm or more. On the other hand, if the granule is too large, the heat insulating effect is reduced, the edge portion is reduced, and the effect due to the concentration of the electric field / magnetic field is reduced. Therefore, the particle size is preferably 10 mm or less, preferably 5 mm or less. The size and shape of the granules are not necessarily uniform.
[0014]
  For optical applications, it is generally desirable that the light absorption of the thin film be small. Therefore, when the film raw material has the same composition as the desired thin film, it is preferable that the form of the particles to be ejected is molecular rather than dissociated to be atomic. This is because the dissociated material does not necessarily return to its original state. As a result of earnest research on this, it was found that the shape of the particles that jump out depends on the type of gas introduced during sputtering. Inert gases such as Ar, which are commonly used for sputtering, tend to break up the particles that jump out, while oxygen, nitrogen, hydrogen, and gases containing these make the particles jump out. And jump out in the molecular state. For this reason, in the case of manufacturing an optical thin film, it is particularly preferable to introduce a gas containing at least one of oxygen, nitrogen, or hydrogen.
[0015]
  Note that oxygen, nitrogen, hydrogen, and a gas containing these rarely combine with the film raw material only by sputtering the film raw material. Therefore, the optical thin film produced in this way is considered to have almost the same composition as when the film raw material is heated and evaporated to form a film on the substrate.
[0016]
  MgF particularly useful as an optical thin film₂In the case of sputtering using Si, the film formation rate can be sufficiently increased if the surface temperature of the target is 450 ° C. or higher. On the other hand, when the temperature is 800 ° C. or higher, the vapor pressure of the film material increases to a pressure close to the introduced gas, and the evaporated molecules reach the substrate as they are, and the difference from simple vapor deposition becomes small. In the case of vapor deposition, unlike the case of sputtering, the scratch resistance is low. MgF₂In the case of vapor deposition, the scratch resistance is remarkably lowered unless the substrate is heated to about 300 ° C., and it cannot be practically used. However, by keeping the surface temperature of the target at 800 ° C. or less, the scratch resistance is high. A membrane is obtained. In particular, MgF during film formation₂By setting the temperature to 500 ° C. or higher, a film with less absorption can be obtained, and by setting the temperature to 700 ° C. or lower, a high-performance antireflection film with higher scratch resistance can be formed. As the gas to be introduced, oxygen or nitrogen is particularly preferable in consideration of economy, availability, safety and the like.
[0017]
  The optical thin film produced in this way has a stoichiometric ratio and almost no absorption in the visible region, and its refractive index is about 1.38. Therefore, this optical thin film has a sufficient antireflection effect even with a single layer, and can be used as an antireflection film for spectacle lenses including sunglasses and goggles.
[0018]
  In the present invention, since there is no need to heat the substrate, there is no limitation on the material of the synthetic resin spectacle lens that can be applied. Therefore, in addition to diethylene glycol bisallyl carbonate (trade name “CR-39”), it can be applied to any synthetic resin such as polycarbonate resin, polyurethane resin, polystyrene resin, polyvinyl chloride resin, and acrylic resin.
[0019]
  The invention according to claim 2 is a granular MgF having a particle size of 0.1 to 10 mm.₂As a film raw material, while introducing one or more gases selected from oxygen, nitrogen, or hydrogen into the vacuum chamber, high-frequency power is applied and MgF₂Plasma is generated on the top, and this plasma causes MgF₂While maintaining the surface at a temperature of 450 to 600 ° C., MgF₂By sputtering with positive ions of the introduced gas.₂At least a part of the molecular state, and MgF in this molecular state₂A step of forming a film on the substrate of the spectacle lens and a step of forming a film made of a metal oxide or silicon oxide on the substrate, and an antireflection film is formed by these steps. And
[0020]
  In the present invention, the antireflection film on the synthetic resin spectacle lens according to claim 1 is made of MgF.₂And a metal oxide and / or silicon oxide can be used to form a film having a higher antireflection effect.
[0021]
  According to a third aspect of the present invention, in the second aspect of the present invention, the metal oxide or silicon oxide is mainly composed of one or more of Zr, Ti, Ta, Al, In, Sn, and Si. It is characterized by.
[0022]
  In Claim 2, MgF₂A metal oxide or silicon oxide combined with Zr, Ti, Ta, Al, In, Sn, Si, or a combination thereof, as a main component, high stability and excellent optical properties A high performance antireflection film can be formed. In particular, a high antistatic effect can be obtained by using an oxide film containing at least one of In or Sn, which is not a dielectric, or a silicon monoxide film as one layer in the multilayer film.
[0023]
  The invention of claim 4 is the invention of claim 2, wherein the metal oxide or silicon oxide is formed by magnetron sputtering.
[0024]
  In this invention, MgF in the invention of claim 2₂By forming a metal oxide or silicon oxide to be combined with the magnetron sputtering method, a high-performance antireflection film excellent in durability such as high scratch resistance and productivity can be formed.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
  FIG. 1 shows a film forming apparatus used in the first embodiment. A substrate 2 is provided above the vacuum chamber 1 so as to be able to rotate. MgF with a particle diameter of 1 to 5 mm, which is a film material₂The granule 3 is placed on a magnetron cathode 5 having a diameter of 4 inches (about 100 mm) in a quartz plate 4. The cathode 5 is connected to a 13.56 MHz high frequency power source 7 via a matching box 6. In order to keep the temperature of the cathode 5 constant, cooling water 8 whose water temperature is controlled to 20 ± 0.5 ° C. is allowed to flow on the lower surface of the cathode. Gas inlets 9 and 10 are inserted in the side surface of the vacuum chamber 1, and a shutter 11 is disposed between the cathode 5 and the substrate 2. The distance between the cathode 5 and the substrate 2 is 100 mm, and the rotation axis of the substrate 2 and the central axis of the cathode 5 are eccentric by a distance of 50 mm.
[0026]
  Set the substrate 2 which is a lens made of urethane-based synthetic resin having a refractive index of 1.60, and 7 × 10^-5The inside of the vacuum chamber 1 is evacuated to a vacuum level of Pa. Then O₂4 x 10 gas from the gas inlet 9^-1Introduced up to Pa. Electric power is supplied from the high frequency power source 7 to the magnetron cathode 5 to generate plasma. MgF₂The granules 3 are heated by this plasma, maintained at a temperature commensurate with the cooling capacity of the cooling water 8 on the lower surface of the cathode, and sputtered.
[0027]
  Here, by rotating the substrate 2 and opening the shutter 11, MgF is formed on the substrate 2.₂A film is formed. After the time when the optical film thickness becomes 130 nm, the shutter 11 is closed. When the wavelength of the plasma emission spectrum during the film formation was inspected, when the input power was 400 W or more, in addition to Mg atoms, MgF molecules and MgF₂Light emission from the molecules was observed, and it was confirmed that at least a part of the film raw material jumped in the molecular state.
[0028]
  FIG. 2 is a characteristic diagram showing changes in the surface temperature of the granules 3 and the film formation rate on the substrate 2 when the input power is changed. The characteristic curve A is the surface temperature, and the characteristic curve B is the film formation rate. . The surface temperature of the granules 3 was measured with an infrared radiation thermometer. It can be seen that when the input power is 400 W or more, the surface temperature rises to about 450 ° C. or more, and the film formation rate is rapidly increased. On the other hand, when the input power is 800 W, the surface temperature rises to about 800 ° C.
[0029]
  As a result of analyzing the film formed with the input power between 400 W and 800 W by EPMA, the composition ratio of Mg: F is 1: 1.8 to 1.95, and the larger the input power, the larger the amount of F. ing. O introduced as process gas₂It was also confirmed that (oxygen) was hardly present in the film. Further, as a result of analysis by FT-IR, in the state of Mg in the film, bonding with F was recognized, but bonding with oxygen was not recognized. Furthermore, as a result of analysis by XRD, the crystallinity was low and no clear peak was observed.
[0030]
  Next, the film was subjected to scratch resistance test and adhesion test. Scratch resistance test is 1cm²A steel wool test was performed by rubbing the coated surface with 10 strokes of # 0000 mesh steel wool applied with a load of 1 kg per unit. The adhesion test was performed by forming 11 cutting lines that reach the base material at intervals of 1 mm on the antireflection film with a knife in both vertical and horizontal directions.²100 pieces of Nozama were prepared, and a cellophane tape was affixed thereon to peel off rapidly, and a cross-cut test was performed to count the number of eyes removed. The steel wool test was evaluated as follows.
A: Slightly scratched B: Slightly scratched (better level than CR-39 with hard coat)
C: Slightly scratched (same level as hard-coated CR-39, level at which there is no practical problem)
D: Very many scratches E: Peeling of the film occurs.
[0031]
  As a result of performing a cross-cut test on the film of the present embodiment, peeling of the film did not occur under any conditions. Further, as a result of the steel wool test, when the input power was less than 500 W, it was ranked A, 500-700 W was ranked B, and 800 W was ranked C. Furthermore, it became E rank in the thing of 900W. Thus, when the input power was 800 W or less, sufficient scratch resistance could be obtained without providing an organic hard coat layer.
[0032]
  Next, measurement results of the refractive index n and the absorption coefficient k by spectroscopic ellipsometry manufactured according to the present embodiment are shown in FIGS. FIG. 12 shows the refractive index, and FIGS. 13 to 16 show the absorption coefficient k when the surface temperature of the granule 3 is 700 ° C., 600 ° C., 500 ° C., 450 ° C. (the input power at this time is approximately 700 W, respectively) 600W, 500W, 400W). As shown in FIGS. 13 to 16, the absorption coefficient k in the visible region (400 to 700 nm) is approximately 0.02 or less even when the granule 3 surface temperature is 450 ° C., and in all other cases, 1.6 × 10^-3The following is a practical level as a low refractive index optical film for spectacle lenses.
[0033]
  It can be seen that the surface temperature of the granules 3 is preferably 500 ° C. or higher in order to improve the transmittance of the spectacle lens. In addition, the refractive index n was about 1.38 as shown in FIG.
[0034]
  FIG. 4 shows the measurement result of the spectral reflectance of the antireflection film of the present embodiment. The reflectance is reduced to 0.8% or less at the center wavelength, and it has good antireflection characteristics as a single-layer antireflection film. If the particle size of the granule was in the range of 0.1 mm to 10 mm, similar results were obtained and there was no problem.
[0035]
  O to introduce₂Gas pressure is 5 × 10^-2Pa ~ 5x10⁰In any range of Pa, an antireflection film having good optical characteristics and durability was obtained although required input power was slightly different.
[0036]
(Comparative Example 1)
  MgF₂MgF instead of granules 3₂FIG. 3 shows the result of an experiment similar to that of Embodiment 1 performed using the sintered body. A is the surface temperature, and B is the deposition rate. In the case of using a sintered body, unlike the case of granules, the temperature hardly increases even when the input power is increased, and thus the temperature hardly rises. That is, it is a state of sputtering that is usually performed, the film formation rate is extremely slow, and it is not practical. For example, when the input power is 600 W, the film formation time for which the optical film thickness is 130 nm in Embodiment 1 is 18 seconds, but it takes 11 minutes to obtain the same film thickness in Comparative Example 1.
[0037]
  In addition, the thin film produced in Comparative Example 1 has an absorption coefficient of 0.1 or more in the visible range, and cannot be used for optical purposes. Furthermore, it was confirmed that the composition ratio of the thin film manufactured in Comparative Example 1 was 1: 1.5 to 1.7 for Mg: F, and the amount of F was considerably insufficient. Moreover, it was confirmed that the crystallinity is slightly high.
[0038]
(Comparative Example 2)
  In this comparative example, MgF is used by a widely used vacuum deposition method.₂A film was formed. When the substrate was not heated, the film was formed under two conditions when heated to 300 ° C. Under either condition, the absorption coefficient is 10^-3The composition ratio of the film was as follows: Mg: F was 1: 1.9 to 2.0. When the substrate is heated to 300 ° C., the crystallinity is high and the scratch resistance is high, which is a practical level. However, when the film is formed for a synthetic resin spectacle lens, that is, when the substrate is not heated, the crystallinity is low. Since the scratch resistance was remarkably low as E rank, it did not become a practical level.
[0039]
(Embodiment 2)
  Using the same apparatus as in the first embodiment, N is introduced from the gas inlet 9.₂1 × 10^-1Up to Pa, Ar 3 × 10 from the gas inlet 10^-2Introduced up to Pa. Compared to Embodiment 1, the temperature rise was slightly less, and the target surface temperature rose to 450 ° C. or higher when the input power was 500 W or higher. As a result of film formation on the substrate with an input power of 650 W and a film formation time of 21 seconds, the spectral reflectance of the film was exactly the same as in FIG. The light absorption in the visible range was 1% or less, which was sufficiently practical. As a result of performing the same test as in the first embodiment, there was no peeling of the film in the crosscut test, and the result of the steel wool test was also B rank.
[0040]
(Embodiments 3 and 4)
  FIG. 17 shows a film forming apparatus used in this embodiment. In this apparatus, two vacuum tanks having the same configuration as in the first embodiment are partitioned and connected by a gate valve 12. The substrate can be transferred between the vacuum chambers 1 and 1 'by a transfer mechanism (not shown). In vacuum chamber 1, the input power was 600 W, and the film was formed by the same method as in the first embodiment. In the vacuum chamber 1 ′, a metal plate such as Ta or Zr was used as a target. The magnetron cathode is connected to a DC power supply 13. O from the gas inlet 9 '₂Introducing Ar from the gas inlet 10 ', and Ta by Ta reactive sputtering method₂O₅, ZrO₂Or the like is formed on the substrate 2 '.
[0041]
  A diethylene glycol bisallyl carbonate (CR-39) substrate provided with an organic hard coat was used as the substrate 2, and MgF having a desired film thickness was formed on the substrate 2 in the vacuum chambers 1 and 1 ', respectively.₂And Ta₂O₅, ZrO₂An antireflection film was formed by alternately forming a synthetic resin spectacle lens. The film configuration is shown in Table 1, and the spectral characteristics of Embodiments 3 and 4 are shown in FIGS. 5 and 6, respectively. The antireflection films of Embodiments 3 and 4 have extremely excellent characteristics with a reflectance of 0.5% or less over the entire wavelength range of 400 to 700 nm, which is the visible region. Moreover, there was no peeling of the film in the crosscut test, and the result of the steel wool test was also B rank.
[0042]
(Embodiment 5)
  In this embodiment, an apparatus similar to that of the second embodiment is used. In the vacuum chamber 1, ITO (In₂O₃SnO₂Was added at 5% by weight). In the vacuum chamber 1, the input power was 500 W, and the film was formed by the same method as in the first embodiment. In the vacuum chamber 1 ′, O gas is introduced from the gas inlet 9.₂Then, Ar was introduced from the gas inlet 10 ', and an ITO film was formed on the substrate by DC reactive magnetron sputtering.
[0043]
  As the substrate 2, a diethylene glycol bisallyl carbonate (CR-39) substrate with an organic hard coat was used. On the substrate 2, MgF having a desired film thickness in the vacuum chambers 1 and 1 ′.₂, And ITO were alternately formed to form an antireflection film, thereby producing a synthetic resin spectacle lens. The film configuration is shown in Table 1, and the spectral characteristics are shown in FIG. As shown in FIG. 7, the antireflection film has a reflectance of approximately 0.5% or less at a wavelength of 420 to 700 nm, and has extremely excellent characteristics. In this embodiment, ITO, which is not a dielectric, is used as a part of the antireflection film, so that a spectacle lens having excellent conductivity and no dust adhesion due to charging could be obtained. Moreover, there was no peeling of the film in the crosscut test, and the result of the steel wool test was also B rank.
[0044]
(Embodiments 6 and 7)
  A synthetic resin spectacle lens with an antireflection film was prepared using an apparatus substantially the same as in the second embodiment. However, there are three cathodes 5 in the vacuum chamber 1 ′. The cathode 5 was made of a metal such as Ta, Zr, or Al, or Si doped with boron to impart conductivity. In the vacuum chamber 1, the input power was 400 W, and the film was formed by the same method as in the first embodiment. In the vacuum chamber 1 ′, O gas is introduced from the gas inlet 9.₂Then, Ar is introduced from the gas inlet 10 ', and a metal or silicon oxide film is formed on the substrate 2 by DC reactive sputtering.
[0045]
  A diethylene glycol bisallyl carbonate (CR-39) substrate without hard coating is used as the substrate 2, and MgF having a desired film thickness is provided on the substrate in the vacuum chambers 1 and 1 ', respectively.₂Further, an antireflection film was formed by alternately forming metal or silicon oxide, and a synthetic resin spectacle lens was produced. The film configuration is shown in Table 1, and the spectral characteristics of Embodiments 6 and 7 are shown in FIGS. The antireflection films of the sixth and seventh embodiments have extremely excellent characteristics with a wavelength of 420 to 700 nm and a reflectance of 0.5% or less, particularly 0.25% or less in the seventh embodiment.
[0046]
  In these embodiments, since the film thickness of each layer of the antireflection film is constituted only by a multiple of λ / 4 (λ = 520 nm), the film thickness can be easily controlled, and there is little variation in film thickness. The variation in appearance color, which is very important as a prevention film, is also reduced. Moreover, there was no peeling of the film in the crosscut test, and the result of the steel wool test was also B rank.
[0047]
(Embodiments 8 and 9)
  A three-layer film is provided in advance on a diethylene glycol bisallyl carbonate (CR-39) substrate provided with an organic hard coat, and MgF is formed thereon using the same apparatus as in the first embodiment.₂A film was formed, and a total of four spectacle lenses with an antireflection film were prepared. In the vacuum chamber 1, the input power was 500 W, and the film was formed by the same method as in the first embodiment. The film configuration is shown in Table 1, and the spectral characteristics of Embodiments 8 and 9 are shown in FIGS. The antireflection films of the eighth and ninth embodiments have extremely excellent characteristics with a reflectance of approximately 1% or less at a wavelength of 420 to 700 nm, particularly 0.3% or less in the ninth embodiment. Moreover, there was no peeling of the film in the crosscut test, and the result of the steel wool test was also B rank.
[0048]
[Table 1]

[0049]
【The invention's effect】
  According to the present invention, a fluoride film having a low refractive index and no light absorption, which is suitable as an antireflection film for a synthetic resin spectacle lens, can be formed at a high speed by a sputtering method, whereby a synthetic resin spectacle lens with an antireflection film is provided. Can be obtained.
[0050]
  Further, according to the present invention, a fluoride film having a high film strength, a low refractive index and no light absorption can be formed at high speed by a sputtering method, whereby a synthetic resin spectacle lens with an antireflection film can be obtained.
[0051]
  Furthermore, according to the present invention, it is possible to obtain a synthetic resin spectacle lens with an antireflection film that has an antistatic effect and is difficult to adhere to dirt.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a film forming apparatus used in the present invention.
FIG. 2 is a characteristic diagram showing the relationship between the granule surface temperature and the film formation rate on the substrate in the first embodiment.
3 is a characteristic diagram showing the relationship between the surface temperature of granules and the film formation rate on a substrate in Comparative Example 1. FIG.
FIG. 4 is a spectral reflectance characteristic diagram of the first embodiment.
FIG. 5 is a spectral reflectance characteristic diagram of the third embodiment.
FIG. 6 is a spectral reflectance characteristic diagram of the fourth embodiment.
FIG. 7 is a spectral reflectance characteristic diagram of the fifth embodiment.
FIG. 8 is a spectral reflectance characteristic diagram of the sixth embodiment.
FIG. 9 is a spectral reflectance characteristic diagram of the seventh embodiment.
FIG. 10 is a spectral reflectance characteristic diagram of the eighth embodiment.
FIG. 11 is a spectral reflectance characteristic diagram of the ninth embodiment.
FIG. 12 is a spectral reflectance characteristic diagram of the first embodiment.
FIG. 13 is a characteristic diagram of an absorption coefficient when the granule surface temperature is 700 ° C. in the first embodiment.
14 is a characteristic diagram of an absorption coefficient when the granule surface temperature is 600 ° C. in Embodiment 1. FIG.
FIG. 15 is a characteristic diagram of an absorption coefficient when the surface temperature of the granule in Embodiment 1 is 500 ° C.
FIG. 16 is a characteristic diagram of the absorption coefficient when the granule surface temperature in the first embodiment is 450 ° C.
FIG. 17 is a cross-sectional view of another film forming apparatus used in the present invention.
[Explanation of symbols]
    1 Vacuum chamber
    2 Substrate
    3 granules
    4 Quartz dishes
    5 Cathode
    6 Matching box
    7 High frequency power supply
    8 Cooling water
    9 Gas inlet
    10 Shutter

Claims (4)

Granular MgF ₂ having a particle size of 0.1 to 10 mm is used as a film material, and one or more gases selected from oxygen, nitrogen, or hydrogen are introduced into the vacuum chamber, and alternating current power is supplied to form MgF. ₂ is generated, and the surface of MgF ₂ is maintained at a temperature of 450 to 600 ° C. by the plasma, and at least a part of MgF ₂ is in a molecular state by sputtering MgF ₂ with positive ions of the introduced gas. A method of manufacturing a synthetic resin spectacle lens, wherein the film is formed on a spectacle lens substrate by MgF _{2 in a} molecular state. Granular MgF ₂ having a particle diameter of 0.1 to 10 mm is used as a film material, and one or more gases selected from oxygen, nitrogen, or hydrogen are introduced into the vacuum chamber, and high-frequency power is applied to form MgF. ₂ is generated, and the surface of MgF ₂ is maintained at a temperature of 450 to 600 ° C. by the plasma, and at least a part of MgF ₂ is in a molecular state by sputtering MgF ₂ with positive ions of the introduced gas. A step of forming a film on the substrate of the spectacle lens with MgF _{2 in the} molecular state, and a step of forming a film made of a metal oxide or silicon oxide on the substrate, these steps A method for producing a synthetic resin spectacle lens, comprising: forming an antireflection film by:   The invention according to claim 2, wherein the metal oxide or silicon oxide is made of a synthetic resin characterized in that the main component is any one of Zr, Ti, Ta, Al, In, Sn, Si, or a plurality thereof. A method of manufacturing a spectacle lens.   3. The method of manufacturing a synthetic resin spectacle lens according to claim 2, wherein the metal oxide or silicon oxide is formed by magnetron sputtering.

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