JP2006171204A - Method for manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical element for reducing the number of film deposition steps of a surface protective film in an optical element having a surface protective film on each of a plurality of surfaces. <P>SOLUTION: A method is provided for manufacturing an optical element having a surface protective film (water repellent/stain resistant treatment film) on each of both surfaces (optical faces) of an optical lens. An antireflection film is deposited in an antireflection film deposition chamber (vacuum chamber) 24, followed by simultaneous deposition of surface protective films by using heat evaporation sources 32, 32A opposing to the both surfaces of the work (lens base) w held in a surface protective film deposition chamber (vacuum chamber) 24. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an optical element comprising a plurality of surface protective films for imparting water / oil repellency, antifouling properties and the like on an optical substrate.

  Here, lenses such as spectacles and photographic lenses are mainly described as examples of optical elements, but the optical elements are not limited to lenses. That is, the present invention can be applied to a front glass or a front filter of various displays, an optical prism, or the like.

  In the case of spectacles and photographic lenses, it is desirable that the water droplets do not adhere because the image formation is distorted when the water droplets adhere. The cause of water droplet adhesion is attributed to an antireflection film (optical inorganic thin film) for reducing or increasing the reflectance on the surface of a hydrophilic inorganic glass substrate or an organic glass substrate. The metal oxide / halide layer, which is the film forming material for the antireflection film, is inherently hydrophilic, and may become uneven if dirt such as hand rubs or dust adheres to it, or if fine scratches occur. It is because it becomes a hydrophilic surface.

  The antireflection film is usually formed by a PVD (Physical Vapor Deposition) method typified by vacuum deposition, sputtering, ion plating or the like (all are performed in a vacuum chamber). For this reason, the surface of the antireflection film has fine irregularities, more easily adheres to dirt, etc., is difficult to remove even after adhesion, easily causes fine scratches, and increases the tendency of water droplet adhesion. There is a point.

  In general, it is desirable to form the antireflection film on both sides from the viewpoint of improving light transmittance. However, the film formation is first performed on one side of the lens substrate, and then the lens substrate. It was necessary to reverse the film to form a film on the other surface. Simultaneous film formation of both surfaces of the antireflection film is not preferable because highly accurate film thickness control is required. In order to form both surfaces of the antireflection film simultaneously, the structure of the film forming apparatus is complicated, and it is necessary to make the substrate holder flat, so that it is difficult to form a film uniformly over a large area. Further, problems such as a film-forming chemical holding mechanism and a film thickness control method also occur.

  In order to prevent water droplet adhesion and antifouling of the inorganic optical thin film, water repellent is applied to the outermost surface. It is conceivable to carry out an antifouling treatment. By carrying out this treatment, the slipping property is increased, and wiping scratches and the like are hardly attached. Therefore, the thin film formed by the water repellent / antifouling treatment becomes a surface protective film.

  And as a prior art concerning water-repellent / anti-fouling treatment, the following publications describe known literature inventions with the following contents.

    Patent Documents 1 and 2 ... A silazane compound such as fluoroalkylsilazane is impregnated into a porous material (sintered filter, steel wool, etc.), and water-repellent treatment is performed by vacuum evaporation and heating vapor deposition on the inorganic coating film.

    Patent Document 3: An organic substance-containing cured substance layer made of a polymer obtained by polymerizing an organic polysiloxane polymer or a perfluoroalkyl group-containing compound is formed on an inorganic coating film after being immersed and cured (reacted). To form a water-repellent treatment.

  However, although certain water-repellent performance was obtained by the above technology, optical parts that have undergone these treatments, especially eyeglass lenses, remove oily dirt such as dirt, sweat, fingerprints, hair liquids, etc. that are attached by wearing. The performance was insufficient.

  As a method for solving this problem, the present inventors changed the film to a thin film of an organic group silane compound having a fluorine-modified organic group and a reactive silyl group, thereby providing water repellency with a conventional performance and a new antifouling property. The inventors previously proposed “an optical element having a surface protective film” having the following configuration (see Patent Document 4).

“In an optical element including a surface protective film on an optical substrate, the surface protective film is formed of a fluorine organic group-introduced silane compound having a silyl group reactive with a fluorine-modified organic group. "
The water repellent treatment technology is excellent in water repellency and antifouling properties. The film formation of the surface protective film is usually performed after the single-sided film formation of the antireflection film, followed by the single-sided film formation of the surface protective film in a continuous vacuum chamber. In the same manner, the other surfaces of the antireflection film and the surface protective film were sequentially formed to manufacture a lens (optical element).

  However, it has been found that when the other surface of the antireflection film is formed, the previously formed fluorine-containing silane compound type surface protective film deteriorates.

In order to suppress the deterioration of the previously deposited surface, the surface on which the surface protective film has been deposited is masked with various metal masks, various resin masks / films, etc. so that the reflected electrons do not hit the surface. However, a special jig is required and the man-hour for masking is increased.
JP-A-5-215905 (abstract, etc.) JP-A-6-340966 (abstract, etc.) Japanese Patent Publication No. 6-5324 (abstract) Japanese Unexamined Patent Publication No. 2004-61879 (abstract)

  In view of the above, an object of the present invention is to provide an optical element manufacturing method capable of reducing the man-hours for forming the surface protective film in the optical element manufacturing method including the surface protective film on a plurality of optical surfaces. .

  As a result of diligent development to solve the above-mentioned problems, the present inventors have come up with a method for manufacturing an optical element having the following configuration.

  In the method of manufacturing an optical element in which an optical substrate includes a plurality of optical surfaces, and each optical surface is provided with a surface protective film (water-repellent / antifouling treatment film), each heating evaporation source facing each optical surface is Each of the surface protective films is formed at the same time.

  Since the surface protective film is simultaneously formed on the plurality of optical surfaces, the number of manufacturing steps of the optical element can be significantly reduced as compared with the case where the film is conventionally formed separately. Further, the above-described problem (deterioration of the surface protective film formed previously) does not occur when the antireflection film (optical inorganic thin film) and the surface protective film are formed on each side.

  The antireflection film is usually formed by an electron beam method using an electron gun, an ion assist method using plasma, an ion plating method, a sputtering method, or the like. In forming the antireflection film, reflected electrons are generated from the electron gun in the former method, and ions such as argon and oxygen are generated in the film formation process by the plasma in the latter method. These reflected electrons and ions may deteriorate the surface protective film previously formed. However, in the method of the present invention, since all of the optical surfaces (both sides) of the antireflection film are formed and then the surface protective film is formed on both sides simultaneously, there is no possibility that such a problem occurs.

  In the above configuration, when the surface protective film is a fluorine-containing silane compound coating, the effect of the present invention is remarkable. This is because the fluorine-containing silane compound coating film is easily affected by the reflected electrons and plasma ions.

  Usually, the surface protective film is formed on and in contact with the antireflection film formed on the optical substrate, and the optical inorganic thin film is formed on the hard coat formed on the optical substrate through a primer coat if necessary. To form.

  In each of the above structures, the surface protective film is formed by attaching a surface protective film mainly composed of an anti-reflective film-containing fluorinated silane compound to a lump of fibrous conductive material and depositing it on the optical element by vacuum deposition. It is desirable to form a film. The surface protective film thus formed is excellent in water repellency / antifouling performance.

  And although the optical base material in the manufacturing method of this invention may be a prism base material, it is normally set as the lens base material provided with two optical surfaces, a front surface and a back surface.

  In the method for manufacturing an optical element having each configuration described above, a surface protective film forming apparatus used for forming the surface protective film has the following configuration.

  A heater for vapor deposition of a surface protective film forming material is arranged in a vacuum chamber and a vacuum chamber at a position where vapor deposition can be performed facing each optical surface of an optical substrate (work) carried in and held. To do.

  The optical element manufacturing method of the present invention is premised on an optical element having a surface protective film on a plurality of surfaces (two surfaces in the case of a lens: front surface and back surface) of an optical substrate. Here, an inorganic optical thin film provided with an antireflection film on both sides is taken as an example, but the inorganic optical thin film may be a mirror film, or an optical element having no inorganic optical thin film and having a surface protective film on both sides. The present invention is also applicable.

  A basic configuration of an optical element to which the present invention is applied is, for example, shown in FIG. That is, a primer coat 12, a hard coat 14, an antireflection film (optical inorganic thin film) 16, and a surface protection film (water repellent / antifouling treatment film) 18 are sequentially formed on both surfaces of the optical substrate (lens substrate) 10. It is a thing. Here, the primer coat 12 and the hard coat 14 may be omitted.

  The optical substrate may be an inorganic glass substrate or an organic glass substrate.

Examples of the inorganic glass include crown glass (n _D = 1.52 to 1.72), flint glass (n _D = 1.53 to 1.88), and the like.

  Examples of organic glass base materials include polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene, polyvinyl chloride, polyethylene terephthalate, polyurethane, aliphatic allyl carbonate, aromatic allyl carbonate, polythiourethane, etc. Can do.

  From the standpoint of scratch resistance (especially in the case of an organic glass substrate), usually, the hard coat 12 is formed. Further, when the hard coat 14 is formed, the primer coat is used to increase the impact resistance. 12 is interposed (formed) between the substrate and the substrate.

  (1) The hard coat material is not particularly limited as long as it can impart scratch resistance and the like to the glass surface, but the following silicone type (i) or acrylic type (ii) can be preferably used. The hard coat is formed by a general-purpose method, usually a dipping method (dipping method) or a spin coat method.

(i) silicone hard coat;
For example, a catalyst and metal oxide fine particles (including composite fine particles) are added to a hydrolyzate of an organoalkoxysilane, and the viscosity is adjusted so that it can be applied with a diluting solvent. Furthermore, a surfactant, an ultraviolet absorber and the like can be appropriately added to this hard coat solution.

  1) As the organoalkoxysilane, those represented by the following general formula can be used.

R1 _a R2 _b Si (OR3) _{4- (a + b)}
(However, R1 is an alkyl group having 1 to 6 carbon atoms, vinyl group, epoxy group, methacryloxy group, and phenyl group, and R2 is a hydrocarbon group having 1 to 3 carbon atoms, a halogenated hydrocarbon group, an aryl group, R3 represents an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group, and a = 0 or 1, b = 0, 1 or 2.

  More specifically, it is described in Patent Document 4, paragraphs 0029 to 0035.

(ii) acrylic hard coat;
For example, a polyfunctional acrylic oligomer having 3 or more acryloyloxy groups in one molecule, a monomer, a monomer having a target function, an oligomer, and a photopolymerization initiator are added as essential components. If necessary, additives such as polymerization inhibitors, leveling agents and ultraviolet absorbers, and modifiers such as thermoplastic resins and metal oxide fine particles can be added.

  More specifically, the hard coat is described in Patent Document 4, paragraphs 0037 to 0050.

  (2) The primer coat is preferably formed using a primer coating having excellent impact resistance.

  Specifically, 1) a TPU primer composition in which metal oxide inorganic fine particles are added to a urethane-based thermoplastic elastomer (TPU), and 2) the entire or main component of the coating film-forming polymer is an ester-based thermoplastic elastomer (TPEE). The TPEE primer composition to which the same metal oxide inorganic fine particles as those added are added can be suitably used. The primer coat is usually formed by a dipping method (dipping method) or a spin coat method, similarly to the hard coat.

  More specifically, the primer coat is described in paragraphs 0053 to 0056 of Patent Document 4.

  The antireflective film (optical inorganic thin film) 16 is optically formed by forming a single layer made of ceramics such as metal oxides and metal halides and a metal film or a multilayer thin film made of two or more substances. The reflectance is reduced or increased.

  Thin film materials include titanium, tantalum, zirconium, niobium, antimony, yttrium, indium, neodymium, tin, lanthanum, cerium, magnesium, aluminum, silicon, zinc, etc. Inorganic halides such as oxides, magnesium, lanthanum, aluminum, lithium, silicon, germanium, chromium, aluminum, gold, silver, copper, nickel, platinum, iron, etc. Examples thereof include a metal mixture (including a sintered body and an alloy) as a component.

  This antireflection film is usually formed using a dry plating method (PVD method) such as a vacuum deposition method, a sputtering method, an ion plating method, an arc discharge method or the like.

  Moreover, as a surface protective agent which is a film forming material for the surface protective film, a general-purpose fluorine-containing silane compound-based material can be used.

  In particular, among these, it is desirable to use a fluorine organic group-introduced silane compound having a fluorine-modified organic group and a reactive silyl group as a main component. For example, it is represented by the following chemical formula.

具体的には、信越化学工業（株）製「KY-130」或いはダイキン工業（株）製「オプツールDSX」
を、フッ素系溶剤（例えば、住友3M(株）製「HFE-7200」、信越化学工業(株）製「FRシンナー」
、ダイキン工業(株）製「デムナムソルベント」等）で適当に希釈したものを使用できる。

Specifically, “KY-130” manufactured by Shin-Etsu Chemical Co., Ltd. or “OPTOOL DSX” manufactured by Daikin Industries, Ltd.
Fluorine solvents (for example, “HFE-7200” manufactured by Sumitomo 3M Co., Ltd., “FR thinner” manufactured by Shin-Etsu Chemical Co., Ltd.)
, “Demnam Solvent” manufactured by Daikin Industries, Ltd.) and the like can be used.

  The heater for evaporating the surface protective agent is not particularly limited, and examples thereof include a halogen heater and a resistance heater.

  The surface protective agent is heated after adhering the surface protective agent to a lump of fibrous conductive material and fixing it to the upper and lower vapor deposition heating evaporation sources installed in the vacuum chamber. To deposit on the optical element and form a surface protective film on the optical element.

  Next, an example of the apparatus used for the manufacturing method of the optical element of this invention is shown in FIG.

  This apparatus includes a plurality of connected vacuum chambers (three in the illustrated example), that is, a preliminary vacuum chamber 20, an antireflection film deposition chamber (electron beam deposition chamber) 22, and a surface protective film deposition chamber 24. . A gate valve (seal door) 26 that can be automatically opened and closed is arranged in front and rear (loading / unloading) of each vacuum chamber in the workpiece transfer direction, and each vacuum chamber 20, 22, 24 is configured. Yes. Of course, the degree of vacuum in each vacuum chamber can be adjusted by exhausting independently.

  An electron gun 28 and a deposition hearth 30 disposed at an irradiation position of an electron beam from the electron gun 28 are disposed on the bottom side of the antireflection film deposition chamber 22. Here, assuming that the antireflection film has a multilayer structure made of materials having different refractive indexes, it is desirable to provide a plurality of vapor deposition hearts. In this case, the electron beam B is normally guided by a magnetic field.

  In addition, a heater for vapor deposition (evaporation source setting unit) of a surface protection material (heating evaporation source) above and below (the ceiling side and the floor surface side) across the workpiece conveyance path of the surface treatment film forming chamber 24. 32, 32A are disposed, and evaporation direction correction plates 34, 34A are disposed on the evaporation material radiation direction side (lower surface and upper surface) of the vapor deposition heaters 32, 32A. That is, the vapor deposition heaters 32 and 32A are arranged at positions where the evaporation side surface 32a faces each optical surface (surface to be processed) of the lens substrate (object to be processed) and can be evaporated. The vapor deposition heater is usually a resistance heater or a halogen heater.

The evaporation direction correction plates 34 and 34A are attached to each lens substrate (object to be processed: workpiece) to correct the film thickness of the evaporated substance to be uniform. The film thickness is corrected by adjusting the shape (area) of the correction plates 34 and 34A.

Reference numerals 36 and 36A denote control power sources for the vapor deposition heater 32.

  A dome-shaped (circular cross-section) work holding plate 38 on which a plurality of lens base materials (objects to be processed) can be set is capable of sequentially transporting the vacuum chambers 20, 22 and 24. . The work holding plate 38 includes a plurality of work set holding holes 38a that can hold the work so that both surfaces of the work can be exposed. The work holding plate 38 is connected to a drive rotation shaft (built-in drive source) 40 so as to be able to rotate at a low speed during the vapor deposition process, and transport means (chain conveyor or the like: not shown) via the rotation shaft 40 or a hanging chuck. .). The rotating shaft 40 may be arranged independently in each vacuum chamber, and when the work holding plate 38 is carried in, the rotating shaft 40 may be connected to the rotating shaft 40 to be independently rotatable.

  A method for producing the optical element of the present invention using the above apparatus will be described.

  1) First, a primer coat and a hard coat are formed in advance by dipping (immersion) on both surfaces of an optical base material (organic glass) in advance, and a front surface treatment is performed on the lens base material (optical base material). . Furthermore, in this embodiment, an antireflection film treatment is performed on one side of the workpiece in advance. The film formation method of the antireflection film is not particularly limited, and can be performed by a method in which the surface treatment film formation chamber 24 does not form the surface treatment in the same apparatus as described above.

2) Next, the degree of vacuum in each of the vacuum chambers 20, 22 and 24 is adjusted. At this time, the set vacuum varies depending on the required specifications of the antireflection film and the surface protection film. For example, the vacuum chamber is appropriately set within the range of ¹ to 10 ⁻⁴ Pa, the antireflection film deposition chamber: 10 ⁻¹ to 10 ⁻⁵ Pa, and the surface treatment film deposition chamber: 1 to 10 ⁻⁴ Pa.

  In addition, a vapor deposition material is set in the vapor deposition hearth 30 in the antireflection film deposition chamber 24. When a workpiece is carried in, the electron gun 28 is turned on, and the electron beam B can be irradiated onto the vapor deposition material. ing. Here, for convenience of explanation, the case where the antireflection film is a single layer is taken as an example, but in the case of a multilayer (two or more layers), a plurality of hearts 30 are provided.

  Further, heating evaporation sources (surface protective agents) are set in the upper and lower vapor deposition heaters (evaporation source setting units) 32 and 32A in the surface protective film forming chamber. When the work holding plate 38 on which the work w is set is carried in, the heating power sources 36 and 36A are turned on so that the evaporation source can be heated.

  3) A required number of workpieces w are set on the workpiece holding plate 38 (the surface on which the antireflection film is not formed is on the lower side) and carried into the preliminary vacuum chamber 20. At this time, the preliminary vacuum chamber 20 can be heated and used as a preliminary heating chamber for stabilizing the temperature of the workpiece.

4) Then, the work holding plate 38 is carried into the antireflection film forming chamber 22. In the antireflection film deposition chamber 22, the electron beam from the electron gun 28 is irradiated onto the vapor deposition material in the vapor deposition hearth 30. At this time, the work holding plate 38 is rotated at a low speed by the rotating shaft 40 (for example, 5 to 20 min ⁻¹ ). For this reason, on the side where the antireflection film is not formed, the vapor deposition particles of each work (lens base material) w are uniformly attached. By repeating this vapor deposition, a single-layer or multiple-layer antireflection film having the required antireflection film characteristics (optical characteristics) is formed on the workpiece.

  5) The work w after the film formation process of the antireflection film is carried into the surface protection film forming chamber while the work is set. Then, the heating power sources 36 and 36A of the upper and lower vapor deposition heaters 32 and 32A are turned on to evaporate the heating evaporation source (surface protective agent). Then, since the inside is a vacuum, the evaporated particles travel substantially straight in the direction of evaporation due to the evaporation energy. For this reason, the evaporated particles from the upper evaporation source 32 go straight downward, and the evaporated particles from the lower evaporation source 32A go straight upward. Thus, a surface protective film (water repellent / antifouling treatment film) is simultaneously formed on both surfaces of each workpiece (lens substrate) w.

  Examples carried out to confirm the effects of the present invention will be described below together with comparative examples. (1) The following was used for the optical substrate (lens body). In the following description, “part” indicating a blending unit is a mass unit unless otherwise specified.

"CR-39": Refractive index 1.50 (manufactured by RPG)
“MR-7”: Refractive index 1.67 (Mitsui Chemicals, Inc.)
(2) The primer (composition) was prepared as follows.

To 100 parts of commercially available TPEE “Pesresin A-160P”, 57 parts of titania-based metal oxide fine particles “Optlake 1120Z (S-7.G)”, 350 parts of methyl alcohol as a diluent, and silicone-based surfactant “L- Prepare a primer composition by mixing 1 part 7001 "and stirring until uniform.
(3) The hard coat (composition) was prepared as follows.

  To 109 parts of γ-glycidoxypropyltrimethoxysilane, 40 parts of tetraethoxysilane and 27 parts of γ-glycidoxypropylmethyldimethoxysilane, 160 parts of methyl alcohol is added, and 38 parts of 0.01N hydrochloric acid are added dropwise with stirring. Then, hydrolysis is performed for a whole day and night to prepare a hydrolyzate.

The hydrolyzate is mixed with 390 parts of colloidal silica, 1 part of a silicone surfactant (“SILWET L-7001” manufactured by Nihon Unicar) and 1.5 parts of acetylacetone iron as a catalyst, and stirred for a whole day to hard coat. A composition is prepared.
(4) Each design example of the optical inorganic thin film (antireflection film) is as follows.

<Design Example 1>
While the vacuum chamber is heated to 60 ° C., the pressure is evacuated to 1.33 × 10 ⁻³ Pa, oxygen ion cleaning is performed, and then from the substrate side.
First layer SiO ₂ refractive index 1.46 Optical film thickness 26 nm
Second layer ZrO ₂ refractive index 2.05 Optical film thickness 81 nm
Third layer SiO ₂ refractive index 1.46 Optical film thickness 22 nm
Fourth layer ZrO ₂ refractive index 2.05 Optical film thickness 132 nm
Fifth layer SiO ₂ refractive index of 1.46 optical thickness 131nm
Vacuum deposition is performed in this order to form an antireflection film.

<Design example 2>
While the vacuum chamber is heated to 60 ° C., the pressure is evacuated to 1.33 × 10 ⁻³ Pa, oxygen ion cleaning is performed, and then from the substrate side.
First layer SiO ₂ refractive index 1.46 Optical film thickness 26 nm
Second layer TiO ₂ refractive index 2.36 Optical film thickness 34 nm
Third layer SiO ₂ refractive index 1.46 Optical film thickness 45 nm
Fourth layer TiO ₂ refractive index 2.36 Optical film thickness 120 nm
Fifth layer SiO ₂ refractive index of 1.46 optical thickness 18nm
Sixth layer TiO ₂ refractive index 2.36 Optical film thickness 94 nm
Seventh layer SiO ₂ refractive index 1.46 Optical film thickness 129 nm
The antireflection film is formed by performing vacuum deposition in the order of. The _second , fourth and sixth layers of TiO ₂ are performed by oxygen ion assisted deposition.

<Design example 3>
While the vacuum chamber was heated to 60 ° C., the pressure was evacuated to 1.33 × 10 −3 Pa and oxygen ion cleaning was performed.
First layer ZrO ₂ refractive index 2.05 Optical film thickness 15 nm
Second layer SiO ₂ refractive index 1.46 Optical film thickness 65 nm
Third layer ZrO ₂ refractive index 2.05 Optical film thickness 33 nm
Fourth layer SiO ₂ refractive index 1.46 Optical film thickness 300 nm
Fifth layer ZrO ₂ refractive index 2.05 Optical film thickness 119 nm
Sixth layer SiO ₂ refractive index 1.46 Optical film thickness 18 nm
7th layer TiO ₂ refractive index 2.35 optical film thickness 88 nm
Eighth layer SiO ₂ refractive index 1.46 Optical film thickness 131 nm
Vacuum deposition is performed in this order to form an antireflection film.
(5) Surface protective agent (heating evaporation source)
The heating evaporation source was prepared as follows.

Fluorine-based coating agent (trade name KY-130 manufactured by Shin-Etsu Chemical Co., Ltd., 20% solid content) was diluted with a fluorine-based solvent (product FR thinner manufactured by Shin-Etsu Chemical Co., Ltd.) to prepare 3.0%. Filled with 0.5 parts of steel wool (Japan Steel Wool Co., Ltd. # 0, wire diameter 0.025mm) into a cylindrical body (capacity: inner diameter 16mm x inner height 6mm) with an open top (chemical filling amount 1.0 And then dried at 120 ° C. for 1 hour.
(6) Surface Protection Film Formation Method In the surface protection film formation chamber shown in FIG. 1, the upper and lower heaters are configured as follows, and the degree of vacuum is 0.01 Pa and the film formation rate is 0.6 A / s. Then, a surface protective film (film thickness: 0.005 μ) was formed on both sides or one side.

Film-forming method (both sides) a ... Upper heater: Molybdenum resistance heater,
Lower heater: Molybdenum resistance heater,
Film formation method (both sides) b ... Upper heater: Halogen heater
Lower heater: Molybdenum resistance heater Film formation method (one side) c ... Lower heater: Molybdenum resistance heater (7) Preparation of workpiece (object to be processed) The performed surface is referred to as “R1 surface”, and the “opposite side surface of“ R1 surface ”is referred to as“ R2 surface ”. The antireflection film on the R1 surface is formed by removing the surface protective film formation chamber from the apparatus shown in FIG. 2 once in the atmosphere without setting the surface treatment agent (evaporation source) in the heater. It is a thing.

  Work 1... After depositing a hard coat on the CR-39 base material using the hard coat composition by dipping treatment (pickup speed: 105 mm / min), the surface of the optical base material of Design Example 1 A work 1 was formed by forming five layers of antireflection films composed of alternating layers of silicon oxide and zirconia oxide.

  Work 2: Using the primer coat composition and the hard coat composition on the MR-7 base material, the primer coat and the hard coat were sequentially formed by dipping treatment (both being pulled up: 105 mm / min). Then, the antireflection film of the design example 1 was formed on the optical base material in the same manner as the work 1 to obtain a work 2.

  Work 3: After the primer coat and the hard coat were formed on both surfaces of the MR-7 base material in the same manner as the test piece 2, the silicon oxide and the titanium oxide of the design example 2 were formed on the R1 surface of the optical base material. Seven layers of antireflection films composed of alternating layers were formed as Work 3.

  Work 4: After the primer coat and the hard coat were formed on both surfaces of the MR-7 base material in the same manner as the test piece 2, the silicon oxide and titanium oxide of Design Example 3 were formed on the R1 surface of the optical base material. Workpiece 4 was formed by forming an eight-layer antireflection film made of zirconium oxide.

  Work 5: A surface protective film was formed on the R1 surface of the work 1 by the film forming method c to obtain a work 5.

Work 6... A surface protective film was formed on the R1 surface of the work 4 by the film forming method c to obtain a work 6.
(5) Preparation of test piece for evaluation Using the apparatus shown in FIG. 2 on the R2 surface of each workpiece, the antireflection film and the surface protective film were formed in the combinations shown in Table 1, and each Example -A test piece for evaluation of a comparative example was prepared.

  And about each test piece, the evaluation test of each following item was done.

1) Film formation processing time Time required to form the surface protective layer on the R1 and R2 surfaces Judgment criteria: ○: within 150 s, Δ: 151 to 250 s, x: 251 s or more 2) Surface slippery glasses The surface of the membrane was rubbed 5 times with a wipe (“Toraysee” manufactured by Toray Industries, Inc.), and the degree of slipperiness was sensoryly evaluated.

Judgment criteria: ◎: Good sliding property, ○: Good sliding property
Δ: Slightly slipped, ×: Not slippery at all 3) Magic repelling property With an oil-based magic pen (“Magic Ink No. 500” manufactured by Teranishi Kagaku Kogyo Co., Ltd.), a 1 cm long line was drawn on the test piece to confirm repelling property.

Judgment criteria: ○: Play, △: Play only at the periphery of the drawn line, ×: Do not play 4) Wiping property After confirming the magic playing property of 3) above, whether or not wiping can be done by reciprocating 5 times with tissue paper To test.

Judgment criteria: ○: Wipe off within 5 round trips.
Δ: Wipe off within 10 round trips
×: Dirt remains after 10 reciprocations 5) Scratch test A 1.0 kg load is applied to steel wool (# 0000), and the surface of each test piece is scratched at 50 times / 50 s by the transmitted light of a fluorescent lamp. Judgment was made according to the following criteria.

Judgment criteria: ○: Scratch area is less than 10%
Δ: Scratch area is less than 60%
X: Scratch area is 60% or more 6) Water repellency test The contact angle with pure water was measured with a contact angle meter (CA-D type manufactured by Kyowa Interface Science Co., Ltd.).

Judgment criteria: ○: Contact angle of 105 ° or more,
△: Same as above 100 °
X: Less than 100 ° 7) Wiping durability (i) A 600 g load is applied to lens wiping (Microstar manufactured by Teijin Ltd.) and the surface of the surface protective layer is rubbed back and forth 10,000 times to change the contact angle before and after that. Judgment was made according to the following criteria.

Criteria: ○: Contact angle change 3 ° or less
: Less than 6 °
X: 6 ° or more (ii) A 600 g load was applied to the chamois skin soaked in room temperature water, the surface of the surface protective layer was rubbed back and forth 10,000 times, and the change in contact angle before and after that was judged according to the following criteria.

Criteria: ○: No change in contact angle (less than ± 1 °)
Δ: Change in contact angle is less than 6 °
×: Change in contact angle 6 ° or more <Discussion>
Table 1 showing the test results shows the following.

  In the embodiment of the present invention, the total film formation time of the surface protective film can be shortened to about ½ of that of the comparative example (conventional), and both surface slipperiness and magic playability are good on the R1 surface / R2 surface. There is almost no difference in the characteristics of the surface protective film.

  In contrast, the comparative example, which is a conventional example, has a long total film formation time of 3 min or more, and the performance of the surface protective film on the R1 surface (surface slipperiness / magic flipping property) is later formed. It is inferior to the R2 plane.

Model sectional view of an optical element to which the present invention is applied It is a conceptual diagram of an antireflection film / surface protective film forming apparatus used in the method for manufacturing an optical element of the present invention.

Explanation of symbols

22 Antireflection film deposition chamber (electron beam deposition chamber)
24 Surface protection film deposition chamber 32 Heating heater for vapor deposition (heating vapor deposition source set part)
28 Work holding plate 40 Drive rotary shaft w Work (optical substrate)

Claims (7)

  In the method of manufacturing an optical element in which an optical substrate includes a plurality of optical surfaces, and each optical surface is provided with a surface protective film (water repellent / antifouling treatment film), each heating evaporation source facing each optical surface A method for producing an optical element, wherein the surface protective films are simultaneously formed using a film.   The method for producing an optical element according to claim 1, wherein the surface protective film is a fluorine-containing silane compound film.   The method for producing an optical element according to claim 1, wherein the surface protective film is formed in contact with an optical inorganic thin film formed on the optical base material.   4. The method of manufacturing an optical element according to claim 3, wherein the optical inorganic thin film is formed on a hard coat formed on the optical base material through a primer coat as necessary.   The surface protective film is formed by adhering a surface protective film containing the fluorine-containing silane compound as a main component to a lump of fibrous conductive material and depositing it on an optical element by vacuum deposition. The manufacturing method of the optical element in any one of Claims 1-4.   6. The method of manufacturing an optical element according to claim 5, wherein the optical substrate is a lens substrate having two optical surfaces, a front surface and a back surface. The method for producing an optical element according to any one of claims 1 to 6, wherein the surface protective film forming apparatus is used for forming a surface protective film,
A heater for vapor deposition of the surface protection film forming material is disposed in the vacuum chamber at a position where vapor deposition can be performed facing each optical surface of the optical substrate (work) carried in and held in place. A surface protective film forming apparatus.

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