JP2005234311A - Optical element and optical element manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic lens with high heat resistance having a sufficient antireflection effect on a hard coat layer having high adhesion and scratch resistance.
A plastic base material 40, and a plastic lens 10 in which a first coating layer 41, a second coating layer 42, and an antireflection thin film 43 are laminated on the base material 40 are provided. provide. In addition to the first composition containing a silane compound and metal oxide fine particles that improve scratch resistance, the first coating layer 41 contains a polyfunctional epoxy compound that improves adhesion in a solid content weight ratio of about 5% to 25%. The second coating layer 42 includes the first composition and does not include the second composition. The hard coat layer composed of these coating layers 41 and 42 has high adhesion on the substrate side and high scratch resistance on the outside. Further, the hard coat surface is subjected to a hydrophilic treatment, and then an antireflection film made of an organic thin film is laminated.
[Selection] Figure 2

Description

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

Plastic lenses are widely used as eyesight correction lenses and eyeglass lenses such as sunglasses in recent years because they are lighter and less susceptible to breakage than conventional glass lenses and are easily dyed. The performance required for optical materials, especially spectacle lenses, is that the optical performance is a high refractive index and a high Abbe number, and the physical properties are not only low specific gravity but also high heat resistance, high It is strength and high wear resistance. If the refractive index is high, the lens becomes thin, and if the Abbe number is high, the chromatic aberration of the lens can be reduced. High heat resistance and high strength are important from the standpoints of facilitating secondary processing, the reliability of equipment using optical elements, the safety of users using the same, and the like. High wear resistance (scratch resistance) is important for preventing the surface of an optically important element from being damaged during use, and can improve the reliability of the optical element.
JP-A 61-26637 JP-A-62-234101 Japanese Patent Laid-Open No. 62-178901

  Early plastic lenses have been cited as having a disadvantage of low wear resistance, and techniques for improving the disadvantage have been proposed. The main technology is to improve the wear resistance by attaching a hard coat layer to the surface of the plastic lens. Specifically, a hard coat having a thickness of about 0.5 to 4 μm such as silicon or acrylic. A film is provided on the surface of the plastic lens to improve the wear resistance of the lens. Patent Document 1 proposes a method of forming a hard coat layer using a sol of a silane compound and various inorganic oxide fine particles.

  Patent Documents 2 and 3 disclose that an antireflection film is provided on the lens in order to reduce ghosting and flickering caused by lens surface reflection. In Patent Document 3, it is pointed out that there is a drawback that the antireflection film peels off in a scaly shape when used for a long time, and the first layer laminated on the hard coat layer is a zirconium oxide that functions as a binder. It is disclosed that the adhesion strength of the antireflection film can be improved by using silicon dioxide as a main component and forming the equivalent layer by combining the second layer with the first layer. .

  However, when the adhesion between the antireflection film and the hard coat layer is improved, the adhesion between the hard coat layer and the base material is reversed due to deformation due to the difference in thermal expansion coefficient between the antireflection film and the hard coat layer. The situation that becomes a problem occurs. That is, as the adhesion between the antireflection film and the hard coat layer is improved, the hard coat layer may be more easily peeled off from the substrate. One of the main functions of the hard coat layer is to impart high wear resistance (scratch resistance). For this reason, in Patent Document 1, strength and hardness are achieved by a sol of a silane compound and various inorganic oxide fine particles. High hard coat layer is formed to improve wear resistance. In order to increase the adhesion between the base material and the hard coat layer, it is necessary to increase the resin component functioning as a binder. If the resin component is increased, the component contributing to wear resistance is reduced, so the hard coat layer Major functions will be degraded. In addition, the hard coat layer formed from the sol of silane compound and various inorganic oxide fine particles tends to weaken the adhesion to the resinous substrate with the passage of time, improving the adhesion to the antireflection film. However, if the adhesion between the hard coat layer and the base material is questioned, sufficient durability may not be obtained.

  Therefore, an object of the present invention is to provide a highly durable optical element including a hard coat layer having high adhesion and scratch resistance and a method for producing the same. It is another object of the present invention to provide an optical element having high adhesion, including an antireflection film, having no peeling, and having high durability, and a method for manufacturing the same.

  In the present invention, a resinous base material and a first coating layer laminated on the base material, the first composition improving the scratch resistance and the second composition improving the adhesion And a second coating layer laminated on the first coating layer, the first coating layer including the first composition and not including the second composition, An optical element having an antireflection thin film laminated on a second coating layer is provided. In the present invention, a first coating layer including a first composition that improves scratch resistance and a second composition that improves adhesion is laminated on a resinous substrate. A second step of laminating a second coating layer containing the first composition and not containing the second composition on the first coating layer, and on the second coating layer, And a step of laminating a thin film for antireflection.

  Since the first coating layer and the second coating layer include the first composition that improves the scratch resistance, the first coating layer basically functions as a hard coat layer. Since the first coating layer laminated on the base material includes the second composition for improving adhesion, the first coating layer has scratch resistance, but in addition to that, a layer having high adhesion to the base material. Can be formed. On the other hand, since the second coating layer does not include the second composition that improves the adhesion, the second coating layer can exhibit the most scratch resistance by the first composition. Since the first coating layer and the second coating layer have the same first composition, the first coating layer can be used even if the second coating layer does not contain the second component that improves adhesion. Adhesion with is maintained. Therefore, the optical element of the present invention is provided with a hard coat layer having high adhesion on the inner side facing the substrate and high scratch resistance on the outer side on the opposite side. And since the scratch resistance of the outer layer is ensured, the adhesion of the inner layer can be improved even if the scratch resistance is sacrificed to some extent, and the adhesion of the inner layer can be improved. Therefore, the outer layer can improve the scratch resistance at the expense of adhesion. And since an inner layer and an outer layer contain the common 1st composition, the adhesiveness between these layers is also ensured. For this reason, due to the synergistic effect of the inner layer and the outer layer, the adhesion can be further increased, and a hard coat layer having higher scratch resistance can be formed on the surface of the substrate. Therefore, even in an optical element having an antireflection film in close contact with the hard coat layer, there is no fear that the hard coat layer will be peeled off, and the optical element including the antireflection film has high adhesion, no peeling, and high durability, and its manufacture A method can be provided.

  Accordingly, a plastic lens suitable for a spectacle lens can be provided by the method for manufacturing an optical element of the present invention, and spectacles having a high refractive index and high scratch resistance can be provided. The optical element is not limited to a plastic lens or glasses, but includes an optical element of an image display element, a prism, an optical fiber, an element for an information recording medium, a filter, and the like.

  An example of the first composition for improving the scratch resistance is one containing a silane compound and metal oxide fine particles. Moreover, the 2nd composition which improves adhesiveness contains a polyfunctional epoxy compound. In order to obtain sufficient adhesion to the resinous substrate in the first coating layer, it is desirable that the polyfunctional epoxy compound contained in the second composition is contained in an amount of 5% or more in terms of solid content. In order to ensure scratch resistance in the outer second coating layer, a certain level of scratch resistance is required in the first coating layer. Therefore, it is desirable that the first coating layer has a polyfunctional epoxy compound at a solid content weight ratio of 25% or less. More preferably, the first coating layer contains the polyfunctional epoxy compound in the range of 5% to 20% in terms of solid content weight ratio.

  Specific examples of the polyfunctional epoxy compound contained in the second composition include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl. Examples include ether.

  Specific examples of the silane compound contained in the first composition include vinyltrialkoxysilane, vinyltrichlorosilane, vinyltri (β-methoxy-ethoxy) silane, allyltrialkoxysilane, acryloxypropyltrialkoxysilane, methacryloxypropyltri Alkoxysilane, methacryloxypropyl dialkoxymethylsilane, γ-glycidoxypropyltrialkoxysilane, β- (3,4-epoxycyclohexyl) -ethyltrialkoxysilane, mercaptopropyltrialkoxysilane, γ-aminopropyltrialkoxysilane N-β (aminoethyl) -γ-aminopropylmethyl dialkoxysilane, tetramethoxysilane and the like. Two or more of these may be used in combination. In addition, it is more effective to use after hydrolysis.

Further, specific examples of the metal oxide fine particles contained in the first composition include Al ₂ O ₃ , SnO ₂ , Sb ₂ O ₅ , Ta ₂ O ₅ , CeO ₂ , La ₂ O ₃ , Fe ₂ O ₃ , One or more inorganic oxide fine particles of ZnO, WO ₃ , ZrO ₂ , In ₂ O ₃ , TiO ₂ dispersed in a colloidal form in a dispersion medium such as water, alcohol or other organic solvent and / or SiO 2 ₂ , Inorganic of Al ₂ O ₃ , SnO ₂ , Sb ₂ O ₅ , Ta ₂ O ₅ , CeO ₂ , La ₂ O ₃ , Fe ₂ O ₃ , ZnO, WO ₃ , ZrO ₂ , In ₂ O ₃ , TiO ₂ Composite fine particles composed of two or more kinds of oxides are dispersed in water, alcohols or other organic solvents in a colloidal form. Further, in order to enhance the dispersion stability in the coating liquid, it is also possible to use those obtained by treating the surface of these fine particles with an organosilicon compound or an amine compound. In this case, examples of the organosilicon compound used include monofunctional silane, bifunctional silane, trifunctional silane, and tetrafunctional silane. Regarding the treatment, the hydrolyzable group may be carried out untreated or hydrolyzed. In addition, after the treatment, it is preferable that the hydrolyzable group reacts with the OH group of the fine particles, but there is no problem in stability even if a part of the hydrolyzable group remains. Examples of amine compounds include ammonium or ethylamine, alkylamines such as triethylamine, isopropylamine and n-propylamine, aralkylamines such as benzylamine, alicyclic amines such as piperidine, and alkanolamines such as monoethanolamine and triethanolamine. is there. The addition amount of these organosilicon compound and amine compound is desirably in the range of about 1 to 15% with respect to the weight of the fine particles.

  The above-described metal oxide fine particles each preferably have a particle size of about 1 to 300 millimicrons, and the amount used is preferably 10 to 70% by weight of the solid content. If it is less than 10% by weight, the desired refractive index cannot be obtained, and the scratch resistance of the coating film becomes insufficient. On the other hand, if it exceeds 70% by weight, cracks may occur in the coating film.

  In the production method of the present invention, when the first and second coating layers are applied, the above composition can be diluted with a solvent as necessary. As the solvent, solvents such as water, alcohols, esters, ketones, ethers and aromatics are used.

  In the present invention, the first and second coating layers may contain a small amount of a curing catalyst, a surfactant, an antistatic agent, and an ultraviolet absorber, if necessary, in addition to the first and second compositions. In order to improve coating performance and coating performance after curing, such as antioxidants, light stabilizers such as hindered amines and hindered phenols, disperse dyes, oil-soluble dyes, fluorescent dyes and pigments The additive may be included.

  In the optical element of the present invention, the first coating layer can be generated by the dipping method in the first step, and the second coating layer can be generated by the dipping method in the second step. Further, in the third step, an antireflection thin film can be formed by a wet method. The antireflection thin film can also be formed by a manufacturing method such as vapor deposition or sputtering. However, the antireflection film made of an organic thin film can suppress the occurrence of cracks on the surface when exposed to a high-temperature environment, and an optical element having high heat resistance can be obtained. In addition, film formation by a wet method is desirable in that a vacuum process can be omitted as compared with the vapor deposition method. For example, known methods such as a dipping method, a spin coating method, a spray coating method, and a flow coating method can be used. In consideration of uniformly forming a thin film of 50 nm to 150 nm in a curved shape like a plastic lens, a dipping method or a spin coating method is preferable.

  As described above, since the optical element of the present invention has high adhesion between the hard coat layer having the first and second coating layers and the substrate, the adhesion between the hard coat layer and the antireflection film is improved. By doing so, peeling of the film from the substrate can be prevented in total, and durability can be improved. One method for improving the adhesion between the second coating layer of the hard coat layer and the antireflection film is to hydrophilize the surface of the second coating layer. When the optical element is manufactured, the second coating is formed after the second coating layer is formed between the second step and the third step, and before the antireflection thin film is laminated. It is possible to provide a pretreatment step for hydrophilizing the surface of the layer so that the contact angle is 60 ° or less. By subjecting the surface of the second coating layer to a hydrophilic treatment, hydroxyl groups are drawn to the surface and adhesion to the antireflection thin film can be improved. In the pretreatment step, the surface of the second coating layer can be subjected to a hydrophilic treatment by roughening by polishing or the like, cleaning with ultraviolet rays-ozone, or plasma treatment.

  The refractive index of the antireflection thin film is preferably at least 0.10 lower than the refractive index of the second coating layer, and the film thickness is preferably about 50 to 150 nm. If the thickness is deviated, sufficient antireflection characteristics cannot be obtained. The constituent components of the antireflection thin film are not particularly limited as long as the refractive index difference from the second coating layer is 0.10 or more, and known materials can be used. For example, a silicon-based, acrylic-based, epoxy-based, urethane-based or melamine-based resin or its raw material monomer is used alone or in combination with two or more other resins and raw material monomers. When considering various properties such as heat resistance, chemical resistance, and scratch resistance as a plastic lens, it is preferable to use a low refractive index layer containing a silicon-based resin. In addition, it is more preferable to add a particulate inorganic substance for adjusting the refractive index. Examples of the fine inorganic particles include colloidally dispersed sols, and specific examples include silica sol, magnesium fluoride sol, calcium fluoride sol, and the like.

  Further, the antireflection thin film is formed using a composition containing an A component which is an organosilicon compound represented by the following general formula (1) and a B component which is a silica-based fine particle having an internal cavity. It is preferable to form a film.

R ¹ R ² _n SiX ¹ _3-n (1)
(In the formula, n is 0 or 1.)
Here, R ¹ in the component A is an organic group having a polymerizable reactive group or a hydrolyzable functional group. Specific examples of the polymerizable reactive group include a vinyl group, an allyl group, an acryl group, a methacryl group. Group, epoxy group, mercapto group, cyano group, amino group, etc. Specific examples of hydrolyzable functional groups include alkoxy groups such as methoxy group, ethoxy group, methoxyethoxy group, chloro group, bromo group, etc. And a halogen group, an acyloxy group, and the like.

R ² is a hydrocarbon group having 1 to 6 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a butyl group, a vinyl group, and a phenyl group. X ¹ is a hydrolyzable functional group, and specific examples thereof include alkoxy groups such as methoxy group, ethoxy group and methoxyethoxy group, halogen groups such as chloro group and bromo group, acyloxy groups and the like.

  Specific examples of the A component silane compound include vinyltrialkoxysilane, vinyltrichlorosilane, vinyltri (β-methoxy-ethoxy) silane, allyltrialkoxysilane, acryloxypropyltrialkoxysilane, methacryloxypropyltrialkoxysilane, methacryl Oxypropyl dialkoxymethylsilane, γ-glycidoxypropyltrialkoxysilane, β- (3,4-epoxycyclohexyl) -ethyltrialkoxysilane, mercaptopropyltrialkoxysilane, γ-aminopropyltrialkoxysilane, N-β (Aminoethyl) -γ-aminopropylmethyl dialkoxysilane, tetramethoxysilane and the like can be mentioned.

  These A components may be used in combination of two or more. In addition, it is more effective to use after hydrolysis.

  Specific examples of the component B include silica sol composed of silica-based fine particles having a particle diameter of 10 to 1000 nm. Silica sol is often used in a colloidal dispersion in an organic solvent such as water, alcohols or cellosolves. In order to lower the refractive index of the antireflection layer (low refractive index layer) and increase the antireflection effect, hollow spherical silica in which cavities are formed in the silica-based fine particles as the above-mentioned B component More preferably, system fine particles are used. This is because in the case of hollow spherical silica-based fine particles, a cavity is formed inside, and a gas or a solvent is included in the cavity, so that a reduction in refractive index is achieved.

  In addition, the antireflection thin film coating composition of the present invention includes a polyurethane resin, an epoxy resin, a melamine resin, a polyolefin resin, in addition to the above-described organosilicon compound and silica-based fine particles having internal cavities. Various resins such as urethane acrylate resins and epoxy acrylate resins, and various monomers such as methacrylates, acrylates, epoxies, and vinyls as raw materials for these resins can be added. Among them, it is preferable to add various fluorine-containing polymers or various fluorine-containing monomers in order to reduce the refractive index. The fluorine-containing polymer at this time is preferably a polymer obtained by polymerizing a fluorine-containing vinyl monomer, and preferably has a functional group copolymerizable with other components. Such an antireflection film composition can be used by diluting with a solvent, if necessary. As the solvent, solvents such as water, alcohols, esters, ketones, ethers and aromatics are used.

  In addition to the above, the antireflection thin film in the present invention may contain a small amount of a curing catalyst, a surfactant, an antistatic agent, an ultraviolet absorber, an antioxidant, a hindered amine / hindered phenol, if necessary. It may contain an additive for improving coating properties such as light stabilizers such as disperse dyes, oil-soluble dyes, fluorescent dyes and pigments, and improving film performance after curing.

  According to the present invention, it is possible to provide various optical elements including a plastic lens having high heat resistance and scratch resistance, excellent adhesion to a substrate, and sufficient antireflection effect. Moreover, the manufacturing method of the plastic lens with an antireflection film by the wet method in the present invention can omit the vacuum process and can be more easily manufactured as compared with the vapor deposition method.

(Production method)
FIG. 1 shows an outline of a lens manufacturing process according to the present invention. FIG. 2 schematically shows the configuration of the lens (work) 10 in a cross-sectional view in the process of manufacturing the lens shown in FIG.

  First, in step 31, a plastic lens substrate 40 having a refractive index of 1.67 is formed using a lens fabric for Seiko Super Sovereign (hereinafter abbreviated as SSV) manufactured by Seiko Epson Corporation (FIG. 2A). ). Next, in step 32, a first hard coat layer (first coating layer) 41 is laminated on the plastic substrate 40 by a dipping method (first step, FIG. 2B). Subsequently, in step 33, a second hard coat layer (second coating layer) 42 is laminated on the surface of the first hard coat layer 41 by a dipping method (second step, FIG. 2 (c)). . Further, in step 34, the surface 42a of the second hard coat layer 42 is hydrophilized so that the contact angle is 60 ° or less (pretreatment, FIG. 2 (d)). In step 35, an antireflection film 43 is formed on the hydrophilic surface 42a by a wet method (FIG. 2E).

  In the case of a spectacle lens, the plastic lens 10 formed in this way is processed into a shape that matches the frame, and spectacles are manufactured by combining with the frame. Further, after the antireflection film 43 is formed, a water-repellent antifouling layer may be laminated on the surface thereof.

(Coating solution)
The coating solutions used in the following Examples 1 to 6 and Comparative Example 1 were prepared as follows. An outline of the coating liquids (coating liquids) H-1, H-2, and H-3 is shown in FIG.

  Coating liquid H-1 is 264 parts of propylene glycol methyl ether and metal oxide fine particles of methanol-dispersed titanium dioxide-zirconium dioxide-silicon dioxide composite fine particle sol (manufactured by Catalyst Kasei Kogyo Co., Ltd., solid content concentration 20 wt%) 1000 226 parts of γ-glycidoxypropyltrimethoxysilane and glycerol polyglycidyl ether of multifunctional epoxy compound (manufactured by Nagase Chemical Industries, Ltd., trade name “Denacol EX-313”) Prepared by mixing 40 parts. To this mixed solution, 60 parts of 0.1N aqueous hydrochloric acid solution was added dropwise with stirring. After further stirring for 4 hours and aging overnight, 3 parts of Fe (III) acetylacetonate, a silicon surfactant (Nihon Unicar Co., Ltd.) Product, trade name “L-7001”) was added, and the mixture was stirred for 4 hours and then aged overnight. This coating liquid H-1 contains a polyfunctional epoxy compound in a solid content weight ratio of 10%. The refractive index is 1.67.

  Coating liquid H-2 is 146 parts of propylene glycol methyl ether and methanol-dispersed titanium dioxide-zirconium dioxide-silicon dioxide composite fine particle sol (catalyst chemical industry Co., Ltd., solid content concentration 20 weight) of the metal compound of the first composition. %) 1000 parts were mixed, and then 226 parts of γ-glycidoxypropyltrimethoxysilane as a silane compound and 101 parts of tetramethoxysilane were mixed for adjustment. The coating liquid H-2 does not contain a polyfunctional epoxy compound. 120 parts of 0.1N hydrochloric acid aqueous solution was added dropwise to this mixed liquid with stirring, and the mixture was further stirred for 4 hours and then aged overnight, and then 2 parts of Fe (III) acetylacetonate, a silicon surfactant (Nihon Unicar Co., Ltd.) Product, trade name “L-7001”) was added, and the mixture was stirred for 4 hours and then aged overnight. The refractive index is 1.67.

  Coating liquid H-3 is 327 parts of propylene glycol methyl ether and metal oxide fine particles of methanol-dispersed titanium dioxide-zirconium dioxide-silicon dioxide composite fine particle sol (manufactured by Catalyst Kasei Kogyo Co., Ltd., solid content concentration 20 wt%) 1000 Then, 113 parts of γ-glycidoxypropyltrimethoxysilane as a silane compound and 120 parts of glycerol polyglycidyl ether as a polyfunctional epoxy compound were prepared. To this mixed solution, 31 parts of 0.1N hydrochloric acid aqueous solution was added dropwise with stirring. After further stirring for 4 hours and aging overnight, 4 parts of Fe (III) acetylacetonate, a silicon surfactant (Nihon Unicar Co., Ltd.) Product, trade name “L-7001”) was added, and the mixture was stirred for 4 hours and then aged overnight. The refractive index is 1.67. This coating liquid H-3 has basically the same composition as the coating liquid H-1, but was adjusted by adding the polyfunctional epoxy compound to a solid content weight ratio of 30%.

  Coating liquid C-1 is for an antireflection film, and is prepared by mixing an A component containing an organosilicon compound represented by the following general formula (1) and a B component containing silica-based fine particles having internal cavities. Prepared.

R ¹ R ² _n SiX ¹ _3-n (1)
Specifically, 18.8 g of propylene glycol monomethyl ether (hereinafter referred to as PGME) and 8.1 g of γ-glycidoxytrimethoxysilane as component A were mixed, and then 2.2 g of 0.1N hydrochloric acid aqueous solution was stirred. Dropped and stirred for 5 hours. To this solution, 20.7 g of isopropanol-dispersed hollow silica sol (solid content concentration 20 wt%) as component B was added and mixed well, then 0.04 g of Al (C ₅ H ₇ O ₂ ) ₃ as a curing catalyst, silicon A coating stock solution having a solid concentration of 20% was obtained by adding 0.015 g of a surfactant (Nihon Unicar L7604) and stirring and dissolving. In order to dilute the coating solution, a PGME solution containing a 300 ppm silicon surfactant (Nihon Unicar L7604) was prepared, and 35.3 g of the coating stock solution was mixed with 114.7 g of the PGME solution containing the surfactant for dilution. Then, the mixture was sufficiently stirred to prepare a coating liquid C-1 for an antireflection film having a solid content concentration of about 4.7%.

(Evaluation methods)
The plastic lens 10 manufactured in Examples 1 to 6 and Comparative Example 1 was subjected to a heat resistance test, an antireflection effect test, an adhesion test for the surface treatment layer, and a scratch resistance test, and the characteristics thereof were evaluated. Each evaluation result is shown in FIG. In the heat resistance test, the crack generation temperature is measured. The prepared lens 10 is put into a predetermined spectacle frame, and then the entire spectacle frame is placed in an oven at 40 ° C. and heated for 30 minutes. After taking out from the oven, it is allowed to stand at room temperature for 30 minutes, and then visually evaluated in a dark box for cracks in the lens. When no crack is generated, the oven temperature is increased by 10 ° C. and heated again for 30 minutes, and the same evaluation is performed. The test is performed until the temperature of the oven reaches 100 ° C., and the temperature at which a deep crack is generated is defined as a crack generation temperature. “◎” in the table of FIG. 4 indicates that no crack is generated even at a crack generation temperature of 100 ° C. or 100 ° C., indicating that a lens having extremely high heat resistance was obtained. “◯” indicates that the crack generation temperature is 80 ° C. to 90 ° C. and the heat resistance is high. “X” indicates that the crack generation temperature is 70 ° C. or less, indicating that the heat resistance is low.

  In the antireflection effect test, the surface reflectance of the produced lens 10 is measured with a spectrophotometer (Hitachi U-3500), and the average reflectance (one side) in the visible light region (400 nm to 800 nm) is evaluated. . In this evaluation, “◎” indicates that the average reflectance is 2% or less, which indicates that the antireflection effect is very large. “◯” indicates that the average reflectance is 3.5% or less, indicating that there is a sufficient antireflection effect. “X” indicates that the average reflectance exceeds 3.5%, indicating that there is almost no antireflection effect.

  In the adhesion test of the surface treatment layer, in the lens 10, the lens fabric (base material) 40 and the surface treatment layer (the first hard coat layer 41, the second hard coat layer 42, and the reflection) formed thereon. The adhesion of the protective film 42 (including the prevention film 42) is evaluated based on the state after the sunshine weather exposure test and the acceleration test. In the exposure test, the lens 10 was exposed for 120 hours with a sunshine weather meter using a xenon lamp. After that, in the acceleration test, the lens 10 was placed in a constant temperature and humidity chamber set in an atmosphere of a temperature of 60 ° C. and a humidity of 99% for 7 days. put. The state of the lens 10 left under these conditions is evaluated by a cross-cut tape test according to JISD-0202. That is, using a knife, cuts are made on the substrate surface at intervals of 1 mm to form 100 squares of 1 mm square. Next, a cellophane tape (manufactured by Nichiban Co., Ltd., trade name “Cellotape” (registered trademark)) is strongly pressed onto it, and then suddenly pulled away from the surface in the direction of 90 degrees, and then the coating film remains. The squares are visually observed and evaluated as an adhesion index.

  In the evaluation of the adhesion test, “◎” indicates that the remaining area of the coat film is 100% and the adhesion is very high, and “◯” indicates that the remaining area of the coat film is 95% to 100%. It indicates that the adhesion is high, “Δ” indicates that the remaining area of the coating film is 50% or more and less than 95%, and indicates that the adhesion is slightly inferior, and “×” indicates the coating film. The remaining area is less than 50%, indicating poor adhesion.

  The scratch resistance test was performed using steel wool (## 0000 manufactured by Nippon Steel Wool Co., Ltd.). -10 (good)). In the scratch resistance test, “「 ”indicates very high scratch resistance in steps 10 to 8,“ ◯ ”indicates high scratch resistance in steps 7 to 6, and“ Δ ”indicates scratch resistance in steps 5 to 4. Is slightly lower, and “x” indicates that the scratch resistance is low in stages 3 to 1.

(Example 1)
In Example 1, the coating liquid H-1 containing a polyfunctional epoxy compound was applied to the plastic substrate 40 prepared in Step 31 by a dipping method (pickup speed 30 cm / min) in Step 32, and after application. The first hard coat layer 41 was formed on the lens substrate 40 with a 0.8 μm coating liquid H-1 by heat curing at 80 ° C. for 20 minutes. Furthermore, in Step 33, the coating liquid H-2 is applied on the first hard coat layer 41 by a dipping method (pulling speed 35 cm / min), and after application, air-dried at 80 ° C. for 30 minutes, Baking was performed at 120 ° C. for 180 minutes to form a 1.2 μm second hard coat layer 42.

  Furthermore, in step 34, the surface 42a of the workpiece 10 on which the first and second hard coat layers 41 and 42 were formed on the base material 40 was polished with alumina to make it hydrophilic. Specifically, the workpiece 10 was supported by a suction pad, and while being rotated at 800 rpm, a 400 g load was applied to a sponge roll impregnated with an alumina-based abrasive rotating at 350 rpm and wiped off. After wiping, the adhered abrasive was completely removed with pure water and a sponge. Thereafter, rinsing was performed with IPA (isopropyl alcohol) while rotating the workpiece 10 at 1000 rpm, and a workpiece 10 having a surface contact angle θ of 53 ° was obtained.

  In addition, when wiping in step 34, the rotational speed of the workpiece is preferably 500 to 1000 rpm, and the rotational speed of the sponge is preferably 200 to 500 rpm. The rotation speed when rinsing is preferably 500 to 1500 rpm. Instead of alumina polishing, it is also possible to peel the surface by spraying abrasive grains, or to peel the surface by eye screening by spraying dry ice or fine particles of ice.

  Furthermore, in step 35, the coating liquid C-1 was apply | coated to the workpiece | work 10 by the immersion method (pull-up speed 10 cm / min). After coating, baking was performed at 100 ° C. for 180 minutes to form an antireflection film (low refractive index layer) 43. The antireflection film 43 had a thickness of 90 nm and a refractive index of 1.37.

  As shown in FIG. 4, the evaluation of the lens 10 manufactured according to Example 1 is “◎” in all of the heat resistance test, the antireflection effect test, the adhesion test of the surface treatment layer, and the scratch resistance test. This indicates that the lens is very high in heat resistance, has a very high antireflection effect, has very high adhesion to the entire layer formed on the surface, and has very high scratch resistance.

(Example 2)
In Example 2, steps 31, 32, and 33 are performed in the same manner as in Example 1 above, and the first hard coat layer 41 with the coating solution H-1 containing polyfunctional epoxy and the coating not containing polyfunctional epoxy are used. A workpiece (lens) 10 provided with the second hard coat layer 42 made of the liquid H-2 was manufactured. At this time, when applying the first hard coat layer 41 in Step 32, the pulling rate by the dipping method was slightly slowed to 20 cm / min, and after the application, heat curing treatment was performed at 100 ° C. for 15 minutes.

  In step 34, the surface was hydrophilized by UV ozone cleaning. That is, in step 34, ultraviolet (UV) -ozone cleaning is performed by converting the organic compound into a volatile substance and removing it from the contaminated surface by the decomposition of the organic compound by the ultraviolet ray and the strong oxidation action in the generation and decomposition processes of ozone. Although developed for this purpose, the surface can be roughened by washing and can be used for hydrophilic processing. Specifically, the workpiece 10 was cleaned for 3 minutes using a UV-ozone cleaning device (OC-250615-D + A manufactured by Iwasaki Electric Co., Ltd.). The cleaning time is preferably between 0.5 and 3 minutes. The contact angle θ of the workpiece 10 subjected to ozone cleaning for 3 minutes was 51 °.

  In Step 35, as in Example 1, the coating liquid C-1 is applied to the workpiece 10 by a wet method (immersion method) to form an antireflection film 43 having a film thickness of 90 nm and a refractive index of 1.37. Filmed.

  As shown in FIG. 4, the evaluation of the lens 10 manufactured according to Example 2 is “◎” in all of the heat resistance test, the antireflection effect test, the adhesion test of the surface treatment layer, and the scratch resistance test. This indicates that the lens is very high in heat resistance, has a very high antireflection effect, has very high adhesion to the entire layer formed on the surface, and has very high scratch resistance.

(Example 3)
In Example 3, Steps 31, 32, and 33 are performed in the same manner as in Example 1 described above, and the first hard coat layer 41 with the coating liquid H-1 containing polyfunctional epoxy and the coating not containing polyfunctional epoxy are used. A workpiece (lens) 10 provided with the second hard coat layer 42 made of the liquid H-2 was manufactured.

In step 34, the surface was subjected to hydrophilic processing by plasma treatment. Specifically, plasma treatment was performed for 1 minute using a discharge treatment apparatus (manufactured by Vacuum Instrument Industry Co., Ltd.). The plasma processing conditions were such that the degree of vacuum was 90 to 110 × 10 ⁻³ Torr, the current was 70 ± 10 mA, the voltage was 0.6 ± 0.1 KV, and the discharge time was 15 to 60 seconds. The contact angle θ of the plasma-treated workpiece 10 was 56 °, indicating hydrophilicity.

  In Step 35, as in Example 1, the coating liquid C-1 was applied by a wet method to form a film thickness antireflection film 43 having a film thickness of 90 nm and a refractive index of 1.37.

  As shown in FIG. 4, the evaluation of the lens 10 manufactured according to Example 3 is “◎” in all of the heat resistance test, the antireflection effect test, the adhesion test of the surface treatment layer, and the scratch resistance test. This indicates that the lens is very high in heat resistance, has a very high antireflection effect, has very high adhesion to the entire layer formed on the surface, and has very high scratch resistance.

Example 4
In Example 4, an SSV substrate 40 is prepared in Step 31 as in Example 1, and in Step 32, the coating liquid H-3 containing 30% of a polyfunctional epoxy compound is pulled up by an immersion method at a speed of 35 cm / min. After coating, the first layer 41 having a thickness of 0.9 μm was formed on the lens substrate 40 by heat curing at 80 ° C. for 30 minutes.

  In Step 33, as in Example 1, the coating liquid H-2 not containing a polyfunctional epoxy compound was further applied by an immersion method (pickup speed 30 cm / min). After the coating, it was air-dried at 80 ° C. for 20 minutes and then baked at 120 ° C. for 180 minutes to form a further 0.8 μm second layer 42 on the 1.2 μm hard coat layer.

  In step 34, as in Example 1, the surface 42a was hydrophilized by alumina polishing. The contact angle θ of the lens (work) 10 was 55 °. In Step 35, as in Example 1, the coating liquid C-1 was applied by a wet method to form an antireflection film 43 having a thickness of 90 nm and a refractive index of 1.37.

  As shown in FIG. 4, the evaluation of the lens manufactured according to Example 4 is “◎” in the heat resistance test, the antireflection effect test, and the adhesion test of the surface treatment layer, and the scratch resistance test is “×”. "Met. Therefore, the lens manufactured according to Example 4 has a very high heat resistance, a very high antireflection effect, and a very high adhesion of the entire layer formed on the surface, but a low scratch resistance. It is a lens.

(Example 5)
In Example 5, Steps 31, 32, and 33 are performed in the same manner as in Example 1 above, and the first hard coat layer 41 with the coating liquid H-1 containing polyfunctional epoxy and the coating not containing polyfunctional epoxy are used. The workpiece 10 provided with the second hard coat layer 42 made of the liquid H-2 was manufactured.

  Thereafter, step 34 was omitted and the contact angle θ was measured to be 83 °. In step 35, step 34 is omitted, and the coating liquid C-1 is applied by a wet method without hydrophilic processing, and an antireflection film 43 having a film thickness of 90 nm and a refractive index of 1.37 is formed. .

  As shown in FIG. 4, the evaluation of the lens manufactured according to Example 5 is “◎” in the heat resistance test and the antireflection effect test, and “×” in the adhesion test and the scratch resistance test of the surface treatment layer. "Met. Therefore, the lens manufactured according to Example 5 has a very high heat resistance and a very large and excellent antireflection effect. However, the adhesion of the entire layer formed on the surface is low, and the scratch resistance is also high. This indicates a low lens.

(Example 6)
In Example 6, steps 31, 32, and 33 are performed in the same manner as in Example 1 above, and the first hard coat layer 41 with the coating liquid H-1 containing polyfunctional epoxy and the coating not containing polyfunctional epoxy are used. The workpiece 10 provided with the second hard coat layer 42 made of the liquid H-2 was manufactured.

Thereafter, step 34 was omitted and the contact angle θ was measured to be 83 °. In step 35, step 34 is omitted, and a commercially available lens is subjected to antireflection processing (manufactured by Seiko Epson Corporation, antireflection processing by vapor deposition, transmittance 99% type) without hydrophilic processing. An antireflection film 43 having a five-layer structure of alternating SiO ₂ and TiO ₂ , a film thickness of 250 nm, and a refractive index of 1.37 was formed.

  As shown in FIG. 4, the evaluation of the lens manufactured according to Example 6 is “、” in the antireflection effect test, the adhesion test of the surface treatment layer, and the scratch resistance test, and the heat resistance test is “×”. "Met. Therefore, the lens manufactured according to Example 6 has a very large antireflection effect, a very large adhesion of the entire layer formed on the surface, and a very large scratch resistance. This indicates that the lens has low properties.

(Comparative Example 1)
In Comparative Example 1, the SSV base material 40 is prepared in Step 31 as in Example 1, and in Step 32, the coating liquid H-2 not containing the polyfunctional epoxy compound is pulled up by an immersion method at a speed of 35 cm / min. Was applied. After the application, the first layer 41 having a thickness of 1.2 μm was formed on the lens base material by heat curing at 80 ° C. for 30 minutes.

  In step 33, coating liquid H-1 containing a polyfunctional epoxy compound was further applied by an immersion method (pickup speed 30 cm / min). After the application, it was air-dried at 80 ° C. for 20 minutes, and further baked at 120 ° C. for 180 minutes to form a second layer 42 of 0.8 μm.

  In step 34, hydrophilic processing was performed by alumina polishing in the same manner as in Example 1. The contact angle θ of the workpiece 10 was 55 °. Further, in Step 35, as in Example 1, the coating liquid C-1 was applied to the workpiece 10 by a wet method to form an antireflection film 43 having a thickness of 90 nm and a refractive index of 1.37.

  As shown in FIG. 4, the evaluation of the lens manufactured in Comparative Example 1 is “「 ”in the heat resistance test and the antireflection effect test, and“ × ”in the adhesion test and the scratch resistance test of the surface treatment layer. "Met. Therefore, the lens manufactured according to Comparative Example 1 has a very high heat resistance and a very large and excellent antireflection effect. However, the adhesion of the entire layer formed on the surface is low, and the scratch resistance is also high. This indicates a low lens.

  From the results of Examples 1 to 6 and Comparative Example 1, the first hard coat layer 41 was formed with the coating liquid H-1 or H-3, and the second hard coat layer 42 was formed with the coating liquid H-2. It can be seen that the deposited lens basically has good adhesion to the surface treatment layer, and the adhesion of the surface treatment layer including the hard coating layers 41 and 42 including the antireflection film 43 is very high. In the lens of Example 5, although the first hard coat layer 41 was formed with the coating liquid H-1 and the second hard coat layer 4 was formed with the coating liquid H-2, The adhesion of the surface treatment layer is poor. Similarly, in the lens of Example 6 in which the pretreatment in step 34 is omitted, it is compared that the adhesion of the surface treatment layer is good. In the antireflection film by the coating liquid C-1, the antireflection film is prepared without any pretreatment. In the evaluation of the adhesion of the surface treatment layer, it is considered that the antireflection film is peeled off.

  On the other hand, the lens of Comparative Example 1 in which the first hard coat layer 41 is formed with the coating liquid H-2 and the second hard coat layer 42 is formed with the coating liquid H-1, In spite of the treatment, the adhesion of the surface treatment layer is poor, indicating that the adhesion of the hard coat layer is poor. The coating liquids H-1, H-2 and H-3 are all components (first composition) suitable for improving scratch resistance, and are metal oxide fine particles of methanol-dispersed titanium dioxide-zirconium dioxide. -It contains a silicon dioxide composite fine particle sol and a silane compound. The coating liquids H-1 and H-3 contain a glycerol polyglycidyl ether of a polyfunctional epoxy compound that is an effective component (second composition) for improving adhesion, Liquid H-2 is not included. Therefore, a hard coat layer containing a component that improves adhesion is formed on the side of the base material 40, and a hard coat layer that does not contain an effective component for improving adhesion is formed on top of that. It can be seen that the adhesion to the substrate as the hard coat layer can be improved.

  Further, in Example 5, since the anti-reflection film is peeled off because no pretreatment is performed, the hard coat layer has a two-layer structure, but the first composition is obtained without performing the pretreatment. Since they are common, no delamination occurs, and it can be seen that the hard coat layer functions as a unit.

  In addition, as can be seen from the evaluation of Examples 1 to 4, the adhesion including the hard coat layer is very good even in the lens in which the pretreatment is performed to improve the adhesion between the hard coat layer and the antireflection film. By adopting the present invention, even with a structure in which films having different compositions are laminated on the hard coat layer, adhesion to the lens substrate including the hard coat layer can be ensured. In Example 6 in which the inorganic antireflection film was formed, the adhesion between the antireflection film and the hard coat layer was good even without pretreatment, and the adhesion to the substrate including the hard coat layer was good. is there. However, thermal cracks are generated due to the inorganic antireflection film, and the heat resistance of the lenses of other examples is low.

  As described above, the adhesion can be improved by making the hard coat layer into a two-layer structure. However, in the lens 10 of Example 4 in which the first hard coat layer 41 is formed with the coating liquid H-3, the scratch resistance is high. Is not good. The coating liquid H-1 is prepared so that the polyfunctional epoxy compound contains 10% by weight of the solid content, whereas the coating liquid H-3 contains 30% of the polyfunctional epoxy compound by weight of the solid content. It is prepared as follows. In Example 4, since the strength or hardness of the first hard coat layer 41 formed with the coating liquid H-3 is insufficient, it is considered that the scratch resistance of the entire hard coat layer is lowered. It is done. Therefore, the first hard coat layer 41 is also required to have a certain degree of scratch resistance in addition to the adhesion, and the polyfunctional epoxy compound is preferably 25% or less, preferably 20% or less in terms of solid content by weight. Conceivable. Moreover, the big effect is seen in the adhesive improvement by a polyfunctional epoxy compound is a case where 5% or more is contained by solid content weight ratio. Therefore, it is preferable that the coating liquid for forming the hard coat layer on the substrate side contains a polyfunctional epoxy compound in a solid content weight ratio of about 5 to 25%, and a solid content weight ratio of about 5 to 20%. More preferably it is included.

  In the above, a plastic lens used for eyeglasses is manufactured as an optical element, and durability such as heat resistance, antireflection effect, adhesion, and scratch resistance is evaluated, but the optical element applicable to the present invention is There are various types such as a panel of an image display device, a prism, an optical fiber, an optical system of an information recording medium, and an optical filter, without being limited to spectacle lenses or other lenses.

It is a flowchart which shows the manufacturing method of the plastic lens which concerns on this invention. It is a figure which shows the structure of the plastic lens corresponding to FIG. It is a figure which shows the composition of the coating liquid used for the Example. It is a figure which shows evaluation of the lens of an Example and a comparative example.

Explanation of symbols

10 Workpiece (plastic lens)
40 Lens base material, 41 1st coating layer (1st hard coat layer)
42 2nd coating layer (2nd hard coat layer), 43 Antireflection film

Claims (14)

A resinous substrate;
A first coating layer laminated on the substrate, the first coating layer including a first composition for improving scratch resistance and a second composition for improving adhesion;
A second coating layer laminated on the first coating layer, the second coating layer including the first composition and not including the second composition;
An optical element having an antireflection thin film laminated on the second coating layer. In Claim 1, said 1st composition contains a silane compound and metal oxide fine particles,
The second composition is an optical element containing a polyfunctional epoxy compound.   3. The optical element according to claim 2, wherein the first coating layer contains the polyfunctional epoxy compound in a solid content weight ratio of 5 to 25%.   The optical element according to claim 1, wherein the surface of the second coating layer is subjected to a hydrophilic treatment.   2. The optical element according to claim 1, wherein a refractive index of the antireflection thin film is at least 0.10 or more lower than a refractive index of the second coating layer and a film thickness is 50 to 150 nm. In claim 1, the antireflection thin film is an organosilicon compound represented by the following general formula (1):
An optical element containing silica-based fine particles having an internal cavity.
R ¹ R ² _n SiX ¹ _3-n (1)
(In the formula, R ¹ is a polymerizable reactive group or an organic group having a hydrolyzable functional group, R ² is a hydrocarbon group having 1 to 6 carbon atoms, and X ¹ is a hydrolyzable functional group. And n is 0 or 1.)   The optical element according to claim 1, wherein the optical element is a plastic lens.   Eyeglasses having the plastic lens according to claim 7. A first step of laminating a first coating layer including a first composition for improving scratch resistance and a second composition for improving adhesion on a resinous substrate;
A second step of laminating a second coating layer containing the first composition and not containing the second composition on the first coating layer;
And a step of laminating an antireflection thin film on the second coating layer. In Claim 9, in the first step, the first coating layer is generated by an immersion method, and in the second step, the second coating layer is generated by an immersion method,
In the third step, the optical element manufacturing method for producing the antireflection thin film by a wet method.   The optical element according to claim 9, further comprising a pretreatment step of performing a hydrophilic treatment on the surface of the second coating layer so that a contact angle is 60 ° or less between the second step and the third step. Production method.   12. The method of manufacturing an optical element according to claim 11, wherein in the pretreatment step, the surface of the second coating layer is roughened.   12. The method of manufacturing an optical element according to claim 11, wherein in the pretreatment step, the surface of the second coating layer is subjected to ultraviolet-ozone cleaning. 12. The method of manufacturing an optical element according to claim 11, wherein, in the pretreatment step, the surface of the second coating layer is subjected to plasma treatment.

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