JPH0314321B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a synthetic resin lens, and particularly to a synthetic resin lens with excellent adhesion of an antireflection film formed on the lens surface, and is typified by spectacle lenses, camera lenses, etc. It is used for optical lenses. [Prior Art] In general, transparent synthetic resins, such as poly(diethylene glycol bisallyl carbonate), polymethyl methacrylate, polycarbonate, polystyrene, and polyvinyl chloride, have the following properties in addition to transparency:
It is applied to various optical parts fields by taking advantage of its own advantages such as light weight, easy processing, and impact resistance. Among optical components, the use of synthetic resin lenses in particular is expanding to include, for example, eyeglass lenses, camera lenses, projector lenses, Fresnel lenses, automobile headlight lenses, and prisms. For synthetic resin lenses, polymethyl methacrylate is used for sunglasses because it is easy to mass-produce, polycarbonate is used for safety glasses such as hard hats because of its excellent impact resistance, and poly(diethylene glycol bisallyl carbonate) is used as a material for synthetic resin lenses. Because it has excellent optical properties, it is mainly used in eyeglass lenses for vision correction. However, not only lenses made of the above-mentioned transparent synthetic resin materials but also glass lenses undergo reflection of light on the lens surface, resulting in a decrease in visual transmittance and the appearance of a reflected image called a ghost. Therefore, it is necessary to reduce reflection on the lens surface and increase light transmittance, and an antireflection film is usually provided on the lens surface.
The antireflection film is made of, for example, inorganic fluoride such as MgF ₂ , LiF, ThF ₄ , cryolite, or SiO, SiO ₂ ,
Metal oxides such as ZrO ₂ , CeO ₂ , WO _{2 ,} etc. are formed as a single-layer or multi-layer coating on the lens surface by methods such as vacuum evaporation or sputtering. Synthetic resin lenses have lower heat resistance than glass lenses when forming an anti-reflection film on their surfaces, so there are restrictions on film materials and formation methods. In terms of adhesion and durability of anti-reflection coating,
Its properties are not necessarily satisfactory, and there is a drawback that the antireflection film peels off after long-term use. For these reasons, various proposals have been made regarding means for forming an antireflection film on the surface of a synthetic resin lens. For example, the surface of a synthetic resin lens can be coated with alkaline liquid beforehand.
Methods have been disclosed for improving the adhesion of antireflection films by chemical treatments using acids, amines, etc., or physical treatments using plasma, sputter etching, corona discharge, etc. Furthermore, as a method of forming a primer layer on the surface of a synthetic resin lens and forming an antireflection film thereon, silane coupling agents, melamine resins, etc. have been proposed as materials for the primer layer, and the applicant of the present invention proposed a material for a primer layer made of a modified melamine resin in JP-A-58-59254. [Problems to be Solved by the Invention] When forming an antireflection film on the surface of a synthetic resin lens, chemical or physical treatment of the lens surface requires additional steps before and after these treatments. In addition, physical processing requires expensive equipment, which inevitably leads to cost disadvantages. In addition, in the method of forming the primer layer, the yield decreases in the formation process, and depending on the type of primer material, the formed primer layer may deteriorate over time, and this may result in an anti-reflection coating. There is a problem that the adhesion of the film also decreases, resulting in peeling of the film. [Means for Solving the Problem] In view of the above-mentioned problems, the inventor of the present invention has developed a special treatment for the lens surface to improve the adhesion between the lens surface and the anti-reflection film in a method for forming an anti-reflection film on a synthetic resin lens. By modifying the synthetic resin lens base material without forming a primer layer or
In order to solve the above problems, we conducted various studies and examinations. As a result, the anti-reflection coating formed on the surface of the lens is made of a polymer made by blending a specific alkoxysilane compound with a monomer that yields a transparent polymer suitable for synthetic resin lenses, and has excellent adhesion. The present invention was completed based on the knowledge that it has excellent properties and does not impair transparency, mechanical properties, etc. That is, the present invention is a synthetic resin lens made of a transparent synthetic resin, characterized in that the transparent synthetic resin contains an alkoxysilane compound, and has an excellent adhesion of an antireflection film. In the present invention, the transparent synthetic resin is not particularly limited as long as it is a known resin for lenses and can be polymerized by containing an alkoxysilane compound as a monomer. Alternatively, a lens may be formed by blending an alkoxysilane compound into a syrup-like prepolymer and completing the polymerization through a polymerization process. As the transparent synthetic resin, the following monomers such as diethylene glycol bisallyl carbonate, diallyl phthalate, methyl methacrylate, methyl acrylate, cyclohexyl methacrylate, 2-hydroxy-methacrylate, 2-hydroxy-acrylate, 2,2-bis(4-methacryloyloxyethoxy) can be used. phenyl)propane, styrene, α-
Examples include polymers made of methylstyrene, chlorostyrene, and the like. It may also be a copolymer consisting of two or more of the above monomers. Among the polymers made of the above-mentioned monomers, poly(diethylene glycol bisallyl carbonate) can be cited as the most suitable one in view of the incorporation of the alkoxysilane compound and various properties of the polymer as a synthetic resin lens. Moreover, the synthetic resin lens made of poly(diethylene glycol bisallyl carbonate) containing an alkoxysilane compound has particularly excellent adhesion of the antireflection film formed on its surface. (Hereinafter, poly(diethylene glycol bisallyl carbonate) will be representatively explained as the transparent synthetic resin.) The alkoxysilane compound in the present invention is one that forms an organosiloxane structure, and when heated, it dehydrates. A condensation reaction occurs to form an organosiloxane structure.It is usually in the form of an organic solvent solution of a partially hydrolyzed condensate and is used as a hard coating agent for synthetic resins.Alkoxy used in the present invention Examples of silane compounds include tetraalkoxysilane, a tetrafunctional compound represented by Si(OR) ₄ (where R is a lower alkyl group, the same applies hereinafter), and methyl, a trifunctional compound represented by CH ₃ Si(OR) ₃ . trialkoxysilane,
It is a polyfunctional alkoxysilane compound such as phenyltrialkoxysilane, a trifunctional compound represented by C ₆ H ₅ Si(OR) ₃ . More specific examples of such alkoxysilane compounds include tetraethoxysilane (ethylsilicate), which is typical as tetraalkoxysilane; methyltrimethoxysilane and methyltriethoxysilane as methyltrialkoxysilane; and phenyltrialkoxysilane. Examples include phenyltriethoxysilane compounds. These alkoxysilane compounds can be easily obtained commercially. In the present invention, the content of the alkoxysilane compound contained in the transparent synthetic resin is set to an amount that does not significantly reduce the optical properties and mechanical strength of the synthetic resin lens, for example, when blending it into the monomer from which the transparent synthetic resin is obtained. A suitable polymer is blended in an amount of 0.1 to 20% by weight based on the monomer. It has been found that by containing the alkoxysilane compound in an amount within this range, the adhesion of the antireflection film formed on the surface of the molded lens is significantly improved. Therefore, in order to further enhance the adhesion effect and to promote and ensure the siloxane structure of the alkoxysilane compound, an inorganic or organic acid as a hydrolysis and condensation catalyst for the alkoxysilane compound is used as a monomer. Preferably, the lens is made of a synthetic resin made of a polymer added to and polymerized. Examples of acids that can be used as catalysts include hydrochloric acid and acetic acid, and the amount added depends on the amount of the alkoxysilane compound.
The amount is preferably 0.01 to 5 parts by weight per 100 parts by weight. In the synthetic resin lens of the present invention, the material of the antireflection film formed on the lens surface exhibits excellent adhesion, especially when it is a metal oxide type material. The reason for this improvement in adhesion is not clear, but it is due to the chemical bonding between the siloxane structural molecules, which are extremely homogeneously dispersed on the lens surface and in the thickness direction, and the antireflection coating material, especially the metal oxide material. It is assumed that this is due to A synthetic resin lens is usually manufactured by the following method. That is, a mixed solution prepared by adding and dissolving a radical polymerization initiator into a monomer obtained from a transparent synthetic resin is injected into a mold in which a glass mold has been previously installed through a gasket and heated. Superimpose.
The manufacturing method of the present invention can also employ such a method. However, the method is not limited to this method. In the present invention, for example, diethylene glycol bisallyl carbonate is blended with a required amount of an alkoxysilane compound, a radical polymerization initiator, and a catalytic amount of acid, and a mixed solution is poured into a mold and heated. As the radical polymerization initiator, diisopropyl peroxycarbonate, which is commonly used in the polymerization of diethylene glycol bisallyl carbonate, is suitable, but other suitable radical polymerization initiators include di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, dicarbonate, etc. -n-bis(4-
peroxycarbonates such as tert-butylcyclohexyl) peroxydicarbonate and tert-butylperoxyisopropyl carbonate;
Alternatively, peroxides such as benzoyl peroxide and lauryl peroxide can be used. Such a polymerization initiator is usually used in an amount of 1 to 5% by weight based on the monomer, and an amount within this range is sufficient in the present invention. In the synthetic resin lens of the present invention, for the purpose of imparting various properties to the molded lens, additives such as UV absorbers such as 2, 4
- derivatives such as dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone,
It may contain benzotriazole substitutes, hindered phenols, hindered amines, etc. as oxidation-resistant agents, quaternary ammonium salts as antistatic agents, nonionic surfactants, etc. The heating temperature as a polymerization condition varies depending on the type of monomer obtained from the transparent synthetic resin used, and is carried out at the optimum temperature for each.
For example, diethylene glycol bisallyl carbonate is heated to about 125°C by gradually increasing the temperature from room temperature of about 25°C.
The temperature is raised to ℃, but the time required is
It is appropriate to allow 24 to 48 hours to complete the polymerization. After cooling, the molded lens is removed from the mold and immediately subjected to an antireflection film formation process. If necessary, an antireflection film formation process is performed after a cleaning process. Typical methods for forming anti-reflection films include vacuum evaporation, ion plating,
These methods include the CVD method and the sputtering method, and any method can be used to produce the synthetic resin lens of the present invention. Anti-reflection coating materials are typically metal oxides such as silica, alumina, zirconia, magnesium oxide, cerium oxide, beryllium oxide, indium oxide, hafnium oxide, or magnesium fluoride, cerium fluoride, lanthanum fluoride, and lithium fluoride. , sodium fluoride and other fluorides are used, and such antireflection film materials can also be used in the synthetic resin lens of the present invention. In addition, gold,
It may be colored by adding a small amount of silver, copper, chromium, aluminum, etc. Anti-reflective coatings made of the above anti-reflective coating materials are usually made into a single layer structure using one specific type with a specific thickness, or a multilayer structure using several specific types with a specific thickness. Although the synthetic resin lens of the present invention is formed by laminating layers, the synthetic resin lens of the present invention may be formed by any structure. Therefore, in the anti-reflection film material,
SiO ₂ has the most remarkable effect of improving adhesion through chemical bonding with siloxane molecules that are homogeneously present in the lens. For example, SiO ₂ by vacuum evaporation method,
The anti-reflective film, which is formed by alternating ZrO ₂ to a specific thickness, has excellent adhesion and durability as well as anti-reflective performance, and for example, no peeling or cracking was observed in forced environment tests. do not have. [Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited only to these Examples. Examples 1 to 6 Diethylene glycol bisallyl carbonate as a monomer from which a transparent polymer is obtained, one selected from tetraethoxysilane, methylethoxysilane, and phenyltriethoxysilane as an alkoxysilane compound, and a hydrolysis catalyst for an alkoxysilane compound One selected from acetic acid (99.5%) and hydrochloric acid (36%) as a polymerization initiator, and diisopropyl peroxydicarbonate (Pyrol IPP: a product of NOF Corporation) as a polymerization initiator in accordance with the blending amounts shown in Table 1. and mix well to prepare a clear mixture. This mixture was injected into a lens molding cell formed by a glass mold and gasket, maintained at 33°C for 1.5 hours, and then
The temperature was raised to 33-63℃ over 14 hours, then maintained and raised at each temperature repeatedly, such as 63℃ for 45 minutes, 63-93℃ for 45 minutes, and 93℃ for 1 hour. It took 18 hours to complete the thermal polymerization. Next, the lens was allowed to cool to room temperature, and the lens was released from the mold using a conventional method. No difference in mold release properties was observed between lenses made of diethylene glycol bisallyl carbonate homopolymer. The lens thus molded has a diopter of 0.00, a thickness of approximately 2.5 mm at the center, and is completely transparent. The rate was 93% in both cases. The obtained lens was soaked in a 2% solution of neutral detergent, clean water,
After sequentially performing ultrasonic cleaning in a bath filled with distilled water and isopropyl alcohol, it is dried and placed in a vacuum furnace at 1 x 10 ^-5 Torr and substrate temperature 60 to 100.
The thickness of the metal oxide film from the lens surface side at ℃
SiO ₂ 0.045, ZrO ₂ 0,032, SiO ₂ 0.010, ZrO ₂ 0.086,
A vacuum evaporation process was performed to form an antireflection film to a designed value of SiO ₂ 0.089 μm (each μm). The lenses with the anti-reflection film formed thereon were kept in a humidity-proof tank maintained at a temperature of 50°C and a relative humidity of 95% for 14 and 30 days, respectively, as a humidity test, and then the adhesion of the anti-reflection film was tested using a goblin test, i.e. The adhesive tape was cut into 100 squares at 1 mm intervals and evaluated by a peel test method using an adhesive tape. Table 1 shows the test results for both surfaces of the lens with concave and convex surfaces according to the goblin test. Example 7 Diallyl phthalate was mixed in advance with diethylene glycol bisallyl carbonate according to the amounts shown in Table 1, and tetraethoxysilane, acetic acid, diisopropyl peroxycarbonate, and ditert-butyl peroxide were added and dissolved. A clear mixture was prepared. This mixed solution was injected into a lens molding cell formed by a glass mold and gasket, and heated to 33℃ for 30 minutes.
The temperature was then maintained at 33-63°C over 14 hours, then maintained at each temperature for 45 minutes, 63-93°C for 45 minutes, and 93°C for 1 hour. The polymerization was continued for about 47 hours in total to complete the polymerization. Next, the lens was allowed to cool to room temperature, and the lens was released from the mold using a conventional method. There was no difference in mold releasability from Examples 1 to 6, and a transparent lens with a visual transmittance of 92% was obtained, having the same shape as Examples 1 to 6. The obtained lenses were vacuum evaporated in the same manner as in Examples 1 to 6 to form an antireflection film, and then subjected to a moisture resistance test followed by a cross-cut test. Table 1 shows the test results for both surfaces of the lens with concave and convex surfaces according to the goblin test. Comparative Example 1 A lens was formed in the same manner as in Example 1 except that tetraethoxysilane and acetic acid were not added, and further an antireflection film was formed on the surface of the lens. The obtained lens was kept in a moisture-proof tank for 2 days in the same manner as in Example 1, and then the eye test was performed. Table 1 shows the test results of the uneven surfaces of the lens using the goblin test, and the antireflection film was completely peeled off on both surfaces of the uneven surfaces. Comparative Example 2 After forming a primer layer made of a modified melamine resin as a primer layer on the surface of the lens molded in Comparative Example 1, an antireflection film was formed on the primer layer in the same manner as in Example 1. The obtained lens was tested for moisture resistance in the same manner as in Example 1, and then subjected to a cross-over test. Table 1 shows the test results of the uneven surfaces of the lens using the goblin test, and it was found that most of the antireflection film was peeled off on both surfaces of the uneven surfaces.

[Table] [Effects of the Invention] The synthetic resin lens of the present invention is characterized by containing an alkoxysilane compound, and as a result, the antireflection film formed on the lens surface has exceptional adhesion. Therefore, it has the effect of being excellent in durability. Furthermore, conventionally, in order to improve the adhesion of the anti-reflection film, a pre-treatment process such as special treatment of the lens surface or formation of a pre-coat layer has been required, but such pre-treatment processes can cause defective products. , which is a factor in decreasing yield. However, since the synthetic resin lens of the present invention does not require such a preliminary treatment step, the cause of defective products is eliminated, and it is recognized that it is significantly advantageous in terms of cost.

Claims (1)

[Scope of Claims] 1. A synthetic resin lens made of a transparent synthetic resin, characterized in that the transparent synthetic resin contains an alkoxysilane compound, and has an excellent adhesion of an antireflection film. 2. Claim 1, wherein the alkoxysilane compound is a silane compound selected from tetraalkoxysilane, methyltrialkoxysilane, and phenyltrialkoxysilane, which are polyfunctional compounds forming an organosiloxane structure. Synthetic resin lens. 3. A synthetic resin lens according to claim 1, wherein the transparent synthetic resin is poly(diethylene glycol bisallyl carbonate).