JPH081482B2 - Plastic mirror lenses - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is less likely to be scratched, and The present invention relates to a method for manufacturing a plastic mirror-coated lens that reduces side reflection.

[Conventional technology]

Various types of sunglasses for cashiers are on the market, but recently, particularly overseas, the number of sunglasses in which a glass surface is mirror-coated to give a metallic luster is increasing. However, since these mirror-coated sunglasses are made of glass as a base material, they are heavy and easily broken, and therefore are not suitable for active activities at the time of registering. In order to solve such a problem, it is conceivable that the base material is made organic, and some mirror-coated lenses made of the organic base material are commercially available. However, such a mirror-coated lens has a problem in terms of heat resistance of its material, and its adhesion to a metal is not sufficient, so that the lens has extremely poor scratch resistance.

However, with the recent progress of the vacuum evaporation method, a method of improving the adhesion of metal to a plastic material has been gradually put into practical use. Examples of applying those techniques to plastic mirror-coated sunglasses are disclosed in JP-A-55-46713, JP-A-55-46714, JP-A-55-46715, and JP-A-55-46716. It is disclosed. In these publications, C is a metal that can be used as a mirror coat.
u, Au, Al, Ti, Ni, Cr, Co, Ag, etc. are coated on various plastics by the high frequency ion plating method to improve the adhesion.

[Problems to be solved by the invention]

However, in the actual use of eyeglass lenses and sunglasses,
It is not enough to improve the adhesiveness of the coating film alone, and particularly in the case of plastic lenses, it is an important issue to provide the surface with sufficient scratch resistance. Further, merely coating the plastic lens with a metal causes strong reflection on both surfaces of the coating film, which is disadvantageous in use as a mirror-coated lens and reduces the commercial value.

[Means for solving problems]

The inventors of the present invention have conducted investigations to solve the above-mentioned problems of the prior art. As a result, an organic hard coat film having good scratch resistance is applied to the surface of the plastic as an underlayer, and the organic hard coat film surface is provided. Focusing on the method of applying a mirror coat to, an organic hard coat film such as a silicone-based, acrylic-based, epoxy-based, melamine-based is applied as a base layer,
It has been found that when the organic hard coat film is provided with flexibility, heat resistance and weather resistance and then mirror-coated, the surface hardness of the mirror coat film can be kept high. In addition, the mirror coat film is a multilayer film including a layer made of a metal oxide and a layer made of a metal or a metal oxide,
It has been found that the coated surface can increase the reflection while reducing the reflection on the opposite surface.

The present invention has been made on the basis of such findings, in which the surface of a plastic lens is coated with an organic hard coat such as a silicone-based, acrylic-based, epoxy-based, or melamine-based, and a metal oxide film is formed on the organic hard-coated film surface. A mirror-coated lens made of plastic, wherein a mirror-coated film of a multilayer film including a layer made of a material and a layer made of a metal or a metal oxide is applied.

That is, the lens of the invention of the present application is formed by applying an organic hard coat film of a silicone type, an acrylic type, an epoxy type, a melamine type or the like on any surface of a plastic lens, and applying the following vacuum vapor deposition method onto the organic hard coat film. A mirror coat lens made of plastic, which is provided with a multi-layered mirror coat film consisting of a vapor-deposited film: 1st layer; SiO, TiO ₂ , ZrO ₂ λ / 4 second layer; metal consisting of Cr or Ti, or a lower oxide of these metals, having a film thickness of λ of 450 to 550 nm and a transmittance of 60 to 50% Third layer; TiO ₂ , ZrO ₂ , Ti ₂ O _{3 and} at least one metal oxide having a film thickness of λ / 4 fourth layer; the same metal as those of the second layer or metal oxides thereof, and having a λ of 450 to 550 nm and a transmittance. The thickness of the fifth layer is 20 to 10%; the thickness of SiO ₂ is λ / 4, the sixth layer is SiO, TiO, TiO ₂ , Ti ₂ O ₃ , In the present invention, any one or more kinds of ZrO ₂ metal oxides having a thickness of λ / 4 is used, and the underlayer provided on the surface of the plastic lens may be a silicone type, an acrylic type, an epoxy type, a melamine type, or the like. It is an organic hard coat film having excellent flexibility, heat resistance, and weather resistance. In addition to diethylene glycol bisallylcarbonate polymer (CR-39), there are some materials that are difficult to dye, such as polystyrene and polycarbonate, for the substrate (plastic lens) on which the organic hard coat film is provided. At the same time, a silicone-based organic hard coat film is effective in terms of dyeability. In addition, acrylic type is preferable from the viewpoint of quick curing time of the organic hard coat film, and epoxy type and melamine type are preferable from the viewpoint of film hardness and the like.

The silicone-based organic hard coat film is represented by the general formula (1) and the general formula (2) [Wherein R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ and R ₃ are alkyl groups having 1 to 4 carbon atoms, —CH═CH ₂ , Is an organic group selected from. ] The hydrolysis-condensation product of 1 type or 2 types of alkoxysilane of group A shown by these, or 1 type or 2 types of alkoxysilane of group A, and general formula (3) It is particularly effective to apply a coating solution containing an alkoxysilane represented by [R ₁ is an alkoxy group having 1 to 4 carbon atoms] or a hydrolysis-condensation product with colloidal silica as a main component to cure the coating solution.

Here, as the alkoxysilane of group A, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyltrimethoxysilane, dimethyldimethoxysilane, dimethyldimethoxysilane, phenyltriethoxysilane, cyclohexyltrimethoxysilane, γ- Aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ -Chloropropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane and the like can be mentioned. Examples of the alkoxysilane represented by the general formula (3) include
Examples thereof include tetramethoxysilane and tetraethoxysilane. As the colloidal silica, those having a particle size of 5 mμ to 30 mμ dispersed in water or alcohol are preferable. Hydrochloric acid and acetic acid are preferable as the acid for hydrolyzing the alkoxysilane or colloidal silica. As the curing agent used in the coating liquid of alkoxysilane or colloidal silica, there are imidazole derivatives and the like, but acetylacetone metal salt is particularly effective. The amount of addition is sufficient to cure the colloidal silica and the hydrolyzate of the organosilicon compound, for example, 1 to 10 g per 1 mol of the total of the hydrolyzate of colloidal silica (SiO ₂ conversion) and the organosilicon compound. Is.

Examples of the solvent used in the coating liquid include lower alcohols, esters, ethers and ketones, and isopropyl alcohol, butanol, methyl cellosolve and the like are particularly preferable.

A silicone surfactant may be added to the coating liquid for the purpose of improving the smoothness of the coating film.
Furthermore, for the purpose of improving weather resistance or preventing deterioration of the coating film,
It is also possible to add an ultraviolet absorber, an antioxidant and the like.

Various additives may be added for the purpose of improving practicality such as adhesion to a substrate (plastic lens) and improvement of physical properties.

Further, the addition of sodium acetate, which is generally used for stabilizing the pH of the coating solution and also as a catalyst, is not preferable. The reason is that sodium acetate tends to precipitate toward the film surface after coating and curing the coating composition,
This is because it has an adverse effect on the film formation of the vapor deposition substance, and even if the lens surface is cleaned by hand-wiping or washing before vapor deposition, it is also deposited during vacuum or by heating, which also has an adverse effect.

The composition obtained above is then applied onto the plastic lens by a commonly used dipping and pulling method (a dipping method), a spin coater method, a roll coater method, a spray method or the like.

Curing of the composition applied on the plastic lens
Mainly performed by heat treatment, the heating temperature can be in a wide range, preferably 40 ℃ ~
150 ° C, particularly preferably 80 ° C to 120 ° C. The heating time of 1 to 4 hours or more gives good results.

The organic hard coat film obtained by the heat-curing treatment has excellent abrasion resistance (hardness) as well as flexibility (flexibility), heat resistance, and chemical resistance (alkali).

Before applying the coating liquid, it is preferable to pretreat the plastic lens by alkali treatment, plasma treatment or ultraviolet irradiation treatment.

The substrate to which the organic hard coat film as described above is applied,
Examples thereof include plastic lenses such as diethylene glycol bisallyl carbonate polymer (CR-39), polymethylmethacrylate (PMMA), polycarbonate and polystyrene. By providing the above plastic lens with the above organic hard coat film, the surface hardness can be increased without deteriorating the optical properties of the plastic lens.

The mirror coat film provided on the base layer has a multilayer structure including a layer made of a metal oxide and a layer made of a metal or a metal oxide. Here, the metal oxide is silicon monoxide (Si
O), silicon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ), titanium trioxide (Ti ₂ O ₃ ),
Examples thereof include titanium monoxide (TiO) and lower oxides of Cr, and examples of the metal include Cr or Ti.
As a result of studying various metal oxides and metals capable of more sufficiently maintaining the adhesion and scratch resistance of the mirror coat film, when forming the mirror coat film by the vacuum deposition method, SiO, SiO ₂ , Z
A combination of a metal oxide of rO ₂ or TiO _{2 and} a metal of Cr or Ti is effective.

Further, in the present invention, it is preferable that the number of the mirror coat layers having a multi-layer structure including the underlayer be seven. in this case,
When the underlayer is the first layer, the second layer is a thin film made of one or more metal oxides of SiO, TiO _{2 and} ZrO ₂ , and the third layer is
A thin film made of a metal of Cr or Ti, or a lower oxide of these metals, a fourth layer is a thin film made of one or more kinds of metal oxides of TiO ₂ , ZrO ₂ or Ti ₂ O ₃ , and a fifth layer is A film made of the same metal or metal oxide as the third layer and having a thickness about twice that of the third layer, a sixth layer is a thin film made of SiO ₂ , and a seventh layer is
When each layer of a thin film made of one or more kinds of metal oxides of SiO, TiO ₂ , ZrO ₂ , Ti ₂ O ₃ or TiO is sequentially laminated, a plastic mirror-coated lens having such a multilayered mirror-coated layer is formed. Can be sufficiently used as a spectacle lens, and reflection on the opposite surface of the mirror coat film can be reduced. As the second layer, especially SiO λ / 4 (λ: 450-
50 nm), especially the third layer is Cr or its lower oxide, the fourth layer is especially ZrO ₂ λ / 4, the fifth layer is especially Cr or its lower oxide, and the sixth layer is especially SiO ₂ λ. / 4 and the seventh layer are particularly effective with SiO λ / 4. At this time, the film thickness of Cr is controlled by the transmittance to be arbitrarily changed between 60% and 10%, and the optimum condition of the strength of the mirror and the antireflection should be obtained. Further, it is desirable to provide a film serving as an antireflection film on the surface of the plastic lens opposite to the surface provided with the mirror coat film. As such an antireflection film, there is one in which a multilayer film of SiO, Al ₂ O ₃ , SiO ₂ , ZrO ₂ , TiO ₂ or the like is formed by a vacuum deposition method or the like.

Since the mirror-coated lens of the present invention is made of plastic, it can be dyed as desired before the coating process in order to adjust the transmission color of the lens.

〔The invention's effect〕

According to the invention, the mechanical strength of the coating is high, and It is possible to manufacture a plastic-made mirror-coated lens having a low-reflection and highly reproducible mirror-coated film and having high adhesion to a plastic substrate.

Example of Invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The present invention is not limited to these.

 [Parts] in the examples are parts by weight.

Example 1 Colloidal silica (Snowtex-40, Nissan Chemical)
90 parts, methyltrimethoxysilane 81.6 parts, γ-glycidoxypropylmethyldimethoxysilane 176 parts, 0.5N hydrochloric acid
A solution prepared by adding 2.0 parts, 20 parts of acetic acid and 90 parts of water was stirred at room temperature for 8 hours and left at room temperature for 16 hours.

120 parts of isopropyl alcohol in this hydrolysis solution,
120 parts of n-butyl alcohol, 16 parts of aluminum acetylacetone, 0.2 part of a silicone-based surfactant and 0.1 part of an ultraviolet absorber were added, and the mixture was stirred for 8 hours and then aged at room temperature for 24 hours to obtain a coating solution.

This coating liquid was applied to the plastic lens (CR-39) 1 shown in FIG. 1 and cured by heating to form the organic hard coat film 2. The film thickness of this organic hard coat film 2 was about 3 μm. Then, a SiO (λ / 4, λ: 450 to 550 nm) layer 3 was formed on the organic hard coat film 2 by a vacuum deposition method, a Cr (λ) layer 4 having a film thickness of 60% in transmittance, and ZrO ₂ (λ / 4). Layer 5, Cr (λ) layer 6 having a transmittance of 20%, SiO ₂ (λ / 4) layer 7, Si
A multilayer film was formed by sequentially stacking O (λ / 4) layers 8.

Of the mirror coat layer formed as described above The characteristic diagrams of the spectral reflectance of are shown in FIGS. 2 (a) and 2 (b), respectively. In FIG. 2, A is the spectral reflectance after the hard coat film treatment and B is the spectral reflectance after the mirror coat film treatment. From FIG. 2, in the mirror coat film according to the present embodiment, the reflection on the coat side of the ⊥ face is sufficiently strong over the entire visible range, and nevertheless Reflection of the coating film to the surface side is around 0.7% (lens It can be seen that it also has a sufficiently good antireflection function as well as residual reflection excluding 4% of surface reflection.

Example 2 γ-glycidoxypropyltrimethoxysilane 236
Solution, γ-glycidoxypropylmethyltrimethoxysilane (220 parts), 0.5N hydrochloric acid (2.0 parts), acetic acid (20 parts) and water (100 parts) were stirred at room temperature for 8 hours, and then mirrored in the same manner as in Example 1 below. A multilayer film of the coat was formed.

Example 3 γ-methacryloxypropyltrimethoxysilane 496
Part, 0.5N hydrochloric acid 2.0 parts, acetic acid 20 parts, and water 100 parts were stirred at room temperature for 8 hours to obtain a mirror-coated multilayer film in the same manner as in Example 1.

Example 4 γ-methacryloxypropyltrimethoxysilane 248
Part, colloidal silica (Snowtex-40, Nissan Chemical Co., Ltd.) 150 parts, 0.5N hydrochloric acid 2.0 parts, acetic acid 20 parts, and water 10 parts were stirred at room temperature for 8 hours, and then mirrored in the same manner as in Example 1 below. A coated multilayer film was obtained.

Example 5 100 parts of pentaerythritol tetraacrylate, 80 parts of trimethylolpropane triacrylate, 20 parts of ethylene glycol diacrylate and 2.0 parts of benzoylethyl ether were added to obtain an acrylic coating composition which was polymerized by ultraviolet rays.

This composition was applied to a CR-39 lens, polymerized and cured by irradiation with ultraviolet rays, and a mirror coat film was applied in the same manner as in Example 1 to obtain a multilayer film.

Comparative Example 1 A CR-39 lens was provided with a mirror film by vapor deposition as it was in the example, without forming an organic hard coat film.

 The outline of various test methods will be described below.

(A) Abrasion resistance # 0000 steel wool with a surface load of 500g
After rubbing 1000 times (round trip), the judgment was made as follows.

A: Almost no scratches.

B: A little scratched.

C: Many scratches.

D: Film peeling occurs.

(B) Adhesion 10 × 10 1 mm square goggles were formed, and a peeling test with a cellophane adhesive tape was performed 3 times to check the number of gobangs left.

The cellophane tape used was that of Nichiban JIS-Z-1522.

(C) Appearance The transparency, the colored state, the surface state, etc. were examined by visual observation.

(D) Solvent resistance The change in the mirror-coated multilayer film was examined by immersing it in the following solution at room temperature for 1 hour.

1. Acetone solution 2. Ethanol solution 3. Toluene solution Table 1 shows the test results for Examples 1 to 5 and Comparative Example 1.

As is clear from Table 1, in each of the examples in which the organic hard coat film is applied, the wear resistance is improved as compared with the comparative example. Since the organic hard coat films of Examples 1 and 2 can be dyed, use of such an organic hard coat film is effective for plastic lenses such as polystyrene and polycarbonate which are difficult to dye. The acrylic hard coat film of Example 5 was
Since it is cured by ultraviolet rays, there is an advantage that a work for forming a film having high hardness can be performed speedily.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view of a ⊥ surface of a lens showing an embodiment of the present invention, and FIG. 2 (a) is a reflectance characteristic diagram on the ⊥ surface side of the mirror-coated lens obtained in Embodiment 1. FIG. 2B shows the mirror-coated lens obtained in Example 1. It is a reflectance characteristic view of the surface side. 1 ... CR-39 (plastic base material) 2 ... organic hard coat film 3 ... SiO layer, 4 ... Cr layer 5 ... ZrO ₂ layer, 6 ... Cr layer 7 ... SiO ₂ layer, 8 ... … SiO layer

Claims (3)

[Claims] 1. An organic hard coat film of silicone type, acrylic type, epoxy type, melamine type or the like is formed on either surface of a plastic lens, and the following vapor deposition film is formed on this organic hard coat film by a vacuum vapor deposition method. A mirror coat lens made of plastic, which is provided with a multi-layered mirror coat film consisting of: 1st layer; any one or more kinds of metal oxides of SiO, TiO ₂ , and ZrO ₂ and having a thickness of λ / 4 Second layer; metal composed of Cr or Ti, or a lower oxide of these metals, having a film thickness of λ of 450 to 550 nm and transmittance of 60 to 50% Third layer: TiO ₂ , ZrO ₂ , Ti ₂ O ₃ is one or more kinds of metal oxides and has a film thickness of λ / 4 fourth layer; the same metal as the second layer or these metal oxides, and λ is 450 to 550 nm and the transmittance is 20 to thickness 10% fifth layer; thickness of SiO ₂ is lambda / 4 sixth _{layer; SiO, TiO, TiO 2,} Ti 2 O 3, ZrO 2 in any one Film thickness or more metal oxides lambda / 4 2. A silicone-based organic code coat film has general formulas (1) and (2). [Wherein R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ and R ₃ are alkyl groups having 1 to 4 carbon atoms, Is an organic group selected from. ] The hydrolysis-condensation product of 1 type or 2 types of alkoxysilane of group A shown by these, or 1 type or 2 types of alkoxysilane of group A, and general formula (3) A coating solution containing an alkoxysilane represented by [wherein R ₁ is an alkyl group having 1 to 4 carbon atoms] or a hydrolyzed condensate of colloidal silica as a main component and cured. The mirror-coated lens made of plastic according to item 1. 3. A plastic mirror-coated lens according to claim 1, wherein a multilayer antireflection film is provided on the opposite surface of the plastic lens provided with the mirror-coated film.