JPS61235801A - Mirror coated plastic lens - Google Patents

Abstract

PURPOSE:To enhance market value by hardening a compsn. composed essentially of a colloidal silica and a specified organosilicon compd. with a hardening agent to form an undercoat layer and forming a mirror coat layer of multilayer structure comprising a layer made of metal oxide and a layer made of metal or metal oxide by vapor deposition method or the like. CONSTITUTION:The mirror coat layer of multilayer structure comprising a layer made of metal oxide and a layer made of metal or metal oxide are formed by vapor deposition method or the like on the undercoat layer composed essentially of a colloidal silica and the organosilicon compd. represented by the formula shown on the right in which R1 is 1-6C alkyl and R2 is 1-6C alkylene. The second SiO2 layer has an optical film thickness of lambda/4, lambda being 450-550nm, the third Cr layer has a film thick ness corresponding to transmittance of 50-60% at lambda wavelength, the fourth ZrO2 layer has an optical film thickness of lambda/4, the fifth Cr layer has a film thickness corresponding to 10-20% transmittance at lambda wavelength, the sixth SiO2 layer has an optical film thickness of lambda/4, and the seventh SiO layer has an optical film thickness of lambda/4, thus permitting the obtained coating films to be maintained high in abrasion and scratch resistance, and the obtained lens to overwhelm vulnerability, and have reflection preventing effect, too.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a plastic mirror-coated lens with improved surface scratch resistance and reduced reflection on one side.

[Prior Art] Various types of sunglasses for leisure use are on the market, and recently, especially overseas, there has been an increase in the number of sunglasses whose glass surfaces are coated with a mirror coating to give them a metallic luster. However, since the base material of these mirror-coated sunglasses is glass, they are heavy and break easily, so they are often unsuitable for active leisure activities. In order to solve these problems, it has been considered to make the base material organic, and some mirror coat lenses made of organic base materials are also commercially available. However, such mirror-coated lenses still have problems in terms of heat resistance of the material, and also have insufficient adhesion to metals, resulting in extremely poor abrasion S resistance of the lenses.

However, with recent advances in vacuum deposition methods, methods for improving the adhesion of metals to plastic materials have gradually been put into practical use. An example of applying these technologies to plastic mirror-coated sunglasses is JP-A-55-4671.
Publication No. 3, JP-A-55-46714, JP-A-55
It is disclosed in Japanese Patent Laid-open No. 46715-46715 and Japanese Patent Application Laid-Open No. 55-46716. These publications describe metals that can be used as mirror coats such as Cu, Au%A#, Ti, and N.
Various types of plastics are coated with i, Cr%Co, Ag, etc. using a high frequency ion blating method to improve their adhesion.

[Problem that the invention seeks to solve]

However, for the actual use of eyeglass lenses and sunglasses, improving the adhesion of the coating film alone is not sufficient, and the special Vcf
-) In the case of stick lenses, it is an important issue to provide sufficient scratch resistance on the surface. Also, if you simply coat a plastic lens with metal,
The reflection on both sides of the coated film becomes strong, which is disadvantageous in use as a mirror coated lens and reduces the commercial value.

[Means for solving problems]

In order to solve the problems of the conventional technology described above, BAt et al. focused on a method of applying an organic hard coat film with good scratch resistance as a base layer to the surface of Zo2 Snack, and then applying a mirror coat on top of it. I did a lot of research. As a result, when an organosilicon compound having the general formula % formula % (wherein R1 is an alkyl group having 1 to 6 carbon atoms and R2 is an alkyl group having 1 to 6 carbon atoms) is used together with colloidal silica, Even if the organosilicon compound is contained in a relatively small amount, sufficient flexibility, heat resistance, and weather resistance can be imparted to the coating film, and as a result, the proportion of colloidal silica, which is a hardness imparting component, can be kept high, and this organic hard coat film It has been found that by forming a multilayer structure of metal oxide and metal on top, it is possible to reduce the reflection on the opposite surface while increasing the reflection on the coated surface.

The present invention was achieved based on such knowledge, and the surface of a plastic lens is coated with colloidal silica and the general formula (where R1 is an alkyl group having 1 to 6 carbon atoms, R2 is an alkyl group having 1 to 6 carbon atoms) A base layer consisting mainly of an organosilicon compound represented by (Arkylev group) and cured with a curing agent is applied, and then a layer consisting of a metal oxide and a metal or metal are applied by a method such as vacuum evaporation. This is a mirror coated lens manufactured by Zo2stic, which is characterized by being provided with a mirror coat layer having a multilayer structure including a layer made of an oxide.

In the misfire 8A, the plastic lens is diethylene glycol bisallyl carbonate polymer (CR-
3q) s Polymethyl methacrylate (PMMA)
, polycarbonate, polystyrene, etc.

Additionally, plastic lenses can be dyed as desired before coating to adjust the transmitted color of the lens.

Colloidal silica and the organosilicon compound represented by the general formula are those in which the amount of colloidal silica is 75 to 90 $mog% (5io2 solid content equivalent value) based on the total amount of the organosilicon compound, and the amount of the organosilicon compound is 25 to 5 If the mole content is 1%, the amount of the curing agent is sufficient to cure colloidal silica and the hydrolyzate of the organosilicon compound.

It is a thyl group, a propyl group or a dithyl group. Those in which R2 is a methylene group, an ethylene group, a zolopylene group or a butylene group are preferred.

In addition, in the present invention, as the colloidal silica, in order to avoid leaving as much excess water as possible after the hydrolysis of the organosilicon compound, it is preferable to use water-dispersed colloidal silica (5 in 2 solid content of 40 to 50%) with as high a concentration as possible. is preferred. The particle size is preferably about 5 mμ to 30 mμ. Specific examples of colloidal silica include Snowtex-40 (Kuchiju Kagaku, SiO240 layer concentration, water-dispersed silica), Cataloid 8l-40 (Catalyst Chemical Industry, SiO2
40 layer concentration, water-dispersed silica), Cataloid 8l-5Q
(Catalyst Chemical Industry, 50-layer concentration, water-dispersed silica), etc.

Also, alcohol-dispersed colloidal silica can be used instead of water-dispersed colloidal silica, but when the resulting composition is applied and cured, there are problems such as spiders and small gel-like bumps. Water-dispersed colloidal silica is preferred.

The curing agent used in the present invention includes imidazole derivatives, but acetylacetone metal salts are particularly effective. The amount added is an amount sufficient to harden the colloidal silica and the hydrolyzate of the organosilicon compound, for example, 1 to 10% per mole of the total of colloidal silica (SiO□ equivalent) and the hydrolyzate of the organosilicon compound. Gram.

Examples of the solvent used in the coating composition include lower alcohols, esters, ethers, ketones, etc., and isozorobyl alcohol, butanol, methyl cellosolve, etc. are particularly preferred.

A silicone surfactant can also be added to the base layer composition for the purpose of improving the smoothness of the coating film. Furthermore, it is also possible to add ultraviolet absorbers, antioxidants, etc. for the purpose of improving weather resistance or preventing deterioration of the coating film.

Furthermore, various additives can be added for the purpose of improving practicality such as improving adhesion to the substrate (Zo2 Snacrene F) and physical properties.

Furthermore, the addition of sodium acetate, which is generally used for stabilizing the coating liquid or as a catalyst, is not preferred in case of non-explosion 8A. The reason for this is that sodium acetate tends to precipitate toward the film surface after the coating composition is applied and cured, which has a negative effect on the film formation of vapor-deposited substances.
This is because even if it is left in place, it will cause the same adverse effects as precipitation due to vacuum or heating.

The mirror coat film provided on the base layer has a multilayer structure including a layer made of metal oxide and a layer made of metal or metal oxide. Here, the metal oxide is silicon monoxide (sl
o ), silicon dioxide (51o2), titanium dioxide (Ti
O2) sZirconium dioxide (ZrO2) sTitanium trioxide (T1203), -Titanium oxide (Tie), Cr
Examples of metals include lower oxides of Cr.
Alternatively, T1 can be mentioned. As a result of studying various metal oxides and metals that can more fully maintain the adhesion and scratch resistance of the mirror coat film, we found that when forming the mirror coat film by vacuum evaporation, 5iO18i02, ZrO2, TlO
It has been found that a combination of metal oxides of No. 2 and metals of Cr or T1 is effective.

In the present invention, it is preferable that the mirror coat layer has a multilayer structure including the base layer and has seven layers.

In this case, if the base layer is the first layer, the second layer is 5iO1T
102 or ZrO2, the third layer is a thin film made of Cr or Ti metal, or a lower oxide of these metals, and the fourth layer is TiO2.
2. A thin film made of one or more metal oxides of ZrO2 or Ti2O3; the fifth layer is made of the same metal or metal oxide as the third layer, and has a thickness approximately twice that of the third layer; The 6th layer is a thin film made of 5102, and the 7th layer is SiO,'
When each layer of a thin film made of one or more metal oxides of f'io2, ZrO2, T1□03 or TiO is sequentially laminated, a plastic Mi2-coated lens having a mirror coat layer with such a multilayer structure is formed. It is sufficiently durable for use as a spectacle lens, and can reduce reflection on the opposite side of the mirror coat film. In addition, as the second layer, especially SiO
, the third layer is especially Cr or its lower oxide, the fourth layer is especially ZrO2, the fifth layer is especially Cr or its lower oxide, the sixth layer is especially SiO2, and the seventh layer is especially SiO2. are valid.

The second Si0 layer has an optical thickness of λ/4 (λ: 450 to 5
50 nm), and the third Cr layer has a transmittance (λ) of 60
~50% film thickness, the fourth layer ZrO2 layer has an optical thickness λ/
4. The fifth Cr layer has a thickness of 20 to 10% in terms of transmittance (λ), the sixth SiO2 layer has an optical thickness of λ/4, and the seventh 8iO layer has an optical thickness of λ. /4, the scratch resistance of the mirror coat film and the effect of reducing reflection on the surface opposite to the mirror coat film surface are large.

Next, one example of a method of coating a plastic lens using the base composition will be described.

First, an inorganic acid such as hydrochloric acid or an organic acid such as acetic acid is added to colloidal silica to make it acidic (for example, p
H2-6), then the liquid temperature is raised to 60-50°C, and an organosilicon compound having the above general formula is added dropwise, followed by stirring to hydrolyze the organosilicon compound.

The above-mentioned solvents, such as inglobil alcohol, butanol, methylselonulp, etc., are added to the hydrolyzed mixture, and a predetermined amount of a curing agent is further added.

Although the composition thus obtained has a colloidal silica content of 75 to 95 moe%, it is unlikely to undergo silica formation and its viscosity will not increase.

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

The composition applied to the plastic lens is cured mainly by heat treatment, and the heating temperature can be varied over a wide range, but is preferably 40°C.
-150°C, particularly preferably 80°C - 120°C. A heating time of 1 to 4 hours or more gives good results.

The coating film obtained by heat curing has excellent abrasion resistance (hardness) and flexibility (flexibility).
It also has excellent heat resistance and chemical (alkali) resistance.

Before applying the coating composition of the present invention, the plastic lens is preferably pretreated by an alkali treatment, plasma treatment, ultraviolet irradiation treatment, or the like. In addition, 8i0, Ag2O3, SiO2, ZrC was deposited on the opposite side of the mirror-coated lens (← north side) using normal vacuum deposition.
By applying a multilayer antireflection film such as +2, TiO2, etc., the reflection on the 111 surface of the mirror coated lens can be further reduced.

〔Effect of the invention〕

According to the present invention, the surface hardness (abrasion resistance, scratch resistance) of the coating film can be maintained high, and the mirror coat lens with this coating Mt-base layer has the greatest drawback of conventional plastic mirror coats. It is possible to manufacture lenses that overcome the existing fragility and also have the anti-reflection effect required for eyeglass lenses.

[Embodiments of the invention]

Examples of the present invention will be described below based on the drawings, but the present invention is not limited thereto. In the examples, [parts] are parts by weight.

Example 1 Colloidal silica (Snowtex-40, Nikki Kagaku)
A solution prepared by adding 2.0 parts of 0-5N hydrochloric acid and 20 parts of acetic acid to 240 parts was heated to 35°C, and while stirring, 94.4 parts of γ-glycidoxyprobyltrimethoxysilane was added dropwise to the solution, and the mixture was heated to room temperature. The mixture was stirred for 8 hours and left at room temperature for 16 hours. To this hydrolyzed solution were added 80 parts of methyl seso/l/7", 120 parts of isopropyl alcohol, 40 parts of ethyl alcohol, 16 parts of aluminum acetylacetone, and a silicone surfactant composition.

The proportion of silicon compounds is colloidal silica 5Q
mole% (in terms of f8i02 solid content) and r-glycidoxyzolopyltrimethoxine 2-20 mole%.

This coating composition was applied to the plastic lens (OR-39) 1 shown in Fig. 1 and cured by heating to a thickness of about 6 μm.
A thick organic hard coat film 2 was provided. Next, 510 (λ/4 λ:
450-550 nm) Layer 3, C with a film thickness of 60% in transmittance
r (λ) layer 4, ZrO2 (λ/4) layer 5, transmittance 2
A Cr (λ) layer 6.5io2 (λ/4) layer 7.8i0 (λ/4) layer 8 having a film thickness of 0% was formed.

The spectral reflectances of the upper surface and the cut surface of the mirror coat film formed as described above are shown in Figures 2(a) and 2, respectively.
As shown in Figure (b). In FIG. 2, A is the spectral reflectance after the hard coat film treatment, and B is the spectral reflectance when the mirror coat film is applied. Figure 2 shows that the reflection on the coating side of the surface is sufficiently strong over the entire visible range, and even so, the reflection of the coating film on the surface side is around 0.7% (excluding 4% of the reflection from the top surface of the lens). It can be seen that the film also has a sufficiently good anti-reflection function (residual reflection).

Comparative example 1 Colloidal silica (Snowtex-40, Nichichi Kagaku)
90 parts, 2.0 parts of 0.5N hydrochloric acid, 20 parts of acetic acid, 90 parts of water
of methyltrimethoxy 7271 while stirring.
After dropping 90 parts, it was stirred at room temperature for 8 hours, and 1
After standing for 6 hours, a coating composition was obtained in the same manner as in Example 1.

The proportion of silicon compounds is colloidal silica 3Q
mole% (solid content) and methyltrimethoxysilane 7Q mole%. This coating composition 9CR-39 lens was also treated in the same manner as in Example 1, including cloth, heat curing, and treatment of the mirror coat film.

Comparative example 2 Colloidal silica (Snowtex-40, Nichichi Kagaku)
150 parts, 2.0 parts of 0°5N hydrochloric acid, 20 parts of acetic acid, 5 parts of water
4 parts of methyltrimethoxysilane was added dropwise while stirring, and the mixture was stirred at room temperature for 8 hours.
The mixture was left to stand for 6 hours, and then the same procedure as in Example 1 was carried out to obtain a coating composition.

The proportion of silicon compounds is colloidal silica 5Q
mole% (solid content) and methyltrimethoxysilane 5
It was 0 mole%. The treatment of this coating mirror coat film is the same as in Example 1.

Proportion 3 Colloidal Silica (Snowtex-40, Nichikagaku)
180 parts, 2.0 parts of 0.5N hydrochloric acid, 20 parts of acetic acid, 36 parts of water
Add 1 part of methyltrimethoxysilane while stirring.
After dropping 10 parts, the mixture was stirred at room temperature for 8 hours and left at room temperature for 16 hours, and then a coating composition was obtained in the same manner as in Example 1.

The proportion of silicon compounds is colloidal silica (5Q
mole% (solid content) and methyltrimethoxysilane 4
Q mole%. The coating composition, cR-39 lens>1 cloth, heat curing, and mirror coating film treatment were the same as in Example 1.

Comparative Example 4 472 parts of r-glycidoxypropylmethoxysilane, 100 parts of water, and 10 parts of 0.1N hydrochloric acid were added, stirred for 8 hours and left at room temperature for 16 hours, and coated in the same manner as in Example 1. Get the composition. The processing of this composition ζCR-3 needle storage, heat curing, and mirror coat B were the same as in Example 1.

Comparative Example 5 A CR-39 lens was coated with 8i021gI to a thickness of about 2 μm by vacuum evaporation to form a bar V coat film. The deposition conditions were a vacuum level of 2 x 10-50-5n and a substrate temperature of 80°C. The treatment of the mirror coat film on this lens is the same as in Example 1.

Test Example The test consisted of a hard coat lens in which a coating composition was applied to a CR-39 lens and cured by heating to form a coating film, and a 2 μm thick Si film coated by vacuum evaporation.
A comparison was made between a hard coat lens made of an O2 film and a mirror coat film formed by vacuum deposition on the cured coating film of the hard coat lens. As shown in Example 1, this mirror coat film has a laminated structure of metal oxides SiO 2 , ZrO 2 , SiO 2 and metal Cr, as shown in FIG. It is. Note that this mirror coat film was applied to all the hard coat lenses of Comparative Examples and Example 1 at the same time.

The outline of various test methods will be explained below.

(a) Abrasion resistance (scratch resistance) *Applied load 10 to the surface with oooo steel wool
00. ! After rubbing 500 times (reciprocating) with No. 9, the following judgment was made.

A: It hardly gets scratched.

B: Slight damage.

C: Many excellent scores.

Peeling of D=H occurs.

This test was conducted on both a plastic lens having a hard coat film and a plastic lens having a hard coat film and a mirror coat film.

(1)) Adhesion: 10×10 goblets of 11 m square were made, and a peel test using cellophane adhesive tape was performed 6 times to determine the number of gobs remaining.

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

LC) Appearance: Transparency, coloration, surface condition, etc. were examined by visual inspection.

(cl) Heat Resistance, Hot Water Resistance■ A plastic lens coated with the coating composition and cured was placed in a constant temperature oven at 150° C., and it was examined whether or not there were any cracks in the coating film.

The samples were immersed in O boiling water for 1 hour and examined for any changes in appearance.

(e) Weather resistant xenon long life sea urchin meter WgI-25A
Accelerated exposure was performed for 500 hours using X (Suga Test Instruments), and it was examined whether the coating film had yellowed or deteriorated.

(f) Chemical resistance The coating film was immersed in the following solution for 1 hour at room temperature to examine changes in the coating film.

The test results for 1.10% NaOH solution 2.10% Hag solution 3, acetone solution 4, methanol solution Example 1 and Comparative Examples 1 to 5 are shown in the table below.

As is clear from the above table, Example 1 provides excellent coating stiffness in all aspects of appearance, adhesion, heat resistance, hot water resistance, weather resistance, chemical resistance, and abrasion resistance, whereas Comparative Examples 1 to 1 Sample No. 5 was inferior in at least one of the above properties. Furthermore, in Example 1, the abrasion resistance was improved by I! in a plastic lens having a hard coat film (base layer) and a mirror coat film. #VC was outstanding.

Even in the component systems of colloidal silica and methyltrimethoxysilane shown in Comparative Examples 1 to 3, as the proportion (mole%) of colloidal silica increases, the hardness of the composite film as the underlayer of the mirror coat film increases. However, if the proportion of colloidal silica exceeds 60 mole%, cracks will occur. Therefore, the proportion of colloidal silica cannot be increased beyond this point, and the hardness of the composite film cannot be improved beyond a certain level.

Further, in Comparative Example 4, the hard coat film alone has high film hardness, but when a mirror coat film is provided thereon, the effect of the hard coat film as a base layer is reduced, and the abrasion resistance of the mirror foot is reduced. Furthermore, the wear resistance of Comparative Example 5 is lower than that of Example 1.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view of the d-plane of a lens showing an embodiment of the present invention, FIG. Figure (1)) is a reflectance characteristic diagram on the upper surface side of the mirror coated lens obtained in Example 1. 1...OR-39 (plastic base material) 2...Organic hard coat film 3...8W layer 4...Cr layer
5...ZrO□ layer 6...Cr layer
7...8i02 layer 8...SiO layer

Claims (3)

[Claims] (1) On the surface of the plastic lens, there is colloidal silica and a general formula ▲ mathematical formula, chemical formula, table, etc. A base layer consisting mainly of an organosilicon compound shown in A plastic mirror coat lens characterized by being provided with a mirror coat film having a multilayer structure including a layer. (2) The mirror coat film is coated with SiO on the base layer (first layer).
Claim 1 is formed by sequentially laminating a second layer of Cr, a third layer of Cr, a fourth layer of ZrO_2, a fifth layer of Cr, a sixth layer of SiO_2, and a seventh layer of SiO. Plastic mirror coated lens. (3) The second layer of SiO has an optical thickness of λ/4 (λ: 45
0 to 550 nm), the third layer of Cr has a transmittance (λ) of 60
~50% film thickness, the fourth layer of ZrO_2 has an optical thickness λ/
4. The fifth layer of Cr has a transmittance (λ) of 20 to 10% thickness, the sixth layer of SiO_2 has an optical thickness of λ/4, and the seventh layer of SiO has an optical thickness of λ/4. A plastic mirror coated lens according to claim 2.