JPH077121B2 - Synthetic resin photochromic lens - Google Patents

Description

The present invention relates to a method for producing a synthetic resin photochromic lens having a photochromic thin film made of an inorganic material.

[Conventional technology]

At present, inorganic glasses and synthetic resins are widely used as eyeglass lens materials. Consumers are strongly demanding for photochromic lenses having both visual acuity correction and function, and for example, photochromic lenses using silver halide as an inorganic glass are commercially available. Conventionally, when imparting a photochromic function to an inorganic glass, a method of kneading silver halide into a material has been used. When this method is applied to a concave lens and a convex lens for vision correction, a difference in the thickness of the central portion and the outer peripheral portion of the lens causes a density gradient of coloring during darkening, which results in an unfavorable appearance of the lens.

The method of kneading silver halide into a lens made of synthetic resin is generally used for photochromic performance in casting, which is the most general method for manufacturing lenses, in addition to the above-mentioned problems of concentration gradient. It has a problem that it is inactivated by peroxide as a polymerization initiator.

So far, there have been disclosed some techniques for imparting a photochromic function to a synthetic resin with silver halide, and some techniques for a photochromic thin film with silver halide.

For example, Japanese Patent Publication No.45-12716 discloses a method of mixing a phototropic glass with a synthetic resin.However, the problem of the above-mentioned concentration gradient, and when this method is used, a crack is caused by the glass as a core during casting. It is not practical because it has a problem of easy entry. In Japanese Examined Patent Publication No. 54-33238, a thin film is made of silver halide and tin dioxide by a vacuum deposition method. In this case, not only the extinction ratio is low, but also the durability against repetition is poor, and it is not suitable for synthetic resin lenses. When applied, no adhesion with the lens substrate can be obtained. Separately, JP-A-51-45541 discloses coating silver halide grains with an inorganic material, and JP-A-52-152887 discloses a technique such as alternate dipping in a solution containing silver ions and halogen ions. However, the level of eyeglasses has not yet reached the level of spectacles due to problems such as the problem of the response speed of the color-decoloration reaction and the problem of durability due to repetition. Furthermore, Japanese Examined Japanese Patent Publication No. 54-34770 has Ag-Cu-X.
A technique for a thin phototrope layer using a eutectic mixture (X is Cl, Br) is disclosed.

[Problems to be solved by the invention]

When an Ag-Cu-X eutectic mixture is vapor-deposited by a resistance heating vapor deposition method as shown in Japanese Examined Patent Publication No. 54-34770, it has excellent reactivity to light, but not only has insufficient film strength. However, it has a problem that it cannot be applied to a synthetic resin lens because of poor adhesion to the synthetic resin substrate. Therefore, the present invention solves such a problem, and an object of the present invention is to provide a synthetic resin lens surface with excellent color fading properties and durability, and to provide adhesion to a lens substrate. Provided is a photochromic lens made of a synthetic resin, which is durable in daily use and provided with a photochromic thin film made of an excellent inorganic material.

[Means for solving problems]

The synthetic resin photochromic lens of the present invention is a synthetic resin lens surface, a layer containing a ternary solid solution shown below as a main component and a layer made of an inorganic substance are alternately laminated to form a multilayer film, and an inorganic substance is formed on the uppermost layer. Is provided with a hard coat layer or an antireflection layer.

Ag-Cu-X (where X is Cl, Br, I.) Furthermore, the layer containing the above-mentioned ternary solid solution as a main component has an island structure having islands with a grain size of 400 Å or less. Is characterized by.

The ternary solid solution used in the present invention is AgBr, AgCl, AgI, CuBr.
₂ , CuBr, CuCl ₂ , CuCl, CuI ₂ , CuI, Ag simple substance, Cu simple substance, etc.A compound containing the required three components or a simple substance is selected, and these are mixed, melted, and cooled. can get. In this case, it is possible to contain two or more kinds of halogens as X, and it is possible to change the response speed of darkening depending on the wavelength or change the color tone during darkening by mixing. In order to obtain sufficient photochromic properties, halogen atoms (Cl, Br, I) are 50 ± 10 mol%, Ag and Cu are 50 ± 10
It is preferably in mol%. Further, when obtaining a ternary solid solution by dissolution, an atmosphere of an inert gas such as Ar or N ₂ ,
Alternatively, it is necessary to suppress the generation of oxides such as silver oxide and copper oxide in vacuum.

When the ternary solid solution obtained by the above method is vapor-deposited on the surface of a synthetic resin lens by vapor deposition using resistance heating or electron gun heating, a thin film exhibiting photochromic performance can be obtained. However, the film thickness is 600Å in order to obtain the coloring required for practical use.
The above is necessary.

Further, such an Ag-Cu-X single layer has poor durability such as clouding over time. Si as a protective film to improve durability
Even when a film such as O ₂ or Al ₂ O ₃ is coated, the strength of the Ag-Cu-X single layer having a film thickness of 600 Å or more is weak and Ag-Cu-X
The layer breaks and cannot be put to practical use. We have found that Ag-
In order to improve the strength of the Cu-X layer and the adhesion to the lens substrate, the protective film, etc., SiO ₂ , ZrO ₂ , TiO ₂ , SnO ₂ etc. and Ag-Cu-X were co-evaporated to form a thin film. . However, this method is also not practical because the original photochromic performance is reduced due to the influence of the co-evaporated metal oxide, or the expected strength cannot be obtained.

In the present invention, the thickness of the layer containing Ag-Cu-X as a main component is set to a thickness having a generally known island structure. In this case, the vapor deposition material does not spread over the entire surface of the substrate, and a thin film has not yet been formed.

When the present inventors performed transmission electron microscopy, Ag-Cu
In the substance containing -X as the main component, the particle size of the island that can have an island structure was about 400 Å or less. In the case of such a layer, coloring by light irradiation is slight in a single layer. In the present invention, as shown in FIG. 1, inorganic substances such as SiO ₂ , Al ₂ O ₃ and ZrO _{2 which} have strong film strength and excellent adhesion to a substrate and Ag-C
The above layers containing u-X as a main component are alternately multilayer-deposited,
A multilayer film with sufficient photochromic performance was obtained. When forming a multilayer film on a synthetic resin lens substrate, it is desirable to vapor-deposit an inorganic substance on the substrate to form a multilayer film in order to improve the adhesion to the substrate. The thickness of the inorganic substance is Ag-Cu-
Any thickness may be used as long as it is thicker than the X layer, but in order to obtain sufficient photochromic performance, it is necessary to stack several tens of layers, and in order to suppress the overall film thickness, each film thickness can be suppressed to the minimum. Is desirable. Further, in the present invention, the uppermost layer is made of SiO ₂ , Al ₂ O ₃
A hard coat layer or an antireflection layer made of an inorganic substance such as is provided. The antireflection layer uses silicon dioxide, magnesium fluoride, etc. as the low refractive index material, titanium oxide, zirconium oxide, tantalum pentoxide as the high refractive index material, and aluminum oxide etc. as the medium refractive index material. Can be used.

The layer containing Ag-Cu-X as a main component, the hard coat layer, and the antireflection layer can be formed by a vacuum deposition method, a sputtering method, an ion plating method, or the like.

In order to improve the adhesion between the synthetic resin substrate and the photochromic layer or the layer made of an inorganic substance, it is effective to chemically treat the surface of the synthetic resin substrate with an alkali or an acid, or to perform plasma treatment.

The base lens that can be used in the present invention is diethylene glycol bis (allyl carbonate), polymethyl methacrylate, polycarbonate, polystyrene, dimethacrylate having a nucleus halogen-substituted aromatic ring or diacrylate and a radically polymerizable monomer having an aromatic ring. It is possible to use any of resins such as a copolymer with the above, a diallyl carbonate having a nuclear halogen-substituted aromatic ring, and a radically polymerizable copolymer having an aromatic ring. A synthetic resin lens having an organic hard coat can also be used. In order to improve the adhesiveness of these base lenses, it is preferable to wash them in advance with a solvent such as alcohol.

[Action]

It is generally considered that silver halide exhibits reversible photochromic properties according to the following formula.

(X is a halogen excluding fluorine) Further, it is generally considered that copper contributes to the redox reaction of silver as shown in the following formula and plays a role as a sensitizer for photochromic behavior. And these two It is considered that the reaction of 1 occurs in the solid solution when the light irradiation or the light irradiation is stopped.

In order to function as a photochromic lens by irradiation with light, the released silver atoms gather and the particle size is several tens of Å to several hundred Å
It is considered necessary to form a group of. In the constitution of the present invention, the solid solution containing Ag-Cu-X has an island-like structure composed of islands having a particle size of 400 Å or less, and the particle size is sufficient to exhibit the photochromic function. However, since sufficient coloring cannot be obtained with a single layer, in the constitution of the present invention, the film thickness of the Ag-Cu-X layer as a whole is increased by alternately laminating it with an inorganic substance to obtain a coloring degree that can withstand use. ing. Furthermore, the inorganic substance fills the area around Ag-Cu-X having an island structure, and is very useful for improving the strength of Ag-Cu-X having no strength.

Therefore, according to the configuration of the present invention, it is possible to obtain a photochromic film having dramatically improved film strength and adhesion.

Hereinafter, the present invention will be described in detail based on Examples.
The present invention is not limited to these.

[Example 1] 5.7 g of AgBr and 2.3 g of CuBr were mixed and heated to 500 ° C in a porcelain boat to be melted. Heating was performed in N ₂ gas in order to suppress the formation of oxides and the like, and after dissolution, it was gradually cooled to form a solid solution, which was used as a sample for vapor deposition.

A diethylene glycol bis (allyl carbonate lens cleaned with isopropyl alcohol) was used as a substrate, and the substrate was set on a rotatable dome of a vacuum evaporation machine having an electron beam evaporation source.
O ₂ and Al ₂ O ₂ are set.

As the first layer, SiO ₂ was melted by an electron beam, and 500Å was vapor-deposited on a substrate lens set on a rotating dome. Next, Al ₂ O ₃ was vapor-deposited by 200 Å by the same method to form a second layer. Ag-Cu-Br solid solution sample was used as the third layer with an average of 300 Å
Deposition was carried out by melting with an electron gun so as to form an island-shaped structure having a particle size of the order. In the following, Al ₂ O ₃ was deposited on the corner layer and 500Å the odd-numbered layers were alternately deposited so as to have the Ag-Cu-Br solid solution having the above-mentioned island structure to form a multilayer film up to the 50th layer. Finally 51
As the second layer, 1000 Å of SiO ₂ was vapor deposited to finish. The substrate temperature during vapor deposition was 50 ° C, and the degree of vacuum was 10 ^-5 Torr.

The above film structure is shown in FIG. A multilayer film was formed on the opposite surface of the lens by the same method. The characteristics of the obtained lens were investigated and shown in Table 1. The evaluation of the characteristics was performed according to the following methods.

(A) Extinction ratio: Photochromic lens dimming tester: HE-233 (manufactured by Hasegawa Picco) was used, and the average extinction ratio (average of 400 to 750 nm) in one irradiation test was shown.

(B) Decoloring speed: After irradiating once with the photochromic lens dimming tester, the lens was left in the dark at 20 ° C., and the time until the extinction rate was restored to the extinction rate before the test was measured.

(C) Durability (extinction rate): After exposure to a fade meter with a xenon lamp for 200 hours, the extinction rate test of (ii) was performed and the average extinction rate was shown.

(D) Durability (decoloring speed): After exposure to a fade meter with a xenon lamp for 200 hours, the defoaming speed test of (b) was performed and the time was displayed.

(E) Durability (coloring degree): After being exposed to a fade meter with a xenon lamp for 200 hours, it was left in a dark room at 20 ° C for 24 hours, and the measured average transmittance was 400 to 750 nm. Before exposure, the value was subtracted from the average transmittance when left in a dark room at 20 ° C for 24 hours.

(F) Adhesion: Adhesion was measured by a cross-cut tape test according to JIS D-0202.

That is, cuts are made at intervals of 1 mm on the lens surface with a knife to form 100 1 mm ² squares. Next, after strongly sticking cellophane adhesive tape (“Cellotape” manufactured by Nitto Kagaku Co., Ltd.) onto it, it was peeled off suddenly in the 90 ° direction from the surface, and then there were the squares left by the coat film. And used as an adhesion index.

(G) Abrasion resistance: A load of 1 kg was applied with # 0000 steel wool, and the degree of scratching by rubbing the 10 reciprocating surfaces was evaluated by visually grading the glass into 10 grades with 1 polymethylmethacrylate plate as 10 .

[Example 2] The Ag-Cu-Br solid solution sample used in Example 1 was vapor-deposited on the first layer, that is, the substrate so as to form an island structure waiting for a grain size of about 300 Å, and the second and subsequent layers were formed. Vapor deposition was performed in the same manner as in the fourth and subsequent layers of Example 1. Other conditions were the same as in Example 1.

[Example 3] 3.76 g of AgI and 1.27 g of CuI were ground and mixed in a mortar. Next, the mixture was heated to 610 ° C. in an Ar gas atmosphere to dissolve it, and then gradually cooled to obtain an Ag-Cu-I solid solution.

The same procedure as in Example 1 was performed except that a polycarbonate lens washed with ethyl alcohol was used as the substrate and an Ag-Cu-I solid solution was used.

Example 4 and up to 20 layers of Ag-Cu-Br solid solution and Al ₂ O ₃ alternating stack of Example 1, in the same manner after the Example 1 row Natsuta.

[Example 5] Similar to Example 1 except that the surface of the 51st layer of Example 1 was sequentially coated with Yb ₂ O ₃ , Tu ₂ O ₅ , and SiO ₂ by vacuum evaporation to form an antireflection layer. Done.

[Comparative example]

The same procedure as in Example 1 was carried out except that the Ag-Cu-Br solid solution sample was vapor-deposited to a thickness of 700Å in Example 1.

〔The invention's effect〕

According to the present invention, a multilayer film is formed by alternately stacking layers of Ag-Cu-X solid solution having an island structure having islands having a particle size of 400 Å or less and layers of an inorganic derivative substance. Therefore, the Ag-Cu-X solid solution, which is inferior in strength and adhesiveness, is reinforced so as to be surrounded by an inorganic substance which is excellent in strength and adhesiveness, and as a whole, the photochromic composite which is excellent in strength and adhesiveness with the base material. A multilayer film could be obtained.

The present invention can be sufficiently applied to other optical materials such as window glass and automobile window glass.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. 1 …… SiO ₂ (1000Å) layer 2 …… Al ₂ O ₃ and Ag-Cu-Br solid solution (island structure) multilayer 3 …… Al ₂ O ₃ (300Å) layer 4 …… SiO Layer consisting of ₂ (500Å) 5 ... Base lens.

Claims (1)

[Claims] 1. A hard coat composed of an inorganic substance as the uppermost layer, which is a multilayer film formed by laminating an inorganic substance layer containing the following ternary solid solution as an island structure having a particle size of 400 Å or less on the surface of a synthetic resin lens. A synthetic resin photochromic lens having a layer or an antireflection layer. Ag-Cu-X (where X is Cl, Br, I)