JPS61236521A - Light controlling lens and its production - Google Patents

Abstract

PURPOSE:To produce easily a light controlling lens which provides uniform and excellent photochromism by embedding a light controllable film formed by dispersing an org. photochromic material in a resin having <=25 deg.C second- order transition temp. into a lens consisting of a polymerizable resin. CONSTITUTION:The light controlling lens is produced by providing a light controlling layer 2 and a film 3 thereon on the surface of a transparent film 1 to form the light controllable film 4, holding the film in a mold 5 for casting polymn. and casting and packing the polymerizable compsn. 6 into the mold then polymerizing the compsn. The light controlling layer 2 is formed by dispers ing the org. photochromic material into the resin having <=25 deg.C second-order transition temp. The medium resin has therefore fluidity in terms of molecular at an ordinary service temp., provides the substantial photochromism and ex hibits uniform dispersibility as the compatibility of the photochromic material with the medium resin is high. The easy production of the light controlling lens having the uniform light controlling characteristic is thus made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photochromic lens and a method for manufacturing the same, particularly a photochromic lens whose main body is made of a polymer and a method for manufacturing the same.

[Prior art]

In recent years, lenses made of resin have been gaining popularity as eyeglass lenses because they are lighter than glass lenses and are highly safe in terms of resistance to breakage. Along with this, there has also been an increasing demand for resin lenses to be provided with the additional functions conventionally applied to glass lenses. There is a strong demand for materials to have the property of changing color or changing color and disappearing when placed in a dark place, that is, having light control properties.

In general, inorganic compounds such as silver halide are substances that exhibit photochromism (a phenomenon in which the unique color changes when exposed to light and reversibly returns to its original state when placed in a dark place). It is known, and using this,
It is widely practiced to manufacture photochromic lenses by appropriately dispersing silver halide in glass for lenses.

However, it is virtually impossible to sufficiently uniformly disperse an inorganic photochromic substance in resin, which is an organic substance, and for this reason, it is difficult to obtain resin lenses with good light control properties using the same method as glass lenses. I can't.

On the other hand, various organic compounds exhibiting photochromism are known, and since these organic photochromic substances have high compatibility with resins, it is thought that they can be dispersed relatively uniformly in resins. However, at present, resin lenses with such a configuration have not yet been put into practical use.This is because when organic photochromic substances are dispersed in ordinary solid substances, the expression of photochromism is greatly suppressed, and as a result, This is because no coloration or discoloration occurs when exposed to light, or even if such coloration or discoloration occurs, the color does not fade quickly when placed in a dark place next time.

In light of the above circumstances, research has been conducted in various fields. For example, Japanese Patent Application Laid-Open No. 2003-2013 (Sho) proposed that a so-called hard coat layer be provided on the surface of a resin lens, and that this hard coat layer may contain a finely powdered phototropic glass. 59-107
It was proposed in Japanese Patent Application Laid-open No. 301, and Japanese Patent Application Laid-Open No. 7830/1983 proposed that a similar hard coat layer contain silver halide.
This is proposed in Publication No. 3.

However, even with these techniques, it is still difficult to uniformly disperse the photochromic substance, and as a result, it is not possible to obtain a photochromic lens that is uniform and has excellent photochromic properties.

[Problems to be solved by the present invention]

In view of the above-mentioned circumstances, it is an object of the present invention to provide a photochromic lens that fully exhibits its excellent photochromism using an organic photochromic substance and has uniform and excellent dimming properties.

Further, the present invention aims to provide a method by which the excellent photochromic lens described above can be manufactured easily and reliably.

[Structure and operation for solving the problem] In the present invention, a light control film made by dispersing an organic photochromic substance in a resin having a secondary transition temperature of 25°C or less is embedded in a lens body made of resin. to form a photochromic lens.

Further, in the present invention, a light control film made by dispersing an organic photochromic substance in a resin having a secondary transition temperature of 25° C. or lower is embedded in a polymerizable composition used as a lens base material, and is left in this state. A photochromic lens is manufactured by polymerizing the polymerizable composition to form a resin lens having a photochromic film inside.

According to the present invention, in the photochromic film in the resin lens, the expression of the photochromic action of the organic photochromic substance is not inhibited due to the characteristics of the resin of the medium, and moreover, the compatibility of the organic photochromic substance with the medium resin is Since it is high, it is possible to obtain a uniform dispersion state and a photochromic lens with uniform dimming property, and such an excellent photochromic lens can be manufactured easily and reliably.

The present invention will be specifically explained below.

In the present invention, as shown in FIG. 1, an organic photochromic substance is dispersed and contained on the surface of a first film 1 made of, for example, a transparent resin in a medium made of a resin having the characteristics described below. A light control layer 2 is provided, and a second film 3 made of a transparent resin is provided to cover the exposed surface of the light control layer 2 to form a light control film 4.

Next, as shown in FIG. 2, for example, this light control film 4 is supported in the hollow part of a casting polymerization mold 5, and after polymerization, a liquid polymerizable composition 6 to be used as a lens base material is applied. The polymerizable composition 6 is injected into the mold 5 to fill the mold 5 with the polymerizable composition 6, whereby the light control film 4 is buried in the polymerizable composition 6, and in this state, the polymerizable composition The product 6 is polymerized to produce a photochromic lens made of resin 7 in which a photochromic film 4 is embedded, as shown in FIG.

In the above, the resin serving as a medium for the organic photochromic substance in the light control layer 2 of the light control film 4 has a second-order transition temperature of 25°C or lower, particularly preferably a second-order transition temperature of 0°C or lower. Use transparent resin. The medium resin is not particularly limited as long as the conditions regarding the second-order transition temperature are satisfied, and specific examples include natural rubber, various butadiene-styrene rubbers, neoprene, chloroprene, isoprene, and 1,2-polybutadiene. , various acrylic rubbers, isobutylene, ethylene-propylene rubber, chlorinated polyethylene, various fluororubbers (e.g. vinylidene fluoride-hexafluorinated propylene copolymer, vinylidene chloride-37) ethylene, etc.), various silicone rubbers, ethylene -Vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and others. Of course, the above resins are just examples and are not limited to these, and these resins can be used alone or in combination of two or more.

Conventionally known organic photochromic substances can be used as the organic photochromic substance dispersed in the resin that constitutes the light control layer together with the above-mentioned medium resin. Typical examples include thioindigos, azobenzene dyes, diallylthiocarbazone metal complexes that exhibit photochromism due to isomerization, and dinitrobenzylpyridine that exhibits photochromism based on intramolecular hydrogen transfer. aromatic nitro compounds such as, various chromone derivatives,
Examples of compounds that exhibit photochromism due to ionic or radical dissociation, such as salicylidene aniline, include leuco compounds of triphenylmethane dyes, various imidazole dimers, tetraphenylhydrazines, various spiropyran compounds, spirooxazine compounds, and chromene. Other examples include, but are not limited to, compounds having rings or bilane rings, fulgide compounds, etc., and these organic photochromic substances are one of them.
Although only the seeds may be used, two or more types can also be used in combination. The ratio of the organic photochromic substance to the medium resin is not particularly limited, but is within the range of 0.1 to 100 parts by weight, preferably 0.2 to 50 parts by weight, based on 100 parts by weight of the medium resin. .

The first film 1 or the second film 3 on both sides of the light control layer 2 may be any transparent resin film that is stable to the polymerizable composition to be injected. Specific examples of resin film materials that can be preferably used here include various polyamide resins, ethylene-vinyl acetate copolymer resins, polycarbonate resins, polyvinyl chloride resins, vinylidene chloride resins, and ethylene-vinyl alcohol copolymers. , various acrylic resins such as polystyrene resin, polymethyl methacrylate resin,
Acrylonitrile-styrene-butadiene resin, polyethylene terephthalate resin, 4-methylpentene resin,
Others can be mentioned. Also, for example, crystalline vinylidene fluoride resin, vinyl fluoride resin, polyethylene,
Polypropylene, ethylene-tetrafluoroethylene resin, propylene-tetrafluoroethylene resin, polyphenylene oxide resin, polyvinyl alcohol resin,
Others can be suitably used.

In order to actually form a light control layer, a mixture of a medium resin and an organic photochromic substance is kneaded using a roll or a mixer, and then formed into a layer by press molding or extrusion molding, and an appropriate organic solvent is used. A thin film-like light control layer material is obtained by a method of dissolving or dispersing a medium resin and an organic photochromic substance and then casting it to form a layer, or by other methods.
For example, it is possible to advantageously use means for finally laminating the first film or the second film by means of an adhesive or by lamination.

Further, the first film or the second film is made by an extrusion molding method, and the light control layer is laminated at the same time by a coextrusion method, or the means is bonded onto the first film or the second film by roll rolling. ,
'It is also possible to use a method of casting coating the first film or the second film using a solution in which a medium resin and an organic photochromic substance are dissolved or dispersed in a suitable organic solvent.

The thickness of the light control layer can be freely selected depending on the intended use of the light control material and the type and content of the organic photochromic substance used, but it is usually 0.2 to 200.
It is said to be on the order of microns.

The liquid polymerizable composition that is polymerized and used as a lens base material is not particularly limited, and monomer compositions that are used as materials for ordinary resin lenses can be used as they are. Specific examples include methacrylates such as methyl methacrylate, acrylates, monomers having an allyl group such as diethylene glycol bisallyl carbonate, diallyl phthalate, various methacrylates substituted with bromine or chlorine, acrylates, allyl compounds, and others.

As the mold 5 for cast polymerization, a mold generally made of glass for manufacturing ordinary eyeglass lenses can be used as is.

In the specific scraping process for performing cast polymerization, for example, one side of the mold is filled with the polymerizable composition, a light control film is floated on top of the polymerizable composition, and the other side of the mold is filled with the polymerizable composition through a gasket. After setting the film in a liquid-tight manner, the polymerizable composition is further injected into the mold and polymerized.The light control film is supported in the mold by an appropriate means and the polymerizable composition is injected into the mold. and other methods can be used.

The size and shape of the light control film used can be freely selected. That is, the shape may cover the entire lens to be finally obtained, or it may cover a part of the lens. It is preferable to set the light control film in a mold after the polymerization, thereby preventing the inclusion of air bubbles and ensuring adhesion between the light control film and the resin after polymerization.

The polymerizable composition usually contains a polymerization initiator, and polymerization is carried out by heating it to an appropriate temperature.

〔Effect of the invention〕

As described above, the photochromic lens of the present invention has the photochromic film 4 embedded inside the resin lens, and the photochromic layer of the photochromic film contains an organic photochromic substance in the medium resin. However, since the medium resin generally has a low secondary transition temperature, the medium resin is in a solid state but molecularly stable in the normal operating temperature atmosphere. is in a fluid state, and therefore the inherent photochromism effect of the dispersed organic photochromic substance is fully expressed without being inhibited. The fading of color occurs at a fast response speed when the lens is placed, and therefore, the photochromic lens has excellent photochromic properties even though it is made of resin.

In addition, since the light control layer of the light control film is composed of an organic photochromic substance dispersed in a medium resin, the compatibility between the two is high, making it easy to achieve uniform dispersion of the organic photochromic substance. Therefore, it has uniform dimming characteristics.

Furthermore, in this resin lens, the light control layer of the light control film is completely covered and no surface is exposed to the atmosphere, so the medium resin has a secondary transition temperature as mentioned above. Even if it is virtually rubber-like and soft due to its low temperature, the light control layer is completely protected from the outside and will not be scratched, and will not be exposed to oxygen, moisture, or other chemicals in the outside air. Since the organic photochromic material dispersed in the light control layer is prevented from being adversely affected by the seeds, an excellent light control effect is maintained over a long period of time, resulting in a long service life.

According to the present invention, as described above, it is possible to provide a photochromic lens having excellent photochromic properties and a method for easily and reliably manufacturing such a photochromic lens. Since this photochromic lens is made of resin, it is lightweight and highly safe, and has uniform photochromic properties regardless of the thickness of the lens body made of resin.

The light control film in the present invention does not necessarily have to be a film coated on both surfaces of the light control layer as described above. That is, it is also possible to prepare a light control film consisting only of a light control layer made by dispersing an organic photochromic substance in a specific medium resin as described above, and to use this film alone. However, in this case, depending on the type of medium resin and organic photochromic substance in the light control layer, the type of polymerizable composition and its solvent used, and other conditions, the organic photochromic substance in the light control film may not be able to form into the polymerizable composition. There is a risk that it may be eluted or chemically altered by the action of components in the polymerizable composition.

On the other hand, as in the above example, by using a light control film in which the surface of the light control layer is covered with a film of a suitable resin, the light control layer of the light control film can be prevented from being affected by the polymerizable composition. It is possible to reliably prevent this from happening.

〔Example〕

Examples of the present invention will be described below, but the present invention is not limited thereto.

In an example, 20 g of poly(2-ethylhexyl methacrylate) having a second-order transition temperature of about -10°C was dissolved in 200 g of toluene, and a spiropyran compound 1.3.3-
) Add 0.05 g of dimethylindolino-6'-nitrobenzopyrillospyran to prepare a coating solution for a light control layer, and apply the coating solution on a 9 micron thick polyethylene terephthalate film at a temperature of about 50°C. A light control layer with a thickness of about 35 microns is formed by drying, and a similar polyethylene terephthalate film is placed over the light control layer and heated to a temperature of 6.
A light control film was obtained by press bonding for a short time at 0°C.

This dimming film was cut into a circle with a diameter of 60 μm and placed in a glass mold with a diameter of 60 II 11, and diethylene glycol rubisteryl carbonate was placed in it.
00 parts by weight and 3 parts by weight of isopropyl peroxycarbonate as a polymerization initiator to initiate polymerization at a temperature of 50°C, then at a temperature of 50 to 60°C for 10 hours, and then at a temperature of 60 to 80°C. A photochromic lens according to the present invention was produced by polymerizing at 80° C. for 4 hours and then at 80° C. for 2 hours. This photochromic lens was almost colorless and transparent.

When this photochromic lens was exposed to sunlight, it instantly turned reddish-purple. Immediately after that, it was moved to a dark place and after 5 minutes had elapsed, the rate of decrease in the absorption rate of light with a wavelength of 560n+m was determined to be approximately 50%, which indicates that it has a high fading rate and has an excellent dimming effect. One thing was recognized.

Example 2 A 2-ethylhexyl methacrylate-dodecyl methacrylate copolymer (
Charge weight ratio is 75:25) 10 g to 2 toluene
A coating solution for a light control layer was prepared by adding 0.05 g of the same spiropyran compound used in Example 1 to this solution.
Vinyl alcohol copolymer film “EVAL EP-F”
The above coating solution was applied onto J (manufactured by Kuraray Co., Ltd.) at a temperature of approximately 50°C.
℃ to form a light control layer with a thickness of approximately 20 microns, and a similar ethylene-vinyl alcohol copolymer film was further placed on the light control layer and bonded using a hot press to form a surface protective layer. A light control film according to the present invention was thus produced.

This photochromic film was cut into a circular shape with a diameter of 60III+ and placed in a glass mold with a diameter of 60o+m, and diethylene glycol bisallyl carbon was placed in the glass mold.
) and 3 parts by weight of isopropyl peroxydicarbonate as a polymerization initiator was injected to initiate polymerization at a temperature of 50°C, then at a temperature of 50 to 60°C for 10 hours, and then at a temperature of 60°C. ~80℃ for 4 hours, further temperature 8
A photochromic lens according to the present invention was manufactured by polymerizing at 0° C. for 2 hours. This photochromic lens was almost colorless and transparent.

When this photochromic lens was exposed to sunlight, it instantly turned reddish-purple. Immediately after that, it was moved to a dark place and after 5 minutes, the decrease rate of the absorption rate of light with a wavelength of 560 nm was determined to be about 55%, which shows that it has a high fading rate and has an excellent dimming effect. One thing was recognized.

Example 3 20 g of poly(2-ethylhexyl methacrylate) having a second-order transition temperature of about -10°C was dissolved in 200 g of toluene, and spiropyran compound 1.3.3-
A coating solution for a photochromic layer was prepared by adding 0.05 g of trimethylindolino-6'-nitro-8'-methoxybenzopyryrosbilane, and the coating solution was applied onto a polyethylene terephthalate film with a thickness of 9 microns. A photochromic layer with a thickness of about 35 microns was formed by drying at about 50°C, and a similar polyethylene terephthalate film was placed on the photochromic layer and press-bonded for a short time at a temperature of 60°C to form a photochromic film. Obtained.

This photochromic film was cut into a circular shape with a diameter of 60+mm, placed in a glass mold with a diameter of 60mm, and diethylene glycol bisallyl carbonate 100%
part by weight and 3 parts by weight of isopropyl peroxydicarbonate as a polymerization initiator to initiate polymerization at a temperature of 50°C, then at a temperature of 50 to 60°C for 10 hours, and then at a temperature of 60 to 80°C. ℃ for 4 hours, then at a temperature of 80℃ for 2 hours.
A photochromic lens according to the present invention was manufactured by time polymerization. This photochromic lens had a pale blue color.

When this photochromic lens was exposed to sunlight, it instantly turned dark blue. Immediately after that, it was moved to a dark place, and after 10 minutes, the decrease rate of the absorption rate of light with a wavelength of 590 nm was determined to be about 50%, which shows that it has a high fading rate and has an excellent dimming effect. One thing was recognized.

Example 4 20 g of ethylene-vinyl acetate copolymer [Evaflex 220] (manufactured by Mitsui Polychemical Co., Ltd., vinyl acetate content 28% by weight) having a second-order transition temperature of about -40°C was mixed with toluene 2
A coating solution for a light control layer was prepared by adding 0.05 g of the same spiropyran compound used in Example 3 to this solution. Film "Eval 1"
! The above coating solution was applied onto P-FJ (manufactured by Kuraray Co., Ltd.) and dried at a temperature of about 50°C to form a light control layer with a thickness of about 40 microns, and a similar ethylene-vinyl alcohol copolymer film was prepared. A surface protective layer was formed by covering the optical layer and bonding it using a hot press, thereby producing a light control film according to the present invention.

This light control film was cut into a circle with a diameter of 6 mm and placed in a glass mold with a diameter of 60 vw, and 100 parts by weight of diethylene glycol bisallyl carbonate and 3 parts by weight of isopropyl peroxydicarbonate as a polymerization initiator were added to the mold. A polymerizable composition consisting of
A photochromic lens according to the present invention was manufactured by starting polymerization at a temperature of 50-60°C for 10 hours, then at a temperature of 60-80°C for 4 hours, and further at a temperature of 80°C for 2 hours. This photochromic lens was almost colorless and transparent.

When this photochromic lens was exposed to sunlight, it instantly turned dark blue. Immediately after that, it was moved to a dark place and after 10 minutes, the reduction rate of the absorption rate of light with a wavelength of 590 nm was determined to be about 55%, which shows that it has a high fading rate and has an excellent dimming effect. One thing was recognized.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional view showing an example of a photochromic film used in the present invention, Fig. 2 is an explanatory cross-sectional view of a method for manufacturing a photochromic lens according to the present invention, and Fig. 3 is a cross-sectional view showing an example of a photochromic film used in the present invention. FIG. 2 is an explanatory cross-sectional view showing an example of a photochromic lens. 1... First film 2... Light control layer 3... Second
Film 4... Light control film 5... Cast polymerization mold 6... Polymerizable composition 7... Resin

Claims (1)

[Scope of Claims] 1) A light control film comprising a light control film made by dispersing an organic photochromic substance in a resin having a secondary transition temperature of 25° C. or lower and embedded in a lens body made of resin. light lens. 2) immersing a light control film made by dispersing an organic photochromic substance in a resin having a secondary transition temperature of 25° C. or less in a polymerizable composition used as a lens base material;
A method for producing a photochromic lens, which comprises polymerizing the polymerizable composition in this state, thereby forming a resin lens having a photochromic film inside. 3) The method for manufacturing a photochromic lens according to claim 2, wherein the photochromic film comprises a photochromic layer and a coating film provided on the surface of the photochromic layer.