JPH10260301A - Plastic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the plastic lens which has no interference fringe, superior outward appearance, and excellent resistance to a rub, wear resistance, and shock resistance at low cost by using plastic lens base materials which have various refractive indexes. SOLUTION: An intermediate layers 12 which has a refractive index difference of <=0.03 while a plastic base material 11 and the had coat layer 13 has a refractive index difference of >=0.08 is provided between the plastic lens base material 11 and hard coat layer 13 and the whole of the hard coat layer 13 and intermediate layer 12 can be regarded as optically one layer, thereby providing the plastic lens which has no interference fringe, superior outward appearance, and excellent resistance to a rub, wear resistance, and shock resistance at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic lens which has excellent scratch resistance, abrasion resistance, impact resistance and appearance and is excellent in practical use.

[0002]

2. Description of the Related Art Plastic lenses are lightweight, shock-resistant,
It has the advantages of easy processability, easy dyeing, optical materials,
In particular, it is rapidly spreading in the field of spectacle lenses. However, plastic lenses generally have the disadvantage that they are easily damaged. Therefore, usually, the surface is subjected to a hard coat treatment to improve the scratch resistance.

The refractive index of a plastic lens substrate is 1.5
For relatively low refractive index plastic lenses,
Usually, a hard coat with an organosilicon compound is applied, and the refractive index of this hard coat layer is about 1.5, which is almost the same as that of a plastic lens substrate. On the other hand, a number of high-refractive index plastic lens substrates having a refractive index of 1.6 or more, and even 1.65 or more have been developed in recent years. When a low refractive index hard coat of about 1.5 is applied, the scratch resistance improves, but the light reflectance at the interface between the hard coat layer and the plastic lens substrate increases, and the thickness of the hard coat becomes uneven. Interference fringes due to the nature occur, which causes a problem in appearance.

In order to eliminate such interference fringes, the composition of the hard coat layer has been devised to reduce the difference between the refractive index of the plastic lens substrate and the refractive index of the hard coat layer. A number of techniques have been reported to increase the refractive index of the hard coat layer with the advent of high-refractive-index plastic lens substrates.
No. 54331 discloses a coating technique containing an antimony pentoxide sol and an organosilicon compound. Japanese Patent Application Laid-Open No. 5-287241 discloses a hard coat technique in which an organosilicon compound contains titania, cerium oxide, tin oxide, tungsten oxide, iron oxide, and the like in addition to antimony oxide.

On the other hand, the impact resistance of a plastic lens provided with a hard coat often shows a lower value than the impact resistance of a plastic lens substrate alone. Therefore, in some plastic lenses, a method of improving the impact resistance by providing an intermediate layer for absorbing an impact between a hard coat layer and a plastic substrate has been adopted.
-87223, JP-A-63-14001, JP-A-3-
109502, Japanese Patent Application No. 4-234668, and the like. The refractive index of the intermediate layer provided for improving the impact resistance is set to a value close to the refractive index of the plastic lens substrate for the same reason as described above. That is, by setting the refractive indices of the plastic lens substrate, the intermediate layer, and the hard coat layer to substantially the same value, the occurrence of interference fringes is prevented.

[0006]

However, in order to reduce the refractive index difference between the plastic lens substrate and the hard coat layer, a coating solution for the hard coat layer having a different refractive index according to the type of the plastic lens substrate is required. There has been a problem that a large number of preparations have to be made and a large cost is generated. Furthermore, when an intermediate layer is provided to improve impact resistance, it is necessary to prepare a plurality of coating liquids having different refractive indices also for the intermediate layer. There is a problem that it becomes more difficult to do so.

In order to eliminate the interference fringes of the hard coat layer, it is necessary to reduce the difference in the refractive index from the plastic substrate, and there is no other way to increase the thickness of the hard coat layer. However, when the thickness of the hard coat layer is increased, cracks occur at the time of curing, so that a uniform film cannot be obtained, or the impact resistance is remarkably reduced, which is not suitable for practical use.

Therefore, in the present invention, plastic lenses having excellent appearance without interference fringes and excellent in scratch resistance, abrasion resistance and impact resistance are provided at low cost with plastic lens substrates having various refractive indexes. The purpose is to do.

[0009]

The inventor of the present invention has made intensive studies to solve the above-mentioned problems, and as a result, has found that a hard coat layer having a refractive index different from that of a plastic lens substrate is applied to a plastic lens. By providing an intermediate layer having a refractive index difference of 0.03 or less between the plastic lens substrate and the hard coat layer, the entire hard coat layer and the intermediate layer are optically Can be regarded as a single layer, with no interference fringes and excellent appearance,
It has been found that a plastic lens having excellent scratch resistance and abrasion resistance can be provided at low cost.

Furthermore, it has been found that by providing the intermediate layer with an impact absorbing ability, a plastic lens having excellent impact resistance in addition to the above-mentioned properties can be provided at a low cost. The present invention firstly provides a "plastic lens substrate,
In a plastic lens comprising an intermediate layer formed on the plastic lens substrate and a hard coat layer formed on the intermediate layer, a difference in refractive index between the plastic lens substrate and the hard coat layer is 0.08. A plastic lens, wherein the difference in refractive index between the intermediate layer and the hard coat layer is 0.03 or less. Claim 1 is provided.

Second, "the thickness of the intermediate layer is 1.5 μm
The plastic lens according to claim 1, wherein: (Claim 2) "is provided. Third, “the total thickness of the intermediate layer and the hard coat layer is 3 μm.
3. The plastic lens according to claim 1, wherein the thickness is not less than m, and the entirety of the hard coat layer and the intermediate layer can be optically regarded as one layer. 4. (Claim 3) "is provided.

Fourth, "a plastic lens according to any one of claims 1, 2, and 3, wherein an antireflection layer is provided on the hard coat layer (claim 4)."
I will provide a. Fifthly, the present invention provides "the plastic lens according to any one of claims 1, 2, 3, and 4, wherein the intermediate layer also functions as a shock absorbing layer."

Sixth, the intermediate layer contains at least one of a polyvinyl acetal resin and a polyurethane resin, according to any one of claims 1, 2, 3, 4, and 5. Plastic lens. (Claim 6) "is provided. Seventh, the plastic lens according to any one of claims 1, 2, 3, 4, 5, and 6, wherein the intermediate layer contains a particulate inorganic substance made of a metal oxide. (Claim 7) "is provided.

Eighth, "the particulate inorganic material is selected from at least one selected from the group consisting of aluminum oxide, titanium oxide, zirconium oxide, antimony oxide, beryllium oxide, zinc oxide, tin oxide, cerium oxide, silicon dioxide, and tungsten oxide. Is a particulate inorganic substance,
The plastic lens according to claim 7, wherein the average particle diameter is 1 to 300 nm. (Claim 8) "
I will provide a.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
FIG. 1 shows a film configuration of the plastic lens of the present invention. In FIG. 1, reference numeral 11 denotes a plastic lens substrate. The plastic lens substrate of the present invention is not particularly limited as long as it is optically transparent. Therefore, as specific examples, many substances can be cited, some of which are diethylene glycol bisallyl carbonate (CR39), styrene, α-methylstyrene, chlorostyrene, phenylmethacrylate, phenylacrylate, benzylmethacrylate, benzylacrylate. , Naphthyl methacrylate, naphthyl acrylate,
(Di) methacrylate of tetrabromobisphenol derivative, (di) acrylate of tetrabromobisphenol derivative, diallyl carbonate of tetrabromobisphenol derivative, methyl methacrylate, (di) ethylene glycol methacrylate, (di) ethylene glycol acrylate, vinylnaphthalene, divinylbenzene And 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 3
Hydroxy methacrylate such as 3-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 2,3-hydroxypropyl methacrylate, 2,3-hydroxypropyl acrylate or hydroxy acrylate and xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate,
Reaction products of polyfunctional (poly) isocyanate such as cyclic trimer of hexamethylene diisocyanate, di (2-mercaptoethyl) ether, 1,2-ethanedithiol, di (2-mercaptoethyl) sulfide, 2-mercapto A reaction product of a thiol compound such as ethanol, pentaerythritol tetrakis-3-mercaptopropionate, 4-mercaptomethyl-3,6-dithia-1,8-octanediol and a polyfunctional (poly) isocyanate or a polyfunctional (poly) ene; Examples thereof include, but are not limited to, mixtures thereof.

The plastic lens substrate can be prepared by adding a polymerization initiator to a monomer, placing the monomer in a matrix, and polymerizing by adding heat, ultraviolet light, or both. There is no limitation on the polymerization initiator that can be used in the present invention, but examples include potassium peroxodisulfate, ammonium peroxodisulfate, t-butyl hydroperoxide, di-tert-butyl peroxide, cumene hydroperoxide, acetyl peroxide, benzoyl peroxide. , Lauroyl peroxide, azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, diisopropylperoxycarbonate, t-butylperoxyneodecanonate, dimethyltin dichloride, biacetyl, acetophenone,
Benzophenone, Michler's ketone, benzyl, benzoin, benzoin isobutyl ether, benzyldimethyl ketal, benzoyl peroxide, 1-hydroxycyclohexylphenyl ketone, α-hydroxyisobutylphenone, p-isopropyl-α-hydroxyisobutylphenone, and the like can be given.

In FIG. 1, reference numeral 12 denotes an intermediate layer. The difference between the refractive index of the intermediate layer of the present invention and the refractive index of the hard coat layer is preferably 0.03 or less, and more preferably 0.02 or less.
The following is preferred. If the difference between the refractive index of the intermediate layer and the refractive index of the hard coat layer is larger than this, the interference fringes of the plastic lens after the hard coat cannot be completely eliminated.

The thickness of the intermediate layer is preferably 1.5 μm or more, and the total thickness of the intermediate layer and the hard coat layer is preferably 3 μm or more. When the film thickness is smaller than these values, the interference fringes may not be completely eliminated even if the difference in the refractive index between the plastic lens substrate and the hard coat layer is within the range described above.

The substance constituting the intermediate layer of the present invention is not limited as long as it satisfies the conditions of the refractive index and the film thickness and is optically transparent. Further, by using a substance having a shock absorbing ability for the intermediate layer of the present invention, it is possible to eliminate the interference fringes of the plastic lens and to improve the shock resistance. As a constituent material of the intermediate layer having a shock absorbing ability, a polyvinyl acetal material, a urethane material, an acryl-urethane copolymer material, an epoxy resin material, a melamine resin material, or the like can be used. Also,
Adjustment of the refractive index of the intermediate layer changes the composition of these resins,
This is performed by adding inorganic oxide fine particles.

When a polyvinyl acetal-based substance is used as the substance having a shock absorbing ability, for example, a crosslinked polyvinyl acetal or a mixture of a crosslinked polyvinyl acetal and a particulate inorganic material composed of a metal oxide is used as the intermediate layer. Can be used. That is,
The formation of the intermediate layer made of cross-linked polyvinyl acetal is performed by dissolving a component in which a curing catalyst is dissolved or contained in at least one of a polyvinyl acetal as a main component and a hydrolyzable organosilane compound or a dialdehyde as a cross-linking agent in a solvent. Alternatively, dip coating or spin coating a coating liquid prepared by dispersing a fine particle inorganic material composed of a metal oxide as necessary in the dispersed intermediate layer composition on a plastic lens, and then performing heat treatment. Can be.

As the polyvinyl acetal, those having 0 to 20 carbon atoms in the alkyl group of the acetal portion can be used, preferably those having 0 to 10 carbon atoms, and particularly preferably those having 3 carbon atoms in the alkyl group. It is. A degree of acetalization of 10 to 90% can be used, and preferably a degree of acetalization of 20 to 80% is used. The average degree of polymerization of the polyvinyl acetal is preferably 5,000.
The following, but more preferably 100 to 4.0
00. If the average degree of polymerization is too high, it will be difficult to dissolve in a solvent and the viscosity of the coating solution will be too high, which is not practical. On the other hand, if the average degree of polymerization is too low, the impact resistance when the intermediate layer is formed on a plastic lens is not sufficiently improved, which is not preferable.

As a crosslinking agent for polyvinyl acetal, organosilane compounds such as tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, ethyltriethoxysilane and diethyldiethoxysilane are used. These organosilane compounds may be used alone or as a mixture of two or more. In these organosilane compounds, a hydrolyzable group is hydrolyzed to generate a silanol group, and cross-linking is performed between molecules or within a molecule by dehydration-condensation with a hydroxyl group in polyvinyl acetal by the action of a catalyst and heat. The amount of the organosilane compound to be added is 0.01 to 30% by weight, more preferably 0.1 to 20% by weight, of the intermediate layer coating solution. Further, these organosilane compounds may be added as they are, or may be added after a hydrolysis reaction has been performed in advance.

Also, organotitanium compounds such as tetramethoxytitanium, methyltrimethoxytitanium, dimethyldimethoxytitanium, tetraethoxytitanium, ethyltriethoxytitanium, diethyldiethoxytitanium and the like can be used as a crosslinking agent. These organotitanium compounds may be used alone or as a mixture of two or more. Further, these organotitanium compounds undergo cross-linking between molecules or within a molecule by a hydrolysis and dehydration condensation reaction similarly to the above-mentioned organosilane compounds. The addition amount of these organotitanium compounds is 0.01 to 30% by weight, more preferably 0.1 to 20% by weight of the coating solution for the intermediate layer. Further, these organotitanium compounds may be added as they are, or may be added after a hydrolysis reaction has been performed in advance.

Further, glyoxal, malondialdehyde, succindialdehyde, glutardialdehyde,
A dialdehyde compound such as adipindialdehyde, maleic dialdehyde, phthalaldehyde, isophthalaldehyde, terephthalaldehyde or an acetal compound of dialdehyde can also be used as a crosslinking agent. In the case of a dialdehyde compound, an aldehyde group reacts with a hydroxyl group in polyvinyl acetal by the action of a catalyst or forms an acetal bond by an acetal exchange reaction with an alkyl acetal group. The dialdehyde compound or the acetal compound of dialdehyde may be used alone, or two or more compounds may be used as a mixture. The addition amount of the dialdehyde compound or the acetal compound in the intermediate layer coating solution is 0.01 to 30% by weight,
It is preferably 0.1 to 20% by weight, and when used in a mixture with the organosilane compound and the organotitanium compound, the content is preferably 50 mol% or less of the organosilane compound and the organotitanium compound.

On the other hand, when a urethane-based substance is used as the substance having a shock absorbing ability, for example,
Spin coating a plastic lens substrate surface with a coating solution prepared by dissolving or dispersing in a solvent polyisocyanate, polyol and / or polythiol, a curing catalyst used as required, and inorganic fine particles added for the purpose of adjusting the refractive index. A film obtained by reacting a polyol and / or polythiol with a polyisocyanate by applying by a coating method or a dip coating method and performing a heat treatment can be used.

Specific examples of the polyisocyanate include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, 1,5
-Naphthalene diisocyanate, triphenylmethane triisocyanate, tris (isocyanate phenyl)
Thiophosphate, tetramethylxylene diisocyanate, trimethylhexamethylene diisocyanate,
Examples include monomers such as hexamethylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, and lysine ester triisocyanate and / or adducts having several molecules bonded thereto, and polyisocyanates containing sulfur or halogen groups.

Specific examples of the polyol include a polycarbonate polyol, a polyester polyol, an acrylic polyol, and a mixture thereof. For the reaction between the polyisocyanate and the polyol and / or polythiol, it is desirable to use a curing catalyst. Although there is no particular limitation on the curing catalyst, for example, an organotin compound,
Tertiary amine compounds, organic zinc compounds and the like can be mentioned.

As the solvent for the intermediate layer coating solution, alcohols, ketones, esters, amines, hydrocarbons, halogenated hydrocarbons, mixtures thereof, or aqueous solutions thereof can be used. By changing the amount of the solvent added, it is possible to change the solid content concentration in the coating solution and adjust the viscosity of the coating solution. As the viscosity of the coating liquid increases, the thickness of the intermediate layer also increases. In the case of dip coating, increasing the pulling speed increases the film thickness. In the present invention, the thickness of the intermediate layer is preferably 1.5 μm or more. In this case, the total solid concentration in the coating liquid is 10 μm or more.
%, The lifting speed during dip coating is 1m
m / sec or more.

The metal oxide fine particles dispersed in the intermediate layer include zinc oxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, antimony oxide, silicon dioxide, beryllium oxide, tungsten oxide, cerium oxide and the like, or a composite thereof. There is a body. The refractive index of the intermediate layer is adjusted by changing the amount of the metal oxide fine particles. When using a polyvinyl acetal-based material as a substance having a shock absorbing ability, since the refractive index of a metal oxide is generally higher than the refractive index of polyvinyl acetal,
Increasing the amount of the metal oxide fine particles increases the refractive index of the intermediate layer.

In dispersing the metal oxide fine particles, a fine powder form may be used as the form before the dispersion. However, in order to achieve the object of the present invention, the fine particles are dispersed in a liquid volatile dispersion solvent. It is particularly effective to mix a colloidal dispersion (particulate inorganic substance composed of metal oxide) with a vehicle component (substrate) and then evaporate the volatile dispersion medium. At this time, the average particle diameter of the metal oxide fine particles is preferably 1 to 300 nm, more preferably 1 to 50 nm. If the average particle size is too large, when dispersed in a vehicle component and then cured on a substrate, scattered light is strongly generated and the appearance becomes cloudy, which is not desirable.

In addition, pure water, a leveling agent, a functional material and the like can be added to the intermediate layer of the present invention. For example, various leveling agents for the purpose of improving the surface state at the time of applying the intermediate layer, or ultraviolet absorbers and antioxidants for improving weather resistance,
Further, ordinary dyes, pigments, photochromic dyes and the same pigments can be used. The refractive index is adjusted under the above conditions to prepare an intermediate layer coating solution having a refractive index difference from the hard coat layer of 0.03 or less, and the film is formed on a plastic lens by spin coating or dip coating. The film is formed so as to have a thickness of 1.5 μm or more. At this time, a desired film thickness may be obtained by a single film formation, or a desired film thickness may be obtained by repeating a plurality of film formations.
Before the application of the intermediate layer coating solution, various pretreatments may be applied to the plastic lens in order to improve the adhesion of the intermediate layer to the plastic lens. Examples of the pretreatment include a saponification treatment, a plasma treatment, and a surface treatment with ultraviolet rays. In the saponification treatment, the plastic lens is immersed in an aqueous solution of about 10% by weight of sodium hydroxide at about 60 ° C. for about 5 minutes. Washing is performed in a washing process composed of pure water or the like. On the other hand, the plasma treatment is a method in which the surface of a plastic lens is placed in contact with oxygen plasma, and the surface of the plastic is reacted with oxygen ions or oxygen radicals in the plasma to modify the surface. Further, the surface treatment with ultraviolet rays is a treatment for exposing a plastic lens to ultraviolet rays such as a mercury lamp to improve the hydrophilicity of the surface.

In FIG. 1, reference numeral 13 denotes a hard coat layer. As the hard coat treatment, an organic silicon-based hard coating technique under wet conditions has been put to practical use. The composition of the hard coat liquid is composed of a hydrolyzate of an organoalkoxysilane, metal oxide fine particles, and a metal complex catalyst.The film forming method includes a dipping method and a spin coating method. Let it cure.
In addition, treatment under dry conditions is also possible. Conventionally, in order to eliminate interference fringes, it is necessary to make the refractive index of the hard coat layer completely match the refractive index of the plastic substrate, or to adjust the refractive index to a very close value even if it does not match. As the number of types increases,
It was necessary to prepare various kinds of coating solutions. However, according to the present invention, it has become possible to apply one type of hard coat to various plastic substrates.

As shown in FIG. 2, an antireflection coat can be applied on the hard coat layer, if necessary. As the antireflection coat, a film having a single layer or a multilayer structure based on optical theory is employed. The material is S
iO, SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , Yb ₂ O ₃ ,
CeO ₂ , Ta ₂ O ₃ , TiO ₂ , MgF ₂ , ZrO ₂
Such an inorganic dielectric is used, and the film is generally formed by a vacuum evaporation method, a sputtering method, an ion plating method, or the like.

Further, if necessary, an organic layer having a hydrophobic group such as an alkyl group, a phenyl group, or a polyfluoroalkyl group in a side chain may be provided on the upper layer of the antireflection coating layer for the purpose of preventing stain adhesion and preventing water scorching. It is also possible to form an ultra-thin film of a silicon compound or a fluorine-containing hydrocarbon compound.

[0035]

Hereinafter, the present invention will be described with reference to examples.
The present invention is not limited to these examples. 1. Example 1 (1-1) Preparation of Coating Solution for Intermediate Layer A commercially available degree of butyralization of about 25% and an average degree of polymerization of 2,400
Polyvinyl butyral resin (Wako Pure Chemical Industries, Ltd.) 70
Parts by weight were dissolved in 300 parts by weight of n-butanol. Further, 100 parts by weight of water, 8.5 parts by weight of methyltrimethoxylane as a crosslinking agent, 1.2 parts by weight of p-toluenesulfonic acid as a curing catalyst, and Florad FC as a leveling agent
430 was added in order of 1 part by weight, and the mixture was sufficiently stirred until the mixture became homogeneous. Then, the mixture was filtered through a 0.2 μm membrane filter to prepare a coating solution for an intermediate layer.

(1-2) Measurement of Refractive Index and Measurement of Film Thickness of Intermediate Layer The coating solution prepared in 1-1 above was applied to a plastic flat plate for glasses having a refractive index of 1.60 by a dip coating method at a pulling rate of 6 mm / sec. After that, put it in a heating furnace,
Heated for 0 minutes. The wavelength of the obtained sample is 400
When the spectral reflectivity is measured in the range from 800 nm to 800 nm, the reflectivity shows a periodic change with respect to the wavelength change. At this time, the refractive index of the applied film is determined from the peaks and valleys of the reflectivity curve. The thickness of the intermediate layer of this example was 1.50, and the thickness was 4 μm.

(1-3) A plastic lens for eyeglasses (Nikon NL) having a coating and curing degree of the intermediate layer coating solution of -2.00 diopter, a center thickness of 1.0 mm and a refractive index of 1.60.
III) First, plasma treatment was performed for the purpose of strengthening the adhesion of the intermediate layer. The plasma treatment was performed using "Plasma Reactor PR501A" manufactured by Yamato Scientific Co., Ltd., at an oxygen gas pressure of about 0.2 Torr, an RF output of 200 W, and a treatment time of 30 seconds. Thereafter, the intermediate layer coating solution prepared in the above 1-1 was applied to both surfaces of the plastic lens by a dip coating method at a pulling rate of 6 mm / sec. afterwards,
The plastic lens coated with the intermediate layer coating solution was placed in a heating furnace and heated at 80 ° C. for 30 minutes to cure the intermediate layer.

(1-4) Preparation of Hard Coating Solution Silane Coupling Agent (Sila Ace, manufactured by Chisso Corporation)
180 ml was stirred and 50 ml of 0.001N hydrochloric acid aqueous solution was stirred.
Was added and further stirred. Next, methanol silica sol 6
80 ml were added and stirring was continued. Finally, after adding a small amount of a surfactant using a small amount of iron acetylacetone as a catalyst, the mixture was stirred for 1 hour or more, and then stored in a cool place.

(1-5) Measurement of Refractive Index and Measurement of Film Thickness of Hard Coat Film
The refractive index measurement and the film thickness measurement of the hard coat film were performed in the same manner as in Example-2. However, the lifting speed is 100 cm /
Minutes and the heat treatment time was 4 hours. As a result, the refractive index was 1.50 and the film thickness was 2.5 μm.

(1-6) Coating and Hardening of Hard Coat Solution The hard coat solution obtained in 1-4 above was dipped on both surfaces of the plastic lens having the intermediate layer obtained in 1-3 above (dipping speed). (100 cm / min). The coated lens was heated at 80 ° C. for 4 hours to cure the hard coat layer.

(1-7) Formation of Antireflection Coat Five-layer silicon oxide / zirconium oxide antireflection films are vacuum-deposited on both surfaces of the plastic lens having the intermediate layer and the hard coat layer obtained in 1-6 above. It was formed by a method. (1-8) Performance Evaluation of Plastic Lens The plastic lens having the composite film obtained in 1-7 above was subjected to the following tests to evaluate the performance. The evaluation results are shown in Table 1.

1) Scratch resistance The surface of a plastic lens is coated with steel wool (# 000
In 0), the degree of scratching when rubbing 30 times by applying a load of 600 g was evaluated according to the following criteria. A: The area with the scratch is within 10%. B: The area with the scratch exceeds 10% and is within 30%.

C: The area with the damage is 30% or more. 2) Impact resistance The impact resistance of the plastic lens was evaluated by a hard ball drop test. Approximately 26 from the conditions specified in the FDA standard
Using a 20.0 g hard ball with a heavier weight, let it fall naturally from the height of 127 cm toward the center of the plastic lens.
The number of times before the plastic lens was broken or cracked was used as a measure of the impact resistance of the lens, and the plastic lens was dropped up to 5 times.

3) Interference fringes Light from a fluorescent lamp was applied to a plastic lens in a dark room, and the degree of interference fringes due to reflection was visually evaluated. The evaluation was performed according to the following criteria. A: Almost no interference fringes can be seen. B: Some interference fringes are visible, but not to a degree that poses a practical problem.

C: Interference fringes are conspicuous, which is not preferable for practical use.

[0046]

[Table 1]

2. Comparative Example 1 The procedure of Example 1 was repeated except that the plastic lens was not provided with an intermediate layer. In addition, all evaluation methods were the same as in Example 1. The evaluation results are shown in Table 1. 3. Example 2 (2-1) Preparation of Coating Solution for Intermediate Layer 70 parts by weight of a commercially available polyvinyl butyral resin (manufactured by Wako Pure Chemical Industries, Ltd.) having a degree of butyralization of about 70% and an average degree of polymerization of 700 were mixed with 250 parts by weight of n-butanol. And 150 parts by weight of a composite sol of a particulate inorganic substance composed of tin oxide and a particulate inorganic substance composed of tungsten oxide (manufactured by Nissan Chemical Industries, Ltd., methanol solvent dispersion) is gradually added. The addition was carried out gradually with stirring, but a rotor and a magnetic stirrer were used for stirring. And 100 parts by weight of water,
8.5 parts by weight of methyltrimethoxylane and 1 part by weight of glutaraldehyde as a cross-linking agent, 1.2 parts by weight of p-toluenesulfonic acid as a curing catalyst, and 1 part by weight of a silicone surfactant Florad FC430 as a leveling agent In addition, the mixture was sufficiently stirred until it became uniform, and then filtered through a 0.2 μm membrane filter to prepare a coating solution for an intermediate layer for coating.

(2-2) Measurement of Refractive Index and Measurement of Film Thickness of Intermediate Layer The coating liquid prepared in 2-1 was applied to a plastic flat plate for glasses having a refractive index of 1.50 by a dip coating method at a pulling rate of 7 mm / sec. After that, put in the heating furnace, 80 ℃
For 30 minutes. The obtained sample has a wavelength of 4
When the spectral reflectance is measured in the range of 00 nm to 800 nm, the reflectance shows a periodic change according to the wavelength. At this time, the refractive index and the film of the applied film are determined from the peaks and valleys of the reflectance curve. The thickness could be measured, and the refractive index of the intermediate layer of this example was 1.60 and the film thickness was 4.5 μm.

(2-3) Plastic lens for eyeglasses (CR39) having a coating and curing degree of the intermediate layer coating solution of -3.00 diopter, a center thickness of 1.0 mm and a refractive index of 1.50.
First, plasma treatment was performed for the purpose of strengthening the adhesion of the intermediate layer. The plasma treatment was performed using "Plasma Reactor PR501A" manufactured by Yamato Scientific Co., Ltd., at an oxygen gas pressure of about 0.2 Torr, an RF output of 200 W, and a treatment time of 30 seconds. Thereafter, the intermediate layer prepared in the above 2-1 was applied to both surfaces of the plastic lens by a dip coating method at a pulling rate of 7 mm / sec. Then, the plastic lens coated with the intermediate layer coating solution is placed in a heating furnace,
For 30 minutes to cure the intermediate layer.

(2-4) Preparation of Hard Coating Solution In a reaction vessel equipped with a rotor, 180 parts by weight of γ-glycidoxypropyltrimethoxysilane was charged, and the mixture was stirred thoroughly with a magnetic stirrer. .0
40 parts by weight of a 1 N hydrochloric acid aqueous solution was added all at once. Immediately after the addition, the solution was a heterogeneous solution, but became a uniform and transparent solution while generating heat within a few minutes. The mixture was further stirred for one hour for hydrolysis to obtain a partially condensed hydrolyzate.

A commercially available tin oxide sol (methanol dispersion, average particle diameter 10 to 15 nm) was added to the above hydrolyzate in 6 parts.
30 parts by weight, 4 parts by weight of aluminum ethylenediaminetetraacetate as a curing catalyst, and 0.45 parts by weight of Florad FC430, a silicon-based surfactant as a leveling agent, were sufficiently stirred, and then filtered through a 3 μm membrane filter. Then, a hard coat liquid was prepared.

(2-5) Measurement of Refractive Index and Film Thickness of Hard Coat Film The refractive index measurement and film thickness measurement of the hard coat film were performed in the same manner as in the above section 2-2. However, when the lifting speed is 100
The heat treatment was performed at 80 ° C. for 4 hours at a curing condition of cm / min. As a result, the refractive index was 1.60 and the film thickness was 2.7 μm. (2-6) Application and curing of hard coat liquid The hard coat liquid obtained in 2-4 was dipped on both surfaces of the plastic lens having the intermediate layer obtained in 2-3 above by a dipping method (pulling speed 100 cm / min). ). The coated lens was heated at 80 ° C. for 4 hours to cure the hard coat layer.

(2-7) Formation of Antireflection Coat A four-layer antireflection coat was formed on both surfaces of the plastic lens having the intermediate layer and the hard coat layer obtained in 2-6 by a vacuum EB evaporation method. (2-8) Performance Evaluation of Plastic Lens Using the plastic lens having the composite film obtained in 2-7 above, performance evaluation was performed in the same manner as in 1-8 of Example 1. The evaluation results are shown in Table 1. 4. Comparative Example 2 The procedure of Example 2 was repeated except that the plastic lens was not provided with an intermediate layer. In addition, all evaluation methods were the same as in Example 2. The evaluation results are shown in Table 1. 5. Example 3 (3-1) Preparation of Coating Solution for Intermediate Layer 100 parts by weight of a hexamethylene diisocyanate type polyisocyanate (trade name “CONONADE HX” manufactured by Nippon Polyurethane Industry Co., Ltd.) and a polyester type polyol (trade name “Nipporan 125”) 167 parts by weight, manufactured by Nippon Polyurethane Industry Co., Ltd., 2 parts by weight of zinc octylate as a curing catalyst, and a fluorine-based surfactant (trade name: Florad FC-431, manufactured by Sumitomo 3M Ltd.) as a leveling agent 0.1 Parts by weight, ethyl acetate 360 as solvent
A mixture consisting of parts by weight and 180 parts by weight of methyl ethyl ketone was stirred until a uniform state was obtained, thereby obtaining an intermediate layer coating liquid.

(3-2) Measurement of Refractive Index of Intermediate Layer and Measurement of Film Thickness The coating solution prepared in 3-1 was pulled up on a plastic plate for glasses having a refractive index of 1.60 at a rate of 8 mm / sec by a dip coating method. After application, 1-2 in Example 1
The refractive index and the film thickness of the applied film were measured using the same method as in the above. The refractive index of the intermediate layer in this example was 1.50, and the film thickness was 3.8 μm.

(3-3) Plastic lens for spectacles (Nikon NL) having a coating and curing degree of the intermediate layer coating liquid of -3.00 diopter, a center thickness of 1.0 mm and a refractive index of 1.60.
III) First, saponification treatment was performed for the purpose of strengthening the adhesion of the intermediate layer. The saponification treatment was performed by heating to 60 ° C. 10
The plastic was immersed in a 5% aqueous sodium hydroxide solution for 5 minutes. Thereafter, the intermediate layer coating solution prepared in the above 3-1 was applied to both surfaces of the plastic lens by a dip coating method at a pulling rate of 8 mm / sec. Thereafter, the plastic lens coated with the intermediate layer coating liquid was placed in a heating furnace and heated at 80 ° C. for 30 minutes to cure the intermediate layer.

(3-4) Preparation of Hard Coat Solution In a glass flask containing a stirrer, 675 parts by weight of isopropyl alcohol and bis (trimethoxysilyl)
Add 105 parts by weight of ethane, and add 0.05
50 parts by weight of a prescribed hydrochloric acid solution was added dropwise. After further stirring, the mixture was aged for 24 hours. Next, 170 parts by weight of a methanol-dispersed silica sol and 0.2 parts by weight of a silicon-based surfactant were added, sufficiently stirred, and then filtered to obtain a hard coat liquid.

(3-5) Measurement of Refractive Index and Film Thickness of Hard Coat Film The coating solution prepared in the above 3-4 was pulled up on a plastic flat plate for glasses having a refractive index of 1.60 at a speed of 100 cm / min by a dip coating method. After the application, a heat treatment was performed at 80 ° C. for 4 hours. When the refractive index and the film thickness were measured in the same manner as in 3-2, the refractive index of the hard coat layer was 1.50,
The thickness was 2.3 μm.

(3-6) Coating and Curing of Hard Coat Solution The hard coat solution obtained in 3-4 was dipped on both surfaces of the plastic lens having the intermediate layer obtained in 3-3 by a dipping method (pulling speed). (100 cm / min). The coated lens was heated at 80 ° C. for 4 hours to cure the hard coat layer.

(3-7) Formation of Antireflection Coat A 5-layer antireflection film of silicon oxide / zirconium oxide is vacuum-deposited on both surfaces of the plastic lens having the intermediate layer and the hard coat layer obtained in 1-6 above. It was formed by a method. (3-8) Performance Evaluation of Plastic Lens Using the plastic lens having the composite film obtained in 3-7, performance evaluation was performed in the same manner as in 1-8 of Example 1. The evaluation results are shown in Table 1. 6. Comparative Example 3 The procedure of Example 3 was repeated except that the plastic lens was not provided with an intermediate layer. All evaluation methods were the same as in Example 3. The evaluation results are shown in Table 1.

[0060]

As described above, according to the present invention, a film thickness of 1.5 between the plastic lens substrate and the hard coat layer.
An intermediate layer having a refractive index difference of 0.03 μm or more and a refractive index difference of 0.03 or less from the hard coat layer is provided. Since the refractive index difference between the hard coat layer and the intermediate layer is small, the Fresnel reflection coefficient at the interface between the hard coat layer and the intermediate layer is so small as to be optically negligible. It can be considered as an integral layer.

Since the thickness of the intermediate layer is 1.5 μm or more, when combined with the thickness of the hard coat layer of 1.5 μm or more, the thickness of the integrated layer becomes 3 μm or more, and , Etc., due to their coherence length, under normal light sources, such as this, the level interference fringes of this integral layer virtually disappear.
Therefore, even if the refractive index of the plastic lens substrate and the refractive index of the hard coat layer are significantly different, a lens with no interference fringes, excellent appearance, excellent scratch resistance, and excellent wear resistance,
Since it is not necessary to prepare various hard coat liquids according to the refractive index of the plastic base material, it is possible to provide the hard coat liquid at a low cost.

Further, by providing the intermediate layer with a shock absorbing ability, it has become possible to provide a plastic lens excellent in impact resistance in addition to the above-mentioned various properties at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a surface layer configuration of a plastic lens of the present invention.

FIG. 2 is a diagram showing a surface layer configuration when an antireflection layer is applied to the plastic lens of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Plastic lens base material 12 ... Intermediate layer 13 ... Hard coat layer 21 ... Plastic lens base material 22 ... Intermediate layer 23 ... Hard coat layer 24 ... Anti-reflection layer

Claims (8)

[Claims] 1. A plastic lens comprising a plastic lens substrate, an intermediate layer formed on the plastic lens substrate, and a hard coat layer formed on the intermediate layer, wherein the plastic lens substrate and the hard coat A plastic lens, wherein a difference in refractive index between the intermediate layer and the hard coat layer is 0.08 or less, and a difference in refractive index between the intermediate layer and the hard coat layer is 0.03 or less. 2. The plastic lens according to claim 1, wherein said intermediate layer has a thickness of 1.5 μm or more. 3. The total thickness of the intermediate layer and the hard coat layer is 3 μm or more, and the whole of the hard coat layer and the intermediate layer can be optically regarded as one layer. The plastic lens according to claim 1 or 2, wherein: 4. The plastic lens according to claim 1, wherein an antireflection layer is provided on the hard coat layer. 5. The plastic lens according to claim 1, wherein the intermediate layer also functions as a shock absorbing layer. 6. The plastic lens according to claim 1, wherein the intermediate layer contains at least one of a polyvinyl acetal resin and a polyurethane resin. . 7. The method according to claim 1, wherein the intermediate layer contains a particulate inorganic substance made of a metal oxide.
The plastic lens according to any one of 3, 4, 5, and 6. 8. The fine particle comprising at least one selected from the group consisting of aluminum oxide, titanium oxide, zirconium oxide, antimony oxide, beryllium oxide, zinc oxide, tin oxide, cerium oxide, silicon dioxide, and tungsten oxide. The plastic lens according to claim 7, which is an inorganic substance, and has an average particle diameter of 1 to 300 nm.