JP4862379B2 - Plastic lens and method for manufacturing plastic lens - Google Patents

Description

  The present invention relates to an optical product such as a plastic lens formed by forming a light transmission layer on a plastic substrate and a method for manufacturing the same.

Conventionally, a plastic substrate is used as a base material (substrate) of an optical component such as an eyeglass lens. A plastic substrate is lighter and more moldable than a glass substrate, but its surface is very fragile. Therefore, a hard coat layer is formed on a plastic substrate to improve the scratch resistance.
This hard coat layer is generally formed by impregnating a plastic lens substrate with a hard coat liquid containing silicon dioxide fine particles and a silane coupling agent, spraying, spin coating or dipping, and then coating the film. Is performed by a wet method of drying and curing.

  On the other hand, the coefficients of thermal expansion of the materials (lens substrate, hard coat layer, antireflection film, etc.) constituting the plastic lens are different. For this reason, when viewed from the viewpoint of heat resistance, physical damage such as cracks or breakage may occur due to differences in thermal expansion coefficients. However, the material of the lens substrate and the antireflection film constituting the spectacle lens cannot be changed greatly. This is because the lens substrate is a basic structure for being a plastic lens, and the antireflection film is generally an inorganic film in order to maintain durability and hardness. Therefore, the lens substrate is composed of a lens substrate made of an organic material and an inorganic material. The difference in the coefficient of thermal expansion between the antireflection films is inevitably large. When a hard coat layer, which is an intermediate layer between the lens substrate and the antireflection film, is formed by an impregnation type wet method, the components of this layer are uniform and are composed of organic matter, so that the coefficient of thermal expansion is There is a large difference from the antireflection film. Due to this difference, from the viewpoint of heat resistance, there is a problem that breakage such as cracks and breakage are easily caused physically.

  Therefore, it has been attempted to form a hard coat layer by a dry method. For example, a method of forming a silicon dioxide film by a vacuum deposition method is known. In recent years, formation of a hard coat layer by a plasma CVD method using a silica-based organic metal has been proposed (for example, Patent Documents 1 and 2). Such a hard coat layer exhibits almost the same scratch resistance characteristics as a hard coat layer obtained by a general wet method.

JP-A-9-68601 JP-A-8-190002

However, the hard coat layer by the dry method does not have the problems as the wet method described above, but has another problem. That is, the silicon dioxide film formed by the vacuum evaporation method shows excellent scratch resistance from a film thickness of about 1 μm, but if it exceeds 1 μm, the adhesion to the plastic lens substrate is reduced due to the compressive stress of the silicon dioxide film. However, the film cannot be formed with a sufficient film thickness, and therefore, the scratch resistance cannot be sufficiently satisfied, and it is hardly used at present.
Such drawbacks can be overcome by a plasma CVD method using a silica-based organic metal as described in Patent Documents 1 and 2. However, in general, fine scratches are often generated on the lens substrate surface during lens polishing, and the wet method has an effect of covering the scratches when the hard coat layer is formed. According to the plasma CVD methods described in Patent Documents 1 and 2, since a film is uniformly formed on the surface, there is no so-called scratch disappearance effect peculiar to the wet method. Therefore, the optical properties and heat resistance of the lens (cracking) There was a problem.
Accordingly, an object of the present invention is to provide an optical product having a structure excellent in heat resistance and capable of eliminating fine scratches generated on a lens substrate, and a method for manufacturing the same.

The present invention is an optical product comprising a substrate, a primer layer formed on the substrate, a hard coat layer formed on the primer layer, and an antireflection film formed on the hard coat layer, The primer layer is formed by a wet method, and the hard coat layer has a coefficient of thermal expansion that changes so as to decrease from the substrate side toward the antireflection film side.
According to the optical product of the present invention, since the primer layer is formed by a wet method, even if a scratch is generated on the substrate, the scratch can be effectively covered. Furthermore, since the coefficient of thermal expansion inside the hard coat layer changes so as to decrease from the substrate side toward the antireflection film side, it is positioned in the middle even if the difference in the coefficient of thermal expansion between the substrate and the antireflection film is large. The hard coat layer to be made can alleviate the difference, thereby improving the heat resistance of the entire optical product.

  The primer layer is present at the interface between both the substrate and the hard coat layer, and has the property of achieving both adhesion to both. In addition, it also has properties as an external shock absorbing layer, and has the property of improving impact resistance. Such a primer layer may contain, for example, an organic resin polymer having a polar group or metal oxide fine particles containing titanium oxide.

In the present invention, the hard coat layer is preferably formed by a dry method.
According to this invention, since the hard coat layer is formed by a dry method, the coefficient of thermal expansion inside the hard coat layer can be easily changed. As the dry method, for example, a vacuum deposition method, a chemical vapor deposition method (hereinafter also referred to as “CVD method”), a sputtering method, or the like can be employed.

In the present invention, the optical product is preferably a plastic lens.
According to the present invention, since the optical product is a plastic lens, the coefficient of thermal expansion is large. Therefore, the difference in the coefficient of thermal expansion from that of the antireflection film is large, so that the effect of the present invention is exerted more strongly. Such a plastic lens can be suitably used for spectacles.

The method for manufacturing an optical product of the present invention is a method for manufacturing an optical product in which a primer layer, a hard coat layer, and an antireflection film are formed in this order on a substrate, and the primer layer is formed by a wet method. The hard coat layer is formed so that the coefficient of thermal expansion therein decreases from the substrate side toward the antireflection film side.
According to this invention, the primer layer is formed by a wet method, and the hard coat layer is formed so that the coefficient of thermal expansion inside the primer layer decreases from the substrate side toward the antireflection film side. It is possible to produce optical products that hardly exist and have excellent heat resistance.

In the present invention, the hard coat layer is preferably formed by a dry method, and more preferably a CVD method.
According to the present invention, since the hard coat layer is formed by a dry method, the thermal expansion coefficient inside thereof can be easily controlled. As the dry method, for example, a vacuum deposition method, a chemical vapor deposition method (hereinafter also referred to as “CVD method”), a sputtering method, or the like can be employed. Among these, the CVD method is preferable. As the CVD method, a plasma CVD method which can form a film at a low temperature and can be applied to a plastic substrate having low heat resistance is particularly preferable.
In the plasma CVD method, a raw material gas is chemically activated by plasma discharge under reduced pressure, and a film is deposited by a chemical reaction that is difficult by normal thermal excitation. Electrons and gas molecules accelerated by the electric field collide inelastically, and the molecules are ionized, dissociated or excited to form chemically active species. Since it is a non-equilibrium reaction, films having various compositions can be deposited at a considerably lower temperature than thermal CVD, and are more suitable for forming a plastic substrate having low heat resistance. In addition, a high frequency is often used for generating plasma, but there is also a method of applying a DC voltage. In addition, plasma generated using a magnetic field is diffused.
In the plasma CVD method, a Si-based organic metal such as TEOS (tetraethoxysilane) that is easy to handle and can be stably produced can be used.
Here, the coefficient of thermal expansion of the hard coat layer can be controlled, for example, by changing the formulation of the source gas or changing the composition.

In the present invention, it is preferable to control the coefficient of thermal expansion by changing the output in the CVD method.
According to this invention, since the thermal expansion coefficient is controlled by changing the output in the CVD method, the thermal expansion coefficient inside the hard coat layer can be easily changed with high accuracy. Specifically, by configuring the inside of the hard coat layer so that the composition on the substrate side is rich in organic matter and the composition on the antireflection film side is rich in inorganic matter, the coefficient of thermal expansion inside the hard coat layer Can be controlled continuously or stepwise from a large value to a small value.

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

FIG. 1 is a view schematically showing a cross section of a plastic lens for spectacles (hereinafter also referred to as “lens”) 100 which is an optical product of the present invention.
The lens 100 includes a substrate 1, a primer layer 2 formed thereon, a hard coat layer 3 formed thereon, and an antireflection film 4 formed thereon. Here, the primer layer 2 is formed by a wet method, and the hard coat layer 3 is changed so that the coefficient of thermal expansion therein decreases from the substrate 1 side toward the antireflection film 4 side.
Hereinafter, the configuration of the lens 100 will be described in detail.

(1. Substrate)
Although there is no restriction | limiting in particular as the board | substrate 1 of the lens 100, As a raw material, plastics, such as a diethylene glycol bisallyl carbonate polymer, a polyurethane resin, an acrylic resin, a polycarbonate resin, a polystyrene, are mentioned suitably.
However, in order to reduce the weight and thickness of the substrate, it is preferable to use a material having a high refractive index. It is preferable to use a material having a refractive index of 1.6 or more. For example, a polythiourethane plastic produced by reacting a compound having an isocyanate group or an isothiocyanate group with a compound having a mercapto group, episulfide An episulfide-based plastic produced by polymerizing and curing a raw material monomer containing a compound having a group can be suitably used as the material for the substrate 1.

As the compound having an isocyanate group or an isothiocyanate group as a main component of the polythiourethane plastic, a known compound can be used without any limitation.
Specific examples of the compound having an isocyanate group include ethylene diisocyanate, trimethylene diisocyanate, 2,4,4-trimethylhexane diisocyanate, hexamethylene diisocyanate, and m-xylylene diisocyanate.
Moreover, a well-known thing can be used also as a compound which has a mercapto group. For example, 1,2-ethanedithiol, 1,6-hexanedithiol, aliphatic polythiol such as 1,1-cyclohexanedithiol, 1,2-dimercaptobenzene, 1,2,3-tris (mercaptomethyl) benzene, etc. Aromatic polythiols are mentioned. In addition to the mercapto group, polythiol containing a sulfur atom is more preferably used to increase the refractive index of the plastic lens. Specific examples thereof include 1,2-bis (mercaptomethylthio) benzene, 1, Examples include 2,3-tris (mercaptoethylthio) benzene and 1,2-bis ((2-mercaptoethyl) thio) -3-mercaptopropane.

  The polymerization method for obtaining the substrate material in the present invention is not particularly limited, and a general polymerization method can be used without any limitation. For example, when using a vinyl-type monomer, a raw material can be manufactured by thermosetting using thermal polymerization initiators, such as an organic peroxide. Moreover, a monomer can be hardened by irradiating with ultraviolet rays using a photopolymerization initiator such as benzophenone to produce a material.

When a polythiourethane plastic produced by reacting a compound having an isocyanate group or isothiocyanate group with a compound having a mercapto group is used as a material for a substrate, it has an isocyanate group or an isothiocyanate group. It can be produced by mixing a compound and a compound having a mercapto group, and then adding and mixing a curing catalyst for urethane resin, followed by heat curing.
Specific examples of the curing catalyst include amine compounds such as ethylamine, ethylenediamine, triethylamine, and tributylamine, dibutyltin dichloride, dimethyltin dichloride, and the like.

When an episulfide-based plastic obtained by polymerizing a raw material monomer containing a compound having an episulfide group is used as a substrate material, the compound having an episulfide group can be copolymerized alone or with an episulfide group. After mixing with another monomer, it can be produced by adding and mixing a curing catalyst for epoxy resin and performing polymerization and curing by heating.
There are no particular limitations on the curing catalyst for the epoxy resin, but specific examples include tertiary amines such as dimethylbenzylamine, dimethylcyclohexylamine, diethylethanolamine, dibutylethanolamine, tridimethylaminomethylphenol, and ethylmethylimidazole. And imidazoles.
Examples of other monomers copolymerizable with a compound having an episulfide group include a compound having a hydroxyl group, a compound having a mercapto group, a primary or secondary amine, and a compound having a carboxyl group.
Specific examples of the compound having a hydroxyl group include alcohols such as isopropyl alcohol and n-hexyl alcohol, and polyhydric alcohols such as ethylene glycol, 1,6-hexanediol, pentaerythritol dimethacrylate, and pentaerythritol diacrylate. . Specific examples of the compound having a mercapto group include thiophenol, ethylthioglycolate, bis (2-mercaptoethyl) sulfide, 2,5-dimercaptomethyl-1,4-dithiane, and the like.

(2. Primer layer)
The primer layer 2 is generally provided for the purpose of improving the adhesion between the substrate 1 of the lens 100 and the hard coat layer 3, improving the impact resistance, improving the dyeing property, etc. In the present invention, the surface of the substrate 1 is provided. It also has the effect of eliminating scratches occurring in the surface. That is, the substrate 1 is usually subjected to a polishing process, but so-called polishing scratches are generated, and the substrate 1 is in a state in which mechanical characteristics and optical characteristics are inferior as it is. In the present invention, the primer layer 2 is formed by a wet method, and this polishing flaw can be filled.

Such a primer layer 2 may include, for example, an organic resin polymer having a polar group or metal oxide fine particles containing titanium oxide.
As the organic resin polymer having a polar group, various resins such as a polyester resin, a polyurethane resin, an epoxy resin, a melamine resin, a polyolefin resin, a urethane acrylate resin, and an epoxy acrylate resin can be used. Among these, a polyester resin can be preferably used from the viewpoint of adhesion to a lens substrate containing sulfur atoms and dispersibility of metal oxide fine particles serving as a filler.

  In the polyester resin, the hydroxyl group or epoxy group attached to the ester bond and the side chain in the resin is likely to interact with the plastic lens substrate surface molecule, and exhibits high adhesion. On the other hand, the pH of the polyester resin often shows weak acidity and often coincides with the pH at which the metal oxide fine particles serving as the filler can stably exist. Therefore, the metal oxide fine particles are uniformly dispersed in the primer resin without being localized, and the crosslinking density of the primer layer is stabilized or improved, thereby improving water resistance and light resistance.

  The composition constituting the primer layer 2 includes a resin material, a curing catalyst, a solvent, a colloidal dispersion of fine metal particles, and other additives. The primer layer 2 composition is generally used after being diluted with a solvent. Examples of the dilution solvent include alcohols, ketones, esters, ethers, and the like, and other solvents can also be used. is there. Particularly preferred are diacetone alcohol, ethyl acetate, and methyl ethyl ketone, which may be used alone or as a mixed solvent of two or more.

Further, the primer layer 2 composition may contain a leveling agent for improving applicability, an ultraviolet absorber for improving weather resistance, and an antioxidant.
As a method for applying the composition for the primer layer 2, known methods such as a spray method, a spin coating method, and a dipping method are used. If necessary, the plastic lens substrate may be pretreated by alkali treatment, plasma treatment, ultraviolet treatment, surface polishing treatment with inorganic fine particles, or the like.

The primer layer 2 is obtained by applying the composition for the primer layer 2 to a plastic lens substrate by the method described above and then curing the composition. These curings require a curing catalyst. As the curing catalyst, a tertiary amine compound, an organic tin compound, an organic zinc compound, ammonium perchlorate, a cationic photopolymerization initiator, or a radical photopolymerization initiator is used.
In order to form the primer layer 2, the primer layer composition is applied to the lens and then heated at 70 to 180 ° C., preferably 100 to 130 ° C. At temperatures lower than 70 ° C., the curing reaction hardly proceeds. At a temperature higher than 180 ° C., the plastic lens substrate is deformed. The time required for curing varies depending on the heating temperature, but is 15 to 90 minutes.
Moreover, the required film thickness as the primer layer 2 is 0.05-5 micrometers, Preferably it is 0.1-1 micrometer. If it is thinner than 0.05 μm, the scratch disappearance effect obtained by providing the primer layer 2 is not sufficiently exhibited, and if it is thicker than 5 μm, the surface accuracy is lowered.

(3. Hard coat layer)
For the hard coat layer 3, it is preferable to use a dry method capable of easily changing the thermal expansion coefficient inside the layer, particularly a CVD method capable of easily changing the output. In particular, a plasma CVD method which can be formed at a low temperature and can be applied to a plastic substrate (primer layer constituting resin) having low heat resistance is preferable. By changing the output in the CVD method, the thermal expansion coefficient inside the hard coat layer 3 can be easily changed with high accuracy. Specifically, by configuring the inside of the hard coat layer so that the composition on the substrate side is rich in organic matter and the composition on the antireflection film side is rich in inorganic matter, the coefficient of thermal expansion inside the hard coat layer Can be controlled continuously or stepwise from a large value to a small value.
In the plasma CVD method, a raw material gas is chemically activated by plasma discharge under reduced pressure, and a film is deposited by a chemical reaction that is difficult by normal thermal excitation. Electrons and gas molecules accelerated by the electric field collide inelastically, and the molecules are ionized, dissociated or excited to form chemically active species. Since it is a non-equilibrium reaction, films having various compositions can be deposited at a considerably lower temperature than the thermal CVD method and are suitable for forming a resin substrate having low heat resistance. A high frequency is often used to generate plasma, but there is also a method of applying a DC voltage. In addition, plasma generated using a magnetic field is diffused.

In the plasma CVD method, Si-based organic metal that is easy to handle and can be stably produced can be used.
Examples of the Si-based organic metal include tetramethyldisilazane, tetramethoxysilane, tetraethoxysilane, tetramethylsilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, Dimethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, ethyltrimethylsilane, allyltrimethylsilane, isopropoxytrimethylsilane, methyltrivinylsilane, hexamethyldisiloxane, hexamethyldisilane, 1,3-dimethoxy Tetramethyldisiloxane, dimethyltrimethylsilylamine, acetoxymethyltrimethylsilane, allyldimethylsilane, bis (dimethylamino) methylsilane , T-ethoxytrimethylsilane, divinyldimethylsilane, hexamethylcyclotrisiloxane, hexamethyldisilazane, 1,1,3,3,5,5-hexamethyltrisiloxane, trimethylsilyl isocyanate, vinyl-t-butyldimethylsilane Etc.

(4. Antireflection film)
On the hard coat layer 3, a single-layered and multilayered antireflection film 4 made of an inorganic material is provided, and the light reflectance can be reduced and the light transmittance can be improved. Examples of the inorganic _{substances, SiO, SiO 2, Si 3} N 4, TiO 2, ZrO 2, Al 2 O 3, MgF 2, Ta 2 O 5, Nb 2 O 5 vacuum evaporation method well known with such like The antireflection film 4 can be formed by this thin film formation method.

  According to the present invention, the lens 100 as an optical product includes the substrate 1, the primer layer 2 formed on the substrate 1, the hard coat layer 3 formed on the primer layer 2, and the hard coat layer 3. Since it has the antireflection film 4 formed on the top and the two primer layers are formed by a wet method, even if the substrate 1 has scratches, the scratches can be effectively covered ( Scratch disappearance effect). Further, since the thermal expansion coefficient of the hard coat layer 3 changes so as to decrease from the substrate 1 side toward the antireflection film 4 side, the thermal expansion coefficient of the substrate 1 and the antireflection film 4 is reduced. Even if the difference is large, the heat resistance of the entire optical product (lens 100) can be enhanced by the hard coat layer 3 positioned in the middle mitigating the difference.

The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and is within a range in which the object and effect of the present invention can be achieved. Needless to say, modifications and improvements are included in the content of the present invention. In addition, the specific structure and shape in carrying out the present invention may be used as other structures and shapes within the scope of achieving the object and effect of the present invention.
For example, in the plasma CVD method, in order to change the thermal expansion coefficient by changing the internal structure of the hard coat layer, not only the output, but also, for example, the raw material prescription at the time of performing the plasma treatment or the raw material composition is changed. Can also be controlled.

Moreover, as a dry method for forming the hard coat layer, a vacuum deposition method may be used. The vacuum evaporation method is a method in which a thin film material is heated and evaporated in a high vacuum, and the evaporated particles are deposited on a substrate (primer-containing layer) to form a thin film. Thin film material heating methods include resistance heating, electron beam heating, and arc heating. In the vacuum vapor deposition method for a substrate, inorganic materials that can be used are limited due to the heat resistance of the substrate. For example, SiO ₂ , SiO, ZrO ₂ , TiO ₂ , TiO, Ti ₂ O ₃ , Ti ₂ O ₅ , Al ₂ O ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , CeO ₂ , MgO, Y ₂ O ₃ , SnO ₂ , MgF ₂ , WO ₃ , Cr, etc. can be mentioned. These inorganic substances can be used alone or in combination of two or more. Can be used. In particular, for a substrate made of plastic, it is preferable to use SiO, SiO ₂ , ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , Ti ₂ O ₅ , or Cr that can lower the deposition temperature.

Hereinafter, the optical product of the present invention and the manufacturing method thereof will be described in detail with reference to examples. However, the present invention is not limited to these examples.
[Example 1]
The present embodiment is an example applied as an optical product to the plastic lens 100 for spectacles shown in FIG. After manufacturing the plastic lens 100 for spectacles as follows, the scratch disappearance effect (appearance) and heat resistance of the surface of the lens substrate 1 were evaluated.

  (Formation of primer layer 2) A primer layer (scratch disappearance layer) 2 made of a polyester-based compound is applied on the polished lens substrate 1 so as to have a film thickness of 0.3 μm by an immersion method, and heated ( Cured at 90 ° C. for 5 minutes.

(Formation of hard coat layer 3)
A hard coat film was formed on the lens substrate 1 after the primer layer 2 was formed by a plasma CVD method. As raw materials, an organic silane compound (C ₆ H ₁₈ OSi ₂ ) and oxygen gas (O ₂ ) were used. The processing time was adjusted so that the film thickness of the hard coat layer 3 was 2.5 μm. When the hard coat layer 3 is formed (film formation), the high-frequency output at the start of film formation is set to 100 watts, and is changed to 300 watts at the end of film formation, whereby the material composition inside the hard coat layer 3 is changed. The film was formed while controlling from an organic material rich state to an inorganic material rich state.

(Formation of antireflection film 4)
The antireflection film 4 was formed by alternately laminating SiO ₂ layers and TiO ₂ layers in order from the lens substrate 1 side to form a seven-layer antireflection multilayer film. The SiO ₂ layer was formed by a normal vacuum evaporation method. The TiO ₂ layer was formed by ion-assisted vapor deposition. In the present embodiment, counting from the lens substrate 1 side, the first layer is an SiO ₂ layer having an optical film thickness of 0.083λ, the second layer is a TiO ₂ layer having an optical film thickness of 0.07λ, and the third layer. Is an SiO ₂ layer having an optical thickness of 0.10λ, a fourth layer is a TiO ₂ layer having an optical thickness of 0.18λ, a fifth layer is an SiO ₂ layer having an optical thickness of 0.065λ, and a sixth layer Is an TiO ₂ layer having an optical film thickness of 0.14λ, and an SiO ₂ layer having an optical film thickness of 0.26λ is sequentially laminated to form an antireflection film.

[Comparative Example 1]
Except that the primer layer is not formed on the lens substrate 1 after polishing, the hard coat layer 3 and the antireflection film 4 are formed in the same manner as in Example 1, and the plastic lens 200 for spectacles as shown in FIG. Manufactured. Evaluation was performed in the same manner as in Example 1.

[Comparative Example 2]
A primer layer 2 was formed on the polished lens substrate 1 in the same manner as in Example 1. Thereafter, a hard coat layer 3 ′ as shown in FIG. 3 was formed by the following method. The antireflection film 4 was formed in the same manner as in Example 1.

(Formation of hard coat layer 3 ')
The surface of the primer layer 2 was impregnated with an organic silicon compound to form a film. The thickness of the hard coat layer 3 was 2.5 μm. The organic silicon compound used for the hard coat layer 3 was prepared as follows. In a flask equipped with a stirrer, 100 g of ethyl cellosolve and 100 g of γ-glycidoxypropyltrimethoxysilane were sequentially added with stirring, and then 42.7 g of 0.1N hydrochloric acid was added and stirred for 4 hours. Subsequently, 0.3 g of a silicon-based surfactant (trade name “L-7001” manufactured by Nippon Unicar Co., Ltd.) and methanol-dispersed titanium dioxide-zirconium dioxide-silicon dioxide composite fine particle sol (TiO ₂ / ZrO ₂ / SiO ₂₎ = 68/17/15 (weight ratio), solid content concentration 20.5% by weight, 698.2 g of composite fine particles having a fine particle structure coated with SiO ₂ using a solid solution of TiO ₂ and ZrO ₂ as a core After stirring, the mixture was allowed to stand at 0 ° C. for 24 hours for aging to obtain an organosilicon compound used for the hard coat layer 3.

〔Evaluation methods〕
(Appearance evaluation)
An appearance evaluation test was performed on the samples (plastic lens 100, 200, 300 for spectacles) obtained in each of the above steps. The appearance evaluation test was conducted by a transmission inspection method as shown in FIG. Specifically, first, in an examination room having a black background (floor, wall) F with little reflection, the illuminance is 200 to 250 lux, the illuminance at the test position is 350 to 500 lux, and the environment can be clearly seen with the naked eye. (Conforms to JIS T7313 to T7315). The fluorescent lamp L used was a three-wavelength light emitting daylight white type. Then, after raising and lowering the lenses 100, 200, and 300 and observing scratches remaining on the lenses 100, 200, and 300, the lens 100, 200, and 300 are further rotated by 45 to 90 degrees to raise and lower the scratches again. Observed.
As evaluation criteria, the degree of scratches remaining in the lenses 100, 200, and 300 was ranked in three stages, and evaluation was performed according to the following criteria. Each of 10 samples was evaluated (n = 10).
A: Ultra-thin and shallow scratches B: Thin and shallow scratches C: Deep scratches The scratch generation areas were ranked in three stages, and the size of the scratches was evaluated according to the following criteria.
1: Less than 1/4 of the sample area 2: 1/4 or more to less than 1/2 of the sample area 3: 1/2 or more of the sample area

  The appearance evaluation test may be performed by a reflection inspection method as shown in FIG. 5, or both may be used in combination. In the reflection inspection method of FIG. 5, the environment in the inspection room is the same as the transmission inspection method of FIG. 4, but the evaluation is performed by changing the inclination angle of the lens 100 and the like. Specifically, after observing the degree of scratches of the lens 100 or the like once, the lens 100 or the like is rotated by 45 to 90 degrees and evaluated in the same manner again.

(Heat resistance evaluation)
After the antireflection film 4 is formed, the lenses 100, 200, and 300 are heated in an oven at a predetermined temperature for 30 minutes, and then the presence or absence of cracks is observed with the naked eye. The temperature at which the cracks are generated is defined as the heat resistant temperature of the sample. did. The temperature of the oven started from 40 ° C. and increased by 5 ° C. for evaluation. The higher the temperature at which cracks occur, the better the heat resistance.

[Result]
Table 1 shows the evaluation results of the samples manufactured in Example 1 and Comparative Examples 1 and 2.
It was also confirmed that the expansion coefficient inside the hard coat layer 3 actually changed (inclined) from the substrate 1 side to the antireflection film 4 side. The measurement used Shimadzu Corporation thermomechanical machine opportunity analyzer (TMA-60). The conditions at the time of film formation (when the hard coat layer 3 was formed) were measured for the thermal expansion coefficients of film formation samples having high-frequency outputs of 100 watts, 200 watts, and 300 watts, respectively. The results are shown in Table 2.

From the results shown in Table 1, in the lens 100 of Example 1, the scratch removal effect is excellent compared to the lens 200 of Comparative Example 1 without the primer layer 2 by the wet method, and the hard coat layer 3 ′ is formed by the wet method. It was confirmed that the lens 300 of Comparative Example 2 is superior in heat resistance.
From the results shown in Table 2, by changing the high frequency output in the plasma CVD method, the thermal expansion coefficient in the hard coat layer actually changes so as to decrease from the substrate 1 side toward the antireflection film 3 side. I was able to confirm.

  INDUSTRIAL APPLICATION While this invention is excellent in heat resistance, it can be utilized as a plastic lens for spectacles with the structure which eliminate | eliminates the fine crack produced on the lens board | substrate.

Sectional drawing which shows the structure of the plastic lens for eyeglasses (Example 1) of this invention. Sectional drawing which shows the structure of the plastic lens for spectacles of the comparative example 1. FIG. Sectional drawing which shows the structure of the plastic lens for spectacles of the comparative example 2. FIG. The schematic diagram which shows the evaluation method of the plastic lens for spectacles. The schematic diagram which shows the other evaluation method of the plastic lens for spectacles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate (plastic lens board | substrate), 2 ... Primer layer 3, 3 '... Hard-coat layer, 4 ... Antireflection film, 100, 200, 300 ... Plastic lens for spectacles

Claims (2)

A substrate made of plastic ,
A primer layer formed on the substrate by a wet method ;
And the hard coat layer formed by chemical vapor deposition on said primer layer,
An antireflection film made of an inorganic material formed on the hard coat layer;
A plastic lens having,
The thermal expansion coefficient of the hard coat layer is changed from the substrate side so as to decrease toward the antireflection film side,
A plastic lens characterized by that. A primer layer is formed on a substrate made of plastic by a wet method, a hard coat layer is formed on the primer layer by a chemical vapor deposition method, and an antireflection film made of an inorganic substance is formed on the hard coat layer. A method of manufacturing a plastic lens ,
A method for producing a plastic lens , wherein when forming the hard coat layer, the hard coat layer is formed by changing so as to increase the output in the chemical vapor deposition method.

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