JPH10282302A - Plastic lens and manufacturing method thereof - Google Patents

Abstract

(57) [Problem] To improve the performance of a plastic lens having a hard coat layer made of an ultraviolet curable resin. SOLUTION: The plastic lens of the present invention is obtained by polymerizing a plastic lens substrate, an ultraviolet absorbing layer containing an ultraviolet absorbent and an organic compound and formed on the plastic lens substrate, by irradiating ultraviolet rays or irradiating and heating ultraviolet rays. And a hard coat layer formed on the ultraviolet absorbing layer using a compound containing a substance to be used as a raw material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plastic lens having a hard coat layer cured by ultraviolet rays. The plastic lens of the present invention is excellent in durability such as abrasion resistance, abrasion resistance, impact resistance, and the like, and has good appearance and excellent practicality.

[0002]

2. Description of the Related Art Recently, plastic lenses have advantages such as light weight, easy processability, and easy dyeing, and are therefore rapidly becoming popular in the field of optical materials, particularly lenses for glasses.
However, plastic lenses generally have the disadvantage that they are easily damaged. For this reason, usually, a hard coat layer is formed on the surface of the plastic lens substrate to improve the scratch resistance and the wear resistance.

For example, when a lens is manufactured using a plastic lens substrate having a relatively low refractive index, the refractive index of which is about 1.5, a hard coat layer made of an organosilicon compound is generally formed. To improve the scratch resistance and the like. Hard coat layers in which inorganic oxide fine particles such as silica are added to an organosilicon compound are also known. Further, as a hard coat layer formed on a high refractive index plastic lens substrate having a refractive index of about 1.6 or more,
It has been proposed to apply an organosilicon compound containing high-refractive-index oxide fine particles such as titanium oxide, tin oxide or tungsten oxide onto a substrate.

In general, a hard coat layer formed on a plastic lens substrate often uses a thermosetting resin. Such a conventional hard coat layer is formed by applying a coating liquid to be a hard coat layer to the surface of a base material by a dipping method or a spin coating method, and then performing a heat treatment for several hours and curing the coating liquid. Was. On the other hand, recently, a hard coat layer made of an ultraviolet curable resin has been developed and is becoming popular. For example, JP-A-6-279
No. 705 describes that a hard coat layer is formed by applying an ultraviolet curable paint to the surface of a molded article made of polycarbonate. Also, JP-A-6-4146
No. 8 describes a manufacturing method using a specific ultraviolet curable resin and not performing a stripping step.

The hard coat layer made of the ultraviolet curable resin is cured by applying a resin to the surface of a plastic lens substrate and irradiating the resin with an active energy ray. In this case, the curing time is usually about several seconds to several minutes, and the method using an ultraviolet curable resin is as follows.
The production time is shorter than in the case where a conventional thermosetting resin is used, and the productivity is excellent.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have formed a hard coat layer made of an ultraviolet curable resin on the surface of a plastic lens substrate for spectacles. However, the plastic lens in which the hard coat layer is formed of an ultraviolet curable resin has a problem of yellowing. Furthermore, the present inventors used a dyed plastic lens substrate and formed a hard coat layer made of an ultraviolet curable resin on the surface of the substrate. However, in such a case, there is a problem that the tint of the dyed color changes. In particular, when dyed with an organic dye, the color change was remarkable. These problems are slight enough to be acceptable for many plastic applications such as plastic panels for construction and touch panels, but cannot be ignored for optical lenses that require a high degree of transparency. It is.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a plastic lens which can be easily manufactured and has a hard coat layer made of an ultraviolet curable resin, which does not cause yellowing or color change. And

[0008]

SUMMARY OF THE INVENTION The present inventors have studied the causes of the yellowing and the change in tint of the plastic lens described above. As a result, it was found that ultraviolet rays were applied when a hardening layer was formed by applying an ultraviolet curable resin to the surface of the plastic lens substrate and then curing the resin. As a result of further research, it has been found that when ultraviolet light is irradiated on the base material, the plastic material of the base material is altered by a photochemical reaction, thereby causing yellowing.

[0009] The change in the tint of the dyed plastic lens is considered to be due to the fact that the dye present in the base material is deteriorated by ultraviolet rays. As a result of intensive studies, the present inventors have found that it is sufficient to prevent irradiation of the plastic lens substrate with ultraviolet rays, and have accomplished the present invention. Accordingly, the present invention firstly provides a “plastic lens substrate, an ultraviolet absorbing layer formed on the plastic lens substrate, including an ultraviolet absorber and an organic compound,
A plastic lens (Claim 1), comprising: a hard coat layer formed on the ultraviolet absorbing layer by using a compound containing a substance polymerized by ultraviolet irradiation or ultraviolet irradiation and heating as a raw material. I do. Second, “a process of injecting a monomer into a lens molding matrix,
A step of polymerizing and curing the monomer to form a plastic lens substrate, and applying a substance containing an ultraviolet absorber and an organic compound on the molded plastic lens substrate and heating to form a film and absorb ultraviolet rays. A step of forming a layer, a step of applying a compound containing a substance polymerizable by irradiation with ultraviolet light or irradiation of ultraviolet light and heating on the ultraviolet absorbing layer, and irradiation of the applied compound with ultraviolet light or ultraviolet light. And a step of heating to polymerize the applied compound to form a hard coat layer, and a method for producing a plastic lens (Claim 2).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A plastic lens according to the present invention has an ultraviolet absorbing layer 12 formed on a plastic lens substrate 11, as shown in FIG. Hard coat layer 1 consisting of
3 is formed. In FIG. 1, the ultraviolet absorbing layer 12 and the hard coat layer 13 are formed on both surfaces of the plastic lens substrate 11, but may be formed on only one surface.

As the plastic lens substrate of the present invention, any resin such as a thermosetting resin, a thermoplastic resin, an ultraviolet curable resin, and a radiation curable resin can be used. Examples of specific plastic substrates that can be used include diethylene glycol bisallyl carbonate (CR39), styrene, α-methylstyrene, chlorostyrene, phenyl methacrylate, phenyl acrylate, benzyl methacrylate, benzyl acrylate, naphthyl methacrylate, naphthyl acrylate, and tetrabromo. (Di) methacrylate of bisphenol derivative, (di) acrylate of tetrabromobisphenol derivative, diallyl carbonate of tetrabromobisphenol derivative, methyl methacrylate, (di) ethylene glycol methacrylate, (di) ethylene glycol acrylate, vinylnaphthalene, divinylbenzene, etc. And 2-hydroxyethyl methacrylate, 2-hydroxyethyl Acrylate, 3-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 2,3-hydroxypropyl methacrylate,
A reaction product of a hydroxy methacrylate such as 3-hydroxypropyl acrylate or a polyfunctional (poly) isocyanate such as hydroxyacrylate and xylylene diisocyanate, isophorone didiisocyanate, hexamethylene diisocyanate, and a cyclic trimer of hexamethylene diisocyanate; -Mercaptoethyl) ether, 1,2-ethanedithiol, di (2-mercaptoethyl) sulfide, 2-mercaptoethanol, pentaerythritol tetrakis-3-mercaptopropionate, 4-mercaptomethyl-3,6-dithiar1,8 A reaction product of a thiol compound such as octanediol and a polyfunctional (poly) isocyanate or a polyfunctional (poly) ene and a mixture thereof, polycarbonate, polyethylene, polypropylene, etc. Ren, there may be mentioned a vinyl chloride resin or the like, but is not limited thereto.

The plastic lens substrate can be prepared by adding a polymerization initiator to a monomer, placing the monomer in a matrix, and polymerizing by heat or ultraviolet rays or a combination thereof. When a base material that is polymerized by the combined use of heating and ultraviolet irradiation is used, it is possible to impart the high hardness and the refractive index of the thermosetting resin to the lens mainly composed of the ultraviolet curing resin.

The polymerization initiator which can be used in the present invention is not limited, and examples thereof 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, benzyldimethylketal Benzoyl peroxide, 1-hydroxycyclohexyl phenyl ketone, α-hydroxyisobutylphenone, p-isopropyl-α-hydroxyisobutylphenone, and the like.

In FIG. 1, reference numeral 12 denotes an ultraviolet absorbing layer. The ultraviolet absorbing layer is a substance that transmits visible light and absorbs ultraviolet light,
Contains a so-called ultraviolet absorber. Ultraviolet rays irradiated to cure the hard coat layer are absorbed by the ultraviolet absorbing layer and hardly reach the plastic lens substrate. Therefore, it is possible to prevent yellowing of the plastic lens substrate caused as a result of the photochemical reaction due to ultraviolet rays.

Further, even when the plastic lens substrate is dyed, the ultraviolet ray is absorbed by the ultraviolet absorbing layer, and the ultraviolet ray does not reach the substrate. Therefore, the dye in the base material is not irradiated with the ultraviolet rays, and a change in color tone can be prevented. In general, a hard coat layer made of an ultraviolet curable resin has disadvantages in that the hardness is lower than that of a hard coat layer made of a thermosetting resin and the scratch resistance is poor. However, the provision of the ultraviolet absorbing layer makes it possible to increase the amount of ultraviolet light that can be applied to the plastic lens substrate. Increasing the amount of ultraviolet light to be irradiated will accelerate the curing of the ultraviolet-curable resin, so that the hardness of the hard coat layer made of the ultraviolet-curable resin can be increased and the scratch resistance can be improved. Become. The hard coat layer can also be formed by adding a curing agent which cures by heating to an ultraviolet curable resin and retaining the properties of the thermosetting resin.

The thickness of the ultraviolet absorbing layer depends on the amount of the ultraviolet absorbing agent contained in the film, the amount of ultraviolet rays to be irradiated, and the like, but is usually preferably about 0.05 μm to 10 μm.
When the film thickness is less than 0.05 μm, there arises a problem that the ultraviolet absorbing ability becomes insufficient, and when the film thickness is more than 10 μm, there arises a problem that the surface hardness of the lens is lowered and cracks are easily formed. .

The ultraviolet absorber usable in the present invention is not particularly limited. Examples thereof include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, -Hydroxy-4-methoxy-benzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-
Benzophenones such as benzophenone, 2,2′4,4′-tetrahydroxybenzophenone, 2-hydroxy-4-allyloxybenzophenone, 2- (2′-hydroxy-5′-methylphenyl) -benzotriazole, 2- (2 Benzotriazoles such as'-hydroxy-3'-5'-di-t-amylphenyl) -benzotriazole, ethyl-2-cyano-3,3-diphenylacrylate, 2-ethylhexyl-2-cyano-3,3
-Diphenyl acrylates such as diphenyl acrylate; inorganic oxides such as zinc oxide, titanium oxide and cerium oxide; and mixtures thereof.

As the matrix component of the ultraviolet absorbing layer, any substance can be used as long as it is optically transparent and dissolves or disperses the ultraviolet absorbing agent well. Further, by using a substance having a shock absorbing capacity as the matrix component, it is possible to simultaneously improve the impact resistance of the plastic lens. Matrix components include polyvinyl acetal, polyvinyl alcohol, urethane (meth) acrylate, epoxy (meth)
Acrylate, polyvinylpyrrolidone, a polyaddition reaction product of a polyene compound and a polyfunctional thiol compound, and the like can be used, but are not limited thereto.

As described above, there is no particular limitation on the matrix component of the present invention. As an example, a case where a crosslinked polyvinyl acetal is used will be described. When a crosslinked polyvinyl acetal is used as a matrix component, a layer having both an impact absorbing ability and an ultraviolet absorbing ability can be formed. The formation of an ultraviolet absorbing layer having a shock absorbing capacity composed of cross-linked polyvinyl acetal,
Dip-coating or spin-coating a plastic lens with polyvinyl acetal as a main component and at least one of a hydrolyzable organosilane compound or dialdehyde as a cross-linking agent, or a curing catalyst, on a plastic lens, followed by heat treatment It can be done by things.

As a cross-linking agent for the ultraviolet absorbing layer having an impact absorbing ability, an organosilane compound such as tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane or the like is used. . These organosilane compounds may be used alone or as a mixture of two or more.

Also, organotitanium compounds such as tetramethoxytitanium, methyltrimethoxytitanium, dimethyldimethoxytitanium, tetraethoxytitanium, ethyltriethoxytitanium, diethyldiethoxytitanium and the like can be used as the crosslinking agent. These organotitanium compounds may be used alone or as a mixture of two or more. Further, a dialdehyde compound such as glyoxal, malondialdehyde, succindialdehyde, glutardialdehyde, adipindialdehyde, maleic dialdehyde, phthalaldehyde, isophthalaldehyde, terephthalaldehyde or an acetal compound of dialdehyde may also be used as a crosslinking agent. it can.

The ultraviolet absorbing layer having an impact absorbing ability includes
The refractive index and hardness can be adjusted by mixing inorganic oxide fine particles such as titanium oxide, tin oxide, tungsten oxide, zirconium oxide, iron oxide, silicon oxide, aluminum oxide, and indium oxide. These oxide fine particles may be mixed alone, or may be mixed in a state where a plurality of fine particles are mixed or in a composite form. That is, it is also possible to mix both the oxide fine particles for adjusting the hardness and the refractive index and the ultraviolet absorber into the ultraviolet absorption layer having the shock absorption capacity.

Further, a case where a thermosetting polyurethane resin is used will be described as another example of the matrix of the ultraviolet absorbing layer. As specific examples of the thermosetting polyurethane,
Reaction products of polyisocyanates with polyols and / or polythiols can be mentioned. Specific examples of the polyisocyanate include tolylene diisocyanate, 4,4
-Diphenylmethane diisocyanate, xylylene diisocyanate, 1,5-naphthalenedi isocyanate,
Bonds monomers and / or several molecules such as triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate, tetramethylxylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, lysine ester triisocyanate, etc. Adducts, polyisocyanates containing sulfur or halogen groups, and the like.

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.

When the above-mentioned thermosetting polyurethane resin is used as the matrix of the ultraviolet absorbing layer,
The lens can be provided with shock absorption resistance. The composition of the film of the hard coat layer made of an ultraviolet-curable resin is not particularly limited, and examples thereof include a polyfunctional acrylate compound, a polyfunctional epoxy acrylate compound, an acrylated aliphatic urethane compound, and an organic material containing these compounds. And a mixture containing a mixture of the above. Further, in addition to the above organic substances, metal oxide fine particles such as titanium oxide, tin oxide, tungsten oxide, zirconium oxide, iron oxide, silicon oxide, aluminum oxide, and indium oxide can be contained. These fine particles may be mixed alone, or may be mixed in a state where a plurality of fine particles are mixed or in a composite form.

The thickness of the hard coat layer is usually 0.05 μm
When the film thickness is less than 0.05 μm, there arises a problem that the surface hardness of the lens decreases.
If the thickness is more than 0 μm, problems such as a decrease in the impact resistance of the lens and a crack during the formation of the hard coat layer occur. In the plastic lens of the present invention, an antireflection film 24 can be provided on the hard coat layer 23 as shown in FIG. Examples of the substance used for the antireflection film include metals, metal oxides, and fluorides, and typical examples thereof include silicon oxide, zirconium oxide, titanium oxide, and magnesium fluoride. The number of layers may be either a single layer or multiple layers. Examples of the method for forming the antireflection film include a vacuum evaporation method, a sputtering method, an ion plating method, and an ion beam assist method. Further, on the anti-reflection film, to form a water-drain prevention film made of a polymer obtained by polymerizing a polysiloxane-based polymer or a perfluoroalkyl group-containing compound, or a silazane compound, a siloxazane compound, an alkoxysilane-based compound, or the like. Is also possible.

The plastic lens of the present invention is manufactured by the following manufacturing method. 1) A polymerization initiator is added to a monomer, which is a raw material of a plastic lens substrate, to produce a monomer solution, which is stirred. This monomer solution is poured into a matrix composed of glass and a gasket or tape. 2) The master mold into which the monomer liquid has been injected is placed in a heating furnace and gradually heated from room temperature to about 100 ° C. Alternatively, the matrix into which the monomer solution has been injected is placed in an ultraviolet irradiation device, and irradiated with ultraviolet light for several seconds to several minutes to polymerize, thereby curing the monomer resin and molding a plastic lens substrate. 3) In the case of a dyed plastic lens, the lens substrate is dyed. As a dyeing method, a so-called pot dyeing method in which a plastic lens substrate is immersed in a solution in which a dye is dissolved or dispersed at a certain temperature for a certain time, or a non-flowable substance containing a dye is applied to the surface of the plastic lens and then heated. ,
After the dye is diffused into the plastic lens substrate, any method can be used as long as it is a method generally used for dyeing a substrate made of plastic, such as a so-called transfer method for removing a non-flowable substance. is there. Of course, if there is no need to dye the plastic lens substrate, this step is not performed. 4) A solution containing an ultraviolet absorber and a matrix component was applied to the surface of the plastic lens substrate molded in 2 or the surface of the dyed plastic lens substrate dyed in 3 by spin coating or dip coating. After that, an ultraviolet absorbing layer is formed by heating. The heating temperature at this time is about 25 ° C. or more and about 150 ° C. or less, and it is preferable to perform heating at 120 ° C. or less. 5) A hard coat liquid composed of an ultraviolet curable resin as described above is applied by a spin coating method or a dip coating method on the ultraviolet absorbing layer formed on the surface of the plastic lens substrate in 4 above. Thereafter, the hard coat layer is formed by irradiating ultraviolet rays for several seconds to several minutes. 6) When forming an anti-reflection film, a single-layer film or a multi-layer film is formed using an inorganic substance by a vacuum evaporation method or the like. However, this step is not performed when the antireflection film is not provided.

When molding a plastic lens substrate using a thermoplastic resin, the molding is performed by performing an injection molding step instead of the steps 1 and 2. Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples.

[0029]

Example 1 (1-1) Polymerization of Plastic Lens Substrate After mixing 10 ml of methyl methacrylate monomer and 10 ml of styrene monomer, a small amount of a crosslinking agent and 20 mg of azobisisobutyronitrile as a polymerization initiator were added and stirred. did. Next, this monomer solution was poured into a matrix composed of a gasket and a glass plate. Thereafter, the mixture was placed in a heating furnace and gradually heated from room temperature to 100 ° C. over 12 hours to carry out polymerization. After being removed from the heating furnace, the mold was released to obtain a colorless and transparent plastic lens substrate.

(1-2) Preparation of Coating Solution for Forming Ultraviolet Absorbing Layer Polyvinyl Butyral (Wako Pure Chemical Industries, Ltd.) 700
After dissolving 630 parts by weight of n-butanol in parts by weight, 400 parts by weight of methanol, 100 parts by weight of water, and 4.2 parts by weight of tetramethoxysilane as a crosslinking agent were added and stirred until uniform. Next, 1.2 parts by weight of P-toluenesulfonic acid as a curing catalyst and a surfactant FC430 (manufactured by Sumitomo 3M Limited) 1 as a leveling agent
Then, 70 parts by weight of a cerium oxide-based ultraviolet absorber (Neidral W-100, manufactured by Taki Kagaku Co., Ltd.) was added, and the mixture was further stirred, followed by filtration with a 3 μm membrane filter.

(1-3) Film Formation of UV Absorbing Layer As a pretreatment, the surface of the plastic lens substrate is made hydrophilic by immersing it in a 10% NaOH aqueous solution at 60 ° C. for 5 minutes. It has become. Thereafter, the substrate was taken out of the aqueous solution and dried. Hot air was used for drying. Next, a coating solution for forming the ultraviolet absorbing layer prepared in 1-2 above is coated on both surfaces of the plastic lens substrate having a hydrophilic surface by a dipping method.
The composition was cured by heating at 00 ° C. for 15 minutes.

(1-4) Formation of Hard Coat Layer Acrylic silane-based hard coat solution UVHC8553 containing colloidal silica particles (Toshiba Silicon Co., Ltd.) is provided on both sides of the plastic lens having the ultraviolet absorbing layer obtained in the above 1-3. Dip Coat). This is placed at a distance of 5 cm from the UV lamp (H-Lamp made by Fusion), and UV light is applied to both sides of the plastic lens by about 3 cm.
The coating was cured by irradiation for a minute to form a hard coat layer.

(1-5) Formation of antireflection film On both surfaces of the plastic lens having the ultraviolet absorbing layer and the hard coat layer obtained in 1-4, a silicon oxide / zirconium oxide based five layers were formed by vacuum evaporation. An anti-reflection film was formed. As described above, the above 1-1 to 1-5
UV absorbing layer, hard coat layer,
A comparison was made between a plastic lens provided with an antireflection film and a plastic lens substrate not provided with an ultraviolet absorbing layer, a hard coat layer and an antireflection film. as a result,
There was no difference in the color of the lens.

[0034]

Example 2 (2-1) Polymerization of Plastic Lens Substrate Diethylene glycol bisallyl carbonate (CR-3)
9) 0.95 g of diisopropyl peroxycarbonate as a polymerization initiator was added to 28 g of the monomer to prepare a monomer solution, which was poured into a matrix formed of a gasket and a glass plate. Thereafter, the mixture was placed in a heating furnace and gradually heated from room temperature to 80 ° C. over 12 hours to perform polymerization. After taking out the cured lens substrate from the heating furnace, it was released from the mold to obtain a colorless and transparent plastic lens substrate.

(2-2) Dyeing of plastic lens substrate Disperse dye MLP YELLOW 1g, MLP RED 1g, MLP BLUE
1 g (all manufactured by Mitsui Toatsu Chemicals, Inc.) was dispersed in 1 l of pure water together with 1 g of a surfactant, Nikka San Salt # 7000 (manufactured by Nichika Chemical Co., Ltd.) to prepare a dyeing solution. The dyeing solution was heated to 90 ° C., and the plastic lens substrate obtained in 2-1 was immersed for 10 minutes to dye brown.

(2-3) Preparation of Coating Solution for Forming Ultraviolet Absorbing Layer Xylylenediisocyanate-based polyisocyanate (Takenate D-110N, manufactured by Takeda Pharmaceutical Co., Ltd.)
8. 0.0 parts by weight and a polyester-type polyol (Nipporan 125, manufactured by Nippon Polyurethane Industry Co., Ltd.)
0 parts by weight, 0.2 parts by weight of zinc octylate as a curing catalyst, and a fluorinated surfactant (FC-4) as a leveling agent
31, manufactured by Sumitomo 3M Ltd.) was added to 60 parts by weight of ethyl acetate, and the mixture was stirred until it became uniform to prepare a mixed solution. Further, 6 parts by weight of a benzophenone-based ultraviolet absorber Uvinul D50 (manufactured by BASF) was added to the mixture, and the mixture was stirred until the mixture became uniform. Then, the mixture was filtered with a 3 μm membrane filter.

(2-4) Formation of UV Absorbing Layer The plastic lens dyed in 2-2 is immersed in a 10% NaOH aqueous solution at 60 ° C. for 5 minutes as a pretreatment to make the surface of the substrate hydrophilic. did. Thereafter, the lens was taken out of the aqueous solution, and the lens was dried with warm air.
Next, the coating solution prepared in the above 2-3 was coated by dipping on both surfaces of the plastic lens whose surface was hydrophilized, and cured by heating at 60 ° C. for 30 minutes.

(2-5) Formation of Hard Coat Layer On both sides of the dyed plastic lens having the ultraviolet absorbing layer obtained in 2-4, a hard coat liquid (Diabeam NR- 205, manufactured by Mitsubishi Rayon Co., Ltd.). Thereafter, the plastic lens having a hard coat layer formed thereon was placed at a distance of 15 cm from a 160 W mercury lamp, and ultraviolet rays were irradiated from both sides of the lens to cure the lens, thereby forming a hard coat layer.

(2-6) Formation of an antireflection film A silicon oxide / zirconium oxide system was formed on both surfaces of the dyed plastic lens on which the ultraviolet absorbing layer and the hard coat layer obtained in 2-5 above were formed by a vacuum evaporation method. An antireflection film consisting of five layers was formed. As described above, the above 2-1
To 2-6, a dyed plastic lens having an ultraviolet absorbing layer, a hard coat layer and an antireflection film, and a dyed plastic lens having no ultraviolet absorbing layer, hard coat layer and antireflection film,
-1 was compared with the plastic lens produced in the step. As a result, there was no difference in the tint of the lens. [Comparative Example 1] Steps 1-2 and 1 in Example 1
Except for omitting -3 and not providing an ultraviolet absorbing layer on the surface of the plastic lens substrate, all were performed using the same materials and manufacturing method as in Example 1. That is, a plastic lens (lens A) having a configuration in which a hard coat layer made of an ultraviolet curable resin was formed on the surface of the plastic lens substrate and an antireflection film was further formed thereon.

The appearance of the lens A was compared with that of a plastic lens substrate (lens B) on which no ultraviolet absorbing layer, hard coat layer and antireflection film were formed. as a result,
The lens A was colored pale yellow compared to the lens B, and the tint was changed. Comparative Example 2 The procedure of Example 2 was repeated except that steps 2-3 and 2-4 were omitted, and the plastic lens substrate was not provided with an ultraviolet absorbing layer. That is, a plastic lens (lens C) having a configuration in which a hard coat layer made of an ultraviolet curable resin was formed on the surface of the plastic lens substrate, and an antireflection film was further formed thereon.

When the lens C was compared with a plastic lens (lens D) not provided with an ultraviolet absorbing layer, a hard coat layer, and an antireflection film, that is, the plastic lens produced in Step 2-1 of Example 2, the lens C was The brown was slightly darker than the lens D, and the tint had changed.

[0042]

As described above, according to the present invention, the ultraviolet rays irradiated in the step of forming the hard coat layer are absorbed by the ultraviolet absorbing layer and hardly reach the plastic lens substrate. Therefore, it is possible to prevent discoloration of the plastic lens substrate caused by the irradiation of the ultraviolet rays, and to obtain a plastic lens having excellent transparency.

When the plastic lens substrate is dyed, according to the present invention, since the ultraviolet ray is absorbed by the ultraviolet ray absorbing layer, the dye in the substrate is not irradiated with the ultraviolet ray. Therefore, the deterioration of the dye can be prevented, so that the change in the color of the dyed plastic lens can be prevented. Therefore, even if the lens is used under different ultraviolet irradiation conditions, the color of the dyed lens manufactured under the same condition hardly causes a difference during use,
It became possible to produce dyed plastic lenses of the same color with good reproducibility.

Further, by selecting a substance having an impact absorbing ability as a matrix component of the ultraviolet absorbing layer, it is possible to simultaneously improve the impact resistance of the plastic lens in addition to the above-mentioned prevention of color change. . Also,
Since the irradiation amount of the ultraviolet ray that can be applied to the hard coat layer can be increased as compared with the related art, the curing reaction for forming the hard coat layer can be sufficiently promoted. Therefore, a hard coat layer having higher hardness can be formed, and the scratch resistance of the hard coat layer made of an ultraviolet curable resin can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an embodiment of a plastic lens according to the present invention.

FIG. 2 is a schematic side view of another embodiment of the plastic lens according to the present invention.

[Explanation of symbols]

 11, 21 ... plastic lens substrate 12, 22 ... ultraviolet absorbing layer 13, 23 ... hard coat layer 24 ... anti-reflection film

Claims (2)

[Claims] 1. A plastic lens substrate, an ultraviolet absorbing layer containing an ultraviolet absorber and an organic compound and formed on the plastic lens substrate, and a substance which is polymerized by irradiation with ultraviolet light or irradiation with ultraviolet light and heating. A plastic lens, comprising: a compound as a raw material; and a hard coat layer formed on the ultraviolet absorbing layer. 2. A step of injecting a monomer into a lens molding matrix, a step of polymerizing and curing the monomer to form a plastic lens substrate, and an ultraviolet absorber and a UV absorber on the molded plastic lens substrate. A step of forming a film by applying and heating a substance containing an organic compound to form an ultraviolet absorbing layer, and applying a compound containing a substance polymerized by ultraviolet irradiation or ultraviolet irradiation and heating onto the ultraviolet absorbing layer. A method for producing a plastic lens, comprising: a step of applying, and a step of irradiating the applied compound with ultraviolet rays or irradiating and heating ultraviolet rays to polymerize the applied compound to form a hard coat layer. .