JPH11258408A - Manufacture of plastic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of the unevenness in the ultraviolet ray absorbing power and the surface roughness and to uniformly disperse an ultraviolet ray absorbent into the water by dispersing the ultraviolet ray absorbent into an aqueous solution after the disperse dye treatment, and dipping a plastic lens into the aqueous solution to provide the lens with the ultraviolet ray absorbing power. SOLUTION: A ultraviolet ray absorbent is dispersed into the water after the disperse dye treatment, and a lens is dipped in this aqueous solution. That is, by performing the disperse dye pretreatment to the ultraviolet ray absorbent which is originally inferior to the dispersibility in the water, the ultraviolet ray absorbing power can be applied to the lens similarly as the conventional plastic lens dyeing method. The ultraviolet ray absorbent is uniformly impregrated from a lens surface in the water, so that the ultraviolet ray absorbing power can be uniformly and fully applied to the lens. The ultraviolet ray absorbent is uniformly dispersed in the water, so that the generation of the surface roughness caused by the cohesion of the ultraviolet ray absorbent on the lens surface can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a plastic lens having an ultraviolet absorbing ability.

[0002]

2. Description of the Related Art Plastic lenses are lighter and thinner than conventional glass lenses, have a high impact strength, and are safe and highly functional. Therefore, plastic lenses are used as eyeglass lenses for vision correcting lenses and sunglasses. I have. Recently, a spectacle lens is provided with an ultraviolet absorbing ability, and a wavelength of 400
There is an increasing demand to protect the eyeballs or skin from harmful ultraviolet rays of nm or less, and various manufacturing methods have been proposed to manufacture plastic lenses having an ultraviolet absorbing ability.

[0003] As a method generally called a kneading method,
For example, a method of mixing an ultraviolet absorber with a polymerizable monomer, injecting it into a molding die, polymerizing and curing the material, and imparting an ultraviolet absorbing ability to the lens material itself is exemplified. In this kneading method, a sufficient amount of ultraviolet absorbers cannot be obtained unless a large amount of ultraviolet absorber is mixed in the polymerizable monomer. However, in this case, the ultraviolet absorber floats on the surface of the lens, thereby inhibiting the polymerizability or causing the lens itself to be remarkably yellowed. On the other hand, there is another method called a solvent dyeing method.For example, a dye solution is prepared by simultaneously adding an ultraviolet absorber and a usual disperse dye, and the lens is immersed in the dye solution to absorb ultraviolet light from the lens surface. A method of impregnating an agent and imparting an ultraviolet absorbing ability is introduced in JP-A Nos. 1-200033 and 9-269401. Such a solvent dyeing method is a preferable manufacturing method for a spectacle lens that requires a large variety and a small amount of production, since the lens substrate can be provided with an ultraviolet absorbing ability by post-processing as compared with the kneading method. .

[0004]

However, in the solvent dyeing method described in Japanese Patent Application Laid-Open No. 1-200033, water is used as a dispersing solvent. However, there is a problem in that the non-uniform impregnation results in unevenness in the ultraviolet absorbing ability of the lens surface. In order to uniformly impregnate the lens surface with the ultraviolet absorbent, methods such as extending the immersion time of the lens or immersing the lens at a higher temperature than before have been adopted. In the latter case, when a lens having low heat resistance is used, the lens is deformed by high temperature. In addition, the rate at which surface irregularities (a state where the lens surface has irregularities) is high on the lens surface due to the aggregation of the ultraviolet absorbent on the lens surface, and the appearance of the lens may be poor. Such surface irregularities cause a decrease in the adhesion of a secondary processing film such as a hard coat layer or an antireflection film, and have been extremely problematic in production.

[0005] On the other hand, Japanese Patent Application Laid-Open No. 9-269401 discloses that the dispersibility of an ultraviolet absorber is enhanced by using an organic solvent as a dispersing solvent in a solvent dyeing method, and the ultraviolet absorbing ability is uniformly provided on the lens surface. How to give is introduced. However, particularly when an organic solvent is used as the dispersion solvent, depending on the combination of the lens substrate and the organic solvent, the surface of the lens substrate is damaged, causing surface irregularities (a state in which irregularities are formed on the lens surface). The appearance may be poor. In addition, when an organic solvent having a low flash point is generally used in the production process, a special exhaust device is required for safety and health, which is not preferable in terms of working environment. Furthermore, the organic solvent remains on the surface of the lens substrate, so that the adhesiveness between the lens substrate and the hard coat layer is reduced, and the appearance is likely to be poor. is there. In addition, there is a problem that the production cost is high because a large amount of expensive organic solvents must be used.

Therefore, it is preferable to use water instead of an organic solvent as a dispersing solvent and to develop a method of uniformly dispersing the UV absorber in water without agglomeration in water. It is believed that it can be provided.

Therefore, in the present invention, in order to impart the ultraviolet absorbing ability to the lens without causing unevenness in the ultraviolet absorbing ability on the lens surface and without causing surface irregularity due to the aggregation of the ultraviolet absorbing agent on the lens surface. It is another object of the present invention to provide a method for uniformly dispersing an ultraviolet absorber in water.

[0008]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies. As a result, the ultraviolet absorbent was converted into a disperse dye, then dispersed in water, and the lens was immersed in this aqueous solution. By doing so, the inventor found that the above object could be achieved, and completed the present study.

The method of forming a disperse dye in the present invention is not particularly limited, but it is preferable to carry out a treatment of mixing a surfactant and an ultraviolet absorber. It is particularly preferable that the surfactant used at this time is an anionic surfactant.

Further, the ultraviolet absorber to be converted into a disperse dye in the present invention is preferably composed of one of benzophenone and benzotriazole or a combination of these two.

According to the method of manufacturing a plastic lens according to the present invention, a plastic lens used for a correction lens, a fashion lens, and the like can be manufactured.

The method for producing a plastic lens according to the present invention can be provided with a UV-absorbing ability by post-processing the molded lens, so that it is preferable for other kinds, eyeglass lenses and the like that require small-quantity production. Is the way.

In the present invention, the ultraviolet absorbing agent, which originally has poor dispersibility in water, is converted into a disperse dye by pretreatment, so that the lens can be provided with ultraviolet absorbing ability in the same manner as a general plastic lens dyeing method. . The UV absorber is impregnated uniformly from the lens surface in water,
Ultraviolet light absorbing ability can be imparted uniformly to the entire lens. Also, since the UV absorber is uniformly dispersed in water, the UV absorber does not agglomerate on the lens surface to cause surface irregularities. Adhesion is not impaired.

The disperse dyeing used in the present invention is to perform a pretreatment so that the ultraviolet absorber can be uniformly dispersed in water, and the method is not particularly limited.
Generally, the following method is used. After mixing the ultraviolet absorber with a dispersant such as a surfactant, the mixture is pulverized using a peptizer such as a colloid mill, a sand mill, or a disper, and dispersed into fine particles having an average particle size of about 1 μm or less. Then, it is dried to make powder or granules, or used as liquid. The type of surfactant used at this time is not particularly limited, and nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like are used. Specific examples of nonionic surfactants include:
Alkyl allyl ether type such as polyoxyethylene octyl phenyl ether, alkyl ether type such as polyoxyethylene 2-ethylhexyl ether, alkyl ester type such as polyoxyethylene oleate, alkyl amine type such as polyoxyethylene alkylamine, sorbitan oleate Examples thereof include sorbitan derivative types such as ate and polycyclic phenyl ether types such as polyoxyethylene polycyclic phenyl ether. Specific examples of the anionic surfactant include sulfonic acid types such as dialkyl succinate sulfonic acid Na salt and naphthalene sulfonic acid formalin condensate Na salt, and the like.
Sulfuric acid ester type such as polyoxyethylene alkyl ether sulfate and the like can be mentioned. Specific examples of the cationic surfactant include a quaternary ammonium salt type and an imidazoline type such as an alkyl imidazoline. Specific examples of the zwitterionic surfactant include a betaine type such as an alkyl betaine. For better dispersibility in an aqueous solution, it is preferable to use an anionic surfactant. Among them, it is preferable to use a sulfonic acid type anionic surfactant such as a dialkyl succinate sulfonic acid Na salt or a naphthalene sulfonic acid formalin condensate Na salt.

When converting the ultraviolet absorber into a disperse dye, a single surfactant may be used. Further, in order to obtain sufficient dispersibility in an aqueous solution, two or more surfactants may be used to convert the ultraviolet absorber into a disperse dye.

By pre-treating the ultraviolet absorbent and dispersing it into a dye as described above, uniform dispersion in water becomes possible, and the ultraviolet absorption ability is imparted to the plastic lens using a general dyeing pot or the like. Can be.

At this time, the lens used may be a lens base material, but even if a surface layer such as a hard coat is present on the lens surface, an ultraviolet absorbent is impregnated into the lens through the hard coat layer. Therefore, it is possible to provide an ultraviolet absorbing ability. At this time, the hard coat layer may be a single hard coat layer with respect to the lens substrate, or may have a structure of two or more layers in which the hard coat layer and the shock absorbing coat layer are combined. .

The ultraviolet absorber used in the present invention is not particularly limited, but is preferably an ultraviolet absorber having a molecular weight of 1,000 or less because of easy impregnation from the lens surface. For example, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone Benzophenone-based ultraviolet absorbers, such as 2-hydroxy-4-benzyloxybenzophenone, 2- (2
-Hydroxy-4-octyloxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-butylphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole,
2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chloro-benzotriazole, 2-
(2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chloro-benzotriazole, 2-
Benzotriazole ultraviolet absorbers such as (2'-hydroxy-3 ', 5'-di-t-amylphenyl) -benzotriazole; salicylate ultraviolet absorbers such as phenyl salicylate and 4-t-butyl-phenyl salicylate; Examples include cyanoacrylate-based ultraviolet absorbers such as ethyl-2-cyano-3,3-diphenylacrylate and 2-ethylhexyl-2-cyano-3,3-diphenylacrylate.

Among these ultraviolet absorbers, it is particularly preferable to use benzophenone-based and benzotriazole-based ultraviolet absorbers from the viewpoints of ultraviolet absorbing ability, durability, and a wide absorption wavelength range.

In the present invention, it is very effective to use a plurality of ultraviolet absorbers simultaneously in order to obtain a sufficient ultraviolet absorbing ability. As a method of combining a plurality of UV absorbers, the UV absorber which has been dispersed and dyed alone may be mixed at the time of being poured into water such as a dyeing pot, or the plurality of UV absorbers may be mixed at the stage of disperse dyeing. You may mix and make a disperse dye simultaneously.

When imparting an ultraviolet absorbing ability to a plastic lens by using the ultraviolet absorbent made into a disperse dye of the present invention, a dyeing pot used for general lens dyeing can be used. In addition, a large number of lenses may be processed simultaneously by using a large water tank whose temperature is adjusted.

When dispersing the ultraviolet dye of the present invention into water in a dyeing pot or the like, a dispersant such as a surfactant may be further added to assist the dispersion of the ultraviolet absorber. At this time, phenylphenol, benzyl alcohol and the like are often used as a carrier for dyeing.

When the plastic lens having an ultraviolet absorbing ability according to the present invention is used as a lens for correcting eyesight or a fashion lens, it is preferable to apply an antireflection film in order to increase light transmittance and prevent flicker due to surface reflection. Further, it is particularly preferable to provide a hard coat layer for enhancing the adhesion between the lens substrate and the anti-reflection film and preventing the surface from being damaged.

Preferred examples of the hard coat layer include those obtained by applying and curing a coating composition containing the following (a) and (b) as main components.

(A) One or more silane compounds having at least one or more reactive groups.

(B) silicon oxide, antimony oxide, zirconium oxide, titanium oxide, tin oxide, tantalum oxide,
Metal fine particles such as tungsten oxide and aluminum oxide; composite metal fine particles using two or more of titanium oxide, cerium oxide, zirconia, silicon oxide, and iron oxide; tin oxide fine particles using composite metal fine particles of tin oxide and tungsten oxide At least one selected from composite metal fine particles coated with.

The component (b) is an effective component for adjusting the refractive index of the hard coat and increasing the hardness, and can be used alone or as a mixture. However, the film forming property is poor only with the component (b), and a transparent and tough film can be obtained by using the component (a) together. Although the component (a) can be used as it is, it is more preferable to use it after hydrolysis since the water resistance and hardness of the film can be improved.

The thickness of the hard coat layer is usually from 0.2 μm to
It is preferably about 10 μm, more preferably 1 μm to 3 μm.
It is about μm. In the present invention, a hard coat in which a primer layer is provided between the lens material and the hard coat layer can also be used. This primer layer has the effect of further improving the adhesion between the lens material and the hard coat layer, and improving the impact resistance of the lens after the hard coat treatment.

In coating the hard coat layer and the primer layer, preferably, the raw material components of each layer are diluted with a suitable solvent system such as an alcohol or water system, and a general coating method such as dip, spin or spray is used. It can be performed by coating and heat curing.
Curing can be performed simply by heating, but by adding an appropriate curing catalyst, a hard film can be formed in a short time. Specific examples of the curing catalyst include perchlorates such as magnesium perchlorate and ammonium perchlorate, and chelate compounds such as aluminum acetylacetonate.

The above components (a) and (b) as the hard coat layer can provide sufficient coating performance by themselves, but they add to the appearance, durability and other functions of the hard coat layer. In addition, other components can be added. For example, it is effective to add a polyhydric alcohol, a polycarboxylic acid, a polycarboxylic anhydride, or an epoxy compound in order to improve the water resistance of the hard coat layer or to impart dyeability. Examples of the polyhydric alcohol that can be used include, for example, difunctional alcohols such as (poly) ethylene glycol, (poly) propylene glycol, neopentyl glycol, catechol, resorcinol, and alkanediol; or trifunctional alcohols such as glycerin and trimethylolpropane. Alcohol, polyvinyl alcohol and the like can be mentioned. Examples of the polycarboxylic acid include malonic acid, succinic acid, adipic acid, azelaic acid, maleic acid, o-phthalic acid, terephthalic acid, fumaric acid, itaconic acid, and oxaloacetic acid. Examples of the polycarboxylic anhydride include succinic anhydride, maleic anhydride, itaconic anhydride, 1,2-dimethylmaleic anhydride, phthalic anhydride, hexahydrophthalic anhydride, and naphthalic anhydride. Examples of the epoxy compound include diglycidyl ethers of difunctional alcohols such as (poly) ethylene glycol, (poly) propylene glycol, neopentyl glycol, catechol, resorcinol, and alkanediol, and glycerin;
Examples include di- or triglycidyl ethers of trifunctional alcohols such as trimethylolpropane. When these additives are added, a film having higher hardness can be obtained particularly by adding a curing catalyst.

Further, in order to prevent deterioration of the hard coat layer due to ultraviolet rays, an ultraviolet absorber, an antioxidant, a light stabilizer and the like can be used. As the ultraviolet absorber or the antioxidant / light stabilizer, for example, salicylic acid ester, benzophenone type, benzotriazole type, cyanoacrylate type, nickel complex salt type, phenol type, hindered amine type, hindered phenol type compound and the like are used. it can.

In order to eliminate coating defects such as yuzu skin and cissing at the time of application, a surfactant and a flow control agent can be used. Among them, silicone-based or fluorine-based surfactants are effective.

When used as a correcting lens, the optical performance is further improved by applying an antireflection film to the surface of the hard coat layer as described above. As an anti-reflection film,
A multilayer film obtained by laminating thin films having different refractive indices,
As long as the reflectance is reduced, either an inorganic substance or an organic substance can be used. However, in order to emphasize the surface hardness and prevention of interference fringes, it is most preferable to provide a single-layer or multilayer antireflection film made of an inorganic substance. Examples of inorganic substances that can be used include oxides or fluorides such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, hafnium oxide, and magnesium fluoride. It can be applied by a method.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments, but the present invention is not limited to these embodiments. (Dispersion dyeing of ultraviolet absorber) (Example 1) 2,2'-dihydroxy-4-methoxybenzophenone (trade name CYASO) as an ultraviolet absorber
RB UV-24: Shiroishi Calcium Co., Ltd.)
prepare. Desroll SH as an anionic surfactant
10 g of (Nippon Emulsifier Co., Ltd.) is prepared. These are sufficiently ground in a mortar to form a fine powder. Here water 2
After adding 0 g and stirring thoroughly, water is evaporated by a dryer. The solidified portion is taken out and thoroughly ground in a mortar to obtain a fine powder, which is referred to as a disperse dyeed ultraviolet absorber A.

(Example 2) 2- (2)
-Hydroxy-4-octyloxyphenyl) benzotriazole (trade name: SEESORB 707: Cipro Chemical) is prepared in an amount of 10 g, and sufficiently ground in a mortar to form a fine powder. Escol 30 as a liquid surfactant
20 g of (Nippon Emulsifier Co., Ltd.) is prepared, into which a fine powdered ultraviolet absorber is added and sufficiently stirred. After the stirring, the moisture is evaporated by a dryer, the solidified portion is taken out, and then sufficiently ground again in a mortar to obtain a fine powder, which is a dispersion dye-converted ultraviolet absorber B.

Example 3 As an ultraviolet absorber,
8 g of 2 ', 4,4'-tetrahydroxybenzophenone (trade name UVINUL D-50: Gokyo Sangyo Co., Ltd.) and 2- (2-hydroxy-5-t-octylphenyl) benzotriazole (trade name CYASORB U)
V-5411: Shiroishi Calcium Co., Ltd.) is prepared and ground sufficiently while mixing in a mortar to form a fine powder. 30 g of Escor 30 (Nippon Emulsifier Co., Ltd.) is prepared as a liquid surfactant, and a fine powdered ultraviolet absorber is added thereto and sufficiently stirred. After the stirring, the moisture is evaporated by a dryer, the solidified portion is taken out, and is sufficiently ground again in a mortar to obtain a fine powder, which is a dispersion-dyeed ultraviolet absorber C.

(Provision of UV Absorbing Ability to Plastic Lens) The abbreviations, trade names, substance names and manufacturing methods of the plastic lenses used in the examples are shown below. Abbreviation: trade name, substance name or production method CR-NC: polymer of diethylene glycol bisallyl carbonate RX-NC: manufactured by Seiko Epson Corp. Lens fabric for Seiko Plux II Hard RX RX-HC: manufactured by Seiko Epson Corp. Seiko Plux II Hard RX SL-NC: Lens fabric for Seiko Super Lux manufactured by Seiko Epson Corp. (Example 4) A constant temperature water tank whose water temperature is adjusted to 90 ° C. is prepared, and a glass beaker containing 1 liter of water is placed in a constant temperature water tank. Submerge in and use as staining pot. The disperse dyeed ultraviolet absorber is added to the dyeing pot in the amount shown in Table 1.
After adding 3 cc of surfactant NES-203 (Nikko Chemicals) as a dispersant and 10 cc of benzyl alcohol as a dyeing carrier to the dyeing pot, the mixture is stirred with good stirring and used as a dyeing pot. CR-NC was prepared as a plastic lens, and the lens was completely submerged in the dyeing pot while stirring the dyeing pot.
After one minute, it was removed from the dyeing pot. The evaluation items and the contents of the evaluation experiments are shown below.

Ultraviolet absorption: Spectrophotometer CP-30
Using 00 (Hitachi), the absorption spectrum in the ultraviolet region was measured, and the absorptance at a wavelength of 400 nm was obtained, and classified into the following rank. At this time, the measurement position of the absorption spectrum was changed at several places, and it was confirmed whether or not the ultraviolet absorption ability was uneven.

A: Ultraviolet rays are almost absorbed. (Absorptance at a wavelength of 400 nm: 90 to 100%) B Ultraviolet rays are almost absorbed. (Absorptance at a wavelength of 400 nm: 70 to 90%) C Insufficient absorption of ultraviolet rays. (Absorptance at a wavelength of 400 nm: 50 to 70%) D Ultraviolet rays are not absorbed. (Absorbance at a wavelength of 400 nm: 50% or less) Surface Arrangement State: The state of the lens surface was observed with the naked eye, and the presence or absence of surface arrangement was confirmed. The lens used at this time has an S power of -5.0 diopters and a C power of 0.
A 0 diopter single focus lens was used. As used herein, the term “surface irregularity” refers to the degree to which the irregularities on the lens surface can be clearly observed with the naked eye due to the aggregation of the ultraviolet absorber or the influence of the dispersion solvent.

Lens shape: The curved state of the lens center was visually observed and classified into the following ranks. The lens used at this time had an S power of -5.0 diopters,
A single focus lens having a C power of 0.0 diopters was used.

A: There is no curvature at all. (The difference between the curvature at the time of design and the curvature at the time of molding is 0 to 1%) B It is slightly curved. (Difference is 1 to 3%) C It is slightly curved. (Difference is 3 to 5%) D Curved. (Difference is 5 to 10%) E It is extremely curved. (Difference is 10 to 20%) F Cannot be used. (The difference is 20% or more) (Examples 5 to 9) Example 4 except that the disperse dyeed ultraviolet absorber shown in Table 1 and the lens shown in Table 1 were used.
A lens was prepared under the same conditions as described above, and was evaluated in the same manner as in Example 4. Table 2 shows the results.

Example 10 A lens was prepared under the same conditions as in Example 4, except that the disperse dyeed ultraviolet absorber shown in Table 1 and the lens shown in Table 1 were used. This lens is immersed in the following coating composition a, and is immersed at 20 cm / min.
Then, the coating composition was applied to the surface of the lens by pulling it up at a speed of 130 ° C., and heated at 130 ° C. for 1.5 hours to produce a lens provided with a hard coat layer. The same evaluation as in Example 4 was performed. Table 2 shows the results.

Coating composition a: 23 g of γ-glycidoxypropyltrimethoxysilane, colloidal silica dispersed in methanol (trade name: OSCAL-113)
2: Catalysis Chemical Co., Ltd.) 45 g and methyl cellosolve 32 g were thoroughly stirred, 2 g of 0.05 N hydrochloric acid was added, and the mixture was stirred for 30 minutes. Further, a silicone surfactant (trade name: L-7604: Nippon Unicar Co., Ltd.)
03 g was added and stirred to prepare a coating composition.

(Comparative Example 1) An ultraviolet absorber shown in Table 1
A lens was produced under the same conditions as in Example 4 except that the lens shown in Table 1 was used. At this time, instead of using a disperse dyeed ultraviolet absorber, the ultraviolet absorbers shown in Table 1 were ground in a mortar and used after being pulverized. Evaluation was performed in the same manner as in Example 4 using this lens. Table 2 shows the results.

Comparative Example 2 An ultraviolet absorber shown in Table 1
Similarly, using the lens shown in Table 1, the staining time of the lens was 6
A lens was manufactured under the same conditions as in Example 4 except that the time was extended to 0 minutes. At this time, instead of using a disperse dyeed ultraviolet absorber, the ultraviolet absorbers shown in Table 1 were ground in a mortar and used after being pulverized. Evaluation was performed in the same manner as in Example 4 using this lens. Table 2 shows the results.

(Comparative Example 3) A thermostatic bath filled with diethylene glycol instead of water is prepared, and the liquid temperature is adjusted to 120 ° C. A glass beaker filled with 1 liter of diethylene glycol is submerged in a thermostat and used as a dyeing pot. The finely powdered ultraviolet absorber shown in Table 1 is added thereto and sufficiently stirred. While stirring the dyeing pot, the lenses shown in Table 1 were submerged therein and taken out after 30 minutes. Evaluation was performed in the same manner as in Example 4 using this lens. Table 2 shows the results.

(Comparative Example 4) A thermostatic bath filled with isobutyl alcohol instead of water is prepared, and the liquid temperature is adjusted to 90 ° C. A glass beaker filled with 1 liter of isobutyl alcohol is submerged in a thermostat and used as a dyeing pot. The finely powdered ultraviolet absorber shown in Table 1 is added thereto and sufficiently stirred. While stirring the dyeing pot, the lenses shown in Table 1 were submerged therein and taken out after 30 minutes. Evaluation was performed in the same manner as in Example 4 using this lens. Table 2 shows the results. When a hard coat film was applied to this lens in the same manner as in Example 10, the adhesion between the lens substrate and the hard coat film was clearly worse than that of the lens of Example 10, and the lens was actually used. It was not at a level we could do.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

According to the method for producing a plastic lens of the present invention, a plastic lens having a surface layer of a lens substrate uniformly impregnated with an ultraviolet absorbent can be obtained.
It is possible to manufacture a plastic lens having an excellent ultraviolet absorbing ability. Further, the ultraviolet absorbent does not aggregate on the lens surface, and a plastic lens excellent in appearance can be obtained.

Claims (5)

[Claims] 1. A method for producing a plastic lens, which comprises dispersing an ultraviolet absorbent into a disperse dye, dispersing the dispersion in an aqueous solution, and immersing the plastic lens in the aqueous solution to impart an ultraviolet absorbing ability. 2. The method of manufacturing a plastic lens according to claim 1, wherein when the ultraviolet absorbent is converted into a disperse dye, a treatment is carried out by mixing a surfactant and the ultraviolet absorbent. Manufacturing method. 3. The method of manufacturing a plastic lens according to claim 2, wherein the surfactant is an anionic surfactant. 4. The method for producing a plastic lens according to claim 1, wherein the ultraviolet absorber comprises at least one of a benzophenone type and a benzotriazole type or a combination of these two types. Of manufacturing plastic lenses. 5. A plastic lens manufactured by the method for manufacturing a plastic lens according to claim 1.