Lens made of synthetic resin and method for producing the same

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a synthetic resin lens, and more particularly to a synthetic resin lens obtained from a photopolymerizable composition having good optical properties and mechanical properties, and a method for producing the same.

【0002】

[Conventional technology]

Conventionally, various inorganic glasses and synthetic resins have been used as optical lens materials. Various physical properties are required for optical lens materials, but in the field of spectacle lenses, for example, high refractive index, high Abbe number, and low specific gravity are extremely important. That is, if the lens used has a high refractive index and a low specific gravity, the thickness and weight of the lens can be reduced, and if the number of Abbe numbers is high, light dispersion is small and a comfortable wearing feeling can be obtained. Because.

【0003】

Therefore, the material for spectacle lenses tends to have a higher refractive index year by year, and this tendency is particularly remarkable in synthetic resin lenses, which have a low specific gravity and are extremely lightweight as compared with inorganic glass. ..

【0004】

In the field of spectacle lenses, as a material for synthetic resin lenses, there is a material called "CR-39" made from diethylene glycol bisallyl carbonate as a typical early example. This material was so light compared to previous inorganic glass lenses that it quickly penetrated the world. However, since this material has a low refractive index of about 1.50, the entire lens becomes thick, which is not satisfactory as a lens for spectacles. Therefore, in order to realize the thinning of the lens, research on increasing the refractive index has been actively conducted. As a result, for example, a urethane resin material obtained by polymerizing thiol and isocyanate (Japanese Patent Laid-Open No. 2-270859) achieves a refractive index of 1.60 or more, and further, an episulfide resin material containing an episulfide compound (Japanese Patent Laid-Open No. 2-270859). In Japanese Patent Application Laid-Open No. 9-71580), the thinning of the lens was rapidly accelerated, such as achieving a refractive index of 1.70 or higher.

【0005】

However, the material obtained by urethane polymerization of thiol and isocyanate is a synthetic resin obtained by a urethane reaction, and a lens having a high refractive index, a high Abbe number, and excellent impact resistance can be obtained, but it can be handled as a two-component type. It is inconvenient. Smell is generated when processing the lens. There are problems such as poor moldability (low pass rate). Further, the current situation is that a material containing an episulfide compound has problems not only in odor and moldability but also in impact resistance and cost. Further, these high-refractive-index and ultra-high-refractive-index resins are synthetic resins obtained by a urethane reaction or an episulfide ring-opening reaction, and both require a long thermosetting time because photopolymerization is difficult. A polymerization method by polymerization was required. Therefore, for example, in the production of lenses for spectacles, since the polymerization time is as long as about 10 to 20 hours, it takes a long time to occupy the mold used in the lens production, that is, the glass mold. Therefore, in the case of mass production of lenses, there is a drawback that the capital investment becomes very large because a large number of glass molds and a large polymerization facility are required. In fact, high-refractive-index resins and ultra-high-refractive-index resins by urethane reaction and episulfide ring-opening reaction have been put into practical use, but since both adopt the thermal polymerization method, a large capital investment is required. The current situation.

【0006】

On the other hand, the method of manufacturing a lens using photopolymerization is effective for mass-producing lenses in a short time because the polymerization time of photopolymerization is shorter than that of thermal polymerization and the lens manufacturing time can be shortened. Polymerization method. For example, in the field of spectacle lenses, the polymerization time is about several minutes, so that the occupancy time of the glass mold used is shortened. Therefore, in the same time as when a single lens is manufactured by thermal polymerization, the lens manufacturing operation can be repeated many times in photopolymerization. In other words, even when mass-producing lenses, compared to thermal polymerization, it does not require so many glass molds and large polymerization equipment, so there is a feature that capital investment does not increase.

【0007】

As a high refractive index material capable of photopolymerization, for example, a material using polyfunctional thiomethacrylate (Japanese Patent Laid-Open No. 1-26613) or a prepolymerized product of thiol and vinyl monomer (prepolymer) can be prepared and obtained. (Japanese Patent Laid-Open No. 4-57831), materials using a novel sulfur compound (Japanese Patent Laid-Open No. 8-183816), and the like have been proposed. These materials are high-refractive index materials capable of not only thermal polymerization but also photopolymerization over time.

【0008】

However, Japanese Patent Application Laid-Open No. 1-26613 has a problem that the obtained resin is hard and brittle because it has a large cross-linking effect because it is polyfunctional. Further, Japanese Patent Application Laid-Open No. 4-57831 has a problem that the lens manufacturing time cannot be shortened because a complicated prepolymerization step is required for photopolymerization. Further, in Japanese Patent Application Laid-Open No. 8-183816, mass production technology has not been established because it is a new substance, and moreover, characteristics required for an optical lens such as high cost, high specific gravity, impact resistance, Abbe number, and transparency. Has a great many problems, such as not being able to obtain enough. In fact, some of these materials have achieved a refractive index of 1.60 or higher, but only materials with a low refractive index have been put into practical use.

【0009】

On the other hand, as a material using the ethylene oxide (EO) -modified tetrabromobisphenol A dimethacrylate described in the structural formula (1) of the present invention, for example, EO-modified tetrabromobisphenol A dimethacrylate and another radically polymerizable monomer are used. Combined materials (Japanese Patent Laid-Open No. 60-258501), materials combining EO-modified tetrabromobisphenol A dimethacrylate with monofunctional bromine compound and vinyl compound (Japanese Patent Laid-Open No. 63-215706), EO-modified tetra A material in which glycidyl ether, a nuclear-substituted phenol, is added to bromobisphenol A dimethacrylate (Japanese Patent Laid-Open No. 6-49133) has been proposed, and a resin having excellent transparency and heat resistance as well as high refractive index has been proposed. It is known to be obtained.

【0010】

[Problems to be Solved by the Invention]

However, since this EO-modified tetrabromobisphenol A dimethacrylate is a powder by itself, a solvent for dissolving the powder is required. Therefore, when the content of EO-modified tetrabromobisphenol A dimethacrylate is too large, it is difficult to introduce it in a large amount because the dissolution is insufficient and precipitation occurs. Moreover, although this EO-modified tetrabromobisphenol A dimethacrylate has a high refractive index, the Abbe number was never satisfactory.

【0011】

That is, JP-A-60-258501, JP-A-63-215706, and JP-A-6-49133 are all high because the content of EO-modified tetrabromobisphenol A dimethacrylate is limited. It has a problem that it is difficult to achieve a refractive index and a high Abbe number at the same time.

【0012】

As described above, the conventional high refractive index materials have problems such as difficulty in handling, odor, moldability, and photopolymerization. Further, even a material capable of photopolymerization has a problem that sufficient characteristics required for an optical lens such as impact resistance and transparency cannot be obtained.

【0013】

Therefore, an object of the present invention is not only to have a high refractive index and a high Abbe number, but also to have a low specific gravity, sufficient characteristics required as an optical lens such as impact resistance and transparency, and not only thermal polymerization. It is an object of the present invention to provide a synthetic resin lens capable of photopolymerization and a method for producing the same.

【0014】

[Means for solving problems]

As a result of diligent studies on this situation, the present inventors have made EO-modified tetrabromobisphenol A dimethacrylate (hereinafter referred to as component A) represented by the structural formula (1) bifunctional. It was discovered that the precipitation of component A in the composition can be suppressed by the addition reaction with the above thiols. As a result, since a large amount of A component can be introduced, not only a high refractive index can be achieved, but also a high Abbe number can be realized at the same time by containing a thiol (sulfur compound), and further photopolymerization is possible. We have succeeded in developing a very excellent optical lens material, and have completed the present invention here.

【0015】

That is, in the present invention, the EO-modified tetrabromobisphenol A dimethacrylate represented by the following structural formula (1) is 20 to 80% by weight, the bifunctional or higher thiol is 5 to 40% by weight, and the bifunctional or higher acrylic group. A copolymer obtained by copolymerizing a composition consisting of 20 to 70% by weight of a compound having a methacrylic group or a vinyl group and 0 to 40% by weight of a monomer copolymerizable with these. A synthetic resin lens having a refractive index of 1.58 or more and an Abbe number of 35 or more, and a method for manufacturing the same.

【0016】

[Chemical 2]

<img file="JP2002182002A_D0001.tif" />【0017】

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, it is appropriate that the component A is contained in an amount of 20 to 80% by weight, preferably 40 to 60% by weight. This makes it difficult to achieve the high refractive index characteristic of the present invention when the A component is less than 20% by weight, and completely suppresses the precipitation of the A component when it exceeds 80% by weight. This is because it becomes difficult.

【0018】

Further, the bifunctional or higher functional thiol is preferably 5 to 40% by weight, preferably 10 to 35% by weight. This is because when the amount of bifunctional or higher thiol is less than 5% by weight, not only the precipitation of component A cannot be completely suppressed, but also it becomes difficult to achieve the high Abbe number characteristic of the present invention, which is 40% by weight. If it exceeds%, it becomes difficult to maintain sufficient mechanical strength as an optical lens.

【0019】

Examples of bifunctional or higher thiols at this time include bifunctional sulfur compounds such as ethylene glycol bisthioglycolate (EGTG) and thiodietanthiol (DMDS), trimethylolpropanthritol thioglycolate (TMTG), and trimethylol. Trifunctional sulfur compounds such as propanetristhiopropionate (TMTP), tetrafunctional sulfur compounds such as pentaerythritol tetrakisthioglyconate (PETG), pentaerythritol tetrakisthiopropionate (PETP), and others can be mentioned. It is not limited to.

【0020】

The addition reaction between the component A and the bifunctional or higher functional thiol can be carried out at room temperature without a catalyst, but the reaction can be carried out in a warmed state, preferably at 30 to 80 ° C. after adding a basic catalyst. preferable.

【0021】

As the catalyst to be added at this time, a known basic catalyst can be used. Examples include, but are not limited to, tertiary amines such as triethylamine and trimethylamine, and secondary amines such as diethylamine and dimethylamine. The amount of these amines added is preferably 0.1 to 1.0% by weight based on 100% by weight of the composition.

【0022】

Further, in the present invention, in order to impart various properties to the above reaction product, a compound having a bifunctional or higher functional acrylic group, methacrylic group or vinyl group is added to the composition in an amount of 20 to 70% by weight, preferably 30 to 30 to 70% by weight. Contains 60% by weight. When the amount of the compound having a bifunctional or higher functional acrylic group, methacrylic group or vinyl group is less than 20% by weight, it becomes difficult to maintain sufficient mechanical strength as an optical lens, and when it exceeds 70% by weight, it becomes difficult to maintain sufficient mechanical strength. This is because it becomes difficult to achieve the high refractive index and high Abbe number, which are the features of the present invention.

【0023】

Examples of compounds having a bifunctional or higher functional acrylic group, methacryl group or vinyl group include neopentyl glycol diacrylate (NPG), polyethylene glycol diacrylate (A-400), tetramethylolmethane triacrylate (TMM-3), etc. Polyfunctional acrylate, 2-hydroxy-1,3-dimethacrylate (701), polyethylene glycol dimethacrylate (ED), 2,2-bis (4-methacryloxypolyethoxyphenyl) propane (BPE-500), trimethylol Examples include, but are not limited to, polyfunctional methacrylates such as propanetrimethacrylate (TMPT), polyfunctional vinyl monomers such as divinylnaphthalene (DVN), divinylbenzene (DVB), and trivinylbenzene (TVB). Absent.

【0024】

Further, in the present invention, in addition to the above components, a monomer copolymerizable with those components can be added as needed. However, when it is added in an amount of more than 40% by weight in the composition, it becomes difficult to maintain sufficient mechanical strength as an optical lens, so a range of 0 to 40% by weight is preferable.

【0025】

The monomer at this time may be any as long as it can be copolymerized with the above components, but the monomer itself is also high in order not to impair the high refractive index characteristic of the present invention. The refractive index is desirable. Examples include, but are not limited to, styrene (St), α-methylstyrene dimer (MSD), benzyl methacrylate (BzMA), 2-phenylphenol polyethoxyacrylate (OPP-1), and the like. ..

【0026】

Further, the thiol, unsaturated ester, and unsaturated vinyl compound introduced at this time do not necessarily have to be one type each. That is, in order to impart various properties to the obtained copolymer, it is possible to introduce a plurality of thiols, unsaturated esters, unsaturated vinyl compounds and the like.

【0027】

The synthetic resin lens of the present invention can be obtained by radical polymerization of the composition obtained as described above, but the viscosity of the composition can be sufficiently lowered by appropriately combining the ratios of the above components. , It is possible to make the fluidity sufficiently high. Therefore, it can be collectively executed in a casting container designed according to an application such as a plate shape, a lens shape, or a cylindrical shape, and can be manufactured easily and at low cost.

【0028】

As a method of radical polymerization, a conventionally known method can be adopted. Examples of the radical polymerization method include a method of ultraviolet polymerization in the presence of a photosensitizer, a method of thermal polymerization in the presence of a radical polymerization initiator, a method of polymerization by electron beam irradiation, and the like. In the present invention, the polymerization method is not particularly limited, but the method of photopolymerization by ultraviolet irradiation is most preferable in consideration of the polymerization time, capital investment and the like.

【0029】

Preferred photopolymerization conditions are an irradiation wavelength of 300 to 400 nm and an irradiation dose of 10 to 10,000 mW / cm.², Irradiation time is 10 to 1,000 seconds.

【0030】

The method of photopolymerizing by irradiating ultraviolet rays in the presence of a photosensitizer is relatively simple in terms of equipment and handling, has a very high curing rate, and can shorten the polymerization time. Therefore, since more polymers can be obtained in a short time, the polymer can be obtained at low cost and with high efficiency, which is a very excellent polymerization method. Examples of photosensitizers that can be used at this time include α-hydroxyisobutylphenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-hydroxy-2-benzoyl propane, and benzyl dimethyl ketal. Examples thereof include, but are not limited to, thioxane, 2-chlorothioxanthone, and azobisisobutyronitrile.

【0031】

The method of heat polymerization in the presence of a radical polymerization initiator is the most common method, and the apparatus and handling are relatively simple. However, since a relatively long thermosetting time is required, there is a drawback that it is difficult to obtain a polymer in a short time. Examples of the radical polymerization initiator that can be used at this time include peroxides such as benzoyl peroxide and di-t-butyl peroxide, 2,2'-azobisisobutyronitrile, and 2,2'-azobis-(. 2,4-Dimethylvaleronitrile) and other azo compounds can be mentioned, but are not limited thereto.

【0032】

Since the method of polymerizing by electron beam irradiation can be polymerized in the absence of a catalyst or a photosensitizer, it is possible to reduce the mixing of impurities into the copolymer, but it requires a very complicated device. It has the disadvantage of increasing investment.

【0033】

Further, the composition at this time may contain a colorant, a heat stabilizer, and other auxiliary materials, if necessary. Further, it is also possible to apply a hard coating agent, a non-reflective coating, or other surface coating to the surface of the obtained copolymer.

【0034】

The synthetic resin lens of the present invention is characterized in that it is a copolymer as described above. Therefore, in addition to the casting polymerization method, a plate material or other copolymer is obtained and then machined. Can also be manufactured.

【0035】

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The evaluation method of the obtained various physical properties is as follows.

【0036】

Refractive index A test piece of 10 mm × 20 mm × 3 mm was prepared, and the refractive index at room temperature (20 ° C) was measured using Abbe Refractive Index Meter 1T manufactured by Atago Co., Ltd. and α-bromonaphthalene as a contact liquid.

【0037】

Abbe number The Abbe number was measured by the same measuring device and measuring method as the above-mentioned refractive index measurement.

【0038】

specific gravity A test piece of 10 mm × 20 mm × 3 mm was prepared, and the specific gravity at room temperature (20 ° C) was measured using SGM-6 manufactured by Metra-Tredo.

【0039】

Impact resistance Ten test samples with a diameter of 78 mm, a radius of curvature of 0.1 mm, and a center thickness of 2 mm were prepared, and a steel ball weighing 16.2 g (diameter 10/16 inch) was dropped from a height of 1.27 m, and the FDA ball drop impact. According to the strength standard, those that did not break even 10 sheets were considered good, and those that did not break even one sheet were considered defective.

【0040】

transparency A flat plate with a center thickness of 2.0 mm was prepared, and the haze was measured using "HGM-2DP" manufactured by Suga Test Instruments Co., Ltd., and those having a haze of 0.3 or less were regarded as good, and those exceeding 0.3 were regarded as defective.

【0041】

Precipitation For the compositions mixed in the ratios of the following Examples and Comparative Examples, a small amount of the composition immediately before the addition of the radical polymerization initiator was taken out after the dissolution of the component A and left at 20 ° C. for 12 hours. After that, the precipitation of the monomer composition was confirmed, and the one in which the precipitation was not visually confirmed was regarded as good, and the one in which the precipitation was clearly confirmed was regarded as defective.

【0042】

Example 1 50 g of component A (BRA), 20 g of pentaerythritol tetrakisthiopropionate (PETP), and 30 g of bismethacryloxypolyethoxyphenylpropane (BPE) were measured in a 200 ml Erlenmeyer flask, and 0.5 g of triethylamine and a stirrer were added and stoppered. Then, the component A was dissolved by stirring at 60 ° C. for 3 hours. After that, the mixture was cooled to room temperature, and after adding 2000 ppm of the photopolymerization initiator IRGACURE184 (Nippon Ciba Geigy Co., Ltd.) and thoroughly stirring, it was injected into a casting mold composed of two glass plates and a gasket, and the ultraviolet irradiation device With an irradiation dose of 800 mW / cm²Ultraviolet polymerization was carried out under the conditions of an irradiation distance of 50 cm and an irradiation time of 10 min. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0043】

As a result, a good copolymer having the physical characteristics shown in Table 1 below could be obtained.

【0044】

Examples 2 to 5 The compositions were prepared at the ratios shown in Examples 2 to 5 of Table 1, respectively, 0.5% by weight of triethylamine and a stirrer were added, the mixture was stoppered, and the mixture was stirred at 60 ° C. for 3 hours. A component was dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket to heat the mixture. Polymerization was performed. The thermal polymerization was gradually heated from 45 ° C to 100 ° C over 10 hours in a hot air circulation furnace, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0045】

As a result, a good copolymer having the physical characteristics shown in Table 1 below could be obtained.

【0046】

Comparative example 1 As a comparative example, copolymerization was carried out under the condition that the component A was less than 20% by weight.

【0047】

The composition is prepared at the ratio shown in Comparative Example 1 in Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0048】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but the refractive index was 1.58 or less and the Abbe number was 35 or less, and problems were confirmed in the refractive index and Abbe number.

【0049】

Comparative example 2 As a comparative example, copolymerization was carried out under the condition that the component A exceeded 80% by weight.

【0050】

The composition is prepared at the ratio shown in Comparative Example 2 in Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0051】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but as a result of the precipitation test, the monomer was precipitated and suspended matter was confirmed, so the subsequent test was not performed.

【0052】

Comparative example 3 As a comparative example, copolymerization was carried out under the condition that the amount of the compound having a bifunctional or higher functional acrylic group, methacrylic group or vinyl group was less than 20% by weight.

【0053】

A composition is prepared at a ratio as shown in Comparative Example 3 in Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0054】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but as a result of the precipitation test, the monomer was precipitated and suspended matter was confirmed, so the subsequent test was not performed.

【0055】

Comparative example 4 As a comparative example, copolymerization was carried out under the condition that bifunctional or higher functional thiols exceeded 40% by weight.

【0056】

The composition is prepared at the ratio shown in Comparative Example 4 of Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove the component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0057】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but the strength of the obtained resin was insufficient as it was softer even at room temperature, and problems were confirmed in the refractive index and impact resistance.

【0058】

Comparative example 5 As a comparative example, copolymerization was carried out under the condition that the amount of the monomer copolymerizable with the main component of the present invention exceeded 40% by weight.

【0059】

The composition is prepared at the ratio shown in Comparative Example 5 in Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0060】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but the strength of the obtained resin was insufficient as it was softer even at room temperature, and problems were confirmed in the refractive index, Abbe number and impact resistance. It was.

【0061】

Comparative example 6 As a comparative example, copolymerization was carried out under the condition that a compound having a bifunctional or higher functional acrylic group, a methacrylic group or a vinyl group exceeded 70% by weight.

【0062】

The composition is prepared at the ratio shown in Comparative Example 6 in Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0063】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but the refractive index was 1.58 or less, and a problem was confirmed in the refractive index.

【0064】

Comparative example 7 As a comparative example, copolymerization was carried out with a composition in which thiol was not added under the condition that the amount of bifunctional or higher thiol was less than 5% by weight.

【0065】

A composition is prepared at a ratio as shown in Comparative Example 7 of Table 1, 0.5% by weight of triethylamine and a stirrer are added, the mixture is stoppered, and the mixture is stirred at 60 ° C. for 3 hours to remove component A. Dissolved. After that, the mixture is cooled to room temperature, 0.1 g of the radical polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is added, and the mixture is injected into a casting mold composed of two glass plates and a gasket for polymerization. Was done. The polymerization was gradually heated in a hot air circulation furnace from 45 ° C to 100 ° C over 10 hours, held at 100 ° C for 2 hours, and then gradually cooled to 65 ° C. After that, the copolymer was taken out from the casting mold to obtain a finished product.

【0066】

As a result, a resin having the physical characteristics shown in Table 1 was obtained, but as a result of the precipitation test, the monomer was precipitated and suspended matter was confirmed, so the subsequent test was not performed.

【0067】

[table 1]

<img file="JP2002182002A_D0002.tif" />【0068】

[Effect of the invention]

The synthetic resin lens of the present invention not only enables a high refractive index of 1.58 or more and a high Abbe number of 35 or more, but also facilitates photopolymerization, which causes inconvenience in the work process and handling. Can also be resolved. Therefore, a method for easily obtaining an excellent synthetic resin lens having a high refractive index and a high Abbe number has become possible.