阅读说明：本技术 环氧丙烯酸酯类中等折射光学透镜用树脂组合物及其制备方法 (Epoxy acrylate resin composition for medium refractive optical lens and preparation method thereof ) 是由 张东奎 卢守均 洪吉杓 于 2018-04-05 设计创作，主要内容包括：本发明涉及环氧丙烯酸酯类光学透镜,尤其,涉及折射率为1.53～1.58、且离型性、热稳定性、耐光性及压缩强度优秀的环氧丙烯酸酯类中等折射光学透镜用树脂组合物及其制备方法。本发明提供环氧丙烯酸酯类中等折射光学透镜用树脂组合物,其包含：50重量百分比至70重量百分比的双酚A环氧丙烯酸酯,含环氧基化合物的含量为0.7重量百分比以下；21重量百分比至45重量百分比的甲基丙烯酸甲酯；以及1重量百分比至17重量百分比的反应性稀释剂,环氧丙烯酸酯类中等折射光学透镜用树脂组合物的固相折射率为1.53～1.58。根据本发明,控制环氧丙烯酸酯的制备过程中所残留的含环氧基化合物的含量并在组合物中含有大量的甲基丙烯酸甲酯,由此以良好的状态维持透明性和阿贝数,可通过低的生产费用制备离型性、热稳定性及耐光性优秀且压缩强度也很高的环氧丙烯酸酯类中等折射光学透镜。本发明的环氧丙烯酸酯类中等折射光学透镜代替以往的中等折射光学镜头在多种领域中广泛使用。(The present invention relates to an epoxy acrylate optical lens, and more particularly, to a resin composition for an epoxy acrylate medium refractive optical lens having a refractive index of 1.53 to 1.58 and excellent in mold release property, thermal stability, light resistance and compressive strength, and a method for preparing the same. The present invention provides a resin composition for epoxy acrylate medium refractive optical lenses, comprising: 50 to 70 weight percent of bisphenol A epoxy acrylate, the content of the compound containing epoxy groups is less than 0.7 weight percent; 21 to 45 weight percent of methyl methacrylate; and 1 to 17 weight percent of reactive diluent, wherein the solid phase refractive index of the resin composition for the epoxy acrylate medium refractive optical lens is 1.53 to 1.58. According to the present invention, an epoxy acrylate-based medium refractive optical lens having excellent release properties, thermal stability and light resistance and high compressive strength can be manufactured at low production cost by controlling the content of an epoxy group-containing compound remaining in the process of manufacturing an epoxy acrylate and by containing a large amount of methyl methacrylate in a composition, thereby maintaining transparency and abbe number in a good state. The epoxy acrylate type mesorefractive optical lens of the present invention is widely used in various fields instead of the conventional mesorefractive optical lens.)

1. A resin composition for an epoxy acrylate medium refractive optical lens, comprising:

50 to 70 weight percent of bisphenol A epoxy acrylate represented by the following chemical formula 1, the content of the epoxy group-containing compound being 0.7 weight percent or less;

21 to 45 weight percent of methyl methacrylate; and

1 to 17 weight percent of a reactive diluent,

the refractive index of the solid phase is 1.53 to 1.58,

chemical formula 1:

wherein n is 0 to 15.

2. The resin composition according to claim 1, wherein the content of the epoxy group-containing compound is 0.01 to 0.6 percent by weight.

3. The resin composition according to claim 1, wherein the epoxy group-containing compound contains a compound represented by the following chemical formula 2 to chemical formula 3,

chemical formula 2:

wherein n is 0 to 15,

chemical formula 3:

wherein n is 0 to 15.

4. The resin composition according to claim 1, wherein the reactive diluent is one or more compounds selected from the group consisting of styrene, divinylbenzene, α -methylstyrene dimer, benzyl methacrylate, chlorostyrene, bromostyrene, methoxystyrene, monobenzyl maleate, monobenzyl fumarate, dibenzyl maleate, dibenzyl fumarate, methylbenzyl maleate, dimethyl maleate, diethyl maleate, dibutyl fumarate, monobutyl maleate, monopentyl maleate, dipentyl maleate, monopentyl fumarate, dipentyl fumarate, and diethylene glycol diaryl carbonate.

5. The resin composition according to claim 1, wherein the reactive diluent is one or more compounds selected from the group consisting of styrene, divinylbenzene, α -methylstyrene, and α -methylstyrene dimer.

6. The resin composition of claim 1, further comprising 0.001 to 10 weight percent of an internal release agent.

7. The resin composition of any one of claims 1 to 6, wherein the composition further comprises 0.01 to 5 weight percent of a thermal stabilizer.

8. The resin composition according to claim 7, wherein the heat stabilizer is one or more compounds selected from the group consisting of triphenyl phosphite, diphenyldecyl phosphite, phenyl didecyl phosphite, diphenyldodecyl phosphite, diphenylisodecyl phosphite, trisnonylphenyl phosphite, diphenylisooctyl phosphite, tributyl phosphite, tripropyl phosphite, triethyl phosphite, trimethyl phosphite, tris (monodecyl phosphite), tris (monophenyl) phosphite.

9. An epoxy acrylate medium refractive optical lens is characterized in that,

obtained by polymerizing a resin composition for an optical lens comprising:

50 to 70 weight percent of bisphenol A epoxy acrylate represented by the following chemical formula 1, the content of the epoxy group-containing compound being 0.7 weight percent or less;

21 to 45 weight percent of methyl methacrylate; and

1 to 17 weight percent of a reactive diluent,

chemical formula 1:

wherein n is 0 to 15,

the refractive index of the solid phase is 1.53-1.58.

10. The epoxy acrylate based medium refractive optical lens according to claim 9, wherein the epoxy group-containing compound is contained in an amount of 0.01 to 0.6 wt%.

11. The epoxy acrylate based medium refractive optical lens according to claim 9, wherein the epoxy group-containing compound comprises a compound represented by the following chemical formula 2 to chemical formula 3,

chemical formula 2:

wherein n is 0 to 15,

chemical formula 3:

wherein n is 0 to 15.

12. The epoxy acrylate based medium refractive optical lens according to claim 9, wherein the reactive diluent is one or more compounds selected from the group consisting of styrene, divinylbenzene, α -methylstyrene, and α -methylstyrene dimer.

13. The epoxy acrylate based medium refractive optical lens of any one of claims 9 to 12 wherein the resin composition further comprises 0.01 to 5 weight percent of a thermal stabilizer.

14. The epoxy acrylate based mesorefractive optical lens of claim 13, wherein the heat stabilizer is one or more compounds selected from the group consisting of triphenyl phosphite, diphenyldecyl phosphite, phenyldidecyl phosphite, diphenyldodecyl phosphite, diphenylisodecyl phosphite, trisnonylphenyl phosphite, diphenylisooctyl phosphite, tributyl phosphite, tripropyl phosphite, triethyl phosphite, trimethyl phosphite, tris (monodecyl phosphite), and tris (monophenyl) phosphite.

15. The epoxy acrylate based medium refractive optical lens of claim 9 wherein the resin composition further comprises 0.001 to 10 weight percent of an internal release agent.

16. A method for producing an epoxy acrylate type intermediate refractive optical lens, comprising the step of placing the resin composition of claim 1 in a mold and polymerizing.

Technical Field

The present invention relates to an epoxy acrylate optical lens, and more particularly, to a resin composition for an epoxy acrylate intermediate refractive optical lens having a refractive index of 1.53 to 1.58 and excellent releasability, thermal stability, compressive strength, transparency and color, and a method for preparing the same.

Background

A lens disclosed in 1936 using polymethyl-methacrylate (PMMA) as an acrylic resin is also called an acrylate lens, has an abbe number of 57, and thus has high transparency, a refractive index as low as 1.49, and low heat resistance and surface strength as compared to CR-39 of similar refractive index.

In 1992, the DISO company of Japan first developed an acrylic high-refractive resin lens by mixing tetrabromobisphenol A diacrylate (diacid of tetrabromobisphenol A) with a reactive diluent such as styrene, but it was not put into practical use because of insufficient thermal stability and light resistance of the lens.

Then, Japanese patent laid-open Nos. Hei 6-49133 and Hei 7-206974 disclose only methods for producing lenses by mixing tetrabromobisphenol A diacrylate with divinylbenzene, styrene, phenyl methacrylate, isocyanate and the like. Such optical lenses are improved in light resistance and heat resistance, but have a problem of color change when hard-coated due to low thermal stability.

In order to solve these problems, a lens having refractive index of 1.58 to 1.61, in which thermal stability and light resistance of a spectacle lens are greatly improved by mixing tetrabromobisphenol A diacrylate with a reactive diluent such as styrene and methylstyrene and adding an acid phosphate, is disclosed in Korean laid-open patent No. 10-2004-0083942. The epoxy acrylate lens has high refractive index, high Abbe number, excellent optical properties such as transparency, light weight and heat resistance, and low material cost.

However, when an epoxy acrylate lens is produced, the thermal stability, release property and light resistance are lowered for unknown reasons. Further, a reactive diluent for adjusting viscosity and reaction rate is required, and one or more of styrene, divinylbenzene, α -methylstyrene dimer, benzyl methacrylate, chlorostyrene, bromostyrene, methoxystyrene, dibenzylmaleate, and the like are used alone or in combination. The diluent chosen will have an impact on the productivity and optical properties of the lens and will also impact the cost of production. For example, styrene, which is currently frequently used and is present in high amounts in the resin, reduces the strength.

On the other hand, various resins such as polyethylene glycol bisallylcarbonate, polymethyl methacrylate, diallyl phthalate, polystyrene, and polycarbonate have been used for conventional optical lenses having a medium refractive index range.

An optical resin composition provided in european patent 06905a2, in which 5 to 40 parts by weight of an acrylic and bisphenol a type epoxy reactant, 5 to 40 parts by weight of an acrylic and bistetrabromobisphenol a type epoxy reactant, 5 to 20 parts by weight of diallyl dibenzoate (phenate), vinyl toluene and polystyrene are mixed in 15 to 50 parts by weight of styrene, but the composition has a problem of insufficient thermal stability.

Japanese Kokai publication Sho-53-7787 discloses an optical lens obtained by polymerizing 85 wt% of diallyl isophthalate and 15 wt% of diethylene glycol bisallylcarbonate, in which case the lens is successfully made thinner and thinner, but still has a disadvantage of weak impact resistance.

Plastic lenses made from a copolymer formed from modified dipropylene phthalate and dibenzyl fumarate and lenses made from a copolymer formed from dipropylene phthalate and methyl acrylate are provided in japanese laid-open patents sho 62-235901 and sho 64-45412 and japanese patent hei 1-60494, and they still have a problem of weak impact resistance.

Korean granted patent No. 10-0431434 discloses a monomer composition for a medium refractive optical lens, which is formed of diallyl ester oligomer, dialkyl maleate, diethylene glycol bisallyl carbonate, and diallyl adipate, and has a refractive index ranging from 1.53 to 1.55. Although the impact resistance of the optical lens is improved as compared with a conventional intermediate refractive lens, the abbe number and transparency are rather reduced and the heat resistance is low.

In the case of epoxy acrylate lenses, optical properties such as transparency and abbe number are good, so that the quality in terms of thermal stability, mold release property, light resistance, compressive strength, etc. is improved and the production cost is reduced, and the lenses are more competitive with medium refractive lenses having a refractive index of about 1.53 to 1.58 than lenses of other materials.

Disclosure of Invention

Problems to be solved by the invention

The present invention aims to show that the problem of the unknown decrease in releasability, thermal stability and light resistance occurring when an epoxy acrylate-based lens is produced is related to the content of an epoxy group-containing compound remaining in the production of an epoxy acrylate and to solve the problem.

Methyl methacrylate is used as a reactive diluent together with conventional styrene, divinylbenzene, α -methylstyrene dimer, and the like, and when the content in the resin is 20% by weight or more, physical properties are problematic on many sides such as whitening and uneven polymerization, and therefore, it is mostly used only in a small amount. However, in the case of using a large amount of methyl methacrylate, the compressive strength is more excellent than in the case of using styrene, and therefore, the compressive strength can be improved without increasing the production cost. The present invention aims to provide a resin composition for an epoxy acrylate type medium refractive optical lens, which contains 20% by weight or more of methyl methacrylate in the lens resin composition, has excellent transparency, Abbe number, thermal stability, light resistance and mold release property, and is excellent in compressive strength and economical.

Means for solving the problems

In order to achieve the above object, the present invention provides a resin composition for an epoxy acrylate type moderately refractive optical lens, comprising: 50 to 70 weight percent of bisphenol A epoxy acrylate represented by the following chemical formula 1, the content of the epoxy group-containing compound being 0.7 weight percent or less; 21 to 45 weight percent of methyl methacrylate; and 1 to 17 weight percent of reactive diluent, wherein the refractive index of the solid phase is 1.53 to 1.58.

Chemical formula 1

Wherein n is 0 to 15.

The resin composition for an epoxy acrylate type medium refractive optical lens may further include 0.001 to 10% by weight of an internal release agent.

Also, the epoxy acrylate resin composition for a medium refractive optical lens may further include 0.01 to 5 weight percent of a heat stabilizer.

The invention provides an epoxy acrylate medium refractive optical lens with a solid phase refractive index of 1.53-1.58, which is obtained by polymerizing a resin composition for an optical lens, which comprises the following components, in a casting mold: 50 to 70 weight percent of bisphenol A epoxy acrylate represented by the following chemical formula 1, the content of the epoxy group-containing compound being 0.7 weight percent or less; 21 to 45 weight percent of methyl methacrylate; and 1 to 17 weight percent of a reactive diluent.

Chemical formula 1:

wherein n is 0 to 15.

Also, the present invention provides a method for manufacturing an epoxy acrylate medium refractive optical lens, including the step of placing a resin composition for an epoxy acrylate medium refractive optical lens in a mold and polymerizing the resin composition.

Effects of the invention

The present invention provides a resin composition for epoxy acrylate medium refractive optical lenses, which has a remarkably improved compressive strength at a low production cost in a medium refractive lens having a solid phase refractive index of 1.53 to 1.58, and is excellent in releasability, thermal stability, light resistance, transparency and abbe number, by controlling the content of an epoxy group in bisphenol A glycidyl ether and containing a large amount of methyl methacrylate in the composition.

Detailed Description

The epoxy acrylate resin composition for a medium refractive optical lens according to the present invention comprises: a bisphenol a epoxy acrylate resin (BPDA) represented by the following chemical formula 1; methyl Methacrylate (MMA); and a reactive diluent, wherein the reactive diluent is a water-soluble polymer,

chemical formula 1:

wherein n is 0 to 15.

The bisphenol a epoxy acrylate resin is generally obtained by reacting bisphenol a glycidyl ether represented by the following chemical formula 2 with acrylic acid, during which an epoxy group-containing compound may be included in the prepared bisphenol a epoxy acrylate resin through unreacted and side reactions.

Chemical formula 2:

wherein n is 0 to 15.

The present inventors have found that the problem of the unknown decrease in releasability, thermal stability and light resistance occurring when an epoxy acrylate lens is produced is related to the content of the epoxy group-containing compound remaining in the production process of bisphenol a epoxy acrylate. Preferably, in the present invention, the content of the epoxy group-containing compound contained in the bisphenol a epoxy acrylate is 0.7 weight percent or less, more preferably, 0.01 to 0.6 weight percent.

In the present invention, the "epoxy group-containing compound" is a compound including compounds represented by the following chemical formulas 2 to 3, thereby including one or more epoxy groups within the compound. Preferably, the epoxy group-containing compound includes compounds represented by the following chemical formulas 2 to 3. The epoxy group-containing compound in the bisphenol A epoxy acrylate can be controlled by adjusting the equivalent weight of acrylic acid. Specifically, when 18 hours have elapsed after the synthesis reaction of bisphenol a epoxy acrylate, a reaction sample in the course of the reaction is obtained to measure the epoxy content in the sample and calculate the content of residual epoxy groups in the reactant in equivalent. Thereafter, the reaction was continued at a reaction temperature of 105 ℃ with the addition of the corresponding equivalent of acrylic acid, and after the lapse of 20 hours, the epoxy content was measured again to confirm whether the desired level was reached. After the confirmation, the reaction may be terminated or, if necessary, the epoxy content may be adjusted by adding an equivalent amount of acrylic acid corresponding to the epoxy content, and continuing the reaction at a temperature of 107 ℃ for 30 minutes to 3 hours and then terminating the reaction. Preferably, the content of the epoxy group-containing compound in the bisphenol a epoxy acrylate is less than 0.01 weight percent, but the preferred content of the epoxy group-containing compound is 0.01 to 0.6 weight percent, more preferably 0.01 to 0.55 weight percent, in view of the quality of the lens and the production cost.

Chemical formula 2:

wherein n is 0 to 15.

Chemical formula 3:

wherein n is 0 to 15.

In the present invention, the content of the epoxy group-containing compound in the bisphenol A epoxy acrylate was measured by the following method.

Method for measuring epoxy group-containing compound

In a clean 200mL beaker, 5g of a sample is placed, 1g of cetyltrimethylammonium bromide (cethyltrimethylammonitum bromide) is added, and the mixture is poured into a beaker with a volume of 9: 1 100mL of a solution of methyl ketone and glacial acetic acid was mixed. Stirring the solution at a temperature of 150 ℃ for 20-30 seconds, heating the solution, cooling the solution at normal temperature, and adding 4-5 drops of gentian violet (crystal violet) to the solution to turn the solution into cyan. With 0.1N HClO₄Solution the solution was titrated. The content of the epoxy group-containing compound is determined by the following formula 1.

Formula 1

In the epoxy acrylate-based resin composition for a medium refractive optical lens according to the present invention, the epoxy acrylate is included in an amount of 50 to 70 wt%, preferably 55 to 65 wt%.

Methyl Methacrylate (MMA) contained in the resin composition of the present invention is used as a reactive diluent together with styrene, divinylbenzene, α -methylstyrene dimer, or the like in conventional epoxy acrylate optical resins. However, unlike styrene or divinylbenzene, etc., it is not necessary to contain a large amount of methyl methacrylate, but usually only about at least 3% to at most less than 20% is used. This is because, when the content of methyl methacrylate in the resin for an optical lens is 20 wt% or more, there occur problems in the physical properties of the lens on various side surfaces such as whitening of the optical lens and uneven polymerization. However, in the present invention, even if a large amount of methyl methacrylate of 20 weight percent or more is contained in the resin, the content of the epoxy group-containing compound in the bisphenol a epoxy acrylate used together is limited to 0.7 weight percent or less, and the content of the bisphenol a epoxy acrylate resin in the resin is 50 to 70 weight percent, whereby the releasability, the thermal stability and the light resistance are all excellent. Meanwhile, by using a large amount of methyl methacrylate instead of styrene, the compressive strength can be greatly improved without additional production cost. Preferably, the content of methyl methacrylate in the resin composition of the present invention is 21 to 45 weight percent, more preferably, may be 25 to 40 weight percent.

The reactive diluent contained in the resin composition of the present invention plays a role of appropriately adjusting the viscosity and polymerization rate of the composition, and is not particularly limited as long as it is used as a reactive diluent in a resin for an epoxy acrylate type optical lens.

Preferably, the reactive diluent may be used alone or in admixture with one or more selected from the group consisting of styrene, divinylbenzene, α -methylstyrene dimer, benzyl methacrylate, chlorostyrene, bromostyrene, methoxystyrene, monobenzyl maleate, monobenzyl fumarate, dibenzyl maleate, dibenzyl fumarate, methylbenzyl maleate, dimethyl maleate, diethyl maleate, dibutyl fumarate, monobutyl maleate, monopentyl maleate, dipentyl maleate, monopentyl fumarate, dipentyl fumarate, and diethylene glycol diaryl carbonate. More preferably, the reactive diluent is one or more compounds selected from the group consisting of styrene, divinylbenzene, α -methylstyrene, and α -methylstyrene dimer.

Methyl methacrylate inevitably contained in the resin composition of the present invention functions as a reactive diluent, and therefore, it is preferable that the content of the other reactive diluent is 1 to 17 weight percent in a small amount. When the content of the total reactive diluent including the reactive diluent different from methyl methacrylate is more than 60 wt%, the viscosity of the composition becomes too low and the tape adhesive is eluted, and in this case, a tape whitening phenomenon and a liquid leakage phenomenon may occur in a curing process after injection, and thus, a phenomenon such as whitening and streaking may occur in the lens.

Under the temperature condition of 25 ℃ according to the cast polymerization, the viscosity of the liquid phase of the resin composition of the invention containing methyl methacrylate and reactive diluent is 20cps to 200cps, the refractive index (nD, 20 ℃) of the liquid phase of the resin composition is 1.48 to 1.55, and the refractive index (nE, 20 ℃) of the solid phase is 1.53 to 1.58. If the viscosity of the liquid phase is less than 20cps, the composition may flow out of the mold when the liquid phase resin composition is injected into a glass mold assembled by a synthetic resin spacer or an adhesive tape and molded, and if the viscosity of the liquid phase is more than 200cps, the composition may be hardly injected into the mold. More preferably, the viscosity is 30cps to 100 cps.

The resin composition of the present invention may further comprise an internal release agent. The internal mold release agent is added to the resin composition before the mold polymerization, whereby the mold release property can be greatly improved after the polymerization. Preferably, the polymeric composition may contain 0.001 to 10 weight percent of the internal release agent.

The internal release agent may be used alone or in combination with two or more of a phosphate ester compound, a silicon surfactant, a fluorine surfactant, an alkyl quaternary ammonium salt, and the like.

The fluorine nonionic surfactant is a compound with perfluoroalkyl in the molecule, Unitine DS-401^TM(Japan, Dajin Industrial Co., Ltd.), Unitine DS-403^TM(Daiki Industrial Co., Ltd., Japan), Eftof EF 122A^TM(New Care Kasei Co., Ltd., Japan), Eftof EF 126^TM(New Care Kasei Co., Ltd., Japan), Eftof EF 301^TM(New Care Kasei Co., Ltd., Japan).

The silicon-based nonionic surfactant is a compound having a dimethylpolysiloxane group in the molecule, and includes Dow Q2-120A^TMAnd the like.

The quaternary alkylammonium salts are generally used as cationic surfactants and include halogen salts, phosphates, sulfates and the like, and examples of chloride salts include cetyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dimethylethyltrimethylammonium chloride, triethyldecylammonium chloride, methyltrioctylammonium chloride, decylammonium chloride and the like.

Preferably, the internal mold release agent may use a phosphate compound. The phosphate ester compound includes, as a compound having a phosphate group, for example, isopropyl phosphate, diisopropyl phosphate, butyl phosphate, dibutyl phosphate, octyl phosphate, dioctyl phosphate, isodecyl phosphate, diisodecyl phosphate, tridecyl diphosphate, a mixture of two or more thereof, and the like. Preferably, as the phosphate ester compound, one selected from the group consisting of nonylphenol polyoxyethylene ether phosphate (5 weight percent of 5 mole ethylene oxide-added substance, 80 weight percent of 4 mole ethylene oxide-added substance, 10 weight percent of 3 mole ethylene oxide-added substance and 5 weight percent of 1 mole ethylene oxide-added substance), polyoxyethylene nonylphenol phosphate (5 weight percent of 9 mole ethylene oxide-added substance, 80 weight percent of 8 mole ethylene oxide-added substance, 10 weight percent of 7 mole ethylene oxide-added substance and 5 weight percent of 6 mole or less ethylene oxide-added substance), nonylphenol polyoxyethylene ether phosphate (3 weight percent of 11 mole ethylene oxide-added substance, 80 weight percent of 10 mole ethylene oxide-added substance, 5 weight percent of 9 mole added substance, and the like, can be used, 6 weight percent of an additional 7 moles of material, 6 weight percent of an additional 6 moles of material), nonylphenol polyoxyethylene ether phosphate (3 weight percent of an additional 13 moles of ethylene oxide material, 80 weight percent of an additional 12 moles of material, 8 weight percent of an additional 11 moles of material, 3 weight percent of an additional 9 moles of material, 6 weight percent of an additional 4 moles of material), nonylphenol polyoxyethylene ether phosphate (3 weight percent of an additional 17 moles of ethylene oxide material, 79 weight percent of an additional 16 moles of material, 10 weight percent of an additional 15 moles of material, 4 weight percent of an additional 14 moles of material, 4 weight percent of an additional 13 moles of material), nonylphenol polyoxyethylene ether phosphate (5 weight percent of an additional 21 moles of ethylene oxide material, and mixtures thereof, 78 weight percent of an additional 20 moles of material7 weight percent additional 19 moles of material, 6 weight percent additional 18 moles of material, 4 weight percent additional 17 moles of material) and dioctyl phosphate and jie-ke uyen^TM(Zelec UN^TM) One or more than two compounds in the group.

The resin composition of the present invention may further comprise a heat stabilizer. Preferably, the heat stabilizer is contained in the resin composition of the present invention in an amount of 0.01 to 5.00 weight percent. When the heat stabilizer is used in an amount of less than 0.01% by weight, the effect of the heat stabilizer is weak, and when the heat stabilizer is used in an amount of more than 5.00% by weight, the polymerization defect rate during curing is high, and the heat stability of a cured product is rather lowered.

For example, the heat stabilizer may be one or more compounds selected from the group consisting of calcium stearate, barium stearate, zinc stearate, cadmium stearate, lead stearate, magnesium stearate, aluminum stearate, potassium stearate, zinc octoate, and the like, which are metal fatty acid salts.

Preferably, one or more compounds selected from triphenyl phosphite, diphenyldecyl phosphite, phenyldidecyl phosphite, diphenyldodecyl phosphite, diphenylisodecyl phosphate, trisnonylphenyl phosphite, diphenylisooctyl phosphite, tributyl phosphite, tripropyl phosphite, triethyl phosphite, trimethyl phosphite, tris (monodecyl phosphite), tris (monophenyl) phosphite, and the like, which are phosphorus-based, may be used. More preferably, diphenylisodecyl phosphate may be used.

Also, 3PbO. PbSO selected as lead group can be used₄.4H₂O、2PbO.Pb(C₈H₄O₄)、3PbO.Pb(C₄H₂O₄).H₂O, etc.

Further, one or more compounds selected from the group consisting of dibutyltin dilaurate, dibutyltin maleate, dibutyltin bis (isooctylmaleate), dioctyltin maleate, dibutyltin bis (monomethyl maleate), dibutyltin bis (laurenethiol), dibutyltin bis (isooctylmercaptoacetate), monobutyltin tris (isooctylmercaptoacetate), dimethyltin bis (isooctylmercaptoacetate), trioctyylmercaptoacetate, dioctylmercaptoacetate, dibutyltin bis (2-mercaptoacetate), butyltin tris (2-mercaptoacetate), dimethyltin bis (2-mercaptoacetate), methyltin tris (2-mercaptoacetate) and the like, which are organic tin compounds, can be used.

Further, 2 or more different types of heat stabilizers may be mixed and used. Most preferably, the use of a phosphorus-based heat stabilizer not only improves the initial color of the molded lens, but also greatly improves the thermal stability of the optical lens without degrading the optical properties such as transparency, impact strength, heat resistance, and polymerization yield.

Further, the resin composition of the present invention may further contain an ultraviolet absorber, an organic dye, an inorganic pigment, a stainblocker, an antioxidant, a light stabilizer, a catalyst, etc., according to the ordinary technique in the field of plastic optical lenses and as needed.

The epoxy acrylic medium refractive lens of the present invention can be prepared by placing the resin composition of the present invention in a mold and polymerizing. According to a preferred embodiment of the present invention, after the resin composition is injected into the mold, the mold is placed in a forced circulation oven and slowly heated from a temperature of 30 ℃ to 120 ℃ and cured, and then cooled to a temperature of 70 ± 10 ℃ and the mold is removed to obtain a lens. Preferably, in this case, a high-purity compound having a purity of 70% to 99.99% is used for all raw materials. Preferably, all raw materials are confirmed for purity and the low purity compound is purified, while the high purity compound is used as it is.

The epoxy acrylate medium refractive optical lens prepared by the preparation method is a medium refractive lens with a solid phase refractive index of 1.53-1.58, and can be used in various fields instead of the conventional medium refractive lens. Specifically, the resin composition is applicable to plastic resin spectacle lenses, three-dimensional polarizing lenses having a polarizing film attached to spectacle lenses, camera lenses, and the like, and is also applicable to recording medium substrates used for prisms, optical fibers, optical disks, and the like, and various optical products such as coloring filters, ultraviolet absorbing filters, and the like.