KR20220161170A - Polymerizable composition and optical material using the same - Google Patents

Abstract

A polymerizable composition according to exemplary embodiments may include: a first polymerizable compound including isophorone diisocyanate and hexamethylene diisocyanate; and a second polymerizable compound comprising 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis(mercaptoacetate). Since the polymerizable composition includes the above-described heterogeneous isocyanate-based compound and heterogeneous polythiol-based compound, the optical properties and mechanical/thermal stability of the optical material prepared therefrom may be excellent.

Description

Polymeric composition and optical material using the same {POLYMERIZABLE COMPOSITION AND OPTICAL MATERIAL USING THE SAME}

The present invention relates to a polymerizable composition and an optical material using the same. More specifically, it relates to a polymerizable composition containing a thiol-based compound and an isocyanate-based compound and an optical material using the same.

Plastic optical materials are lightweight and superior in mechanical properties, dyeability and processability compared to inorganic optical materials such as glass, and are widely used in optical products such as spectacle lenses and camera lenses. Examples of plastic optical materials include acrylic resins, polycarbonates, polythiourethanes, and the like. Among them, polythiourethane-based compounds are widely used as optical materials due to their excellent optical properties and mechanical properties.

A polythiourethane-based compound can generally be prepared by reacting an isocyanate-based compound and a polythiol-based compound. In this case, physical properties of the isocyanate-based compound and the polythiol-based compound as manufacturing raw materials may affect the quality of the optical material to be manufactured.

For example, polythiourethane-based compounds having different structures may be synthesized according to the number and positions of functional groups of the isocyanate-based compound and the polythiol-based compound. In addition, depending on the reactivity of the isocyanate-based compound and the polythiol-based compound, yellowing, whitening, or optical non-uniformity may occur.

Therefore, there is a demand for the development of optical materials capable of exhibiting desired mechanical properties and optical properties. For example, Korean Patent Publication No. 10-2012-0076329 discloses a urethane-based optical material prepared using an isocyanate-based compound.

Korean Patent Publication No. 10-2012-0076329

One object of the present invention is to provide a polymerizable composition having improved optical and mechanical properties.

One object of the present invention is to provide an optical material having improved optical and mechanical properties.

A polymerizable composition according to exemplary embodiments may include a first polymerizable compound including an alicyclic isocyanate compound and a linear or branched aliphatic isocyanate compound; and a second polymerizable compound including a trifunctional polythiol compound having a sulfide group and a tetrafunctional polythiol compound having an ester group.

According to exemplary embodiments, the polymerizable composition may include a first polymerizable compound including isophorone diisocyanate and hexamethylene diisocyanate; and a second polymerizable compound including 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis(mercaptoacetate).

In some embodiments, the amount of isophorone diisocyanate may be 30 parts by weight to 55 parts by weight based on 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

For example, the content of the isophorone diisocyanate may be 35 parts by weight to 50 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

In some embodiments, the content of the hexamethylene diisocyanate may be 5 parts by weight to 20 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

For example, the content of the hexamethylene diisocyanate may be 5 parts by weight to 15 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

In some embodiments, the content of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol in the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound is It may be 30 parts by weight to 45 parts by weight.

For example, the content of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol is 30 parts by weight to 100 parts by weight of the total of the first polymerizable compound and the second polymerizable compound. 40 parts by weight.

In some embodiments, the content of the pentaerythritol tetrakis (mercaptoacetate) may be 5 parts by weight to 20 parts by weight in total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

For example, the content of the pentaerythritol tetrakis (mercaptoacetate) may be 5 parts by weight to 15 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

In some embodiments, a weight ratio of the isophorone diisocyanate to the hexamethylene diisocyanate may be 1 to 9.

In some embodiments, the weight ratio of the 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol to the pentaerythritol tetrakis(mercaptoacetate) may be 1 to 6. .

According to exemplary embodiments, the weight ratio of the first polymerizable compound and the second polymerizable compound may be 20:80 to 80:20.

For example, the content of the first polymerizable compound may be 30% to 70% by weight of the total weight of the polymerizable composition.

For example, the content of the second polymerizable compound may be 30% to 70% by weight of the total weight of the polymerizable composition.

According to exemplary embodiments, the polymerizable composition may have a sulfur content of 24% or more represented by Formula 1 below.

[Equation 1]

((weight of sulfur atoms contained in second polymerizable compound)/(total weight of first polymerizable compound and second polymerizable compound)) ⅹ 100

In exemplary embodiments, the polymerizable composition may further include at least one selected from the group consisting of an internal release agent, a polymerization initiator, a heat stabilizer, a UV absorber, and a bluing agent.

In some embodiments, the amount of the polymerization initiator may be 500 ppm to 3,000 ppm based on the total weight of the polymerizable composition.

In some embodiments, the content of the internal release agent may be 500 ppm to 1,500 ppm based on the total weight of the polymerizable composition.

An optical material according to exemplary embodiments may include a polythiourethane resin prepared from the polymerizable composition described above.

In some embodiments, the optical material may have a solid refractive index of 1.59 to 1.61 at 20°C. For example, the optical material may have a solid refractive index of 1.59 to 1.60 at 20°C.

In some embodiments, the glass transition temperature (Tg) of the optical material may be 105 °C to 120 °C.

In some embodiments, the coefficient of thermal expansion (CTE) of the optical material may be 78 μm/m·°C or less. For example, the thermal expansion coefficient may be measured at a heating rate of 10° C./min using a thermomechanical analyzer (TMA).

In some embodiments, a storage modulus of the optical material at 25° C. may be 3.0 GPa to 4.0 GPa. In one embodiment, the storage modulus of the optical material at 25° C. may be 3.8 GPa or more, for example, 3.8 GPa to 4,0 GPa.

According to exemplary embodiments, the polymerizable composition may include a heterogeneous isocyanate compound and a heterogeneous polythiol compound. Therefore, the optical properties, heat resistance and impact resistance of the cured product of the polymerizable composition and the optical material prepared therefrom may be excellent.

According to exemplary embodiments, the polymerizable composition is an isocyanate compound including isophorone diisocyanate and hexamethylene diisocyanate, and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and penta and polythiol compounds including erythritol tetrakis (mercaptoacetate). In this case, the composition may have excellent polymerizability and reaction stability, and an optical material having excellent heat resistance and impact resistance without striae and cloudiness may be provided.

In addition, the isocyanate compound and the polythiol compound may have a predetermined content and weight ratio. In this case, the storage modulus and glass transition temperature of the cured material may be controlled within a predetermined range, and the impact resistance, heat resistance, and moldability of the optical material may be improved.

According to embodiments of the present invention, a first polymerizable compound including isophorone diisocyanate and hexamethylene diisocyanate, and 4-mercaptomethyl-3,6-dithia-1 A second polymerizable compound containing ,8-octanedithiol (4-mercaptomethyl-3, 6-dithia-1,8-octanedithiol) and pentaerythritol tetrakis (mercaptoacetate) A polymerizable composition comprising

An optical material having excellent refractive index, heat resistance and storage modulus may be provided as the polymerizable composition includes the above-described heterogeneous isocyanate compound and heterogeneous polythiol compound.

Hereinafter, embodiments of the present invention will be described in detail.

<Polymerizable composition>

The polymerizable composition according to exemplary embodiments may include a first polymerizable compound including a heterogeneous isocyanate compound having a different structure and a second polymerizable compound including a heterogeneous polythiol compound having a different structure.

For example, the polymerizable composition may include a first polymerizable compound including an alicyclic isocyanate compound and a linear or branched aliphatic isocyanate compound; and a second polymerizable compound including a trifunctional polythiol compound having at least one sulfide group and a tetrafunctional polythiol compound having at least one ester group.

According to exemplary embodiments, the first polymerizable compound may include isophorone diisocyanate and hexamethylene diisocyanate. For example, the first polymerizable compound may be a mixture of isophorone diisocyanate and hexamethylene diisocyanate.

When the polymerizable composition includes isophorone diisocyanate having an alicyclic structure in its molecular structure, an optical material prepared therefrom may have excellent heat resistance. Accordingly, deformation and cracking of the optical material due to the high-temperature process may be prevented. For example, the polymer formed from the polymerizable composition has a cyclohexyl moiety with excellent structural stability in its molecular structure, and thus has excellent durability against harsh external environments such as high temperature and physical impact.

In addition, as the polymerizable composition includes hexamethylene diisocyanate, generation of bubbles due to curing of the polymerizable composition may be suppressed, and impact strength of the optical material may be improved. Therefore, it is possible to prevent clouding and striae phenomena that may occur when isophorone diisocyanate is used alone, and the mechanical strength of the optical material can be improved.

By including isophorone diisocyanate and hexamethylene diisocyanate together in the first polymerizable compound, an optical material excellent in thermal stability and mechanical properties can be provided while suppressing stria and opacity.

In one embodiment, the content of the isophorone diisocyanate may be 30 parts by weight to 55 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

For example, the content of the isophorone diisocyanate may be 35 parts by weight to 50 parts by weight, preferably 40 parts by weight to 50 parts by weight, based on 100 parts by weight of the total of the first polymerizable compound and the second polymerizable compound. It may be, more preferably 42 parts by weight to 48 parts by weight.

In one embodiment, the content of the hexamethylene diisocyanate may be 5 parts by weight to 20 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

For example, the content of the hexamethylene diisocyanate may be 5 parts by weight to 15 parts by weight, specifically 5.5 parts by weight to 14 parts by weight based on 100 parts by weight of the total of the first polymerizable compound and the second polymerizable compound. have. Preferably, the content of the hexamethylene diisocyanate may be 6 parts by weight to 12 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound, more preferably 6 parts by weight to 11 parts by weight can

When the contents of isophorone diisocyanate and hexamethylene diisocyanate are within the above ranges, both mechanical properties and thermal stability of the optical material may be improved, and strength and heat crack resistance may be excellent.

More preferably, the content of isophorone diisocyanate may be 42 parts by weight to 48 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound, and the content of hexamethylene diisocyanate is 6 It may be parts by weight to 11 parts by weight.

Within the above range, the optical material may have a high storage modulus while improving heat resistance and mechanical properties. In addition, yellowing or whitening of the optical material is suppressed, and uniform and improved optical properties can be implemented.

In some embodiments, the weight ratio of isophorone diisocyanate to hexamethylene diisocyanate can be between 1 and 9.

Specifically, the weight ratio of isophorone diisocyanate to hexamethylene diisocyanate may be 2 to 8.5, preferably 2.5 to 8, and more preferably 3.5 to 7.5. Within the above content range, the optical material may have excellent heat resistance and impact resistance while maintaining excellent optical properties.

For example, when hexamethylene diisocyanate is included in an excessive amount in the first polymerizable compound, structural stability and heat resistance of the optical material may be deteriorated. In this case, when a high-temperature process such as hard coating or dyeing is performed, the center of the lens may be deformed or cracked.

As the first polymerizable compound includes isophorone diisocyanate and hexamethylene diisocyanate to satisfy the above-described content and weight ratio, mechanical properties of the optical material may be secured and heat resistance and heat crack resistance may be excellent.

In one embodiment, the first polymerizable compound may include an additional isocyanate compound in addition to the aforementioned isophorone diisocyanate and hexamethylene diisocyanate within a range that does not impair the object of the present invention. For example, the first polymerizable compound may include other alicyclic isocyanate compounds and/or linear or branched aliphatic isocyanate compounds.

Examples of the alicyclic isocyanate compound are 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane hexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyl dimethylmethane isocyanate, 2,2-dimethyl dicyclohexylmethane isocyanate or norbornane diisocyanate.

Examples of the straight-chain or branched-chain aliphatic isocyanate compound include 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2, 4,4-trimethylhexamethylene diisocyanate, 1,6,11-undeca triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, bis( isocyanatoethyl) carbonate or bis(isocyanatoethyl) ether; and the like.

In some embodiments, the content of the first polymerizable compound may be 30% to 70% by weight of the total weight of the polymerizable composition, preferably 40% to 60% by weight, more preferably 53% to 54% by weight.

Within the above range, the polymerization reactivity of the polymerizable composition may be excellent, and the cured product may have a high crosslinking density. Therefore, optical non-uniformity in a local area can be prevented, and the optical material can have excellent thermal/mechanical stability and optical properties.

According to exemplary embodiments, the second polymerizable compound may include 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis(mercaptoacetate). . For example, the second polymerizable compound may be a mixture of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis(mercaptoacetate).

By including an ester group in the molecular structure of pentaerythritol tetrakis (mercaptoacetate), crack resistance and impact strength of the optical material may be improved, and thermal stability of the optical material may be excellent. In addition, as the polymerizable composition includes pentaerythritol tetrakis (mercaptoacetate) having a tetrafunctional structure, the crosslinking density of the optical material may be improved.

In addition, the reaction rate during the polymerization reaction is controlled by 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol, thereby reducing the polymerization failure rate. Accordingly, the dimensional stability of the optical material can be improved.

Reaction stability of the polymerizable composition is ensured by the second polymerizable compound including 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis (mercaptoacetate) together. It can be, and the thermal stability and mechanical properties of the optical material prepared therefrom can be excellent.

In one embodiment, the content of the 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol is 30 parts by weight of the total 100 parts by weight of the first polymerizable compound and the second polymerizable compound part to 45 parts by weight.

For example, the content of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol is 30 parts by weight to 100 parts by weight of the total of the first polymerizable compound and the second polymerizable compound. It may be 40 parts by weight, preferably 35 parts by weight to 40 parts by weight, more preferably 37 parts by weight to 40 parts by weight.

In one embodiment, the content of the pentaerythritol tetrakis (mercaptoacetate) may be 5 parts by weight to 20 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound.

Specifically, the content of the pentaerythritol tetrakis (mercaptoacetate) may be 5 parts by weight to 15 parts by weight based on the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound, preferably 5 parts by weight Part to 10 parts by weight, more preferably 6 to 9 parts by weight.

When the contents of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis (mercaptoacetate) are within the above ranges, the polymerizable composition has high polymerization reactivity. And, the impact resistance and mechanical strength of the optical material may be excellent.

In addition, since pentaerythritol tetrakis (mercaptoacetate) has low compatibility with isophorone diisocyanate, layer separation between components may occur and uniformity of the mixture may be deteriorated. According to one embodiment, as the contents of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis (mercaptoacetate) are within the above range, the mixture Homogeneity and affinity can be improved, and layer separation of the polymerizable composition can be prevented.

More preferably, the content of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol is 37 parts by weight to 40 parts by weight of the total of 100 parts by weight of the first polymerizable compound and the second polymerizable compound. It may be parts by weight, and the content of the pentaerythritol tetrakis (mercaptoacetate) may be 6 parts by weight to 9 parts by weight. Within the above range, the crosslinking density of the optical material may be improved, so that mechanical properties may be excellent and excellent reaction stability may be obtained. Accordingly, uniformity and dimensional stability of the optical material can be further improved, and uniform and improved optical properties can be maintained for a long period of time.

In some embodiments, the weight ratio of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol to pentaerythritol tetrakis(mercaptoacetate) can be between 1 and 7.

Specifically, the weight ratio of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol to pentaerythritol tetrakis (mercaptoacetate) may be 1 to 6, more specifically 3 to 6 It may be 6, preferably 4 to 6, more preferably 4.19 to 6. Dimensional stability and thermal properties of the polythiourethane-based compound prepared by the polymerizable composition within the weight ratio range may be excellent.

For example, when pentaerythritol tetrakis (mercaptoacetate) is included in an excessive amount in the second polymerizable compound, the reactivity and reaction rate of the polymerizable composition may be excessively increased. In this case, the curing density and structural stability of the optical material may decrease.

As the second polymerizable compound contains 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis (mercaptoacetate) to satisfy the above-described content and weight ratio, An optical material having high heat resistance and high impact resistance can be provided, and the transparency and refractive index of the optical material can be improved.

In addition, in this case, the content of sulfur (S) in the polymerizable composition can be controlled within a predetermined range, so that the refractive index of the optical material can be increased and mechanical properties can be improved.

In some embodiments, the sulfur content of the polymerizable composition may be greater than 24%, for example between 24% and 29%. The sulfur content of the polymerizable composition may be a percentage of the total weight of sulfur atoms included in the polymerizable composition divided by the total weight of the first polymerizable compound and the second polymerizable compound.

In one embodiment, the sulfur content of the polymerizable composition can be calculated by Equation 1 below.

[Equation 1]

((total weight of sulfur atoms included in second polymerizable compound)/(total weight of first polymerizable compound and second polymerizable compound)) ⅹ 100

For example, the sulfur content of the polymerizable composition can be calculated by Equation 2 below.

[Equation 2]

In Equation 2, S _T is the total sulfur content (wt%) included in the polymerizable composition, and _Ni is the number of sulfur atoms included in one molecule of component i of the second polymerizable compound.

The "i-component" may be a term encompassing and referring to the same kind of compounds among the second polymerizable compounds. For example, component 1 may mean 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol, and component 2 may mean pentaerythritol tetrakis (mercaptoacetate). have.

n may mean the number of heterogeneous compounds included in the second polymerizable compound. For example, when the second polymerizable compound contains only 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis(mercaptoacetate), n is 2 days. can

Mw _i is the molecular weight of component i of the second polymerizable compound. wt _i is the content of component i in the polymerizable compound, and may be, for example, a percentage obtained by dividing the weight of component i by the total weight of the first polymerizable compound and the second polymerizable compound.

When the sulfur content of the polymerizable composition is 24% or more, the optical material may have a high refractive index and the thickness of the lens may be reduced. When the sulfur content of the polymerizable composition is 29% or less, the impact resistance of the optical material may be improved and the mechanical properties may be improved.

Preferably, the sulfur content of the polymerizable composition may be 25% to 28%, more preferably 25% to 26%.

In one embodiment, the second polymerizable compound is 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetra In addition to kiss (mercaptoacetate), additional polythiol compounds may be included. Examples of polythiol compounds include 2-(2-mercaptoethylthio)propane-1,3-dithiol, 2,3-bis(2-mercaptoethylthio)propane-1-thiol, 2-(2, 3-bis(2-mercaptoethylthio)propylthio)ethanethiol, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 1,2-bis(2-(2-mercapto) Ethylthio)-3-mercaptopropylthio)-ethane, bis(2-(2-mercaptoethylthio)-3-mercaptopropyl)sulfide, 2-(2-mercaptoethylthio)-3-2 -Mercapto-3-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]propylthio-propane-1-thiol, 2,2'-thiodiethanethiol, 4,14-bis (Mercaptomethyl)-3,6,9,12,15-pentathiahexadecane-1,17-dithiol, 2-(2-mercaptoethylthio)-3-[4-(1-{4- [3-mercapto-2-(2-mercaptoethylthio)-propoxy]-phenyl}-1-methylethyl)-phenoxy]-propane-1-thiol, pentaerythritol tetrakis(3-mercapto propionate), trimethyolpropanetrismercaptopropionate, glyceroltrimercaptopropionate, dipentaepithritol hexamercaptopropionate or 2,5-bismercaptomethyl-1,4-dithio can be heard on the back.

In some embodiments, the content of the second polymerizable compound may be 30% to 70% by weight, preferably 40% to 60% by weight, based on the total weight of the polymerizable composition.

According to exemplary embodiments, the weight ratio of the first polymerizable compound and the second polymerizable compound may be 20:80 to 80:20, preferably 40:60 to 60:40. Reactivity and reaction rate may be appropriately controlled within the above range, and dimensional stability of the cured product may be improved. In addition, optical non-uniformity of the cured product may be prevented, and transparency of the optical material may be excellent.

In some embodiments, the polymerizable composition may have a (NCO)/(SH) equivalent ratio (molar ratio of functional groups) of 0.8 to 1.2, preferably 0.9 to 1.1. Unreacted compounds remaining after curing within the above range can be minimized. Accordingly, the cured product may have low hygroscopicity and a low coefficient of thermal expansion, and may have excellent heat resistance and strength by maintaining an appropriate cured density.

As described above, the polymerizable composition comprises a first polymerizable compound comprising isophorone diisocyanate and hexamethylene diisocyanate, and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and penta A second polymerizable compound including erythritol tetrakis (mercaptoacetate) may be included. Accordingly, the reactivity and reaction rate between the isocyanate compound and the polythiol compound can be appropriately controlled, and an optical material having a uniform refractive index can be manufactured by suppressing the stria phenomenon through a stable polymerization reaction.

In addition, by controlling the content and weight ratio of each of the first polymerizable compound and the second polymerizable compound within a predetermined range, an optical material prepared therefrom may have a high glass transition temperature (Tg) and excellent storage modulus. Accordingly, excellent reliability and dimensional stability can be secured even in a high-temperature process, and the optical material can be prevented from being deformed by heat or damaged by mechanical impact.

In some embodiments, the polymerizable composition may further include additives such as an internal mold release agent, a polymerization initiator, a heat stabilizer, a UV absorber, and/or a blueing agent, if necessary.

The internal release agent may be, for example, a fluorine-based nonionic surfactant having a perfluoroalkyl group, a hydroxyalkyl group or a phosphoric acid ester group; silicone-based nonionic surfactants having a dimethylpolysiloxane group, a hydroxyalkyl group or a phosphoric acid ester group; alkyl quaternary ammonium salts such as trimethylcetyl ammonium salt, trimethylstearyl, dimethylethylcetyl ammonium salt, triethyldodecyl ammonium salt, trioctylmethyl ammonium salt, and diethylcyclohexadodecyl ammonium salt; acidic phosphoric acid esters and the like. These may be used alone or in combination of two or more.

In some embodiments, the content of the internal release agent may be 500 ppm to 1,500 ppm, preferably 600 ppm to 1,000 ppm, based on the total weight of the polymerizable composition. Within the above range, the release of the optical material may be more easily performed, and the appearance characteristics of the optical lens may be excellent.

The polymerization initiator may be a catalyst used for polymerization of a polythiourethane-based resin. For example, dialkyl tin halide type catalysts, such as dibutyl tin dichloride and dimethyl tin dichloride; dialkyl tin dicarboxylate-based catalysts such as dimethyl tin diacetate, dibutyl tin dioctanoate, and dibutyl tin dilaurate; dialkyl tin dialkoxide catalysts such as dibutyltin dibutoxide and dioctyltin dibutoxide; dialkyltindithioalkoxide-based catalysts such as dibutyltindi(thiobutoxide); dialkyl tin oxide catalysts such as di(2-ethylhexyl)tin oxide, dioctyltin oxide, and bis(butoxydibutyltin)oxide; A dialkyl tin sulfide-based catalyst or the like can be used. These may be used alone or in combination of two or more.

In some embodiments, the amount of the polymerization initiator may be 500 ppm to 3,000 ppm, preferably 1,000 ppm to 2,500 ppm, based on the total weight of the polymerizable composition. Within the above range, the polymerization reactivity and reaction rate of the polymerizable composition may be appropriately controlled, and the stability over time of the polymerizable composition may be excellent.

For example, dialkyl tin halide-based catalysts perform the role of a positive catalyst when reacting with 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol, and pentaerythritol tetrakis (mercaptoacetate ) and can act as a co-catalyst when reacting with Therefore, when the content of the polymerization initiator is within the above range, the reactivity of pentaerythritol tetrakis (mercaptoacetate) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol is controlled in a balanced manner. It can be.

The heat stabilizer may include, for example, metal fatty acid-based, phosphorus-based, lead-based, organotin-based compounds, and the like. These may be used alone or in combination of two or more.

The UV absorber may include, for example, benzophenone-based, benzotriazole-based, salicylate-based, cyanoacrylate-based, oxanilide-based compounds, and the like. These may be used alone or in combination of two or more.

The bluing agent may be included as a color control agent for an optical material prepared from the polythiourethane resin. For example, the bluing agent may have an absorption band in a wavelength band from orange to yellow in the visible light region.

The bluing agent may include, for example, a dye, a fluorescent brightening agent, a fluorescent pigment, an inorganic pigment, and the like, and may be selected according to physical properties or resin color required for an optical product to be manufactured. When a dye is used as the bluing agent, for example, a dye having a maximum absorption wavelength of 520 nm to 600 nm, preferably 540 nm to 580 nm, may be used. Preferably, an anthraquinone-based dye may be used.

In some embodiments, the additives may be included in an amount of 0.01% to 5% by weight of the total weight of the polymerizable composition.

<Optical Materials>

According to exemplary embodiments, an optical material manufactured through the above-described polymerizable composition may be provided. For example, the optical material may include a cured product obtained by curing the above-described polymerizable composition. For example, it may include a polythiourethane resin produced through a polymerization reaction of the first polymerizable compound and the second polymerizable compound included in the polymerizable composition.

For example, the polymerizable composition may be degassed under reduced pressure, filtered, and injected into a mold for forming an optical material. Mold injection may be performed at a temperature range of, for example, 10 °C to 40 °C.

After injection into the mold, the temperature may be gradually raised to allow the polymerization reaction to proceed. The temperature of the polymerization reaction may be, for example, 5 °C to 200 °C, preferably 10 °C to 150 °C, and more preferably 25 °C to 125 °C.

For example, the maximum polymerization temperature may be 100 °C to 150 °C, preferably 110 °C to 140 °C, more preferably 115 °C to 130 °C.

The heating rate may be 1 °C/min to 10 °C/min, preferably 3 °C/min to 8 °C/min, and more preferably 4 °C/min to 7 °C/min. The polymerization time may be 10 to 20 hours, preferably 15 to 20 hours.

The reaction rate is appropriately controlled within the above temperature range, so that a lens having uniform optical and mechanical properties can be easily obtained.

After completion of polymerization, an optical material may be obtained by separating the polymerized polythiourethane resin from the mold.

In one embodiment, a curing process may be further performed after separating or releasing the optical material from the mold. The temperature of the curing process may be 110 °C to 150 °C, preferably 110 °C to 140 °C, more preferably 115 °C to 130 °C. The curing process may be performed for 0.5 hour to 10 hours, preferably 1 hour to 8 hours, and more preferably 2 hours to 6 hours.

In some embodiments, the optical material may be an optical lens, specifically a plastic optical lens. The optical material may be manufactured in the form of a spectacle lens, a camera lens, a light emitting diode, or the like according to a mold shape used in manufacturing the optical material, and the center thickness and diameter may be variously adjusted as necessary.

The optical lens has antireflection, hardness enhancement, abrasion resistance improvement, chemical resistance improvement, anti-fogging, surface polishing for color impartation, antistatic treatment, hard coat treatment, anti-reflection coat treatment, and dyeing treatment as needed. surface treatment, etc., can be performed.

As described above, the polymerizable composition comprises a first polymerizable compound comprising isophorone diisocyanate and hexamethylene diisocyanate, and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and penta A second polymerizable compound including erythritol tetrakis (mercaptoacetate) may be included. Accordingly, mechanical/structural stability of the polythiourethane resin prepared from the polymerizable composition may be secured, and optical properties may be excellent.

For example, by adjusting the type and/or content ratio of each of the first polymerizable compound and the second polymerizable compound within the above-described range, an optical material having improved refractive index, heat resistance, and impact resistance may be provided.

In some embodiments, the solid state refractive index (nd20) of the optical material may be 1.59 to 1.61. For example, the solid state refractive index of an optical material can be measured using an Abbe refractometer at a temperature of 20°C. Preferably, the solid-state refractive index of the optical material at 20° C. may be 1.59 to 1.60, more preferably 1.595 to 1.599. Since the optical material has a high refractive index within the above range, for example, the thickness of the optical lens may be reduced, and light dispersion and chromatic aberration may be low.

In some embodiments, a glass transition temperature (Tg) of the optical material may be 105°C to 120°C. For example, the glass transition temperature can be measured with respect to an optical material at a heating rate of 10°C/min. When the glass transition temperature (Tg) of the optical material satisfies the above range, reliability can be excellent even in high-temperature processes such as hard coating and dyeing, and deterioration of optical properties due to deformation of the lens can be prevented even under high-temperature use conditions. have.

Preferably, the glass transition temperature of the optical material may be 105 °C to 113 °C, more preferably 105 °C to 110 °C. Moldability and processability may be improved while maintaining excellent thermal stability of the optical material within the above range.

In some embodiments, the storage modulus of the optical material may be 3.0 GPa to 4.0 GPa, preferably 3.5 GPa to 4.0 GPa. For example, the storage modulus can be measured by a 3-point bending method (heating rate 2°C/min) using a thermomechanical analyzer (TMA) for optical materials at room temperature (25°C). When the storage modulus of the optical material satisfies the above range at room temperature, deformation may be small, dimensional stability may be high, and viscoelasticity and durability may be excellent.

In some embodiments, a thermal expansion coefficient (CTE) of the optical material may be 78 μm/m·° C. or less. For example, the thermal expansion coefficient of the optical material may be 70 μm/m·°C to 78 μm/m·°C, preferably 74 μm/m·°C to 78 μm/m·°C. The thermal expansion coefficient can be measured with a load of 50 g and a heating rate of 10° C./min using a thermomechanical analyzer (TMA). Specifically, it can be measured using the penetration method according to the conditions of a 50g load, a pin wire of 0.5mmφ, and a heating rate of 10°C/min.

Within the above range, the optical material may have excellent heat resistance, and deformation or distortion of the optical material due to high temperature may be prevented. Accordingly, damage to the cured product can be minimized even in a high-temperature process, and the optical material can have excellent dimensional stability.

In some embodiments, the optical material may have a transmittance of 80% or more, preferably 90% or more, for light having a wavelength of 550 nm. For example, the transmittance may be measured by transmitting light having a wavelength of 550 nm in a thickness direction with respect to an optical material having a thickness of 2 mm.

Hereinafter, embodiments provided in the present application will be additionally described with reference to specific experimental examples. The examples and comparative examples included in the experimental examples are merely illustrative of the present invention, but do not limit the scope of the appended claims, and various changes and modifications to the examples are possible within the scope and spirit of the present invention. It is obvious to those skilled in the art, and it goes without saying that these variations and modifications fall within the scope of the appended claims.

Examples and Comparative Examples

(1) Example 1

Preparation of polymerizable composition

42.57 parts by weight of isophorone diisocyanate and 10.74 parts by weight of hexamethylene diisocyanate were added as the first polymerizable compound, and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol as the second polymerizable compound 37.69 parts by weight and 9.00 parts by weight of pentaerythritol tetrakis (mercaptoacetate) were added and then mixed uniformly. Thereafter, 0.2 parts by weight of dimethyl tin dichloride as a polymerization initiator and 0.07 parts by weight of a phosphate ester internal release agent from ZELEC® UN Stepan as an internal release agent were added and mixed uniformly to prepare a polymerizable composition.

Manufacture of optical materials

The polymerizable composition was subjected to a defoaming process at 600 Pa for 1 hour. Thereafter, the polymerizable composition filtered through a 3 μm Teflon filter was injected into a mold including a glass mold and a tape. Polymerization was performed by slowly raising the temperature of the mold from 10° C. to 130° C. for 24 hours at a constant rate. After the polymerization was completed, the mold was separated, and additionally cured at 130° C. for 2 hours to prepare a lens sample in a circular shape with a thickness of 2 mm and a diameter of 75 mm (−3.00D).

(2) Examples 2 to 9, Comparative Examples 1 and 2

Lens samples were prepared in the same manner as in Example 1, except that the compositions and contents of the first polymerizable compound, the second polymerizable compound, and additives were added as shown in Table 1 below.

division
(parts by weight) First polymerizable compound
(A) Second polymerizable compound
(B) polymerization initiator
(C) internal release agent
(D) Furtherance weight ratio Furtherance weight ratio Example 1 42.57 (A-1) 3.96 37.69 (B-1) 4.19 0.2
(C-1) 0.07 10.74 (A-2) One 9.00 (B-2) One Example 2 47.59 (A-1) 7.49 37.18 (B-1) 4.19 0.2
(C-1) 0.07 6.35(A-2) One 8.88 (B-2) One Example 3 40.26 (A-1) 3.08 39.99 (B-1) 5.98 0.2
(C-1) 0.07 13.06 (A-2) One 6.69 (B-2) One Example 4 34.34 (A-1) 1.98 39.61 (B-1) 4.54 0.2
(C-1) 0.07 17.32 (A-2) One 8.73 (B-2) One Example 5 36.66 (A-1) 2.45 40.26 (B-1) 4.95 0.2
(C-1) 0.07 14.94 (A-2) One 8.14 (B-2) One Example 6 39.34 (A-1) 3.08 41.04 (B-1) 5.98 0.2
(C-1) 0.07 12.76 (A-2) One 6.86 (B-2) One Example 7 44.75 (A-1) 5.29 34.96 (B-1) 2.96 0.2
(C-1) 0.07 8.46 (A-2) One 11.83 (B-2) One Example 8 45.59 (A-1) 5.29 40.96 (B-1) 8.50 0.2
(C-1) 0.07 8.62 (A-2) One 4.82 (B-2) One Example 9 50.05 (A-1) 4.21 36.9 (B-1) 4.18 0.2
(C-1) 0.07 4.21 (A-2) One 8.82 (B-2) One Comparative Example 1 50.4 (A-3) - 25.5 (B-1) 1.07 0.2
(C-2) 0.1 23.9 (B-3) One Comparative Example 2 48.5 (A-4) - 26.5 (B-4) 0.98 0.2
(C-2) 0.1 27.0 (B-2) One

The specific component names described in Table 1 are as follows.

First polymerizable compound (A)

1) A-1: Isophorone diisocyanate

2) A-2: Hexamethylene diisocyanate

3) A-3: Norborane diisocyanate

4) A-4: 1,3-bis (isocyanatomethyl) cyclohexane (1,3-bis (isocyanatomethyl) cyclohexane)

Second polymerizable compound (B)

1) B-1: 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane)

2) B-2: Pentaerythritol tetrakis (mercaptoacetate)

3) B-3: Pentaerythritol tetrakis (mercaptopropionate)

4) B-4: 2,5-bis (mercaptomethyl) -1,4-dithiane (2,5-bis (mercaptomethyl) -1,4-dithiane)

Polymerization initiator (C)

1) C-1: dimethyl tin dichloride

2) C-2: dibutyl tin dichloride

Internal release agent (D)

Phosphate ester internal release agent (ZELEC® UN Stepan)

Experimental example

(1) Measurement of sulfur content

The sulfur content of the polymerizable composition according to Examples and Comparative Examples was calculated as a percentage of the total weight of sulfur atoms in the total weight of the polymerizable compound.

Specifically, the sulfur content of the polymerizable composition according to the Examples was calculated by Equation 3 below.

[Equation 3]

Sulfur content (%) = ((B-1 parts by weight × 0.6154) + (B-2 parts by weight × 0.2872)) / (A parts by weight + B parts by weight) × 100

Sulfur content of the polymerizable compositions according to Comparative Example 1 and Comparative Example 2 was calculated using Equations 4 and 5, respectively.

[Equation 4]

Sulfur content (%) = ((B-1 parts by weight × 0.6154) + (B-3 parts by weight × 0.2625)) / (A parts by weight + B parts by weight) × 100

[Equation 5]

Sulfur content (%) = ((B-4 parts by weight × 0.6038) + (B-2 parts by weight × 0.2872)) / (A parts by weight + B parts by weight) × 100

(2) Solid state refractive index measurement

The solid state refractive index (nd20) of the lens samples of Examples and Comparative Examples was measured at 20° C. using an Abbe refractometer (DR-M4).

(3) Measurement of Yellow Index (Y.I.)

Lens samples of Examples and Comparative Examples were prepared in the form of a plastic cylinder (r (radius) x H (height) = 16 mm x 45 mm), and UV / VIS Spectroscopy (PerkinElmer, UV / VIS Lambda 365) in accordance with ASTM E313 standard The yellow index (YI) was measured by transmitting light in the height direction of the plastic cylinder using a .

(4) transmittance measurement

For the lens samples of Examples and Comparative Examples, UV/VIS Spectroscopy (PerkinElmer, UV/VIS Lambda 365) was used to transmit light having a wavelength of 550 nm in a thickness direction and transmittance was measured.

(5) Measurement of glass transition temperature (Tg)

Glass transition temperatures (Tg) of the lens samples of Examples and Comparative Examples were measured in the range of 20 °C to 250 °C at a heating rate of 10 °C/min using DSC (DSC250, TA Instruments Co.).

(6) Measurement of storage modulus (E')

Storage modulus (E ') was measured.

(7) Coefficient of thermal expansion (CTE) measurement

For the lens samples of Examples and Comparative Examples, a thermomechanical analyzer (TMA Q400, TA Instruments) was used for glass transition of each lens sample by the penetration method (50g load, pin line 0.5mmφ, heating rate 10°C/min). The coefficient of thermal expansion before the temperature (Tg) was measured.

(8) Heat crack measurement

After coating the silicone-based hard coating solution on the lens samples of Examples and Comparative Examples, samples were prepared by heating at 100 ° C to 120 ° C for 30 minutes to 120 minutes. After this, the sample was cooled to 20 °C and then heated again. Specifically, every time the temperature rises by 5°C from 20°C, it was heated for 10 minutes and cooled for 30 minutes. Heat-resistant cracks were evaluated by measuring the temperature at which cracks were first observed on the surface while repeatedly heating and cooling to 200 °C.

(9) Measurement of impact resistance (drop-ball test)

Impact resistance was evaluated according to US FDA standards (ANSI Z80.1-410.FDA. Sec 801-410) for the lens samples of Examples and Comparative Examples. Specifically, a 16g steel ball was dropped from a height of 127 cm with respect to the lens samples to observe whether or not the lens samples were cracked or cracked. The evaluation criteria are as follows.

<Evaluation Criteria>

○: Cracks, cracks not observed

×: Cracks, cracks observed

(10) Measurement of static load characteristics

With respect to the lens samples of Examples and Comparative Examples, a static load was applied for 100 N/10 sec according to the ISO 14889:2003 test method to measure whether or not the lens samples were damaged. The evaluation criteria are as follows.

○: no damage observed

×: breakage observed

(11) Assessment of striae

With respect to the lens samples of Examples and Comparative Examples, a mercury lamp light source was transmitted through the prepared lens sample, and the transmitted light was projected onto a white plate to determine whether or not striae occurred based on the presence or absence of contrast. The evaluation criteria are as follows.

<Evaluation Criteria>

A: Striae not observed

B: Observation of stria after 30 mm from the center of the lens sample

C: Observation of stria within 30 mm from the center of the lens sample

(12) Evaluation of whether or not cloudiness occurs

With respect to the lens samples of Examples and Comparative Examples, the sides of the samples were illuminated with a mercury lamp light source, and the occurrence of cloudiness was visually confirmed through light scattered on the surface of the samples. The evaluation criteria are as follows.

<Evaluation Criteria>

A: Cloudiness not observed

B: Observation of cloudiness after 30 mm from the center of the lens sample

C: Observation of clouding within 30 mm from the center of the lens sample

division Example 1 Example 2 Example 3 Example 4 Example 5 Sulfur content (%) 25.78 25.43 26.53 26.88 27.11 refractive index 1.5959 1.5938 1.5994 1.6038 1.5998 Color Index (Y.I) 1.0 1.0 0.9 0.9 1.0 Transmittance (%) 90 90 90 90 90 Glass transition temperature (℃) 105 107 111 106 112 Storage modulus (GPa) 3.8 3.9 3.5 3.7 3.4 Coefficient of thermal expansion (㎛/m ℃) 78 74 75 74 76 Heat resistance crack (℃) 130 130 120 130 120 impact resistance ○ ○ ○ ○ ○ static load characteristics ○ ○ ○ ○ ○ stria evaluation A A A C A cloudiness evaluation A A B A B

division Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Sulfur content (%) 27.23 24.91 26.59 25.25 22.01 23.29 refractive index 1.6003 1.5906 1.5961 1.592 1.5987 1.5986 Color Index (Y.I) 0.9 0.8 0.9 0.8 1.1 0.8 Transmittance (%) 90 90 90 90 90 90 Glass transition temperature (℃) 113 118 124 125 114 118 Storage modulus (GPa) 3.4 3.8 3.5 3.9 3.0 3.2 Coefficient of thermal expansion (㎛/m ℃) 75 70 79 77 79 64 Heat resistance crack (℃) 120 120 110 110 110 110 impact resistance ○ ○ ○ × ○ ○ static load characteristics ○ ○ ○ × ○ ○ stria evaluation B B C C A B cloudiness evaluation B B A A A A

Referring to Tables 2 and 3, when using the polymerizable composition according to the exemplary embodiments, an optical lens having excellent optical properties such as refractive index and transmittance and excellent thermal stability and mechanical properties was provided.

It can be seen that the optical lenses according to Comparative Examples have low storage modulus and deteriorated heat crack resistance. Accordingly, when the polymerizable composition does not include the first polymerizable compound and the second polymerizable compound described above as polymerizable compounds, it can be confirmed that mechanical properties and thermal stability of the optical lens are deteriorated.

Claims (14)

a first polymerizable compound comprising isophorone diisocyanate and hexamethylene diisocyanate; and
A polymerizable composition comprising a second polymerizable compound comprising 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis(mercaptoacetate).
The method according to claim 1, of the total 100 parts by weight of the first polymerizable compound and the second polymerizable compound,
The content of the isophorone diisocyanate is 30 parts by weight to 55 parts by weight, the content of the hexamethylene diisocyanate is 5 parts by weight to 20 parts by weight, the polymerizable composition.
The method according to claim 1, of the total 100 parts by weight of the first polymerizable compound and the second polymerizable compound,
The content of 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol is 30 parts by weight to 45 parts by weight, and the content of pentaerythritol tetrakis (mercaptoacetate) is 5 parts by weight. to 20 parts by weight, a polymerizable composition.
The method according to claim 1, wherein the weight ratio of the 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol to the pentaerythritol tetrakis (mercaptoacetate) is 1 to 6, the polymerizable composition .
The polymerizable composition according to claim 1, wherein a weight ratio of isophorone diisocyanate to hexamethylene diisocyanate is 1 to 9.
The method according to claim 1, wherein the sulfur content represented by the following formula 1 is 24% or more, the polymerizable composition:
[Equation 1]
((total weight of sulfur atoms contained in the second polymerizable compound)/(total weight of the first polymerizable compound and the second polymerizable compound)) ⅹ 100.
The polymerizable composition according to claim 1, further comprising at least one selected from the group consisting of an internal release agent, a polymerization initiator, a heat stabilizer, an ultraviolet absorber and a bluing agent.
The method according to claim 7, wherein the content of the polymerization initiator is 500ppm to 3,000ppm of the total weight of the polymerizable composition, the polymerizable composition.
The polymerizable composition according to claim 7, wherein the content of the internal release agent is 500 ppm to 1,500 ppm based on the total weight of the polymerizable composition.
An optical material comprising a polythiourethane resin prepared from the polymerizable composition of claim 1.
The optical material according to claim 10, wherein the solid state refractive index (nd20) at 20°C is 1.59 to 1.61.
The optical material according to claim 10 , wherein the glass transition temperature (Tg) is 105° C. to 120° C.
The optical material according to claim 10, wherein the coefficient of thermal expansion (CTE) measured at a heating rate of 10 °C/min using a thermomechanical analyzer (TMA) is 78 μm/m °C or less.
The optical material according to claim 10 , wherein the storage modulus at 25° C. is 3.0 GPa to 4.0 GPa.