Abstract: In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of higher quality, in which the reaction temperature of a diamine hydrochloride composition and triphosgene is controlled to a specific range, or a crude diisocyanate composition obtained from the reaction of a diamine hydrochloride composition and triphosgene is distilled at a specific temperature range, or the molar ratio of a diamine hydrochloride and triphosgene is adjusted to a specific range.

Abstract: One embodiment relates to a polymerizable composition and an optical material produced therefrom which has excellent lightfastness and minimized color defects, and more specifically, the polymerizable composition according to one embodiment includes UV absorbers having, as the main absorption wavelength, either a long-wavelength region or a short-Wavelength region Within the UV region, wherein the UV absorbers do not absorb in the Visible light region. Accordingly, the polymerizable composition may be used to provide an optical material having excellent lightfastness and minimized color defects.

Abstract: In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of higher quality by controlling the water content in the diamine hydrochloride composition for preparing a diisocyanate within a specific range.

Abstract: A polythiol composition according to exemplary embodiments includes: a polythiol-based compound; and a benzyl halide-based reaction regulator in an amount of 10 ppm to 2,000 ppm based on a weight of the polythiol-based compound. The reaction rate of the polythiol-based compound and an isocyanate-based compound may be controlled through the reaction regulator to inhibit a generation of stria phenomenon.

Abstract: A polythiol composition according to exemplary embodiments includes a first polythiol compound which provides a maximum peak in a high performance liquid chromatography (HPLC) analysis graph obtained at a wavelength of 230 nm, and a second polythiol compound having a molecular weight greater than that of the first polythiol compound and represented by C9H20S6. A ratio of a peak area of the second polythiol compound to a peak area of the first polythiol compound, which are measured through the HPLC analysis graph at the wavelength of 230 nm, is 0.05 to 5.0%.

Abstract: A xylylene diisocyanate composition according to exemplary embodiments includes xylylene diisocyanate (XDI) and chloromethylbenzyl isocyanate (CBI), and may satisfy a predetermined relationship between an acidity and a content of CBI. Thereby, an optical lens having a high transmittance and improved optical uniformity can be manufactured by controlling a polymerization reaction rate.

Abstract: A polythiol composition according to exemplary embodiments includes a main polythiol compound and a sub-compound having a molecular weight higher than that of the main polythiol compound. A peak area (%) at retention times ranging from 34 to 40 minutes in the high performance liquid chromatography (HPLC) analysis graph obtained at a wavelength of 230 nm, which corresponds to the sub-compound, is 2.5% or less. An optical product having improved transmittance and optical properties may be manufactured through fine adjustment of the sub-compound.

Abstract: The diamine composition according to an embodiment of the present invention comprises a benzylmonoamine having a methyl group in an amount of 10 ppm to 2,000 ppm in the composition. When it is used for the preparation of a diisocyanate composition and an optical material, it is possible to improve the optical characteristics by preventing the occurrence of yellowing, striae, and cloudiness in the optical material and enhancing the mechanical properties such as impact resistance at the same time. In addition, in the process for preparing a diisocyanate composition according to another embodiment, the b* value according to the CIE color coordinate of a diamine composition is adjusted to a specific range, whereby it is possible to enhance not only the yield and purity of the diisocyanate composition but also the optical characteristics of the final optical lens. Thus, the process for preparing a diisocyanate composition can be applied to the preparation of a plastic optical lens of high quality.

Abstract: A polythiol composition according to exemplary embodiments includes at least two different polythiol-based compounds, wherein a peak area (%) of the polythiol compound represented by C8H18S6, which is measured through a high performance liquid chromatographic (HPLC) analysis graph obtained at a wavelength of 230 nm, ranges from 0.90% to 1.30%. By controlling the sub-polythiol compound, an optical product having excellent transmittance and optical properties can be manufactured.

Abstract: A polythiol composition according to exemplary examples includes a tetrafunctional polythiol compound, and a sub-polythiol compound including a compound represented by C13H28S9 and a compound represented by C15H32S10. A ratio of the sub-polythiol compound measured through a high performance liquid chromatography (HPLC) analysis graph is 1% to 5%. By adjusting the content of the sub-polythiol compound, it is possible to manufacture an optical product having excellent transmittance and optical properties.

Abstract: An embodiment relates to a polymeric composition for a polythiourethane-based optical material, wherein the polymeric composition, comprising a particular additive, may appropriately adjust the reactivity of an isocyanate such that viscosity is maintained low for a predetermined period of time, and thus is capable of preparing a high-quality polythiourethane-based optical material, without a complicated purification process. Moreover, a polythiourethane-based optical material according to an embodiment has not only a uniform refractive index, but also a low yellow index, and thus may be used as a variety of plastic optical lenses, such as an eyeglass lens or a camera lens and the like.

Abstract: A diamine composition comprising a benzylmonoamine having a methyl group in an amount of 10 ppm to 2,000 ppm in the composition and use thereof for the preparation of a diisocyanate composition and an optical material. A process for preparing a diisocyanate composition wherein the b* value according to the CIE color coordinate of the diamine composition is adjusted to a specific range, whereby the yield and purity of the diisocyanate composition and the optical characteristics of the final optical lens are enhanced. Use of the process for the diisocyanate composition for preparing a plastic optical lens of high quality.

Abstract: In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of high quality in which the content of water, the content of cations, or the content of an aromatic compound containing 3 or more of chlorine (Cl) in the organic solvent used in the reaction of a diamine hydrochloride composition and triphosgene is adjusted to a specific range.

Abstract: According to an embodiment, the pH of a diisocyanate composition and a diamine hydrochloride composition used in the preparation of an optical lens is adjusted to a specific range, whereby it is possible to enhance not only the yield and purity of the diisocyanate composition but also the optical characteristics of the final optical lens by suppressing the striae and cloudiness. Specifically, according to the process of the embodiment, the amount of an aqueous hydrochloric acid solution introduced to the reaction may be adjusted to control the pH of the diisocyanate composition to a desired range, thereby enhancing the yield and purity. Accordingly, the process for preparing a diisocyanate composition according to the embodiment can be applied to the preparation of a plastic optical lens of high quality.

Abstract: An embodiment relates to an isocyanate composition with improved stability and reactivity and a plastic optical lens using the same. The isocyanate composition has improved stability since the content of chlorine in the composition is adjusted to 22-500 ppm, and thus the isocyanate composition can prevent the deterioration in reactivity even in the long-term storage. Therefore, the isocyanate composition according to an example, even when used after long-term storage after preparation, can be prepared, through polymerization with a thiol-based compound, as a polythiourethane-based optical material with excellent physical properties, such as refractive index, Abbe number, transparency, glass transition temperature, and yellowness, and thus the isocyanate composition is useful in fields of glass lenses, a camera lens, and the like.

Abstract: The embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by using a solid triphosgene composition instead of phosgene gas in the process of preparing a diisocyanate from a diamine through a hydrochloride thereof and by controlling the content of a decomposition product in a triphosgene composition, the b* value according to CIE color coordinate of the triphosgene composition in an organic solvent, or the content of water in the triphosgene.

Abstract: The xylylene diisocyanate composition according to exemplary examples includes xylylene diisocyanate (XDI), and an acidity adjusting agent having a boiling point of 110° C. or higher, wherein the composition has an acidity of more than 100 ppm and 1,000 ppm or less based on a total weight of xylylene diisocyanate (XDI). A polymerization reaction rate is controlled through regulation of the acidity so that an optical lens having high transmittance and improved optical uniformity may be manufactured.

Abstract: The embodiments relate to a process for preparing a polythiol composition, which comprises reacting a halogen compound or an alcohol compound with thiourea to prepare a thiouronium salt solution; and adding a basic solution to the thiouronium salt solution to hydrolyze it. The hydrolysis reaction is terminated when the area of peak A in the graph measured by gel permeation chromatography of the reactant in the hydrolysis step under certain conditions is 0.5% to 8% based on the total peak area. A tetrafunctional polythiol composition having high purity can be obtained. Thus, an optical lens having excellent color, transparency, and refractive index can be obtained.

Abstract: Embodiments relate to a polythiourethane-based plastic lens. When a polythiourethane-based plastic lens is polymerized according to the embodiment, the types, contents, and the like of the polythiol compounds and the isocyanate compounds are adjusted to control the storage moduli at room temperature and high temperatures, their variations, the energy attenuation (KEL) obtained therefrom, and the glass transition temperature, whereby the polythiourethane-based plastic lens thus obtained is enhanced in impact resistance and thermal resistance.

Abstract: A polymerizable composition according to an embodiment includes 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). An optical material which is fabricated from the polymerizable composition and has improved optical, mechanical and thermal properties is provided.