Abstract: Disclosed is a method of producing a high-quality thiourethane-based optical material using a general-purpose polyisocyanate compound. According to the method, the pH of a polythiol compound is adjusted to 3.1 to 7 to prevent the occurrence of whitening, which is a problem of the prior art arising from the dissolution of a pressure-sensitive adhesive from a pressure-sensitive adhesive tape upon lens casting. The pH adjustment increases the reaction rate of a resin composition including the polythiol compound. The use of the polythiol compound whose pH is adjusted enables the production of a thiourethane-based optical material that does not suffer from whitening at the edges of the optical lens and nonuniformity polymerization. Further disclosed are a resin composition for a thiourethane-based optical material, and an optical material including a resin produced by the method.

Abstract: Disclosed is a method of storing a thioepoxy compound and a method of preparing a thioepoxy based optical material using the thioepoxy compound. Particularly, a method of preparing a high-quality thioepoxy based optical material having superior color and thermal stability and less time-dependent change, and being colorless and transparent by inhibiting time-dependent change of the thioepoxy compound during storage is disclosed. In addition, a method of storing the thioepoxy compound for an optical material, the thioepoxy compound having a water content of 500 to 2,500 ppm and stored at ?78 to 10° C., and a method of preparing the thioepoxy based optical material, the method including polymerizing a polymerizable composition including the stored thioepoxy compound, are provided. The high-quality thioepoxy based optical material, which is colorless and transparent, prepared according to the present invention may be broadly used in a variety of fields as a substitute for conventional optical materials.

Abstract: The present invention relates to a thioepoxy compound for an optical material, a polymerizable composition including the thioepoxy compound, and a method for producing a thioepoxy optical material by polymerization of the polymerizable composition. The polymerizable composition further includes 4.1 to 15% by weight of 2,3-epoxypropyl(2,3-epithiopropyl)sulfide and/or 2,3-epoxypropyl(2,3-epithiopropyl)disulfide. The thioepoxy optical material is free from color instability, demolding, and polymerization imbalance, which are problems encountered in general thioepoxy optical materials.

Abstract: Disclosed is a method of preparing a thiourethane based optical material In particular, a method of preparing a high-quality optical material, which is colorless and transparent and is not deformed, at a high yield without generation of striae, whitening, and microbubbles is disclosed. A method of preparing the thiourethane based optical material according to present invention is characterized in that, before cast polymerization, a polymerizable composition including a polythiol compound and a polyisocyanate compound is treated at a specific vacuum condition and then injected into a mold. A thiourethane based optical material prepared according to the present invention may be widely used in a variety of fields as a substitute of conventional optical materials.

Abstract: A method of preparing an optical material by polymerizing a resin composition including a thiol group-containing compound and an isocyanate group-containing compound, particularly, a method of preparing a high-quality urethane-based optical material using a universal polyisocyanate compound. According to one aspect, a resin composition including a polythiol compound and a widely available polyisocyanate compound, as main components, and having a moisture content of 300 to 3,000 ppm is template-polymerized to prepare the optical material. A colorless, transparent, and high-quality urethane-based optical material may be efficiently prepared in high yield using a low-cost and widely available isocyanate compound through template-polymerization using a tape while minimizing generation of white tape residues and foaming.

Abstract: An optical resin composition with superior impact resistance and a method for producing an optical lens from the composition are disclosed. In one embodiment, the optical resin composition for a plastic optical lens has superior impact resistance as well as light-weight, superior moldability, excellent dyeing ability, a high Abbe number and good transparency. The optical lens produced from the composition exhibits superior impact resistance even after multi-coating. The optical resin composition with superior impact resistance has a solid refractive index (nD) of about 1.53 to about 1.57, an Abbe number of about 35 to about 48, a liquid specific gravity of about 0.97 to about 1.25 and a solid specific gravity of about 1.10 to about 1.35, by which the composition comprises a mixture of isophorone diisocyanate and hexamethylene diisocyanate, pentaerythritol tetrakis(3-mercaptopropionate), a UV absorber, a release agent and a polymerization initiator.