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 novel methods for preparing a polythiol compound for use in an optical material and polymerizable compositions including a polythiol compound prepared by the methods. According to the methods, a polythiol compound with uniform color, high purity and high quality can be prepared at reduced cost. The polymerizable compositions can be used to manufacture clear, transparent optical lenses with good heat resistance and excellent optical properties.

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: 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: 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.