Abstract: The present invention provides a polythiol composition containing, as the main component, a polythiol compound (a) having two or more mercapto groups, and containing 0.5% by mass or less of a nitrogen-containing compound (b) in which at least one mercapto group in the polythiol compound (a) is substituted with a group represented by formula (1).

Abstract: According to one preferred embodiment of the present invention, a composition for optical materials, which contains a compound represented by formula (1) and a compound represented by formula (2), is able to be provided. This composition for optical materials enables stable storage of a compound represented by formula (2) at low cost, and also enables stable storage thereof with respect to temperature change. In addition, this composition for optical materials enables the achievement of an optical material which has good light resistance. (In formula (1), in represents an integer of 0-4; and n represents an integer of 0-2.) (In formula (2), m represents an integer of 0-4; and n represents an integer of 0-2.

Abstract: According to one preferred embodiment of the present invention, a composition for optical materials, which contains a compound represented by formula (1) and a compound represented by formula (2), is able to be provided. This composition for optical materials enables stable storage of a compound represented by formula (2) at low cost, and also enables stable storage thereof with respect to temperature change. In addition, this composition for optical materials enables the achievement of an optical material which has good light resistance. (In formula (1), in represents an integer of 0-4; and n represents an integer of 0-2.) (In formula (2), m represents an integer of 0-4; and n represents an integer of 0-2.

Abstract: According to the present invention, a polythiol compound having a total nitrogen content of 50 to 600 ppm inclusive can be provided. According to the present invention, a method for producing the polythiol compound can also be provided, said method being characterized by comprising the steps of: reacting a polyalcohol with thiourea to prepare a thiuronium salt; and adding at least one base selected from the group consisting of hydrazine (hydrate), ammonia and an amine and an inorganic base (that is different from hydrazine (hydrate) or ammonia) to the thiuronium salt in the presence of an organic solvent to hydrolyze the thiuronium salt.

Abstract: According to the present invention, it is possible to provide an optical material composition that contains an episulfide compound represented by formula (1) and an episulfide compound represented by formula (2). According to this optical material composition, it is possible to suppress a reduction in the yield rate caused by molding defects, and possible to obtain an optical material having excellent dyeability. (In formula (1), m and p are each an integer between 0 and 4, and n and q are each an integer between 0 and 2.) (In formula (2), m is an integer between 0 and 4 and n is an integer between 0 and 2).

Abstract: The present invention provides a polythiol composition containing, as the main component, a polythiol compound (a) having two or more mercapto groups, and containing 0.5% by mass or less of a nitrogen-containing compound (b) in which at least one mercapto group in the polythiol compound (a) is substituted with a group represented by formula (1).

Abstract: According to the present invention, it is possible to provide an optical material composition that contains an episulfide compound represented by formula (1) and an episulfide compound represented by formula (2). According to this optical material composition, it is possible to suppress a reduction in the yield rate caused by molding defects, and possible to obtain an optical material having excellent dyeability. (In formula (1), m and p are each an integer between 0 and 4, and n and q are each an integer between 0 and 2.) (In formula (2), m is an integer between 0 and 4 and n is an integer between 0 and 2.

Abstract: Through an optical material composition containing a compound (a), a compound (b), a polythiol (c) and sulfur (d) according to the present invention, good mold release properties are obtained, and the occurrence of separation mark defects can be suppressed. Compound (a): a compound having the structure represented by formula (1): (In formula (1), m is an integer of 0 to 4 and n is an integer of 0 to 2.) Compound (b): a compound having the structure represented by formula (2): (In formula (2), m is an integer of 0 to 4 and n is an integer of 0 to 2.

Abstract: According to the present invention, it is possible to provide a thiol compound represented by formula (1): wherein R1 is CH2SCH2CH2SH, and R2 is hydrogen. In addition, according to the present invention, it is possible to provide a mixture of the thiol compound and 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, wherein the ratio of the thiol compound is 0.001 to 5.0% by mass.

Abstract: By using a method for producing a composition for an optical material using (a) sulfur, (b) a compound having two intramolecular episulfide groups, (c) a compound having one or more (preferably two) SH groups, and (d) an amine compound having a specific structure, in which compound (a) and compound (c) are pre-polymerized in the presence of compound (b) using compound (d) as the pre-polymerization catalyst, the present invention provides a polymerizable composition for an optical material in which the viscosity elevation speed during pre-polymerization is slow and the reaction temperature is approximately room temperature, and that has a low viscosity and shows little increase in viscosity.

Abstract: A composition for an optical material includes (a) a compound having two ?-epithiopropyl groups and having a specific structure, (b) a compound having one ?-epithiopropyl group and one glycidyl group and having a specific structure, (c) polyisocyanate and (d) polythiol, enables the prevention of the occurrence of such a defect that peeling traces linger on a lens. In the composition for an optical material, an embodiment in which (e) sulfur is additionally contained is preferred. Another embodiment of the present invention is a method for producing an optical material, characterized by adding an onium salt as a polymerization catalyst to the composition for an optical material in an amount of 0.0001 to 10% by mass relative to the total amount of the compound (a), the compound (b), polyisocyanate (c) and polythiol (d) and then polymerizing and curing the resultant mixture.

Abstract: Through an optical material composition containing a compound (a), a compound (b), a polythiol (c) and sulfur (d) according to the present invention, good mold release properties are obtained, and the occurrence of separation mark defects can be suppressed. Compound (a): a compound having the structure represented by formula (1): (In formula (1), m is an integer of 0 to 4 and n is an integer of 0 to 2.) Compound (b): a compound having the structure represented by formula (2): (In formula (2), m is an integer of 0 to 4 and n is an integer of 0 to 2.

Abstract: According to the present invention, a polythiol compound having a total nitrogen content of 50 to 600 ppm inclusive can be provided. According to the present invention, a method for producing the polythiol compound can also be provided, said method being characterized by comprising the steps of: reacting a polyalcohol with thiourea to prepare a thiuronium salt; and adding at least one base selected from the group consisting of hydrazine (hydrate), ammonia and an amine and an inorganic base (that is different from hydrazine (hydrate) or ammonia) to the thiuronium salt in the presence of an organic solvent to hydrolyze the thiuronium salt.

Abstract: The present invention is able to provide an optical material composition containing: a polythiol compound satisfying one of the below mentioned i) through iii); and a polyepoxy compound and/or a polyepisulfide compound of which i) the ammonium cation concentration is 0.1-150 ?mol/kg, ii) the thiocyanate anion concentration is 0.1-300 ?mol/kg, or iii) the ammonium cation concentration is 0.1-150 ?mol/kg, the thiocyanate anion concentration is 0.1-300 ?mol/kg, and furthermore the ion concentration product of the ammonium cations and the thiocyanate anions is 0.01-15000 (?mol/kg)2.

Abstract: According to the present invention, a composition for an optical material contains a compound (a), a compound (b), and a polyisocyanate compound (c), and can suppress the generation of striae defects. The compound (a) is a compound having a structure represented by formula (1). The compound (b) is a compound having a structure represented by formula (2).

Abstract: According to the present invention, it is possible to provide a thiol compound represented by formula (1): wherein R1 is CH2SCH2CH2SH, and R2 is hydrogen. In addition, according to the present invention, it is possible to provide a mixture of the thiol compound and 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, wherein the ratio of the thiol compound is 0.001 to 5.0% by mass.

Abstract: A composition for an optical material includes (a) a compound having two ?-epithiopropyl groups and having a specific structure, (b) a compound having one ?-epithiopropyl group and one glycidyl group and having a specific structure, (c) polyisocyanate and (d) polythiol, enables the prevention of the occurrence of such a defect that peeling traces linger on a lens. In the composition for an optical material, an embodiment in which (e) sulfur is additionally contained is preferred. Another embodiment of the present invention is a method for producing an optical material, characterized by adding an onium salt as a polymerization catalyst to the composition for an optical material in an amount of 0.0001 to 10% by mass relative to the total amount of the compound (a), the compound (b), polyisocyanate (c) and polythiol (d) and then polymerizing and curing the resultant mixture.

Abstract: By using a method for producing a composition for an optical material using (a) sulfur, (b) a compound having two intramolecular episulfide groups, (c) a compound having one or more (preferably two) SH groups, and (d) an amine compound having a specific structure, in which compound (a) and compound (c) are pre-polymerized in the presence of compound (b) using compound (d) as the pre-polymerization catalyst, the present invention provides a polymerizable composition for an optical material in which the viscosity elevation speed during pre-polymerization is slow and the reaction temperature is approximately room temperature, and that has a low viscosity and shows little increase in viscosity.

Abstract: A curable composition containing an inorganic compound A having sulfur atom and/or selenium atom, a compound B represented by the following formula 1: wherein m is an integer from 0 to 4, and n is an integer from 0 to 2, and a compound C selected from the group consisting of disulfide compounds which are other than the compound B and have one or more disulfide linkages Inorganic compound A is contained in an amount from 1 to 50 parts by weight and compound B is contained in an amount from 50 to 99 parts by weight when a total of inorganic compound A and compound B is taken as 100 parts by weight. Compound C is contained in an amount from 1 to 20 parts by weight based on 100 parts by weight in total of inorganic compound A and compound B.

Abstract: A curable composition containing an inorganic compound A having sulfur atom and/or selenium atom, a compound B represented by the following formula 1: wherein m is an integer from 0 to 4, and n is an integer from 0 to 2, and a compound C selected from the group consisting of thiol compounds having one SH group and disulfide compounds which are other than the compound B and have one or more disulfide linkages. The inorganic compound A is contained in an amount from 1 to 50 parts by weight and the compound B is contained in an amount from 50 to 99 parts by weight when a total of the inorganic compound A and the compound B is taken as 100 parts by weight. The compound C is contained in an amount from 1 to 20 parts by weight based on 100 parts by weight in total of the inorganic compound A and the compound B.