Abstract: A composition that includes Compound (a) and Compound (b). Compound (a) is represented by formula (1): where: Ar represents an aromatic ring; m represents an integer of 2 to 8; n represents an integer of 0 to 6, provided that m+n is the number of carbon atoms constituting the aromatic ring, or less; and R1 each independently represents an alkylthio group, a halogen group, a hydroxy group, a dialkylthiocarbamoyl group, or a dialkylcarbamoylthio group. Compound (b) is represented by formula (2): where p represents an integer of 0 to 4, and q represents an integer of 0 to 2.

Abstract: Provided is a composition for optical materials that gives optical materials which can have at least one improved property selected from among satisfactory mold releasability after polymerization and curing, unsusceptibility to separation from the mold during polymerization and curing, transparency, and low-level striae. The present invention further provides a compound represented by formula (1). The composition for optical materials comprises the compound represented by formula (1) and a compound represented by formula (2). (In formula (1), X1 and X2 represent O or S, provided that both X1 and X2 are O or that X1 is O and X2 is S.

Abstract: A composition containing: a compound (a) represented by Formula (1): wherein Ar represents an aromatic ring, m represents an integer of 2 to 8, n represents an integer of 0 to 6, provided that m+n is equal to or less than a number of carbon atoms that constitute the aromatic ring, and R1 each independently represents an alkylthio group, an epoxyalkylthio group, a thiol group, a halogen group, a hydroxy group, a dialkylthiocarbamoyl group, or a dialkylcarbamoylthio group; and 1,2,3,5,6-pentathiepane (b).

Abstract: A composition containing: a compound (a) represented by Formula (1): wherein Ar represents an aromatic ring, m represents an integer of 2 to 8, n represents an integer of 0 to 6, provided that m+n is equal to or less than a number of carbon atoms that constitute the aromatic ring, and R1 each independently represents an alkylthio group, an epoxyalkylthio group, a thiol group, a halogen group, a hydroxy group, a dialkylthiocarbamoyl group, or a dialkylcarbamoylthio group; and a polythiol (b).

Abstract: The present invention makes it possible to provide a method for producing a polyfunctional sulfur-containing epoxy compound, the method being characterized in that a polyfunctional thiol is reacted with an epihalohydrin in the presence of a reducing agent to form a polyfunctional sulfur-containing halohydrin, which is then reacted with a basic compound. The reducing agent is preferably at least one selected from the group consisting of sodium borohydride, lithium borohydride, lithium aluminum hydride, diisobutylaluminum hydride, and hydrazine.

Abstract: Provided is a composition for optical materials that gives optical materials which can have at least one improved property selected from among satisfactory mold releasability after polymerization and curing, unsusceptibility to separation from the mold during polymerization and curing, transparency, and low-level striae. The present invention further provides a compound represented by formula (1). The composition for optical materials comprises the compound represented by formula (1) and a compound represented by formula (2). (In formula (1), X1 and X2 represent O or S, provided that both X1 and X2 are O or that X1 is O and X2 is S.

Abstract: The present invention provides a composition for an optical material containing a compound (a) and/or a compound (b) and a compound (c) which are described below. In a preferable embodiment, the proportion of the compound (a) and/or the compound (b) is 0.001-30.0% by mass. The compound (a) is a compound represented by formula (1). The compound (b) is a compound represented by formula (2). The compound (c) is an episulfide compound.

Abstract: The present invention makes it possible to provide a method for producing a polyfunctional sulfur-containing epoxy compound, the method being characterized in that a polyfunctional thiol is reacted with an epihalohydrin in the presence of a reducing agent to form a polyfunctional sulfur-containing halohydrin, which is then reacted with a basic compound. The reducing agent is preferably at least one selected from the group consisting of sodium borohydride, lithium borohydride, lithium aluminum hydride, diisobutylaluminum hydride, and hydrazine.

Abstract: According to the present invention, it is possible to provide a photocurable composition which comprises a cyclic compound (a) represented by formula (1), an episulfide compound (b), and a photopolymerization initiator (c). In a preferred embodiment, the proportion of the cyclic compound (a) in the photocurable composition is 5-80 mass %, the proportion of the episulfide compound (b) is 20-95 mass %, and the proportion of the photopolymerization initiator (c) is 0.1-10 parts by mass per 100 parts by mass of the sum of the cyclic compound (a) and the episulfide compound (b). In the formula, C represents a carbon atom, X represents S, Se, or Te, and a to f are integers of 0-3, provided that 8?(a+c+e)?1, 8?(b+d+f)?2, and (b+d+f)?(a+c+e).

Abstract: The present invention provides a composition for an optical material containing a ring compound (a) represented by formula (1), an episulfide compound (b), and sulfur (c), wherein the content of the ring compound (a) in the composition for an optical material is in the range of 5-70 mass %, the content of the episulfide compound (b) is in the range of 20-90 mass %, and the content of the sulfur (c) is in the range of 1-39 mass %. (In the formula, X represents S, Se or Te. a to f=0 to 3, 8?(a+c+e)?1, 8?(b+d+f)?2, and (b+d+f)?(a+c+e).) This composition for an optical material has a high refractive index as an optical characteristic, and has sufficient heat resistance and good mold release characteristics.

Abstract: According to the present invention, it is possible to provide a photocurable composition which comprises a cyclic compound (a) represented by formula (1), an episulfide compound (b), and a photopolymerization initiator (c). In a preferred embodiment, the proportion of the cyclic compound (a) in the photocurable composition is 5-80 mass %, the proportion of the episulfide compound (b) is 20-95 mass %, and the proportion of the photopolymerization initiator (c) is 0.1-10 parts by mass per 100 parts by mass of the sum of the cyclic compound (a) and the episulfide compound (b). In the formula, C represents a carbon atom, X represents S, Se, or Te, and a to f are integers of 0-3, provided that 8?(a+c+e)?1, 8?(b+d+f)?2, and (b+d+f)?(a+c+e).

Abstract: The present invention provides a composition for an optical material containing a ring compound (a) represented by formula (1), an episulfide compound (b), and sulfur (c), wherein the content of the ring compound (a) in the composition for an optical material is in the range of 5-70 mass %, the content of the episulfide compound (b) is in the range of 20-90 mass %, and the content of the sulfur (c) is in the range of 1-39 mass %. (In the formula, X represents S, Se or Te. a to f=0 to 3, 8?(a+c+e)?1, 8?(b+d+f)?2, and (b+d+f)?(a+c+e).) This composition for an optical material has a high refractive index as an optical characteristic, and has sufficient heat resistance and good mold release characteristics.

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: 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.