Provided an optical material composition which makes it possible to design an optical material exhibiting a broad range of properties. This optical material composition contains a compound (A) represented by formula (1) and a polythiol (a), and does not contain 1,2,3,5,6-pentathiepane (b).

##STR00001##

Provided an optical material composition which makes it possible to design an optical material exhibiting a broad range of properties. This optical material composition contains a compound (A) represented by formula (1) and a polythiol (a), and does not contain 1,2,3,5,6-pentathiepane (b).

##STR00001##

Provided is an optical material composition which makes it possible to design an optical material exhibiting a broad range of properties. This optical material composition contains a compound (A) represented by formula (1), 1,2,3,5,6-pentathiepane (b), and if necessary, a compound (B) represented by formula (2). The content of the compound (B) constitutes 0-30 mass % of the total mass of the composition:

##STR00001##

(In the formula, n m represents an integer which is 0-4, and n represents an integer which is 0-2).

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. ##STR00001##

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. ##STR00001##

The present invention makes it possible to provide a compound represented by formula (1) and a composition for an optical material containing this compound. ##STR00001## (Where m+n=4, m represents an integer of from 0 to 3, and n represents an integer of from 1 to 4.) In addition, the present invention makes it possible to provide a method for producing an optical material, the method including a step for adding 0.0001-10 parts by mass of a polymerization catalyst per 100 parts by mass of the composition for an optical material, polymerizing, and curing.

The present invention makes it possible to provide a compound represented by formula (1) and a composition for an optical material containing this compound. ##STR00001## (Where m+n=4, m represents an integer of from 0 to 3, and n represents an integer of from 1 to 4.) In addition, the present invention makes it possible to provide a method for producing an optical material, the method including a step for adding 0.0001-10 parts by mass of a polymerization catalyst per 100 parts by mass of the composition for an optical material, polymerizing, and curing.

Antifoulant compositions and methods are used for inhibiting fouling on structural parts of a system exposed to a fluid hydrocarbon or petrochemical stream. The antifoulant compositions may comprise at least one polyalkylene anhydride ester (PAAE) dispersant. Other antifoulant compositions may comprise an alkylphenol sulfide (APS).

Antifoulant compositions and methods are used for inhibiting fouling on structural parts of a system exposed to a fluid hydrocarbon or petrochemical stream. The antifoulant compositions may comprise at least one polyalkylene anhydride ester (PAAE) dispersant. Other antifoulant compositions may comprise an alkylphenol sulfide (APS).

A process for producing an episulfide compound for an optical material of the present invention includes a step of chlorinating glycerin to obtain dichloropropanol; a step of epoxidizing the dichloropropanol to obtain epichlorohydrin; a step of reacting the epichlorohydrin with a sulfating agent to obtain a bis(chlorohydrin) (di)sulfide compound thought a thiol compound; a step of epoxidizing the bis(chlorohydrin) (di)sulfide compound under basic conditions to obtain an epoxy compound; and a step of reacting the epoxy compound with a sulfating agent to obtain an episulfide compound represented by following General Formula (1): ##STR00001## wherein, in the formula, n represents 0 or 1.