Abstract: In the production of hydrogen peroxide, when ketone forms are increased upon conversion from higher alcohol components in organic solvents, such increased levels of ketone forms reduce the water content in a working solution and lead to deterioration of catalytic activity. Moreover, increased levels of ketone forms reduce the solubility of anthrahydroquinone compounds and may cause an obstacle to stable and safe operation in the production of hydrogen peroxide due to crystallization and deposition of the anthrahydroquinone compounds. The object of the present invention is to provide a process in which polar solvent-derived altered substances (ketone forms) in a working solution provided for use in the production of hydrogen peroxide via the anthraquinone process are regenerated into the original alcohol components to thereby improve the production efficiency of hydrogen peroxide.

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: The present invention addresses the problem of providing: a catalyst for preliminary reaction and a preliminary reaction method, which are suitable for a composition that is obtained by adding a thiol compound and an isocyanate compound to an episulfide compound; and a polymerizable composition for optical materials, which is capable of preventing yellowing of an optical material which contains a composition that is obtained by adding a thiol compound and an isocyanate compound to an episulfide compound.

Abstract: According to the present invention, a composition for optical material, which is capable of providing a homogeneous optical material, can be prepared through pre-polymerization reaction between (a) an inorganic compound having a sulfur atom and (b) an episulfide compound using a hindered amine as a catalyst, followed by mixing with (c) a polythiol compound and (d) a polyisocyanate compound. Moreover, this composition for optical material can be polymerized and cured to thereby provide an optical material having high refractive index (ne of 1.73 or higher), high strength (an elongation of 13% or more in three-point bend test and good drilling resistance), and high heat resistance (a softening point of 70° C. or higher, as measured by TMA).

Abstract: In the production of hydrogen peroxide, when ketone forms are increased upon conversion from higher alcohol components in organic solvents, such increased levels of ketone forms reduce the water content in a working solution and lead to deterioration of catalytic activity. Moreover, increased levels of ketone forms reduce the solubility of anthrahydroquinone compounds and may cause an obstacle to stable and safe operation in the production of hydrogen peroxide due to crystallization and deposition of the anthrahydroquinone compounds. The object of the present invention is to provide a process in which polar solvent-derived altered substances (ketone forms) in a working solution provided for use in the production of hydrogen peroxide via the anthraquinone process are regenerated into the original alcohol components to thereby improve the production efficiency of hydrogen peroxide.

Abstract: According to the present invention, a polymerizable composition having excellent storage stability can be provided by adding an acid that serves as a stabilizing agent and a free-radical polymerization inhibitor to a polymerizable composition that contains a polythiol compound and an enic compound having a phenylthio backbone as monomer components. In the present invention, an embodiment in which the acid is at least one compound having a protonic-acid-type functional group which is selected from phosphoric acid, phosphonic acid, phosphinic acid, sulfonic acid, sulfoneimide and carboxylic acid is preferred.

Abstract: With the present invention, it is possible to provide a composition for optical materials which comprises: a polythiol compound satisfying any one of the following i) to iii) i) the compound has an ammonium cation concentration of 0.1 to 400 ?mol/kg, ii) the compound has a thiocyanic acid anion concentration of 0.1 to 600 ?mol/kg, and iii) the compound has an ammonium cation concentration of 0.1 to 400 ?mol/kg and a thiocyanic acid anion concentration of 0.1 to 600 ?mol/kg, the product of the ammonium cation concentration and the thiocyanic acid anion concentration being 0.01 to 100,000 (?mol/kg)2; and a polyisocyanate compound.

Abstract: A composition for use in an optical material is disclosed which is capable of providing an optical material satisfying a high refractive index (ne is 1.73 or more), a high strength (an elongation is 10% or more in a three-point bending test and drilling resistance is good), and a high thermostability (a softening point measured by TMA is 70° C. or higher). The optical material such as a lens for two-point frame spectacles is formed by polymerizing and curing a composition for use in an optical resin material containing (a) an inorganic compound having a sulfur atom and/or a selenium atom, (b) an episulfide compound, and (c) a xylylenedithiol compound.

Abstract: According to the present invention, a method for producing bis(?-epoxypropyl)sulfide or bis(?-epoxypropyl)polysulfide can be provided, which is characterized by comprising adding a metal compound selected from the group consisting of a metal hydrosulfide, a metal sulfide and a metal polysulfide to an epihalohydrin at ?5 to 30° C. in such a manner that the molar ratio of the epihalohydrin to the metal compound becomes 5 to 20 to thereby cause the reaction of the epihalohydrin with the metal compound. In a preferred embodiment, the epihalohydrin is epichlorohydrin, the metal hydrosulfide is sodium hydrosulfide or potassium hydrosulfide, the metal sulfide is sodium sulfide or potassium sulfide, and the metal polysulfide is sodium polysulfide or potassium polysulfide.

Abstract: According to the present invention, a polymerizable composition having excellent storage stability can be provided by adding an acid that serves as a stabilizing agent and a free-radical polymerization inhibitor to a polymerizable composition that contains a polythiol compound and an enic compound having a phenylthio backbone as monomer components. In the present invention, an embodiment in which the acid is at least one compound having a protonic-acid-type functional group which is selected from phosphoric acid, phosphonic acid, phosphinic acid, sulfonic acid, sulfoneimide and carboxylic acid is preferred.

Abstract: According to the present invention, a method for producing bis(?-epoxypropyl)sulfide or bis(?-epoxypropyl)polysulfide can be provided, which is characterized by comprising adding a metal compound selected from the group consisting of a metal hydrosulfide, a metal sulfide and a metal polysulfide to an epihalohydrin at ?5 to 30° C. in such a manner that the molar ratio of the epihalohydrin to the metal compound becomes 5 to 20 to thereby cause the reaction of the epihalohydrin with the metal compound. In a preferred embodiment, the epihalohydrin is epichlorohydrin, the metal hydrosulfide is sodium hydrosulfide or potassium hydrosulfide, the metal sulfide is sodium sulfide or potassium sulfide, and the metal polysulfide is sodium polysulfide or potassium polysulfide.

Abstract: The present invention includes a polymerizable composition for optical materials, which contains a thiourethane oligomer that is obtained by preliminarily reacting the whole or a part of a thiol compound and an isocyanate compound in a composition that contains an episulfide compound, the thiol compound and the isocyanate compound, while using a compound represented by formula (2) below as a catalyst for preliminary reaction. (In formula (2), R represents an alkyl group having 1 to 4 carbon atoms; and X represents an organic group which has 2 to 11 carbon atoms and contains a vinyl group, a vinylidene group or a vinylene group.

Abstract: According to the present invention, a composition for optical material, which is capable of providing a homogeneous optical material, can be prepared through pre-polymerization reaction between (a) an inorganic compound having a sulfur atom and (b) an episulfide compound using a hindered amine as a catalyst, followed by mixing with (c) a polythiol compound and (d) a polyisocyanate compound. Moreover, this composition for optical material can be polymerized and cured to thereby provide an optical material having high refractive index (ne of 1.73 or higher), high strength (an elongation of 13% or more in three-point bend test and good drilling resistance), and high heat resistance (a softening point of 70° C. or higher, as measured by TMA).

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: The invention relates to a curable composition preferable as a raw material for optical materials such as adhesive agents for optical elements, coating agents for optical elements, resist materials, prisms, optical fibers, information recording substrates, filters and plastic lenses, and more specifically to a curable composition characterized by containing (A) an episulfide compound, and (B) a polymerization catalyst comprising a tetraalkylphosphonium dialkylphosphate represented by the following general formula (1): wherein R1 to R6 are the same or different, an alkyl group having 1 to 8 carbon atoms or an alkyl group having a hydroxyl group and 1 to 8 carbon atoms, and linear, branched or cycloaliphatic.

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: According to the present invention, a resin compound for optical material, comprising (a) an episulfide compound represented by a specific structural formula, (b) a xylylenedithiol compound and (c) a xylylenediisocyanate compound can be provided. In a preferable embodiment of the present invention, a resin compound for optical material having superb optical properties, a high density and a high thermal resistance can be provided. Also according to the present invention, an optical material obtained by curing the above-described resin compound can be provided.

Abstract: There is provided a coating composition having a good wetting property which is capable of forming a coating film exhibiting a high refractive index, a less discoloration, and excellent transparency and uniformity when polymerized and cured. The present invention relates to a coating composition comprising (A) 100 parts by weight of a thiirane ring-containing compound, (B) 0.0001 to 10 parts by weight of a catalyst for accelerating polymerization of the thiirane ring-containing compound, and (C) 0.005 to 4 parts by weight of a modified silicone oil; a coating film produced from the composition; and an optical product provided with the coating film.

Abstract: According to a preferable embodiment of the present invention, a composition for a resin comprising an inorganic compound having a sulfur atom and/or a selenium atom, an episulfide compound, and a mercaptodisulfide compound can be provided. According to another preferable embodiment of the present invention, a composition for a resin having the viscosity thereof decreased to facilitate a cast polymerization operation and thus to improve the tonality of the obtained optical material can be provided. According to still another preferable embodiment of the present invention, an optical material obtained by curing the above-described composition for a resin and having a high refractive index can be provided.

Abstract: The present invention can provide a composition for optical members, which contains (a) a compound having one or more of any group selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group and a vinyl group and one or more ?-epithiopropyl groups in a molecule. In a preferable embodiment of the present invention, the composition for optical members further contains at least one compound selected from (b) a compound having one or more ?-epithiopropyl groups in a molecule while having no polymerizable unsaturated bond group, (c) an inorganic compound having a sulfur atom and/or a selenium atom, (d) a compound having one or more thiol groups in a molecule, (e) a compound having one or more amino groups in a molecule while having no heterocyclic ring, and (f) a compound having one or more of at least one group selected from the group consisting of a vinyl group, an acryloyl group, a methacryloyl group and an allyl group in a molecule.