Abstract: A process of producing a plastic lens having a high refractive index, a high Abbe's number and good mechanical strength and a plastic lens obtained by that process. A process of producing a plastic lens including a step of polymerizing a mixture of (1) a prepolymer obtained by mixing and reacting from 0.1% by weight to 10% by weight, based on the whole amount of the mixture, of sulfur and an epithio group-containing compound, (2) a polyisocyanate compound, and (3) a polythiol compound; and a plastic lens obtained by this process.

Abstract: A plastic lens which absorbs ultraviolet light having wavelength of about 400 nm and suppresses coloring and a process for producing the lens. A plastic lens may be made from a composition which comprises (A) a lens material monomer comprising diethylene glycol bisallylcarbonate, (B) an organic peroxide-based polymerization initiator, (C) a cobalt compound represented by at least one of CoO.Al2O3 and Co.Al2O4, and (D) at least one ultraviolet light absorbent selected from 2-hydroxy-4-octyloxy-benzophenone, 2,2?,4,4?-tetrahydroxy-4-octyloxybenzophenone and 2,2?,4?-trihydroxy-4-octyloxybenzophenone. A process for producing a plastic lens comprises mixing component (A), component (B), a cobalt fluid comprising component (C) in a dispersant and component (D) and a step of casting the mixed fluid into a mold and polymerizing the fluid to obtain a plastic lens.

Abstract: A plastic lens and process of making it which comprises a plastic substrate comprising a benzophenone derivative represented by following general formula (I): wherein R represents a linear or branched alkyl group having 2 to 12 carbon atoms or an alkoxyl group having 2 to 12 carbon atoms.

Abstract: A process for producing plastic lenses, having higher refractive index and Abbe's number without remarkably deteriorating basic physical properties such as mechanical strength, impact resistance and transparency, and plastic lenses. The process comprises mixing 1) a prepolymer with 2) a mixture comprising sulfur in an epithio group-containing compound and 3) a catalyst.

Abstract: Plastic lenses for spectacles having a high refractive index and a high Abbe's number, and having good transparency, heat resistance, mechanical strength and impact resistance are produced. Plastic lenses for spectacles are produced through polymerization of an epithio group-having compound (a), a polythiol compound (b) and a polyisocyanate compound (c) whereby the ratio (by mol) of the polythiol compound (b) to the polyisocyanate compound (c) is at least 1.2 calculated on the basis of —SH and —NCO groups. The invention also provides a process for preparing such lenses and a catalyst for use in said process.

Abstract: An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow in color, is obtained by adding 2-(2-hydroxy-4-octyloxyphenyl)-benzotriazole to a diethylene glycol bisallylcarbonate monomer, a (thio)urethane monomer or an episulfide monomer, mixing them, and polymerizing the monomer.

Abstract: The present invention provides a process for producing plastic lenses, which are transparent, less colored, are not remarkably deteriorated in basic physical properties such as mechanical strength and impact resistance, and have higher refractive index and Abbe's number, and plastic lenses.

Abstract: A plastic lens which absorbs ultraviolet light having wavelength of about 400 nm and suppresses coloring and a process for producing the lens. A plastic lens may be made from a composition which comprises (A) a lens material monomer comprising diethylene glycol bisallylcarbonate, (B) an organic peroxide-based polymerization initiator, (C) a cobalt compound represented by at least one of CoO.Al2O3 and Co.Al2O4, and (D) at least one ultraviolet light absorbent selected from 2-hydroxy-4-octyloxy-benzophenone, 2,2?,4,4?-tetrahydroxy-4-octyloxybenzophenone and 2,2?,4?-trihydroxy-4-octyloxybenzophenone. A process for producing a plastic lens comprises mixing component (A), component (B), a cobalt fluid comprising component (C) in a dispersant and component (D) and a step of casting the mixed fluid into a mold and polymerizing the fluid to obtain a plastic lens.

Abstract: A process of producing a plastic lens having a high refractive index, a high Abbe's number and good mechanical strength and a plastic lens obtained by that process. A process of producing a plastic lens including a step of polymerizing a mixture of (1) a prepolymer obtained by mixing and reacting from 0.1% by weight to 10% by weight, based on the whole amount of the mixture, of sulfur and an epithio group-containing compound, (2) a polyisocyanate compound, and (3) a polythiol compound; and a plastic lens obtained by this process.

Abstract: A plastic lens and process of making it which comprises a plastic substrate comprising a benzophenone derivative represented by following general formula (I): wherein R represents a linear or branched alkyl group having 2 to 12 carbon atoms or an alkoxyl group having 2 to 12 carbon atoms.

Abstract: Plastic lenses for spectacles having a high refractive index and a high Abbe's number, and having good transparency, heat resistance, mechanical strength and impact resistance are produced. Plastic lenses for spectacles are produced through polymerization of an epithio group-having compound (a), a polythiol compound (b) and a polyisocyanate compound (c) whereby the ratio (by mol) of the polythiol compound (b) to the polyisocyanate compound (c) is at least 1.2 calculated on the basis of —SH and —NCO groups. The invention also provides a process for preparing such lenses and a catalyst for use in said process.

Abstract: An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow in color, is obtained by adding 2-(2-hydroxy-4-octyloxyphenyl)-benzotriazole to a diethylene glycol bisallylcarbonate monomer, a (thio)urethane monomer or an episulfide monomer, mixing them, and polymerizing the monomer.

Abstract: Plastic lenses for spectacles having a high refractive index and a high Abbe's number, and having good transparency, heat resistance, mechanical strength and impact resistance are produced. Plastic lenses for spectacles are produced through polymerization of an epithio group-having compound (a), a polythiol compound (b) and a polyisocyanate compound (c) whereby the ratio (by mol) of the polythiol compound (b) to the polyisocyanate compound (c) is at least 1.2 calculated on the basis of —SH and —NCO groups. The invention also provides a process for preparing such lenses and a catalyst for use in said process.

Abstract: An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow in color, is obtained by adding 2-(2-hydroxy-4-octyloxyphenyl)-benzotriazole to a diethylene glycol bisallylcarbonate monomer, a (thio)urethane monomer or an episulfide monomer, mixing them, and polymerizing the monomer.

Abstract: The present invention provides a process for producing plastic lenses, which are transparent, less colored, are not remarkably deteriorated in basic physical properties such as mechanical strength and impact resistance, and have higher refractive index and Abbe's number, and plastic lenses.

Abstract: A process for producing plastic lenses, having higher refractive index and Abbe's number without remarkably deteriorating basic physical properties such as mechanical strength, impact resistance and transparency, and plastic lenses. The process comprises mixing 1) a prepolymer with 2) a mixture comprising sulfur in an epithio group-containing compound and 3) a catalyst.

Abstract: An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow in color, is obtained by adding 2-(2-hydroxy-4-octyloxyphenyl)-benzotriazole to a diethylene glycol bisallylcarbonate monomer, a (thio)urethane monomer or an episulfide monomer, mixing them, and polymerizing the monomer.

Abstract: An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow, is obtained by dipping a poly(thio)urethane material or a diethylene glycol bisallylcarbonate polymer material in a solution containing: (1) a dibenzoylmethane compound of a general formula (1): wherein R and R′ each represent a linear or branched alkyl or alkoxyl group having from 1 to 8 carbon atoms; and n and n′ are the same or different integers, each falling between 0 and 3, or (2) a benzotriazole compound of a general formula (2): wherein R″ represents a hydrogen atom, a chlorine atom or a bromine atom; and m and m′ each indicate 1 or 2.

Abstract: An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow in color, is obtained by adding 2-(2-hydroxy-4-octyloxyphenyl)-benzotriazole to a diethylene glycol bisallylcarbonate monomer, a (thio)urethane monomer or an episulfide monomer, mixing them, and polymerizing the monomer.

Abstract: Plastic lenses for spectacles having a high refractive index and a high Abbe's number, and having good transparency, heat resistance, mechanical strength and impact resistance are produced. Plastic lenses for spectacles are produced through polymerization of an epithio group-having compound (a), a polythiol compound (b) and a polyisocyanate compound (c) whereby the ratio (by mol) of the polythiol compound (b) to the polyisocyanate compound (c) is at least 1.2 calculated on the basis of —SH and —NCO groups. The invention also provides a process for preparing such lenses and a catalyst for use in said process.