Method for manufacturing diisocyanate and optical lens

Abstract

Provided is a method for manufacturing diisocyanate and an optical lens in which, during the manufacture of diisocyanate from diamine via diamine hydrochloride, use is made of an aqueous hydrochloricacid solution and an organic solvent instead of hydrogen chloride gas and solid-phase triphosgen instead of phosgen gas while reaction conditions are controlled, whereby the diisocyanate of high quality can be manufactured at excellent yield, with the causation of less environmental problems.

Description

technical field

[0001] Embodiments relate to methods of making diisocyanates and optical lenses. More specifically, embodiments relate to methods of preparing diisocyanates using diamine hydrochlorides. In addition, embodiments relate to methods of producing optical lenses using the thus prepared diisocyanates. Background technique

[0002] Isocyanates used as raw materials for plastic optical lenses are produced by a phosgene method, a non-phosgene method, a pyrolysis method, and the like.

[0003] In the phosgene method, amines are used as raw materials and phosgene (COCl 2 ) gases react to synthesize isocyanates. In addition, in the non-phosgene method, dibromomethylbenzene is reacted with sodium cyanate in the presence of a catalyst to synthesize isocyanate. In the pyrolysis method, an amine is reacted with an alkyl chloroformate to prepare a carbamate, which is pyrolyzed at high temperature in the presence of a catalyst to synthesize an isocyanate.

[0004] Among t...

Examples

preparation example Construction

[0033] A method for preparing a diisocyanate according to an embodiment includes preparing at least one diamine selected from the group consisting of o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, norbornenediamine, hydrogenated benzene Dimethylamine, and isophorone diamine; making said diamine react with aqueous hydrochloric acid in a first solvent to obtain diamine hydrochloride; and making said diamine hydrochloride and triphosgene react in a second Reaction in organic solvents to obtain diisocyanates.

[0034]In the method for preparing diisocyanate according to the embodiment, the diamine used as a raw material may be at least one selected from the group consisting of o-xylylenediamine (o-XDA), m-xylylenediamine (m- XDA), p-xylylenediamine (p-XDA), norbornenediamine (NBDA), hydrogenated xylylenediamine (H6XDA), and isophoronediamine (IPDA).

[0035] Preparation of diamine hydrochloride

[0036] First, diamine is reacted with aqueous hydrochloric acid in a firs...

specific Embodiment approach

[0177] Hereinafter, more specific embodiments are shown, but the present invention is not limited thereto.

[0178]

example 1

[0180] Into a 5-liter 4-neck reactor was charged 963.5 g (9.25 mol) of 35% aqueous hydrochloric acid, and then the internal temperature of the reactor was lowered to 15°C to 20°C while stirring. While maintaining the temperature of the reactor at 25°C to 50°C, 600.0 g (4.4 moles) of m-xylylenediamine (m-XDA) was introduced for 1 hour. After the introduction was completed, the internal temperature of the reactor was lowered to 10°C to 20°C, and it was stirred for 1 hour. Thereafter, 1,200.0 g of diethyl ether (Et 2 O) as an organic solvent, and lower the internal temperature of the reactor to -5°C to 0°C, and then stir for 30 minutes to 1 hour. After the reaction was completed, it was vacuum filtered using a filter, and the filtered diethyl ether was recovered for reuse. The recovery of diethyl ether was 73%. After vacuum filtration, m-xylylenediamine (m-XDA) hydrochloride was obtained. In order to remove the residual organic solvent and water, drying was carried out under ...

technical field

[0001] Embodiments relate to methods of making diisocyanates and optical lenses. More specifically, embodiments relate to methods of preparing diisocyanates using diamine hydrochlorides. In addition, embodiments relate to methods of producing optical lenses using the thus prepared diisocyanates. Background technique

[0002] Isocyanates used as raw materials for plastic optical lenses are produced by a phosgene method, a non-phosgene method, a pyrolysis method, and the like.

[0003] In the phosgene method, amines are used as raw materials and phosgene (COCl 2 ) gases react to synthesize isocyanates. In addition, in the non-phosgene method, dibromomethylbenzene is reacted with sodium cyanate in the presence of a catalyst to synthesize isocyanate. In the pyrolysis method, an amine is reacted with an alkyl chloroformate to prepare a carbamate, which is pyrolyzed at high temperature in the presence of a catalyst to synthesize an isocyanate.

[0004] Among t...

Examples

preparation example Construction

[0033] A method for preparing a diisocyanate according to an embodiment includes preparing at least one diamine selected from the group consisting of o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, norbornenediamine, hydrogenated benzene Dimethylamine, and isophorone diamine; making said diamine react with aqueous hydrochloric acid in a first solvent to obtain diamine hydrochloride; and making said diamine hydrochloride and triphosgene react in a second Reaction in organic solvents to obtain diisocyanates.

[0034]In the method for preparing diisocyanate according to the embodiment, the diamine used as a raw material may be at least one selected from the group consisting of o-xylylenediamine (o-XDA), m-xylylenediamine (m- XDA), p-xylylenediamine (p-XDA), norbornenediamine (NBDA), hydrogenated xylylenediamine (H6XDA), and isophoronediamine (IPDA).

[0035] Preparation of diamine hydrochloride

[0036] First, diamine is reacted with aqueous hydrochloric acid in a firs...

specific Embodiment approach

[0177] Hereinafter, more specific embodiments are shown, but the present invention is not limited thereto.

[0178]

example 1

[0180] Into a 5-liter 4-neck reactor was charged 963.5 g (9.25 mol) of 35% aqueous hydrochloric acid, and then the internal temperature of the reactor was lowered to 15°C to 20°C while stirring. While maintaining the temperature of the reactor at 25°C to 50°C, 600.0 g (4.4 moles) of m-xylylenediamine (m-XDA) was introduced for 1 hour. After the introduction was completed, the internal temperature of the reactor was lowered to 10°C to 20°C, and it was stirred for 1 hour. Thereafter, 1,200.0 g of diethyl ether (Et 2 O) as an organic solvent, and lower the internal temperature of the reactor to -5°C to 0°C, and then stir for 30 minutes to 1 hour. After the reaction was completed, it was vacuum filtered using a filter, and the filtered diethyl ether was recovered for reuse. The recovery of diethyl ether was 73%. After vacuum filtration, m-xylylenediamine (m-XDA) hydrochloride was obtained. In order to remove the residual organic solvent and water, drying was carried out under ...

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