In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by controlling the size of the diamine hydrochloride composition, the b* value according to the CIE color coordinate of the diamine hydrochloride composition, or the content of water in the diamine hydrochloride composition within a specific range.

In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by controlling the size of the diamine hydrochloride composition, the b* value according to the CIE color coordinate of the diamine hydrochloride composition, or the content of water in the diamine hydrochloride composition within a specific range.

In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of high quality in which the content of water, the content of cations, or the content of an aromatic compound containing 3 or more of chlorine (Cl) in the organic solvent used in the reaction of a diamine hydrochloride composition and triphosgene is adjusted to a specific range.

In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of high quality in which the content of water, the content of cations, or the content of an aromatic compound containing 3 or more of chlorine (Cl) in the organic solvent used in the reaction of a diamine hydrochloride composition and triphosgene is adjusted to a specific range.

There are provided a method of producing a carbonyl compound by a flow type reaction, including introducing a triphosgene solution into a flow channel (I), bringing the triphosgene solution into contact with a solid catalyst immobilized in at least a part of the flow channel (I) to generate a phosgene solution while the triphosgene solution is flowing through the flow channel (I), joining the phosgene solution and an active hydrogen-containing compound solution that flows inside the flow channel (II), which are subsequently allowed to flow downstream inside a reaction flow channel to be reacted in a presence of a tertiary amine, and obtaining a carbonyl compound in a joining solution; and a flow type reaction system that is suitable for carrying out this production method.

There are provided a method of producing a carbonyl compound by a flow type reaction, including introducing a triphosgene solution into a flow channel (I), bringing the triphosgene solution into contact with a solid catalyst immobilized in at least a part of the flow channel (I) to generate a phosgene solution while the triphosgene solution is flowing through the flow channel (I), joining the phosgene solution and an active hydrogen-containing compound solution that flows inside the flow channel (II), which are subsequently allowed to flow downstream inside a reaction flow channel to be reacted in a presence of a tertiary amine, and obtaining a carbonyl compound in a joining solution; and a flow type reaction system that is suitable for carrying out this production method.

There are provided a method of producing a carbonyl compound by a flow type reaction, including introducing a triphosgene solution into a flow channel (I), bringing the triphosgene solution into contact with a solid catalyst immobilized in at least a part of the flow channel (I) to generate a phosgene solution while the triphosgene solution is flowing through the flow channel (I), joining the phosgene solution and an active hydrogen-containing compound solution that flows inside the flow channel (II), which are subsequently allowed to flow downstream inside a reaction flow channel to be reacted in a presence of a tertiary amine, and obtaining a carbonyl compound in a joining solution; and a flow type reaction system that is suitable for carrying out this production method.

In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of higher quality by controlling the water content in the diamine hydrochloride composition for preparing a diisocyanate within a specific range.

In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of higher quality by controlling the water content in the diamine hydrochloride composition for preparing a diisocyanate within a specific range.

In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of higher quality by controlling the water content in the diamine hydrochloride composition for preparing a diisocyanate within a specific range.