Mitsui Chemicals, Inc.

Kobe Steel, Ltd.

Tadashi Yoshida

Shigetoshi Suzuki

Masahiro Yamagata

Fumihiko Kasuya

Yasumichi Ooto

Akio Saito

Masaaki Sasaki

The present invention relates to a method for decomposing and recovering an isocyanate compound, which comprises: continuously mixing and dispersing into water at high pressure and high temperature an isocyanate compound having at least one isocyanate group or group derived from an isocyanate group in a molten state or solution state, supplying a liquid mixture containing the isocyanate compound and the water at high pressure and high temperature continuously to a reactor, followed by subjecting the isocyanate compound to a decomposition reaction in the reactor, and recovering a raw material for the isocyanate compound or a derivative thereof; and an apparatus for decomposing and recovering an isocyanate compound, which comprises: a reactor which brings water at high pressure and high temperature into contact with an isocyanate compound having at least one isocyanate group or group derived from an isocyanate group to cause a decomposition reaction, a water supply line which continuously supplies the water at high pressure and high temperature to a reactor, a compound supply line which continuously supplies the isocyanate compound in a molten state or solution state to the water supply line, an on-off valve which communicates the compound supply line with a vicinity of a communication portion of the water supply line to the reactor, a dehydrating device which conducts a dehydration of a decomposition reaction product discharged from the reactor, and a purification device which purifies the decomposition reaction product after the dehydration.

Method for decomposing and recovering isocyanate compound

A concentrating method and a concentrating system for concentrating polyisocyanate residues that that can effectively concentrate polyisocyanate residues from crude polyisocyanate comprising polyisocyanate and polyisocyanate residues in a short time and can also suppress increase in viscosity to provide stable transport of the residues and prevent blockage of the transport line, and a treating method and a treating system for decomposing the concentrated components to polyamine. The polyisocyanate residues are first heated on the boil by the distiller to be concentrated to a midterm concentrating rate, and then, the polyisocyanate residues are concentrated to the final concentrating rate by evaporation using a evaporator. This can allow the polyisocyanate residues to be decomposed to polyamine to be recovered by setting a Cl content of a high boiling point distillate fraction concentrated to be not more than 2 weight % and then putting the high boiling point distillate fraction into contact with high temperature and high pressure water to be hydrolyzed by the decomposing apparatus.

Concentrating method, treating method, concentrating system and treating system for polyisocyanate residues

An object of the invention is to provide a decomposing system for polyisocyanate residues that is capable of suppressing reaction of polyisocyanate residues with high temperature and high pressure water to allow smooth start-up of the operation, and a start-up method for the decomposing system for the polyisocyanate residues. The decomposing system is used for hydrolyzing the polyisocyanate residues to polyamine using high temperature and high pressure water, comprising a hydrolyzer, a water feed pipe connected to the hydrolyzer, a residual feed pipe connected to the water feed pipe, a solvent feed line for filling an organic solvent in a solvent filling portion of the residual feed pipe, and a solvent draining line. Upon start-up of the operation, the organic solvent is previously filled in the solvent filling portion via the solvent feed line and the solvent draining line, first, and then, the high temperature and high pressure water is fed from the water feed pipe to the hydrolyzer. Then, the organic solvent is fed from the residual feed pipe to the water feed pipe, first, and then, the polyisocyanate residues are fed thereto.

Decomposing system for polyisocyanate residues, and start-up method for the same

Growing community of inventors

Kamisu, Japan

Tadashi Yoshida