Method for producing 1,5-pentanediisocyanate in the gas phase

A process for preparing pentane 1,5-diisocyanate (PDI) by reacting a stream of pentane-1,5-diamine (PDA) with a stream of phosgene in the gas phase, characterized in that

• a) increasing the temperatures both of the phosgene stream and of the pentane-1,5-diamine (PDA) stream prior to entry into the reactor are in the range of 230-320° C. and
• b) supplying the pentane-1,5-diamine (PDA) stream and the phosgene stream, and an inert gas stream to the reactor by an annular gap nozzle, with the inert gas stream being supplied through the annular gap,
• c) mixing the pentane-1,5-diamine (PDA) stream, the phosgene stream, and the inert gas stream after entry into the reactor and
• d) reacting the amine and the phosgene,
• wherein the sum total of N-carbamoylpiperidine (C6-Im) and N-carbamoyltetrahydropyridines (C6-Az) is <400 ppm based on the weight of the PDI, excluding solvent.