Patent ID: 7754915

Claim:
A process for preparing diisocyanates and triisocyanates of the general formula (I) R(NCO) n (I) where R is a (cyclo)aliphatic or aromatic hydrocarbon radical having up to 15 carbon atoms, with the proviso that at least two carbon atoms are present between two NCO groups and n is 2 or 3, comprising phosgenating diamines and/or triamines of the general formula (II) in the gas phase R(NH 2 ) n (II) where R is a (cyclo)aliphatic or aromatic hydrocarbon radical having up to 15 carbon atoms, with the proviso that at least two carbon atoms are present between two amino groups and n is 2 or 3, wherein the phosgenating is carried out in a tube reactor having a central nozzle and an annular space between the central nozzle and a wall of the tube reactor, wherein turbulence is generated in the central nozzle and in which a feed stream containing the diamines and/or triamines is fed into the tube reactor via the central nozzle and a phosgene-containing feed stream is fed into the tube reactor via the annular space wherein round or angular oblique plates, or a helix, are used as turbulence-generating elements.