METHOD OF PRODUCING DIISOCYANATES IN GASEOUS PHASE Russian patent published in 2009 - IPC C07C265/14 C07C263/10 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing diisocyanates of general formula R(NCO)_n, in which R is a (cyclo)aliphatic hydrocarbon radical which contains up to 15 carbon atoms, preferably from 4 to 13 carbon atoms, under the condition that, there are at least two carbon atoms between two isocyanate groups NCO, and n equals 2, through phosgenation of corresponding amines of general formula R(NH₂)_n, in which R assumes values given above, in a gaseous phase in a tube reactor while feeding heated phosgene and amines into the said reactor. For phosgenation, a tube reactor is used, which has a double-wall guide tube which diverges centrally towards the axis of rotation of the tube reactor, where between the inner and outer walls of the said guide tube there is a concentric annular gap, and the ratio of the cross sectional area of the tube reactor, bounded the inner wall of the guide tube, to the cross sectional area of the tube reactor, bounded by the wall of the tube reactor and the outer wall of the guide tube, ranges from 1:0.5 to 1:4. Temperature of vaporous amines and phosgene which are separate from each other ranges from 200°C to 600°C; vaporous amines in a mixture with inert gas are fed into the tube reactor through a concentric annular gap with stream average velocity of 20-150 m/s, and phosgene is fed into the tube reactor into the remaining region of the cross section of the tube reactor with stream average velocity of at least 1 m/s.

EFFECT: reduced probability of back-mixing and formation of by-products due to improved mixture of educts.

9 cl, 1 dwg, 2 ex