公开(公告)号：DE2625075A1

公开(公告)日：1977-12-22

申请号：DE2625075

申请日：1976-06-04

Applicant: BASF AG

Inventor： HERBIG KLAUS DIPL CHEM DR ,  ROSKE ECKHARD ,  STOCKBURGER DIETER DR ,  BRUNOLD ANDREAS DIPL ING ,  DIETRICH HANS JUERGEN DIPL ING

IPC: C07C20060101 ,  C07C263/10 ,  C07C265/04 ,  C07C271/02 ,  C07C119/042 ,  C07C118/02 ,  C07C125/03

Abstract: Prepn. of carbamoyl chlorides and isocyanates comprises reacting a solid primary amine salt with COCl2 at high temp. The amine salt is pref. a hydrochloride. The reaction temp. is pref. 10-70 degrees C. below the m.pt. of the salt (generally 145-250 degrees C.). The particle size of the salt is pref. 1-500 (esp. 2-50) mu. The reactor can be a rotating tube, a reactor equipped with stirrer paddles, or an fluidised bed reactor in which the support material is pref. Al2O3. The carbamoyl chloride produced can be sepd. from the gaseous reaction products by quenching in an inert solvent; the resulting solnl. can then by distd. to form and isolate the isocyanate. The products are useful as intermediates for biologically active cpds., plant protection agents, polyurethanes, etc. The process is esp. useful for preparing aliphatic diisocyanates, which can be converted to light-stable polyurethanes. The process gives high yields (e.g. 50-98%) and is suitable for use on an industrial scale.