PURIFICATION OF ORGANIC ISOCYANATES

摘要

1481757 Purifying organic isocyanates SUMITOMO BAYER URETHANE CO Ltd 23 May 1975 [4 June 1974] 53825/76 Divided out of 1481755 Heading C2C Organic isocyanates are purified by heating the impure organic isocyanate with an alkylsubstituted phenol and recovering the purified isocyanate by distillation. Preferred isocyanates have the formula R(NCO) n where R is a C 4 to C 12 saturated aliphatic hydrocarbon, a C 5 to C 15 saturated cycloaliphatic hydrocarbon, a C 6 to C 15 aromatic hydrocarbon or a C 7 to C 15 araliphatic hydrocarbon radical and n is 1 to 3. Preferred alkyl-substituted phenols have the general formula wherein R, R1 and R11, which may be the same or different, are each hydrogen or C 1 to C 20 unsubstituted alkyl, at least one of R, R1 and R11 being alkyl. The alkyl-substituted phenol may be used in admixture with a dithiocarbamic acid derivative and/or a triaryl phosphite.