| 摘要 |
1481756 Purifying organic isocyanates SUMITOMO BAYER URETHANE CO Ltd 23 May 1975 [4 June 1974] 53824/76 Divided out of 1481755 Heading C2C Organic isocyanates are purified by heating a mixture of the impure organic isocyanate with a thio-bisphenol and recovering the purified organic isocyanate by distillation. The thiobisphenol may be used in admixture with a dithiocarbamic acid derivative and/or a triaryl phosphite. The isocyanates which may be treated preferably have the formula R(NCO) n wherein R is C 4 to C 12 saturated aliphatic hydrocarbon, C 5 to C 15 saturated cycloaliphatic hydrocarbon, C 6 to C 15 aromatic hydrocarbon or C 7 to C 15 araliphatic hydrocarbon, and n is 1 to 3. The thio-bisphenol preferably has the general formula wherein R and R<SP>1</SP>, which may be the same or different, are C 1 to C 10 unsubstituted alkyl. |
