Purification of organic isocyanates
AssigneeSumitomo Bayer Urethane Co., Ltd.
InventorsYushin Kataoka, Tetsuo Harada, Kenji Takagi
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Abstract
The present invention provides a process for purifying an organic isocyanate which comprises heating an organic isocyanate in admixture with a treating agent selected from the group consisting of a metal salt of mercaptobenzothiazol, a dithiocarbamic acid derivative, an alkyl-substituted phenol, a thio-bisphenol, and a triaryl phosphite at a temperature not lower than 100.degree. C and subsequently distilling the thusly treated mixture to recover a purified organic isocyanate.
Claims21
A process for purifying an organic isocyanate which comprises heating an organic isocyanate in admixture with at least one treating agent selected from the group consisting of a metal salt of mercaptobenzothiazol, a metal salt of alkyl substituted dithiocarbamic acid, an alkyl substituted phenol, a thio-bis-phenol, and a triaryl phosphite at a temperature not lower than 100.degree. C. to thereby convert coloring impurities to tar and subsequently distilling the thusly treated mixture to recover a purified organic isocyanate.
Dependencies are inferred from the claim text.