Stabilisierte Isocyanate

摘要

1,192,859. Isocyanates. TAKEDA YAKUHIN KOGYO K.K. 23 Dec., 1968 [28 Dec., 1967], No. 61137/68. Heading C2C. Organic isocyanates are stabilized against polymerization and coloration by adding a small proportion of (1) sulphur or hydrogen sulphide or (2) a compound containing the grouping A-NH-B, in which A denotes -CO-, -CS-, -SO 2 -, -NO 2 or -CN and B denotes -CO- or -CS- or (3) a compound of any of the formulµ R1CXNHR3, R2(CONHR3) 2 , (CONHR3) 2 or R4SO 2 NHR3, in which X denotes oxygen or sulphur, R1, R3 and R4 denote hydrogen atoms or alkyl or aryl groups which may be substituted by halogen atoms or nitro, cyano, alkyl or alkoxy groups and R2 denotes a divalent hydrocarbon residue, such as an alkylene or arylene residue. Many compounds falling within categories (2) and (3) are specified, as also are a number of mono-, di- or tri-isocyanates to which the invention may be applied. Comparative examples are given of the treatment of dimethylbenzene - #,#1 - diisocyanate and 4,41- diphenylmethane diisocyanate.