摘要 |
Esters of alpha-amino-acids where X = (a) a hydrogen atom, (b) an alkyl, aryl, alkaryl or aralkyl group having at most 22 C atoms, (c)-CnH2nNH2, (d) CnH2nCOOCH2R, or (e) -CmH2mCH-NH2, where n and m each COOCH2R have the value 1 to 10; and R2= C5-21 alkyl group; also, their acid addition salts and the corresponding isocyanates. The diisocyanates are useful for the production of colour-stable polyurethanes. |