甲乙酮肟封闭二苯基甲烷二异氰酸酯的合成

Study on 4,4'-diphenylmethane diisocyanate blocked by ethyl methyl ketoxime

异氰酸酯可作为热硫化型橡胶-金属及其他胶粘剂复合体系的重要组分,需对高活性的异氰酸酯(-NCO)基团进行完全封闭,以保证胶粘剂各组分的相容及稳定性。采用甲乙酮肟封闭二苯基甲烷二异氰酸酯(MDI)预聚体,制备了解封温度130℃的完全封闭型MDI预聚体;研究了投料比、反应温度、反应时间对封闭反应的影响;通过示差扫描量热仪测定了封闭物的解封温度。

In order to insure compatibility and stability of vulcanized adhesion system for metal-rubber and others containing the isocyanate as main componet,so the fnnctional group of isocyanate（-NCO）with higher reactivity must be bloockcd.The influences of raw material proportion,reaction temperature,reaction time,and the treatment of residual NCO were investigated on blocking reaction of 4,4＇ diphenylmethane diisocyanate（MDI）based prepolymer with ethyl lnethyl ketoxime.The blocked isocyanate with low deblocking temperature（130 ℃）ewas determined by DSC.