| 摘要 |
A process for preparing a methyl-blocked ethoxylate comprises heating at 180 DEG -320 DEG C., in the presence of a catalytically effective amount of a noble metal catalyst, an unsubstituted ethoxylate of 3 or more ethoxy units, or a monoalkyl-, monoaryl-, mono- or di-alkylamino- or mono- or di-arylamino ethoxylate of 2 or more ethoxy units, or a monoalkyl- or monoaryl-N,N-bis(ethoxylate) of 2 or more ethoxy units, all of which are derived from vicinal glycols, whereby there is prepared a corresponding methyl-blocked ethoxylate product which, for an unsubstituted ethoxylate starting material is a dimethylethoxylate having two fewer ethoxy units than the starting ethoxylate, and for the other ethoxylate starting materials, is a methylethoxylate having one less ethoxy unit in each ethoxylate group of the starting material. |
