| 摘要 |
Finely divided polyamide powders are prepared by adding anionic catalyst and/or activator in soln. or in finely divided form to a soln. of lactam(s) in several portions at intervals of at least 5 minutes; the addition is preferably in at least 3 portions. The catalyst may be an alkali metal lactam in dimethyl formamide obtained by adding a dispersion of metallic Na, NaNH2 or NaH to the reaction soln. The activator may be an N-acyl lactam. The catalyst may be used at from 2 to 2.5% by wt. of the monomer and the activator at from 0.5 to 5% by wt. Examples disclose the preparation of homopolymers and copolymers from lauric lactam, caprolactam and caprylactam. |
