| 摘要 |
Polyamides used as cements are formed in situ by the alkaline polymerization of single or mixed lactams at temperatures up to 280 DEG C. The preferred lactams are caproic, caprylic, oenanthic, or lauric, the first two being used singly or mixed together in various proportions and the two latter being used in mixtures as minor constituents. Known alkali carriers and activators are included in the compositions and lists of these are given. Cross-linking agents, e.g. methylene-bis-caprolactam, may also be included. Polymerization, with or without heating, may be controlled by applying the lactam melts in two parts, containing the alkali carrier and the activator respectively, or by applying the activator separately in solution. Specifications 900,150 and 900,151 are referred to. |
