| 摘要 |
PURPOSE:To smoothly and simply change over a resin, to enhance the productivity of a molding apparatus and to conserve labor cost at a time when a resin difficult to purge is changed over to other resin by using a polyamide resin having a specific terminal group. CONSTITUTION:A polyamide resin wherein the number (A) of terminal carboxyl groups (-COOH) and the number (B) of terminal N-substituted acid amide groups [-CONRR' (wherein R is a 1-22C hydrocarbon group and R' is a hydrogen atom or a 1-22C hydrocarbon group] satisfy formula I is set to the main component of the purge agent. For example, when a saponified ethylene/vinyl acetate copolymer (EVOH) is changed over to a nylon resin which is, in turn, changed over to EVOH, by allowing this purge agent to flow through an extruder, the generation of a gel like substance is soon eliminated and the change-over of a molding resin can be changed over simply within a short time. |
