PRODUCTION OF MONOMER-CAST POLYAMIDE RESIN ARTICLE

摘要

PURPOSE:To obtain the subject molded article free from hollow defect and having low strain without using a pressurizing apparatus for applying pressure during polymerization by carrying out the anionic polymerization of a specific omega-lactam and a specific polymerizable lactam liquid in a mold. CONSTITUTION:The objective molded article is produced by carrying out the in-mold anionic polymerization of a polymerizable lactam liquid consisting of an substantially anhydrous omega-lactam (preferably omega-laurolactam, etc.) and at least an anionic polymerization catalyst (e.g. sodium hydride) in an amount of 0.1-2.0mol% based on the lactam and an anion polymerization initiator (e.g. N-acetyl-omega-caprolactam) in an amount of 0.05-1.0mol%. The molded article is cooled in a thermal medium of 50-100 deg.C when the surface temperature of the poured lactam liquid begins to decrease after finishing the reaction. The polymerization temperature of the omega-lactam is preferably 130-180 deg.C.