| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a high quality polyamide molding compound for forming a permeation-resistant layer of carbon dioxide for bottles produced from polyethylene terephthalate. SOLUTION: The method for producing a polyamide molding compound comprises a step of adding water to m-xylylene diamine and dicarboxylic acids containing adipic acid and aromatic dicarboxylic acids in a dissolving vessel to dissolve them, producing a mixture of 2-15 mol% aromatic dicarboxylic acids added in relation to the above dicarboxylic acids, and polycondensing the mixture in a reaction vessel, a step of granulating the polycondensate, and a step of drying the granulate. The polycondensation step is performed at a pressure of≤10,000 hPa and a temperature of 255°C-270°C, and the pressure is built up to the above pressure while heating to the above temperature range, and immediately after the mixture has reached the maximum temperature, the above pressure is reduced to atmospheric conditions while maintaining the temperature in the above temperature range, and the polycondensation step is continued at the temperature in the above temperature range and a pressure of <800 hPa, and the granulate is subjected to an underwater crystallization before the drying step. COPYRIGHT: (C)2003,JPO |
