粉末涂料用聚酯树脂合成工艺的研究

Study on the Synthetic Process of Polyester Resin for Powder Coatings

分析了聚酯树脂合成工艺中酯化反应阶段的影响因素、酯化反应进程判断依据以及真空缩聚阶段树脂的黏度变化趋势.结果表明:降低在“跑醇”剧烈温度阶段的升温速率,而提高“跑醇”较少阶段的升温速率,回流比设置为先逐步升高而后逐步降低,蒸馏柱蒸气温度控制在100℃以内有利于平衡升温速率和“跑醇”量;可以依据酯化水质量判断酯化反应进程;真空缩聚阶段树脂的黏度增长速率可分为3个阶段,且在线黏度与锥板黏度具有良好的线性拟合关系.

The influencing factors of esterification reaction stage,the judgment basis of esterification reaction process and the variation trend of resin viscosity in vacuum polycondensation stage were analyzed.The results showed that:reducing the heating rate in the stage of"alcohol running"intense temperature,increasing the heating rate in the stage of"alcohol running"less,setting reflux ratio to gradually increase first and then gradually decrease,and controlling the steam temperature of distillation column within 100℃are beneficial to balance the heating rate and"alcohol running".The process of esterification can be judged by the weight of esterification water,the viscosity growth rate of resin in vacuum polycondensation stage can be divided into three stages,and the online viscosity and cone plate viscosity have a good linear fitting relationship.