绿色环保型微游离甲醛脲醛树脂胶的合成

采用弱碱-弱酸-弱碱工艺，在传统一次加料反应的基础上，尿素与甲醛“分批加入，多点分段”控制反应过程，进行脲醛树脂游离甲醛含量减量化的实验。通过单因素实验，考察F／U物质的量比、羟甲基化温度、缩聚反应pH、改性剂、固化剂等对脲醛树脂胶粘剂游离甲醛含量和性能的影响。结果显示，当甲醛与尿素的物质的量比为1．31；1，羟甲基化反应温度为95—98℃，聚合反应pH4．8—5．1时，可以合成游离甲醛含量在0．1％以下的脲醛树脂胶粘剂，最终使由脲醛树脂胶粘剂制得人造板的性能技术指标达到E0级标准。

Study of Green Environment-Friendly Urea-Formaldehyde Resin for Wood-Based Panel

The process of the weak alkali-weak acid-weak alkali was used this study.On the basis of the tradition technology of adding urea in one potion to synthesize urea-formaldehyde resin,urea and formaldehyde were added by the method of "added in batches,multi-point section",which was controlled to decrease the free formaldehyde of the ura-formaldehyde resin.Individual factor experiments were carried out,which studied the influence of the F/U molar ratio,the first adding urea temperature,the polymerization reacti...