【摘要】 以多聚甲醛代替或部分代替甲醛溶液,甲醇作为改性剂,控制反应条件,制备了高固含量和高稳定性的三聚氰胺甲醛树脂(MF),研究了原料物质的量比、醚化缩聚条件及添加剂对树脂稳定性、固含量及游离甲醛的影响。最佳配方为n(三聚氰胺)∶n(甲醛)∶n(甲醇)=1∶3 5∶5;介质PH值为6 5～7 0,反应时间45min,同时反应体系中加入2 0%尿素和1 0%硼砂混合物时,游离甲醛含量可降至1 0%以下。更多还原

【Abstract】 In this paper,paraformaldehyde was used as substitute for all or partial formaldehyde to prepare high solid content melamine-formaldehyde resin,which was modified by methanol whereafter and the etherification reaction was confroled by reactive condifious such as time and pH of media. The effects of the content of paraformaldehyde and methanol,the mole ratio of melamine to formaldehyde,and the other reaction conditions on the stability,the solid content and the content of the free formaldehyde are further discussed.The optimum formula rafio was n(melamine):n(formaldehyde):n(methanol)=1:3.5:5 and the optimum reaction conditions were that media pH was 6.5～7.0;reaction time,45 min and the content of free-formaldehyde reduced below 1.0% when the mixes of urea 2.0% and borax were added info reaction system.in the meantime.更多还原