耐水耐热型改性脲醛树脂的研制

为降低胶合板水泥模板的制作成本,通过加入三聚氰胺和改性剂聚乙烯醇的方法,并控制好反应过程,制得1种具有较好耐水耐热性改性脲醛树脂,三聚氰胺用量应控制在6%~8%之间,改性剂聚乙烯醇的用量控制在尿素量的3%,尿素应分3次加入反应体系,第3次加入量应为尿素总量的25%左右,缩合反应pH控制在4.8~5.2之间,其使用性能达到酚醛树脂的使用效果,是用于制作胶合板水泥模板理想的新型粘合剂。

Research on a novel modified urea-formaldehyde resin with water-proof and heat-resistance

To reduce the production cost of the plywood cement formwork,a kind of modified urea-formaldehyde resin with water-proof and heat-resistance was prepare by adding melamine and modified agent-polyvinyl alcohol into the synthetic reaction system and controlling the reaction process.The content of melamine was controlling between 6%～8%,the use level of polyvinyl alcohol was 3% of that of urea,the urea was added in reaction system by three times and the use level of urea in 3th time was 25 percent of the total amount and the pH value of reactive system was controlled between 4.8～5.2.The application properties of abtained products attained to that of phenolic resin and showed that it was usable for plywood cement formwork as a novel adhesive.