低甲醛排放脲醛树脂胶的制备及应用

Preparation and application of urea-formaldehyde resin with low formaldehyde emission

尿素与甲醛的物质的量比1∶<1,甲醛分2次加入,尿素分4次加入,增强剂为三聚氰胺,占尿素总量的4%。甲醛分2次加入的目的是使尿素与甲醛的反应动力学中生成的次甲基脲与二羟甲基脲处于最大值。用此工艺制备的UF树脂制成的人造板性能远高于国家标准及国际标准,板材的甲醛释放量达到F四星级标准。

The preparation conditions of the urea-formaldehyde（UF） resin are as follows：the mole ratio of urea and formaldehyde 1： 〈 1,adding formaldehyde in twice,adding urea in separate four times,and melamine（4% by total weight of urea） as the enhancer.The purpose of adding formaldehyde in twice is to make the methylene urea and dimethylol urea produced during the reaction process of urea and formaldehyde in the maximum.The performance of artificial boards prepared with the UF resin produced with the aforesaid process is much over the national and international standards,and the formaldehyde emission of the plywood material reached the F four star level.