High-etherification Melamine Formaldehyde Resin by Dry Method

With melamine and formaldehyde as raw materials,the eco-friendly high-etherification melamine formaldehyde resin was prepared through dry method with low formaldehyde,high solid content and high stability.Meanwhile,the factors such as ratio of the material in each reaction stage,temperature and p H,were discussed to confirm the optimal preparation conditions.The results indicate that,when n(melamine) ∶ n(formaldehyde) = 1 ∶10,reaction temperature was 75 ℃,p H was 9.0,the reaction time was 50 min in the hydroxymethylation reaction stage,and when n(HMM) ∶ n(alcohol) =1∶10,reaction temperature was 65 ℃,p H was 5.5 in etherification reaction stage,the solid content of high-etherification melamine formaldehyde resin was higher than 90%,and the content of hydroxyl methyl was 51.4%,while the free formaldehyde content was less than 0.3%.