METHOD OF PRODUCING IMPREGNATING OLIGOMERS Russian patent published in 2012 - IPC C08L61/00 C08G12/36 C08G12/38 C08G12/40 

FIELD: chemistry.

SUBSTANCE: invention relates to wood processing industry, particularly for impregnating decorative paper when finishing wood boards. The method involves mixing formalin which is brought to the operating hydrogen ion concentration value, melamine and water. The obtained mixture is heated while monitoring miscibility of the obtained oligomer with water. The mixture is then cooled and carbamide is added when the optimum value of miscibility of the oligomer with water is achieved, and miscibility of the oligomer with water is then monitored. The mixture is cooled when miscibility of the oligomer with water reaches the operating value. After cooling, hydrogen concentration of the mixture is brought to 9.5-10.0. Formalin is brought to the operating hydrogen ion concentration value using a modifier catalyst based on a salt of polyfunctional acid. Said salt is obtained by mixing sodium hydroxide, citric acid and water in the following ratio, pts.wt: sodium hydroxide 9-15; citric acid 16-21; water 69-70.

EFFECT: treating formalin with a modifier catalyst enables to prevent a Cannizzaro reaction, which ultimately reduces melamine consumption, reduces content of free formaldehyde while preserving properties of impregnating oligomers.

1 tbl, 5 ex