Urea!-formaldehyde! resin soln. contg. sulphite waste liquor - as wood glue with better pre-bonding strength

摘要

A urea-HCHO resin soln. with a molar ratio of HCHO urea of is not 1.2:1 and a viscosity of 500-1500 mPas at 65% solids and 20 degrees C, is brought to a pH of is not 7.5, and a temp. of is not 40 degrees C, and mixed with stirring, with sulphite waste liquor, the amt. of the liquor is 1-6 wt % solids w.r.t. the resin soln. The soln. is a wood glue. It has improved pre-bonding strength, and the pre-glued wood parts can be transported without sepg.