MODIFIED UREA-FORMALDEHYDE RESIN PRODUCTION PROCESS

FIELD: polymer production. SUBSTANCE: resin applicable in manufacture of resin-bound chipboard, composites, and plywood glues, is prepared by condensation of formaldehyde component with a first portion of urea in presence of viscosity regulator at heating in variable-acidity medium and formaldehyde-to-urea molar ratio (1.9-2.1): 1, followed by after- condensation with additional portion urea at formaldehyde-to-urea molar ratio (1.01-1.5):1 and cooling resultant resin. As formaldehyde component, urea-formaldehyde concentrate, which is composition containing 57.0% formaldehyde, 22.8% urea, and 20.2% water is used at formaldehyde-to-urea molar ratio 1:5. Process is conducted in presence of amine modifier, in particular 10-60% as of polyamine with general formula: wherein n=0 or 1, m= 1 or 2, and n+m=1-3. Modifier is added in one or two times in amount 0.1 to 2.0% of the weight of concentrate jointly with concentrator and in amount 0 to 1.0% in the after-condensation stage. EFFECT: increased viscosity of resin and its reactivity, reduced emission of formaldehyde from resin-bound chipboards. 1 tbl, 2 ex