METHOD FOR PRODUCTION OF CARBAMIDE-FORMALDEHYDE CONDENSATE Russian patent published in 1997 - IPC

FIELD: wood working. SUBSTANCE: carbamide-formaldehyde condensate is prepared by mixing of carbamide and aqueous solution of formaldehyde, their molar ratio being 0.8-2.0:1. The process is carried out in alkali medium at pH 8.2-8.8 at 5-45 C. Solution of condensate is cooled and stabilized by cold ageing within at least 3 h. Mentioned above alkali medium is prepared with the help of alkaline agent, amino compound or its mixture with water or with hydroxide of alkaline metal is used as said alkaline agent. Stable condensates have low content of free formaldehyde, high content of dry substances and low freezing point. EFFECT: minimum labour intensity and minimum energy expenditures. 4 cl, 3 tbl