METHOD OF PRODUCING IMPREGNATION OLIGOMERS Russian patent published in 2014 - IPC C08G12/38 C08G12/40 C08G12/32 

FIELD: chemistry.

SUBSTANCE: described is a method of producing melamine carbamide-formaldehyde oligomers, which includes mixing formalin, brought to the operational hydrogen ion concentration value by a modifier-catalyst based on a salt of a polyfunctional acid, melamine and water, heating the mixture to 90-95°C and cooling upon achieving miscibility of the obtained oligomer with water of 1:1000. Further, the method comprises adding carbamide to the obtained oligomer, cooling the mixture upon achieving miscibility of the oligomer with water of 1:3-1:3.5 and bringing the pH of the mixture to 9.5-10.0. The catalyst-modifier based on a salt of a polyfunctional acid is obtained by mixing sodium or potassium hydroxide, lactic or tartaric acid and water, with the following ratio of components, pts.wt: sodium or potassium hydroxide 13-15, lactic or tartaric acid 16-19, water 68-69.

EFFECT: reduced melamine consumption and low content of free formaldehyde while maintaining processing properties of impregnation oligomers.

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