METHOD OF MANUFACTURING CARBAMIDOFORMALDEHYDE OLIGOMER Russian patent published in 2015 - IPC C08G12/12 C08L61/32 B27N3/02 

FIELD: chemistry.

SUBSTANCE: invention relates to wood-processing industry and can be used in manufacturing carbamidoformaldehyde oligomers, used for production of chipboards. method of manufacturing carbamidoformaldehyde oligomers includes loading formaldehyde, its neutralisation to pH 8.0-9.0 with further loading of the first carbamide portion to its complete dissolution and introduction of parafolmaldehyde with heating with exposure to pH not lower than 6.5, introduction of the second carbamide portion with exposure at said stage to pH not lower than 6.5, after which in order to reduce mixture pH value to 4.5-5.0 ammonium chloride solution is added with heating and the end of the stage is checked by miscibility with water when miscibility 1:2-1:3 is achieved, after which mixture pH is increased to 8.0-8.5 with reduction of temperature to 70-75°C and the third carbamide portion is introduced, after dissolution of which oligomer is subjected to vacuum-drying, and the fourth carbamide portion is introduced to mole ratio of carbamide to formaldehyde 1:1.4 with further oligomer cooling.

EFFECT: method will make it possible to reduce the content of free formaldehyde in carbamidoformaldehyde oligomers and reduce toxicity of chipboards, obtained on their base.

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