METHOD OF PRODUCTION OF UREA-FORMALDEHYDE OLIGOMER Russian patent published in 2014 - IPC C08G12/12 

FIELD: woodworking industry.

SUBSTANCE: method of production of urea-formaldehyde oligomer comprises loading of formalin, its neutralisation to pH 7.0-7.5 with modifier-catalyst based on salt of polyfunctional acid, adding of urea, after dissolution of urea, if necessary, reduction of pH to 6.8-7.2 with ammonium chloride, followed by heating to 90-92°C and keeping for 30 minutes. Further, reduction of pH of the mixture is carried out with a solution of ammonium chloride to 4.2-4.5 and kept at 90-92°C with stirring for 30 min, cooled to 60-65°C, adjusted to pH 6.7-7.0, the catalyst modifier is added while stirring based on salt of polyfunctional acid, urea is added, and kept at 60-65°C while stirring for 30 minutes to obtain an oligomer, it is neutralised with modifier-catalyst based on salt of polyfunctional acid to pH 8.0-8.5. The catalyst-modifier based on salt of polyfunctional acid is used as modifier obtained by mixing caustic soda or potassium hydroxide, lactic acid or tartaric acid and water with the ratio of ingredients in parts by weight: caustic soda or potassium hydroxide 13-15, lactic or tartaric acid 16-19, water 68-69.

EFFECT: reduction of toxicity with improved physical and mechanical properties of plates obtained with the use of urea-formaldehyde oligomer according to the invention.

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