METHOD TO MANUFACTURE GLUE FOR PRODUCTION OF WATERPROOF VENEER Russian patent published in 2015 - IPC C08L61/28 

FIELD: technological processes.

SUBSTANCE: invention relates to woodworking industry, in particular, to production of waterproof veneer. The method includes mixing of carbamide-formaldehyde concentrate with working value of concentration of ions of hydrogen, melamine and water. The produced mixture is heated, at the same time controlling miscibility of the produced oligomer with water. Then the mixture is cooled down, and carbamide is introduced, as the optimal value of oligomer miscibility with water is achieved, with subsequent monitoring over miscibility of oligomer with water. As miscibility of oligomer with water achieves working value, the mixture is cooled down. After cooldown concentration of hydrogen ions in the mixture is increased to pH 9.5-10.0. At the same time reduction of carbamide-formaldehyde concentrate is done with catalyst - modifier on the basis of polyfunctional organic acids: lactic, citric, malic, tartaric. Specified salts are produced by mixing caustic soda and acid at the ratio of components, wt parts: caustic soda 9-15; acid 16-21.

EFFECT: invention reduces consumption of melamine and content of free formaldehyde with preservation of technological properties of adhesive resins.

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