METHOD OF PRODUCING URON-CONTAINING UREA-FORMALDEHYDE RESINS Russian patent published in 2006 - IPC C08G12/12 

FIELD: polymer production.

SUBSTANCE: invention relates to production of urea-formaldehyde resins used as binders in manufacture of wood particle boards, wooden fiberboards, plywood, wood adhesives, and in other industrial fields. Invention provides a method for producing uron-containing urea-formaldehyde resins via consecutive condensation of urea-formaldehyde concentrate with solid urea first at formaldehyde-to-urea molar ratio (5.2-3.3):1, pH below or equal to 3, and temperature above or equal to 80°C and then at molar ratio (2.5-2.65):1 at pH 7.0-9.0 and 20-70°C, urea being added first in amount providing formaldehyde-to-urea molar ratio in resin (2.10-2.40):1 and then in amount providing above ratio equal to (1.50-2.09):1.

EFFECT: simplified resin production technology at the same high physicochemical properties of products based thereon and reduced toxicity of products.

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