METHOD OF STABILIZING (PRODUCING) AQUEOUS SOLUTIONS OF FORMALDEHYDE WITH CARBAMIDE (CARBAMIDE-FORMALDEHYDE CONCENTRATE) Russian patent published in 2019 - IPC C08G12/12 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of stabilizing (producing) aqueous solutions of formaldehyde with carbamide (carbamide-formaldehyde concentrate) by introducing carbamide into an aqueous solution of formaldehyde followed by condensation of the obtained solution. Carbamide is introduced into a formaldehyde solution with temperature of 40–65 °C at pH less than 7 and molar ratio of formaldehyde : carbamide 4.0–6.0:1 with subsequent exposure at temperature of 70–85 °C for 20–60 minutes with subsequent increase of pH to 7.5–8.5 and cooling of obtained product.

EFFECT: disclosed method enables to obtain a carbamide-formaldehyde concentrate which enables to obtain a wide range of thermosetting formaldehyde-containing resins based thereon.

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