METHOD OF PRODUCTION OF ANTIPYRINE Russian patent published in 2006 - IPC B27K3/52 C09K21/12 

FIELD: methods of production of antipyrines for fireproof treatment of wood materials.

SUBSTANCE: proposed method includes interaction of carbamide formaldehyde concentrate of the following composition, mass-%: carbamide, 21-25; formaldehyde, 54-60; the remainder being water with ammonia water taken at equimolar ratio by formaldehyde and ammonia at heating in weak-alkaline medium in presence of aminoalcohol selected from group containing mono-ethanol amine, di-ethanol amine, tri-ethanol amine and amine modifying agent AM-1 added together with ammonia water in the amount of 0.01-0.3 mass-% in terms of carbamide formaldehyde concentrate followed by introduction of carbamide in the amount of 1-10 mass-% per 100 mass-% of carbamide formaldehyde concentrate; then, reaction mixture is cooled and neutralized with ortho-phosphoric acid to pH= 6.0-8.0.

EFFECT: optimization of synthesis process of antipyrines at retained fire resistance efficiency.

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