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

FIELD: methods of production of antipyrines; woodworking industry; production of fire-resistant plate products; construction engineering.

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 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, amine modifying agent AM-1 or their mixtures added together with ammonia water in the amount of 0.01-0.02 mass-% per 100 mass-% of carbamide formaldehyde concentrate at subsequent introduction of 1-10 mass-% of carbamide per 100 mass-% of carbamide formaldehyde concentrate, cooling, neutralization of reaction mixture by orthophosphoric acid to pH=6.0-8.0 and introduction of 0.1-0.5 mass-% of sodium fluosilicate and 0.1-0.8 mass-% of potassium bichromate into synthesized product.

EFFECT: optimization of synthesis of antipyrines at enhanced fire resistance efficiency.

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