METHOD FOR CHEMICAL RECYCLING OF POLYCARBONATE WASTES Russian patent published in 2013 - IPC C07C37/52 C07C39/16 C08J11/10 C08G64/42 

FIELD: chemistry.

SUBSTANCE: amines used are aliphatic amines; the reaction is carried out at temperature of 25-170°C for 25-140 minutes with weight ratio of the aliphatic amine to polycarbonate of not less than 0.9:1; hydrochloric acid is added to the obtained aminolysis product to achieve pH of not higher than 3; diphenylol propane precipitate is separated from the formed suspension and the mother solution is reacted with phosphorous acid and formalin, wherein the formalin is a water-methanol solution of formaldehyde, at temperature not lower than 90°C for not less than 2 hours in ratio of 1 mole amino groups to 1-2 moles of phosphorous acid and 1-2 moles of formaldehyde, followed by neutralisation with aqueous ammonia solution.

EFFECT: method enables comprehensive recycling of polycarbonate wastes to obtain commercial-grade diphenylol propane and an acidic mother solution which is used as a raw material in production of fire-retarding compositions for wood and wood-based materials.

2 dwg, 1 tbl, 15 ex