Method for producing polyester polyols using rigid waste polyurethane and polyisocyanurate foam

Abstract

The subject of the application is a method for producing polyester polyols using waste rigid polyurethane and polyisocyanurate foam, which is characterized in that waste products are introduced into the reactor in an amount of 20 to 90% m / m, wherein with the mixer on and an inert gas flow, preferably nitrogen, of 0.2 - 100 l / min, 10 to 80% m / m of a mixture of polyhydric alcohols containing at least two hydroxyl groups in the molecule and an organometallic catalyst in an amount of 0.1 to 2% m / m, preferably 1% m / m, are added, after which the whole is heated to a temperature of 150 to 300°C, at a pressure of 0 kPa to 1000 kPa and the glycolysis reaction is carried out until the entire foam is decomposed and a clear and homogeneous glycolysate is obtained, and then the excess glycol is removed by distillation at a temperature of 220 to 230°C and under vacuum in negative pressure conditions from -50 kPa to -95 kPa,then the whole is cooled to a temperature of at least 150°C and subsequently the mixture of 30 to 80% m / m of glycolysate, 0 to 50% m / m of phthalic anhydride and 0 to 20% m / m of adipic acid is subjected to the esterification and polycondensation process in the reactor with the mixer switched on and an inert gas flow, preferably nitrogen in the amount of 0.1 to 30.0 l / min.,