METHOD FOR OBTAINING POLYOL DISPERSIONS FROM POLYURETHANE WASTE AND THEIR APPLICATION Russian patent published in 2021 - IPC C08G18/48 C08G18/32 C08J11/24 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing an isocyanate-reactive dispersion of polyols from waste polyurethanes from the consumer area in the presence of polyether alcohols, as well as to the use of an isocyanate-reactive dispersion of polyols for the production of polyurethane materials, in particular rigid polyurethane foams. A method for producing an isocyanate-reactive dispersion of polyols consists in the fact that in the first stage the waste polyurethanes are reacted with a reaction mixture containing at least one dicarboxylic acid or a dicarboxylic acid derivative, at least one polyether alcohol, and at least one suitable free radical initiator for initiating radical polymerization. The reaction is carried out at a temperature of 170°C to 210°C to form dispersion. In a second process step, the resulting dispersion is re-reacted with at least one short-chain diol of 2 to 8 carbon atoms and / or a short-chain triol of 3 to 8 carbon atoms. The reaction is carried out at a temperature of 180°C to 230°C to form isocyanate-reactive polyol dispersion. In the first stage, a polyether alcohol is used having an average molecular weight of 400 to 6000 g / mol and a hydroxyl functionality of 2 to 4.

EFFECT: invention makes it possible to obtain stable isocyanate-reactive recycled polyols, which essentially do not contain free acid groups, thus avoiding negative effects on catalysis in the subsequent production of polyurethane foam.

10 cl, 3 ex