METHOD OF PRODUCING POLYESTER-POLYOLS AND COMPOSITION FOR PRODUCING RIGID POLYURETHANE FOAMS Russian patent published in 1998 - IPC

FIELD: polymer production. SUBSTANCE: invention aims at producing foams useful as heat and sound-insulation and structural materials in a variety of areas, at reusing petrochemical production waste, and at extending polyurethane foam production ways. Polyester-polyols are produced by interaction of ester-containing di- and polycarboxylic acids and their anhydrides (petrochemical production waste) with polyatomic alcohols in presence of reesterification catalyst. In particular, still residues from ethylene glycol regeneration stage, from dimethyl terephthalate synthesis, and light fraction from phthalic anhydride production, or their mixtures are utilized. EFFECT: reduced production expenses. 9 cl, 4 tbl