Fluorine - contg polyurethanes - prepn from hexafluoro-isopropylidene - para, para - diphenyl diisocyanate and hydroxyl contg reagents

摘要

F-contg. polyurethanes, useful for prodn. of foamed plastics, lacquers, adhesives and sealing compsns. and having raised resistance to temp. changes and hydrolysis consist of -O-R-OOCHN-p-C6H4-C(CF3)2-C6H4-p-NHCO- units (where R is derived from OH-contg. reagents (I) such as glycols, OH-contg. polyesters or bisphenols or their F-derivs.), and have n = 7 - 20 degree of polymsn. They are prepd. by reacting (I) with an F-contg. diisocyanate of formula p-OCN-C6H4-C(CF3)2-C6H4-p-NCO (II), in an org. solvent, at 20 - 150 degrees C, using 1 : 1 to 1.5 (I): (II) mol. ratio.