PROCESS FOR THE PRODUCTION OF FLEXIBLE POLYURETHANES

摘要

Disclosed is a process for the production of flexible polyurethanes by interaction of semipolymer prepared in reaction of diisocyanates with polyesters with unsymmetric dimethylhydrazine as macrochain extender on the basis of 0.1-0.5 mol of extender per 1 mol of semipolymer. The interaction of prepared semipolymer with extender is carried out at intensive stirring for 10-15 min at room temperature, 80-100 min at temperature of 35-45 °С, 115-130 min at temperature of 35-50 °С in the presence of acetylacetonate tin dichloride as organometallic catalyst in amount of 0.001-0.1 wt.%. the process allows to obtain flexible polyurethanes that have high fabricability, i.e. high stability and lifetime of their solutions (not less than 6 months).