COMPOSITION FOR LOWERING THE RELEASE TEMPERATURE OF PHENOL- AND LOWER ALKYL SUBSTITUTED PHENOL-BLOCKED ISOCYANATES

摘要

In the preparation of urethane polymers from phenol- and lower alkyl substituted phenol-blocked isocyanates, it is known to use a variety of reagents such as organotin compounds or amine compounds to lower the temperature at which the isocyanate becomes unblocked or reactive. These compounds, however, cause various side effects such as a decrease in the heat stability of the resultant polyurethane. This invention concerns a novel combination of certain tetravalent organotin compounds and certain quaternary ammonium compounds for addition to a phenol- or lower-alkyl substituted phenol-blocked isocyanate system to produce a synergistic lowering of the unblocking temperature in addition to, in the case of a coating compound, providing an unexpected increase in the heat stability of the resultant polyurethane coating.