| 摘要 |
<p>Polyurethane prepolymers hardening in contact with atmospheric moisture Kneading-, cementing- and sealing compsns. pref. containing the prepolymers as binders, pref. mixed with fillers, opt. with pigments, catalysts and other additives, are prepd. by reacting a polyol, pref. polyalkylene glycol(s) and/or polyether triol(s), and a monohydroxy cpd., pref. 9 - 20C fatty monohydric alcohol(s) with an organic diisocyanate and adjusting the reactant ratios such that the monohydroxy cpd. has >=0.5 equiv. OH groups per equiv. OH groups contained in polyol and the resulting prepolymer contains free isocyanate groups. Pref. diisocyanate is added in amounts such that reaction mixture contains 1.5 - 4 isocyanate group equiv. per OH group equiv. originating from polyoll and pref. monohydroxy cpd. is used in amount such that it contains 0.5 - 1.5 equiv. OH groups per OH group equiv. originating from polyol.</p> |
