Polyurea prepolymer compsn. with longer pot life and short curing time - is deriv. of di:isocyanato-di:phenyl:methane, toluylene and isophorone di:isocyanate, hexa:methylene di:isocyanate-1,6 etc.

摘要

An isocyanate-contg mixt of polyurea-prepolymer(s), where the prepolymer is a deriv of diisocyanato-diphenylmethane (MDI), toluylene diisocyanate (TDI), hexamethylene diisocyanate-1,6 (HDI), isophorone diisocyanate (IPDI), hydrogenated MDI (H12MDI), or naphthalene 1,5-diisocyanate (NDI) and a polyol comprising an aromatic or aliphatic polyester, a polycaprolactone, a polycarbonate polyester or a polyether, contains a carboxylic acid or anhydride. Pref. the acid anhydride has mpt. below 70 deg C and is pref. tetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride or 4-methylhexahydrophthalic anhydride. The amt of acid or anhydride is such that the free or potentially free acid gps. form not more than 20% of the free NC0 gps.