Abstract: A polyurethane prepolymer composition may include: (a) a polyurethane prepolymer comprising, as a reaction product, (a1) an excess of diisocyanate and (a2) a polyol; and (b) free diisocyanate monomer in a range of from more than 0 to less than 1.0 wt. %, based on total polyurethane prepolymer weight. The NCO content of the polyurethane prepolymer may be in a range of from 0.2 to 15 wt. %. The polyurethane prepolymer may include less than 75 wt. % of a 2:1 stoichiometric adduct of the diisocyanate and the polyol, based on the total polyurethane prepolymer weight. The polyol (a2) may include two polypropylene glycols with different molecular weights.

Abstract: A polyurethane prepolymer composition may include more than 0 wt. % and less than 1.0 wt. % free diisocyanate monomer. The polyurethane prepolymer may include less than 80 wt. % of a 2:1 stoichiometric adduct of diisocyanate and at least one polyol (perfect prepolymer). Curable compositions may include such polyurethane prepolymer compositions and the such polyurethane prepolymer compositions may be used as adhesives.

Abstract: The present invention relates to a polyurethane prepolymer composition comprising more than 0 wt. % and less than 1.0 wt. % free diisocyanate monomer wherein the polyurethane prepolymer comprises less than 80 wt. % of a 2:1 stoichiometric adduct of diisocyanate and at least one polyol (perfect prepolymer), curable compositions comprising these polyurethane prepolymer compositions and the use of these polyurethane prepolymer compositions as adhesives.