ULTRALOW MONOMER POLYURETHANES

摘要

The present invention relates to ultralow monomer PU prepolymers containing free NCO groups obtainable from polyols, diisocyanates and NCO-reactive compounds, obtainable by reacting at least one polyol with at least one polyisocyanate, wherein the at least one polyisocyanate is used in molar excess relative to the hydroxyl groups of the at least one polyol to obtain a polyurethane prepolymer containing free isocyanate groups; and adding at least one compound having at least one H-acidic functional group to the polyurethane prepolymer containing free isocyanate groups in an amount such that the molar ratio of the free isocyanate groups to H-acidic functional groups (NCO:XH ratio) is 2 to 15, preferably 2.5 to 10, more preferably 3 to 8. Also encompassed are methods for its production, laminating adhesives containing said prepolymer, methods of bonding substrates and the use of the described adhesives for laminating two or more films.