An isocyanate group containing polyurethane prepolymer useful as a moisture hardened adhesive for mineral wool, has flame retarding properties, gives polyurethanes of excellent mechanical properties, and has viscosity ideal for adhesives

摘要

An isocyanate group containing prepolymer obtainable by multi-stage reaction of at least one isocyanate with at least two compounds having at least two H atoms which can react with isocyanate groups. The compounds have (a) at least one polyester alcohol and (b) at least one polyetheralcohol with a halogen atom in the molecule, in the presence of phosphorus containing compounds having no groups which react with isocyanates. Independent claims are included for: (1) preparation of the prepolymer by reaction of the polyesterpolyol with isocyanate, followed by reaction of the intermediate product obtained with the halogenated polyetherpolyol, with addition of the phosphorus containing compound in the first or second reaction phase; (2) preparation of the prepolymer by reaction of the polyesterpolyol with isocyanate, addition of the phosphorus containing compound, followed by reaction with the halogenated polyetherpolyol.