Reactive polyurethane hotmelts are produced by converting a mixture of different (polyester-)polyols with a surplus of a polyisocyanate component. This results in isocyanate-terminated prepolymers with an NCO-content of typically 2 to 5%.
Reactive polyurethane hotmelts combine the properties of regular or conventional hotmelts with the advantages of chemically crosslinking adhesives. Apart from an improved temperature and creep resistance they offer the following advantages:
Solvent-free applications
Moderate viscosity at application temperature
Improved solvent and hydrolysis resistance
Good adhesion to numerous substrates
High initial bond strength
Bayer MaterialScience offers a large range of raw materials for the production of these reactive polyurethane hotmelts.
Desmodur® polyisocyanates and Desmodur E® prepolymers: Baycoll® und Desmophen® Polyester- und Polyetherpolyole:
Desmodur® polyisocyanates and Desmodur E® prepolymers:
